HM Government heating systems, hot water systems, air conditioning, mechanical ventilation, lighting, heat pumps, solar thermal panel, micro-combined heat and power, heating system circulators Compliance Guide

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Domestic Building
Services
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Compliance Guide
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2010 Edition
Amendments to Approved Documents and
Compliance Guides 2010
All references to the Building Regulations 2000
(as amended) should be read as references to
the Building Regulations 2010.
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All references to the Building (Approved
Inspectors etc.) Regulations 2000 should be
read as references to the Building (Approved
Inspectors etc.) Regulations 2010.
There have been no substantive requirements
amendments to either set of regulations, but
please note the simplification of the definition of
‘room for residential purposes’ in regulation 2 of
the Building Regulations 2010. Please also note
that L1(c) has now become regulation 40.
The following tables will help you to find the new
regulation number for regulations which have
been re-numbered in the 2010 Regulations. For
any regulation number not included in the tables
below, the number of the regulation has not changed.
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Approved Document G
Sanitation, hot water safety and water efficiency
1
Building Regulations
Regulation
number
in Building
Regulations
2000
Regulation
number
in Building
Regulations
2010
2(2A)
2(3)
2(2B)
2(4)
2(2C)
2(5)
2(3)
deleted
3(1)(g)
3(1)(h)
3(1)(h)
3(1)(g)
4(1A)
4(2)
4(2)
4(3)
4A
23
4B(1)
22
4B(2)
deleted
Regulation
number
in Building
Regulations
2000
Regulation
number
in Building
Regulations
2010
Regulation
number
in Building
Regulations
2000
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Regulation
number
in Building
Regulations
2010
12(7)
12(8)
20AA
42
13(2)(c)(iii)
13(2)(ii)
20B
43
13(3)
deleted
20C(A1)
44(1)
13(5)
13(3)
20C(1)
44(2)
13(6)
13(4)
20C(2)
44(3)
13(7)
13(5)
20C(3)
44(4)
14(3)(aa)
14(3)(b)
20D
27
14(3)(b)
14(3)(c)
20E
37
14A
15
21(1)
18(1)
15
16
21(2)
18(8)
16A
20
21(3)
18(2)
6(1)(cc)
6(1)(d)
16B
38
21(4)
18(3)
6(1)(d)
6(1)(e)
16C
39
21(5)
18(4)
6(1)(e)
6(1)(f)
17A
24
21(6)
18(5)
6(1)(f)
6(1)(g)
17B
25
21(7)
18(6)
6(1)(ff)
6(1)(h)
17C
26
21(8)
18(7)
6(1)(g)
6(1)(i)
17D
28
22
47
9(1A)
9(2)
17E(4)
29(5)
22B(1)(a)
48(1)(a)
9(2)
9(3)
17E(5)
29(4)
22B(1)(b)
48(1)(b)
9(3)
21(1)
17F
30
9(4)
21(2)
17G
31
9(5)
21(3)
17H
32
9(5A)
21(4)
9(6)
21(5)
12(2)
12(1)
12(2A)
12(2)
12(4A)
12(5)
12(5)
12(6)
17I
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33
17J
35
17K
36
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22B(1)(c)
48(1)(c)
22B(1)(d)
48(1)(g)
22B(1)(e)
48(1)(d)
22B(1)(f)
48(1)(i)
22B(1)(g)
48(1)(j)
22B(1)(h)
48(1)(l)
18
45
22B(1)(ha)
48(1)(m)
19
46
22B(1)(i)
48(1)(n)
20
19
22B(1)(j)
48(1)(o)
12(6)
12(7)
20A
41
22B(1)(k)
48(1)(h)
22B(1)(ka)
48(1)(k)
J2A
J3
J6
J7
22B(1)(l)
48(1)(e)
J3
J4
L1(c)
Regulation 40
22B(1)(m)
48(1)(f)
J4
J5
Schedule 2A
Schedule 3
22B(2)
48(2)
J5
J6
Schedule 2B
Schedule 4
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Building (Approved Inspectors etc.) Regulations
Regulation
number
in Building
(Approved
Inspectors etc.)
Regulations
2000
Regulation
number
in Building
(Approved
Inspectors etc.)
Regulations
2010
Regulation
number
in Building
(Approved
Inspectors etc.)
Regulations
2000
Regulation
number
in Building
(Approved
Inspectors etc.)
Regulations
2010
Regulation
number
in Building
(Approved
Inspectors etc.)
Regulations
2000
Regulation
number
in Building
(Approved
Inspectors etc.)
Regulations
2010
1
1 and 38
13(1)(d)
12(6)(c)
25(2)
25(3)
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3
4
13(2)
12(1)
25(3)
25(4)
4
3
13(3)
12(2)
31A(a)
32(c)
8
10
13(4)
12(3)
31A(b)
32(c)
9
11
13(5)
12(4)
31A(c)
32(e)
10(1)
9(5)
13(6)
12(5)
31A(d)
32(f)
10(2)
9(1)
13A
13
31A(e)
32(h)
10(3)
9(2)
14
14(1)
31A(ea)
32(i)
10(4)
9(3)
15(1)
14(2)
31A(f)
32(j)
10(5)
9(4)
15(2)
14(3)
31A(g)
32(k)
11(1)(a)
8(1)(a)
15(3)
14(4)
31A(h)
32(d)
11(1)(c)
8(1)(b)
16
15
31A(ha)
32(g)
11(2)
8(2)
17
16
31A(i)
32(a)
11A
20(1)
18(1)
17(1)
31A(j)
32(b)
12
20(1) and (3)
18(2)
17(2) and (3)
*Sch 3 7A
Sch 2 8
12A
20(1) and (5)
18(3)
12AA
20(1)
18(4)
12B
20(1)
18(5)
12C
20(1) and (6)
18(6)
12D
20(1) and (2)
19
12E
20(1) and (4)
20
13(1)
12(6)
23A
13(1)(b)
12(6)(a)
24
13(1)(c)
12(6)(b)
25(1)
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17(4)
Sch 3 8
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Sch 2 9
17(5)
Sch 3 9
Sch 2 10
17(6)
Sch 4 7A
Sch 3 8
17(7)
Sch 4 8
Sch 3 9
18
Sch 6 5A
Sch 5 6
19
Sch 6 6
Sch 6 7
24
25(1)
25(2)
Please note that some of the numbering and cross referencing in the forms in Schedule 1 has changed slightly.
*Sch =Schedule
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Domestic Building Services
Compliance Guide
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2010 Edition
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April 2010
Department for Communities and Local Government
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Published by NBS, part of RIBA Enterprises Ltd, and available from:
RIBA Bookshops Mail Order
15 Bonhill Street
London EC2P 2EA
Telephone orders/General enquiries: 020 7256 7222
Fax orders: 020 7374 2737
Email orders: [email protected]
Or order online at: www.thenbs.com/buildingregs
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RIBA Bookshops
RIBA, 66 Portland Place, London W1B 1AD. Telephone 020 7256 7222
Birmingham & Midland Institute, Margaret Street, Birmingham B3 3SP. Telephone 0121 233 2321
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ISBN 978 1 85946 3772
Stock code: 72347
© Crown Copyright, 2010
Copyright in the typographical arrangement rests with the Crown
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This publication, excluding logos, may be reproduced free of charge in any format or medium for research, private study
or for internal circulation within an organisation. This is subject to it being reproduced accurately and not used in a
misleading context. The material must be acknowledged as Crown copyright and the title of the publication specified.
Any other use of the contents of this publication would require a copyright licence. Please apply for a Click-Use Licence
for core material at www.opsi.gov.uk/click-use/system/online/pLogin.asp, or by writing to the Office of Public Sector
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If you require this publication in an alternative format please email [email protected]
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Online via the Communities and Local Government website: www.communities.gov.uk
Contents | 3
Contents
Section 1
Introduction
Section 3
Section 4
Section 5
5
1.1
Scope
1.2
Innovative systems
1.3
European Directives
1.4
Status of guide
1.5
How to use this guide
7
1.6
Key terms
7
1.7
Replacement of primary heating appliances
8
1.8
Energy efficiency standards for compliance with building
regulations – summary table
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Section 2
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5
6
6
Gas-fired space heating and hot water systems
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2.1
Scope of guidance
14
2.2
Gas-fired wet central heating systems
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14
2.3
Gas-fired range cookers with integral central heating boiler
26
2.4
Gas-fired warm air heating
26
2.5
Gas-fired fixed independent space heating appliances
30
2.6
Gas-fired fixed decorative fuel-effect fires
32
2.7
Gas fires for secondary space heating provided as part of a
combined fire and back boiler unit
33
Oil-fired space heating and hot water systems
35
3.1
Scope of guidance
35
3.2
Oil-fired wet central heating systems
35
3.3
Oil-fired range cookers with integral central heating boilers
48
3.4
Continually-burning oil-fired vaporising appliances providing
secondary heating or hot water
49
3.5
Oil-fired fixed independent space heating appliances
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Electric heating systems
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4.1
Scope of guidance
51
4.2
Electric boilers serving central heating systems
51
4.3
Electric heating systems (other than electric boilers for
central heating)
60
Solid fuel heating systems
63
5.1
Scope of guidance
63
5.2
Solid fuel appliances for primary heating
63
5.3
Central heating systems using certain types of solid fuel
appliances
66
Solid fuel appliances for secondary heating
75
5.4
4 | Domestic Building Services Compliance Guide: 2010 Edition
Section 6
Community heating systems
78
6.1
Scope of guidance
78
New and existing community heating schemes
78
6.2
Section 7
Underfloor heating systems
90
7.1
Scope of guidance
90
Underfloor heating in new dwellings
90
7.2
Section 8
Mechanical ventilation systems
97
8.1
Scope of guidance
97
Energy efficiency of mechanical ventilation systems
97
8.2
Section 9
Section 10
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Heat pump systems
99
9.1
Scope of guidance
99
9.2
Key terms
101
9.3
Warm water and hot water heat pumps
101
Comfort cooling systems
10.1 Scope of guidance
Section 11
109
Solar water heating
111
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11.2 Indirect systems
Section 13
111
111
Lighting
122
12.1 Scope of guidance
122
12.2 Key terms
122
12.3 Internal and external lighting
122
Micro-combined heat and power packages
125
13.1 Scope of guidance
125
13.2 Key terms
125
13.3 Micro-CHP systems
Section 14
109
10.2 Air-cooled and water-cooled air conditioners
11.1 Scope of guidance
Section 12
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Heating system circulators
14.1 Scope of guidance
14.2 Circulators
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127
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127
Section 1 Introduction | 5
Section 1
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Introduction
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Note:
Any reference to building regulations in this guide is to building regulations in
England,Wales, Scotland and Northern Ireland.
1.1 Scope
This guide provides detailed guidance for persons installing fixed building services in
new and existing domestic buildings to help them comply with building regulations. It
covers work on both new systems and replacement systems, identifying the differing
requirements where these exist.
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This edition of the guide covers conventional means of providing primary space heating,
domestic hot water, mechanical ventilation, comfort cooling and interior lighting. In
addition, it covers low carbon generation of heat by heat pumps, solar themal panels, and
micro-combined heat and power systems.
The guide also refers to publications which include information on good practice for design
and installation over and above the recommended minimum standards in this guide.
1.2 Innovative systems
It is important to note that this guide covers a range of frequently occurring situations
and deals with the most commonly used fixed building services technologies. In doing so
it neither endorses these methods and technologies nor excludes other more innovative
technologies.
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Innovative technologies are not excluded from the compliance process and alternative
means of achieving compliance with the functional requirements of building regulations
may be possible. Where the technology has been the subject of a recognised testing
procedure that assesses its energy performance, this may be used to indicate that the
system is adequately efficient.
In the event that there is no recognised testing standard, suitable calculations or modelling
methods may be used to show the carbon performance of the system.
6 | Domestic Building Services Compliance Guide: 2010 Edition
1.3 European Directives
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1.4 Status of guide
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Fixed building services products such as boilers, circulators and heat pumps shall at the
appropriate time comply with all relevant requirements of EU Directives, including the
Eco-design of Energy Using Products (EuP) Framework Directive 2005/32/EC and Directive
2009/28/EC on the Promotion of the Use of Energy from Renewable Sources (Renewable
Energy Directive).
Building regulations contain functional requirements (called standards in Scotland), such
as requirements that buildings must be structurally stable, must be constructed and fitted
to ensure reasonable levels of fire protection, and must be reasonably energy efficient.
These functional requirements are often drafted in broad terms, and so it may not always
be immediately clear to a person carrying out work how to comply with the relevant
requirements. Consequently, documents are often issued which provide practical guidance
on ways of complying with specific aspects of building regulations in some of the more
common building situations. Those documents are called Approved Documents in England
and Wales, Technical Handbooks in Scotland and Technical Booklets in Northern Ireland.
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Approved Documents, Technical Handbooks and Technical Booklets are intended to
provide practical guidance but they are not intended to be comprehensive. Consequently,
they may contain references to other documents which will provide more detailed
information and assistance on parts of the guidance. This guide is one of those documents.
It provides more detailed information on the guidance contained in Approved Documents
L1A and L1B, Section 6 of the Domestic Technical Handbook, and Technical Booklet F1
about compliance with the energy efficiency requirements which apply when installing
fixed building services in new and existing buildings.
Note: Following guidance in an Approved Document, Technical Handbook or Technical
Booklet does not guarantee compliance with building regulations. If you follow the
relevant guidance in an Approved Document, Technical Handbook or Technical Booklet
and in any document referred to (such as this guide) which provides additional information
to help you follow that guidance, there is a legal presumption that you have complied with
building regulations. However, in every case it is for the building control body to decide
whether work complies with building regulations. So, you should always check with the
building control body before you start work what they consider it is necessary for you to do
to comply with building regulations.
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Section 1 Introduction | 7
1.5 How to use this guide
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The guide comprises four self-contained fuel-based sections, and nine technology-specific
sections:
•
Fuel-based sections:
Section 2: Gas-fired primary and secondary space heating and hot water
Section 3: Oil-fired primary and secondary space heating and hot water
Section 4: Electric primary and secondary space heating and hot water
Section 5: Solid fuel primary and secondary space heating and hot water
•
Technology-specific sections:
Section 6: Community heating
Section 7: Underfloor heating
Section 8: Mechanical ventilation
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Section 9: Heat pumps
Section 10: Comfort cooling
Section 11: Solar water heating
Section 12: Lighting
Section 13: Micro-combined heat and power
Section 14: Heating system circulators
For any particular application, reference may need to be made to more than one section.
“Supplementary information” that may help with interpreting the minimum energy
efficiency provisions needed to comply with the Building Regulations is in italic font with a
grey background. In some cases there are links to best practice guidance that goes beyond
the recommended minimum requirements.
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1.6 Key terms
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Key terms are defined immediately below and at appropriate points throughout the guide.
They are shown in italic bold font.
Fixed building services means any part of, or any controls associated with:
a. fixed internal or external lighting systems, but does not include emergency
escape lighting or specialist process lighting; or
b. fixed systems for heating, hot water, air conditioning or mechanical ventilation.
8 | Domestic Building Services Compliance Guide: 2010 Edition
New system means fixed building services installed in a new building or for the first time
in an existing building.
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1.7 Replacement
ONof primary heating appliances
Replacement system means fixed building services installed as a replacement for a
system in an existing building.
Seasonal efficiency means the annual efficiency value used by SAP for a heating
appliance. For gas, LPG and oil boilers that have been tested for efficiency, this is SEDBUK1.
When replacing an existing appliance, the efficiency of the new appliance should not be
significantly less than the efficiency of the appliance being replaced. If the replacement
involves a fuel switch, then the relative carbon emissions associated with the new and
existing fuels should be considered when assessing the reasonableness of the proposed
new appliance. The aim is to discourage replacement of an existing appliance by a
significantly less carbon efficient one.
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The minimum requirements are:
Replacement not involving fuel or energy switch
Where the primary heating appliance is replaced by one using the same fuel or energy
supply, the seasonal efficiency of the new equipment should be:
a. as stated in the relevant fuel-based section of this guide; and
b. not worse than two percentage points lower than the seasonal efficiency of the
controlled service being replaced. If the efficiency of the appliance to be replaced
is not known, efficiency values may be taken from Table 4a or 4b of SAP 2009.
Replacement involving fuel or energy switch
If the new heating appliance uses a different fuel, the efficiency of the new service should
be multiplied by the ratio of the CO2 emission factor of the fuel used in the service being
replaced to that of the fuel used in the new service, to obtain the “carbon equivalent
efficiency”. The checks described in paragraphs a. and b. above should then be made. The
CO2 emission factors should be taken from Table 12 of SAP 2009.
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1
The Boiler Efficiency Database is at www.sedbuk.com. Note: The database will give separate winter and summer (i.e. hot water)
efficiencies for boilers, which SAP 2009 (at www.bre.co.uk/sap2009) uses to calculate carbon dioxide emission rates for dwellings. To
avoid confusion with a prospective EuP Directive labelling scheme, the database no longer shows A to G efficiency bands for boilers.
Section 1 Introduction | 9
Examples
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1. An old oil-fired boiler with a seasonal efficiency of 72 per cent is to be replaced by a
dual solid fuel boiler. The new dual solid fuel boiler should have:
a. a seasonal efficiency not less than 65 per cent (from Table 18 in this guide); and
b. a carbon equivalent efficiency not less than 70 per cent.
A dual solid fuel boiler with a seasonal efficiency of 65 per cent will meet condition
b. as its carbon equivalent efficiency is:
65% x (0.274 ÷ 0.206) = 86.5%
where 0.274 and 0.206 kgCO2/kWh are the emission factors for oil and dual solid fuels
respectively.
2. An LPG-fired boiler of 83 per cent efficiency is to be replaced with an oil boiler. The new
oil boiler should have:
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a. a seasonal efficiency not less than 90 per cent (from Table 9); and
b. a carbon equivalent efficiency not less than 81 per cent.
To meet condition b., the seasonal efficiency of the proposed new oil boiler should
therefore be at least:
81% ÷ (0.245 ÷ 0.274) = 90.59%
where 0.245 and 0.274 kgCO2/kWh are the emission factors of LPG and oil
respectively.
1.8 Energy efficiency standards for compliance with
building regulations – summary table
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To assist compliance with the relevant energy efficiency requirements in building
regulations, this guide sets out recommended minimum energy efficiency standards
for space heating, domestic hot water, cooling, ventilation and lighting, and for
microgeneration of heat by heat pumps, solar thermal panels and micro-combined heat
and power packages. They are summarised in the table below.
The sections that follow the table give guidance on how to meet these standards.
It is important to note that many of these recommended minimum standards will
need to be exceeded if the building regulations target carbon dioxide emission
rate (TER) for new dwellings is to be met.
10 | Domestic Building Services Compliance Guide: 2010 Edition
234
Summary of recommended minimum energy efficiency standards for building
services
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Standard2
Building service
Gas-fired wet central heating systems
Seasonal efficiency
SEDBUK 20053
SEDBUK 2009
Condensing boilers
90%
88%
Non-condensing boilers (where permitted)
78%
78%
Range cooker boilers
75%
75%
Gas-fired warm air heating
Efficiency
See Table 4
Efficiency (gross)4
Gas-fired fixed independent space heaters
Gas and LPG primary
63%
Gas and LPG secondary heating
63% (new build) 45% (existing build)
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Decorative fuel-effect
Gas fires in combined fire/backboilers
(replacement systems)
Not specified (set to 20% in SAP
2009)
Efficiency (gross)
Natural gas
Inset live fuel-effect
45%
46%
All types except inset live fuel-effect
63%
64%
Oil-fired space heating and hot water
systems
SEDBUK 2005
Condensing boilers
90%
88%
Non-condensing boilers (where permitted)
86%
86%
Range cooker boilers
80%
80%
LPG
Seasonal efficiency
Electric heating systems
SEDBUK 2009
Efficiency
N
O
I
S
R
E
V
E
N
I
L
N
O
Boilers serving central heating systems
N/A
Warm air systems
N/A
Panel heaters
N/A
Storage systems including integrated storage/
direct systems
N/A
2
All values are minimum values and apply to new and existing buildings, except where stated.
3
The boiler efficiency should meet either the SEDBUK 2005 or SEDBUK 2009 standard. If the SEDBUK efficiency given in boiler
literature is not dated, it should be assumed to be the SEDBUK 2005 value.
4
Efficiency is heat output divided by calorific value of fuel. The net calorific value of a fuel excludes the latent heat of water vapour in
the exhaust, and so is lower than the gross calorific value. Efficiency test results and European standards normally use net calorific
values. SAP 2009, which uses gross values, gives factors in Table E4 for converting net efficiency to gross efficiency (e.g. 0.901 for
natural gas, 0.921 for LPG, 0.937 for oil).
Section 1 Introduction | 11
Summary of recommended minimum energy efficiency standards for building
services (continued)
N
O
I
S
R
E
V
E
N
I
L
ON
Standard2
Building service
Solid fuel heating systems
Efficiency (gross)
Feed
B1
Simple open fire – Inset
37%
Batch
B2
Open fire – freestanding convector
47%
Batch
B3
Open fire inset convector
45% mineral fuels
43% wood fuels
C1/C2
Open fire and boiler (inset or
freestanding)
50%
Batch
D1/D2/D3
Open fire + high output boiler
(trapezium and rectangular grates)
63%
Batch
D4
Open fire + high output boiler
(rectangle)
63%
Batch
E1
Dry room heater (often known as
dry stove)
65%
Batch/
Automatic
E2
Dry room heater – logs only
65%
Batch
E3
Dry room heater – multi-fuel
65%
Batch
E4
Dry room heater – pellet stove
65% part load
70% nominal load
Auto
F
Room heater with boiler
67% mineral fuels
and logs
70% wood pellets –
part load
75% wood pellets –
nominal load
Batch/
Automatic
G1
Cooker without boiler not
exceeding 3.5 kW
65% mineral fuels
55% wood fuels
Batch
G2
Cooker with heating boiler
exceeding 3.5 kW
J2
Independent boiler (batch-fed)
wood logs only
J3
E
N
I
L
ON
N
O
I
S
R
E
V
N
O
I
S
R
E
V
65% mineral fuels
60% wood fuels
Batch
75%
Batch
Independent boiler (batch-fed)
multi-fuel
65% mineral fuels
75% wood logs
Batch
J4
Independent boiler – anthracite
70% up to 20.5 kW
75% above 20.5 kW
Automatic
J5
Independent boiler – wood/ pellets/ 75% nominal load
chips
70% part load
Automatic
Slow heat release appliances
65%
Batch
One-off tiled/mortared stoves
70%
Batch
E
N
I
L
N
O
12 | Domestic Building Services Compliance Guide: 2010 Edition
Summary of recommended minimum energy efficiency standards for building
services (continued)
N
O
I
S
R
E
V
E
N
I
L
ON
Standard2
Building service
Community heating systems
Boilers
Seasonal efficiency
See Non-domestic building services
compliance guide
Mechanical ventilation systems
Specific fan power (SFP) (max)
Intermittent extract ventilation systems
0.5 W/(l/s)
Continuous extract ventilation systems
0.7 W/(l/s)
Continuous supply ventilation systems
0.5 W/(l/s)
Continuous supply and extract with heat
recovery ventilation systems.
1.5 W/(l/s)
Heat recovery
Dry heat recovery efficiency
Balanced mechanical ventilation systems
70%
N
O
I
S
R
E
V
E
N
I
L
ON
Heat pump systems
(BS EN 15450 Tables C1 & C2)
Seasonal Performance Factor
(SPF)
New build
Air/water
Ground/water
Water/water
Comfort cooling systems
Existing build
2.7
2.5
3.5
3.3
3.8
3.5
Energy efficiency ratio (EER)
Air-cooled air conditioners working in cooling
mode
2.4
Water-cooled air conditioners working in
cooling mode
2.5
Fixed air conditioners
> Class C in Schedule 3 of the
labelling scheme (The Energy
Information (Household Air
Conditioners) (No. 2) Regulations,
SI 2005/1726)
N
O
I
S
R
E
V
E
N
I
L
N
O
Solar water heating
Circulation pump power
< 50W
< 2% of peak thermal power of
collector
Section 1 Introduction | 13
Summary of recommended minimum energy efficiency standards for building
services (continued)
N
O
I
S
R
E
V
E
N
I
L
ON
Standard2
Building service
Fixed lighting
Lighting efficacy
Internal light fittings (75%)
45 lamp lumens per circuit-watt
External lighting – automatic presence and
daylight control
lamp capacity < 100 lamp-watts per
light fitting
External lighting – manual switching and
automatic daylight control
45 lumens per circuit-watt
Micro-CHP
Heating plant emission rate
(HPER)
See Section 13.3 a.
Heating system circulators
Europump Labelling Scheme
rating
N
O
I
S
R
E
V
E
N
I
L
ON
Stand-alone, glandless heating system
circulators
A to G
N
O
I
S
R
E
V
E
N
I
L
N
O
14 | Domestic Building Services Compliance Guide: 2010 Edition
Section 2
N
O
I
S
Gas-fired space heating and
hot water
R
E
systems
V
E
N
I
L
2.1 Scope of guidance
ON
This section provides guidance on the specification of gas-fired space heating and hot
water systems5 in dwellings to meet relevant energy efficiency requirements in building
regulations. The guidance applies to systems fuelled by natural gas and liquid petroleum
gas (LPG) and covers:
•
wet central heating systems
•
range cookers with integral central heating boilers
•
warm air heating systems
•
fixed independent space heating devices.
N
O
I
S
R
E
V
E
N
2.2 Gas-fired wet central
heating
systems
I
L
ON
Gas-fired wet central heating systems for dwellings should meet the minimum standards
for:
a. boiler efficiency, system circulation, hot water storage, system preparation and
commissioning in Table 1
b. boiler interlock, zoning, and time and temperature control of the heating and
hot water circuits in Table 2
N
O
I
S
R
E
V
E
N
I
L
N
O
c. pipework insulation in Table 3.
5
All gas appliances must be installed by a competent person in accordance with the current issue of the Gas Safety (Installation and
Use) Regulations. The installation should follow the manufacturer’s instructions and should comply with all relevant parts of the
Building Regulations and, for wet systems, the Water Regulations.
1.0
Efficiency
Gas-fired
wet heating
Supplementary information
The SEDBUK method for determining
efficiency has been revised in SAP
2009. SEDBUK 2009 values are
different from SEDBUK 2005. The
Boiler Efficiency Database at www.
sedbuk.com gives both, together
with separate winter and summer
(i.e. hot water) efficiencies for boilers
that are used by SAP 2009 to calculate
the carbon dioxide emission rate for
dwellings. If the SEDBUK efficiency
given in a boiler manufacturer’s
literature does not give a date, it should
be assumed to be the SEDBUK 2005
value.
The CLG “Guide to the condensing
boiler installation assessment
procedure for dwellings” sets out the
approved procedure for establishing
the exceptional circumstances in which
boilers may be of the non-condensing
type.
Replacement systems
Replacements not involving a fuel
or energy switch
a. The boiler seasonal efficiency
should be as defined for new
systems; and
b. not worse than two percentage
points lower than the seasonal
efficiency of the controlled service
being replaced. If the efficiency
of the system or appliance to be
replaced is not known, efficiency
values may be taken from Table 4a
or 4b of SAP 2009.
Replacements involving fuel or
energy switch
a. If the new heating system or
heat generating appliance uses a
different fuel, the efficiency of the
new service should be multiplied by
the ratio of the CO2 emission factor
of the fuel used in the service being
replaced to that used in the new
service before making the checks in
a. and b. above. The CO2 emission
factors should be taken from Table
12 of SAP 2009.
New systems
a. The boiler SEDBUK 2005 efficiency
shou ld be not less than 90% (or
88% as rated by SEDBUK 2009).
b. In existing dwellings, in the
exceptional circumstances defined
in the CLG Guide to the condensing
boiler installation assessment
procedure for dwellings6, the boiler
SEDBUK 2005 (or SEDBUK 2009)
efficiency should be not less than
78% if natural gas-fired, or not less
than 80% if LPG-fired.
c. The boiler efficiency for heating
boilers that are combined with
range cookers should be as defined
in Section 2.3 Gas-fired range
cookers with integral central
heating boiler.
Table 1: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for gas-fired wet central heating systems
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
Guide to the condensing boiler installation assessment procedure for dwellings, CLG, 2005. Available from www.planningportal.gov.uk/approveddocuments
N
O
I
S
R
E
V
E
N
I
L
ON
6
6
Section 2 Gas-fired space heating and hot water systems | 15
2.0
System
circulation
a. Space heating systems and
domestic hot water primary
circuits should have fully pumped
circulation.
b. If the boiler manufacturer’s
instructions advise installation of
a bypass, an automatic bypass
valve should be provided and the
manufacturer’s instructions on
minimum pipe length followed.
a. As for new systems.
b. When boilers are replaced,
existing systems with semi-gravity
circulation should be converted to
fully pumped circulation.
N
O
I
S
R
E
V
E
N
I
L
N
O
1.0
Efficiency
(continued)
Replacement systems
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Gas-fired
wet heating
Where condensing boilers are fitted,
systems should be designed so as to
provide low primary system return
temperatures, preferably less than 55
degC, which maximise condensing
operation. Low temperature heat
emitters such as underfloor heating
and weather compensation are
examples of techniques which provide
low return water temperatures.
Supplementary information
Table 1: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for gas-fired wet central heating systems (continued)
16 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
3.0
Hot water
storage
Gas-fired
wet heating
Replacement systems
a. As for new systems, but
a. Vented copper hot water storage
b. for replacement copper vented
cylinders should comply with the
cylinders and combination units, the
heat loss and heat exchanger
standing loss should not exceed
requirements of BS 1566:2002
Q = 1.28 x (0.2+0.051V2/3) kWh/day,
Part 1.
where V is the volume of the
b. Copper hot water storage
cylinder.
combination units should comply
with BS 3198:1981.
c. Primary storage systems should
meet the insulation requirements
of the Hot Water Association
Performance specification for
thermal stores.
d. Unvented hot water storage system
products should comply with BS
EN 12897: 2006 or an equivalent
standard as set by an accredited
test body such as the British Board
of Agrément, the Water Research
Council, or KIWA.
New systems
If a vented cylinder is made from an
alternative material to copper then
the heat loss and heat exchange
characteristics should be tested in
accordance with BS EN 12897:2006.
The HWA thermal storage specification
is available for free download from
www.hotwater.org.uk.
Supplementary information
Table 1: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for gas-fired wet central heating systems (continued)
N
O
I
S
R
E
V
E
N
I
L
ON
British Standards
BS 1566: 2002 “Copper indirect
cylinders for domestic purposes. Open
vented copper cylinders. Requirements
and test methods”.
BS EN 12897 “Water supply.
Specification for indirectly heated
unvented (closed) storage water
heaters”.
BS 3198 “Copper hot water storage
combination units for domestic
purposes”.
Section 2 Gas-fired space heating and hot water systems | 17
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
3.0
Hot water
storage
(continued)
Gas-fired
wet heating
e. The standing heat loss for all hot
water storage vessels in a, b, c
and d above should not exceed
Q = 1.15 x (0.2+0.051V2/3) kWh/day,
where V is the volume of the
cylinder.
f. All hot water vessels should
carry a label with the following
information:
i. type of vessel (vented,
unvented, combination unit or
thermal store);
ii. nominal capacity in litres;
iii standing heat loss in kWh/day;
iv. heat exchanger performance in
kW;
v. reference to product compliance
with relevant standard (e.g. BS
1566, BS 12897) and logos of
accreditation bodies as required.
For labelling requirements for other
heat inputs, see relevant sections (e.g.
Section 11 for solar).
New systems
Replacement systems
Supplementary information
Table 1: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for gas-fired wet central heating systems (continued)
18 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
4.0
System
preparation
and water
treatment
Gas-fired
wet heating
Replacement systems
a. As for new systems.
New systems
a. Central heating systems should be
thoroughly cleaned and flushed
out before installing a new boiler.
b. During final filling of the system, a
chemical water treatment inhibitor
meeting the manufacturer’s
specification or other appropriate
standard should be added to the
primary circuit to control corrosion
and the formation of scale and
sludge.
c. Installers should also refer to the
boiler manufacturer’s installation
instructions for appropriate
treatment products and special
requirements for individual boiler
models.
d. Where the mains total water
hardness exceeds 200 parts per
million, and if required by the
manufacturer, provision should be
made to treat the feed water to
water heaters and the hot water
circuit of combination boilers to
reduce the rate of accumulation of
limescale.
e. For solar thermal systems, see
Section 11.
Inhibitors should as a minimum be
BuildCert approved.
Limescale can be controlled by the
use of chemical limescale inhibitors,
combined corrosion and limescale
inhibitors, polyphosphate dosing,
electrolytic scale reducers or water
softeners.
The relevant standard for water
treatment is BS 7593:2006 “Code
of practice for treatment of water in
domestic hot water central heating
systems”.
BS 7593 notes that soft water has
an increased potential for corrosion,
and this may influence the choice of
corrosion inhibitor. Where water is
artificially softened, it is advisable to
feed unsoftened water not only to
drinking water taps, but also to the
boiler primary circuit. In soft water
areas, the boiler manufacturer should
be consulted for advice.
In order to avoid loss and consequent
replacement of circulating fluid and
water treatment when removing
radiators for service or maintenance,
it is advisable to install radiator valves
that can isolate not only the heating
circuit but also seal off the radiators.
Supplementary information
Table 1: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for gas-fired wet central heating systems (continued)
Section 2 Gas-fired space heating and hot water systems | 19
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
5.0
Commissioning
Gas-fired
wet heating
Replacement systems
a. As for new systems.
New systems
a. On completion of the installation
of a boiler or hot water
storage system, together with
associated equipment such as
pipework, pumps and controls,
the equipment should be
commissioned in accordance with
the manufacturer’s instructions.
These instructions will be specific
to the particular boiler or hot water
storage system.
b. The installer should give a full
explanation of the system and its
operation to the user, including the
manufacturer’s User Manual where
provided.
The Benchmark System
The Benchmark Commissioning
Checklist can be used to show that
commissioning has been carried out
satisfactorily. Benchmark licenceholders provide a checklist with the
appliance for completion by the
persons commissioning the system
so that they can record that all the
checks have been made and the
results show efficient operation of the
equipment in compliance with building
regulations. The Benchmark checklist
should be provided to the builder, or
the householder in the case of work
in existing dwellings, an appointed
agent, or the end user.
A Benchmark Commissioning Checklist
will be included in all HHIC gas boiler
manufacturer members’ installation
manuals to help installers record
information about the installation
in order to assist with servicing
and repairs. For example, details of
system cleaners and inhibitors can be
recorded.
Supplementary information
Table 1: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for gas-fired wet central heating systems (continued)
20 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
N
O
I
S
R
E
V
E
N
I
L
N
O
5.0
Commissioning
(continued)
Replacement systems
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Gas-fired
wet heating
Only manufacturing companies who
hold a Benchmark licence will be
eligible to use the Benchmark logo
and the approved log book wording
and layout. (Benchmark is registered
as a European Collective Mark by
the Heating and Hot Water Industry
Council and the content is copyright.)
Supplementary information
Table 1: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for gas-fired wet central heating systems (continued)
Section 2 Gas-fired space heating and hot water systems | 21
N
O
I
S
R
E
V
E
N
I
L
ON
22 | Domestic Building Services Compliance Guide: 2010 Edition
Table 2: Recommended minimum standards for control of gas-fired wet central
heating systems
Gas-fired
wet heating
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Replacement
systems
1.0
Boiler
interlock
a. Boiler-based systems should have a boiler
control interlock in which controls are wired
so that when there is no demand for either
space heating or hot water, the boiler and
pump are switched off.
b. The use of thermostatic radiator valves
(TRVs) alone does not provide interlock.
a. As for new
systems.
2.0
Space
heating
zones
a. Dwellings with a total usable floor area up
to 150 m2 should be divided into at least
two space heating zones with independent
temperature control, one of which is
assigned to the living area.
b. Dwellings with a total usable floor area
greater than 150 m2 should be provided
with at least two space heating zones, each
having separate timing and temperature
controls.
c. For single-storey open-plan dwellings in
which the living area is greater than 70%
of the total floor area, sub-zoning of
temperature control is not appropriate.
a. As for new
systems.
a. All dwellings should have a separate hot
water zone in addition to space heating
zones.
b. A separate hot water zone is not required if
the hot water is produced instantaneously,
such as with a combination boiler.
a. As for new
systems.
3.0
Water
heating
zones
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 2 Gas-fired space heating and hot water systems | 23
Table 2: Recommended minimum standards for control of gas-fired wet central
heating systems (continued)
Gas-fired
wet heating
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Replacement
systems
a. As for new
4.0
a. Time control of space and water heating
systems unless
Time control
should be provided by:
only the hot water
of space
i. a full programmer with separate timing
cylinder is being
and water
to each circuit; or
replaced and
heating
ii. two or more separate timers providing
separate time
timing control to each circuit; or
control for the
iii. programmable room thermostat(s) to
hot water circuit
the heating circuit(s), with separate
is not present.
timing of the hot water circuit.
In this case it is
b. For dwellings with a total usable floor area
acceptable to
greater than 150 m2, timing of the separate
space heating zones can be achieved by:
have a single
timing control
i. multiple heating zone programmers; or
for both space
ii. a single multi-channel programmer; or
heating and hot
iii. programmable room thermostats; or
iv. separate timers to each circuit; or
water.
v. a combination of (iii) and (iv) above.
c. Where the hot water is produced
instantaneously, such as with a combination
boiler, time control is only required for space
heating zones.
N
O
I
S
R
E
V
E
N
I
L
ON
a. Separate temperature control of zones
5.0
within the dwelling should be provided
Temperature
using:
control
i. room thermostats or programmable
of space
heating
room thermostats in all zones; and
ii. individual radiator controls such as
thermostatic radiator valves (TRVs) on all
radiators other than in reference rooms
(with a thermostat) and bathrooms.
a. As for new
systems.*
N
O
I
S
R
E
V
E
N
I
L
N
O
24 | Domestic Building Services Compliance Guide: 2010 Edition
Table 2: Recommended minimum standards for control of gas-fired wet central
heating systems (continued)
Gas-fired
wet heating
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
6.0
a. Domestic hot water systems should be
Temperature
provided with a cylinder thermostat and a
control of
zone valve or three-port valve to control the
domestic
temperature of stored hot water.
hot water
b. In dwellings with a total floor area greater
than 150 m2 it would be reasonable to
provide more than one hot water circuit,
each with separate timing and temperature
controls. This can be achieved by:
i. multiple heating zone programmers; or
ii. a single multi-channel programmer; or
iii separate timers to each circuit.
c. Non-electric hot water controllers should
not be used. Also, in some circumstances,
such as with thermal stores, a zone valve is
not appropriate; a second pump could be
substituted for the zone valve.
Replacement
systems
a. As for new
systems
for planned
replacement
of hot water
cylinders on all
fully pumped
installations,
and on gravity
circulation
installations.
b. In exceptional
circumstances,
such as
emergency
replacement or
where the cylinder
or installation
is of a type that
precludes the
fitting of wired
controls, either
a wireless or
thermomechanical
hot water cylinder
thermostat would
be acceptable.
N
O
I
S
R
E
V
E
N
I
L
ON
Supplementary information
More details on control systems can be found in manufacturers’ literature and on
the The Association of Controls Manufacturers (TACMA) website at
www.heatingcontrols.org.uk.
Controls may be provided by any boiler management control system that meets the
specified zoning, timing and temperature and boiler interlock control requirements.
*When an individual system component – such as the boiler or a room thermostat – is
being replaced, it is not necessary to upgrade the whole system. However, while not
essential for compliance with building regulations, in the case of a boiler replacement,
because the system has to be drained down, it would be good practice to install
thermostatic radiator valves (or equivalent) on all radiators other than in the room with
the main thermostat, provided the radiators are suitable and pipework does not need to
be altered.
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 2 Gas-fired space heating and hot water systems | 25
Table 3: Recommended minimum standards for insulation of pipework in gas-fired wet
central heating systems
New systems
N
O
I
S
R
E
V
E
N
I
L
ON
Supplementary information
a. Pipes should be insulated to comply with the
maximum permissible heat loss indicated in
the Supplementary Information column, and
labelled accordingly, as follows:
i. Primary circulation pipes for heating and hot
water circuits should be insulated wherever
they pass outside the heated living space or
through voids which communicate with and
are ventilated from unheated spaces.
ii. Primary circulation pipes for domestic
hot water circuits should be insulated
throughout their length, subject only to
practical constraints imposed by the need
to penetrate joists and other structural
elements.
iii. All pipes connected to hot water storage
vessels, including the vent pipe, should be
insulated for at least 1 metre from their
points of connection to the cylinder (or they
should be insulated up to the point where
they become concealed).
iv. If secondary circulation is used, all pipes kept
hot by that circulation should be insulated.
Insulation of pipework in unheated areas
Extra provision may need to be made to
protect central heating and hot water
pipework in unheated areas against freezing.
Guidance is available in:
• BS 5422:2009 “Method for specifying
thermal insulating materials for pipes,
tanks, vessels, ductwork and equipment
operating within the temperature range
-40°C to +700°C”.
• BRE Report No 262 “Thermal insulation:
avoiding risks”, 2002 Edition.
Pipe outside
diameter
Maximum
heat loss*
Replacement systems
8 mm
7.06 W/m
a. Whenever a boiler or hot water storage vessel
is replaced in an existing system, any pipes that
are exposed as part of the work or are otherwise
accessible should be insulated as recommended
above – or to some lesser standard where
practical constraints dictate.
10 mm
7.23 W/m
12 mm
7.35 W/m
15 mm
7.89 W/m
22 mm
9.12 W/m
28 mm
10.07 W/m
35 mm
11.08 W/m
42 mm
12.19 W/m
54 mm
14.12 W/m
Where insulation is labelled as complying with
this guide, it must not exceed the following
heat loss levels:
N
O
I
S
R
E
V
E
N
I
L
ON
E
N
I
L
N
O
N
O
I
S
R
E
V
*In assessing the thickness of insulation
required, standardised conditions should
be assumed in all compliance calculations,
based on a horizontal pipe at 60°C in still air
at 15°C. Further guidance on converting heat
loss limits to insulation thickness for specific
thermal conductivities is available in TIMSA
“HVAC guidance for achieving compliance
with Part L of the Building Regulations”.
26 | Domestic Building Services Compliance Guide: 2010 Edition
2.3 Gas-fired range cookers with integral central
heating boiler
N
O
I
S
R
E
V
E
N
I
L
ON
Note:
This section does not apply to appliances with fully independent boiler and cooker parts
within a shared case. For these, the standards for the boiler are as set out in Section 2.2.
Gas-fired range cookers with integral central heating boiler (within a single appliance
body), provided as new systems or replacement systems, should meet the following
standards:
a. The appliance should have two independently controlled burners (one for the
cooking function and one for the boiler).
b. The integral boiler should have a seasonal efficiency (SEDBUK 2005 or
SEDBUK 2009) in excess of 75%. The manufacturer’s declaration of appliance
performance and SEDBUK value should include the following words:
i.
N
O
I
S
R
E
V
E
N
I
L
ON
Seasonal efficiency (SEDBUK) = xx %
ii. Case heat emission value = yy kW
iii. Heat transfer to water at full load = zz kW
iv. The values are used in the UK Government’s Standard Assessment Procedure
(SAP) for the energy rating of dwellings. The test data from which the values
have been calculated has been certified by {insert name and/or identification
of Notified body}. See: www.rangeefficiency.org.uk.
If the integral boiler is a condensing boiler, the declaration should make clear
whether the efficiency has been calculated in accordance with SEDBUK 2005 or
SEDBUK 2009. If it does not, then SEDBUK 2005 must be assumed.
N
O
I
S
R
E
V
E
2.4 Gas-fired warm airN
heating
I
L
N
O
c. The integral boiler should meet the minimum standards for system circulation,
hot water storage, system preparation, commissioning, controls and insulation in
Tables 1, 2 and 3 (gas-fired central heating systems).
Gas-fired warm air heating systems provided as new systems and replacement systems
should meet the minimum standards for:
a. efficiency and installation in Table 4; and
b. zoning, time control and temperature control for space heating in Table 5a, and
for space heating combined with water heating in Table 5b.
Section 2 Gas-fired space heating and hot water systems | 27
Table 4: Recommended minimum standards for efficiency and installation for
gas-fired warm air heating systems
Gas-fired
warm air
heating
1.0
Efficiency
N
O
I
S
R
E
V
E
N
I
L
ON
New and replacement systems
a. Gas-fired warm air units should meet
the requirements, as appropriate to
the design of the appliance, of:
i. BS EN 778: 2009; or
ii. BS EN 1319: 2009.
b. If a gas-fired circulator is incorporated
in the warm air unit to provide
domestic hot water, it should be able
to deliver full and part load efficiency
at least equal to that prescribed by
BS EN 483:2000.
c. The manufacturer’s declaration
of appliance performance should
include the following words:
i. Combined warm air unit and
circulator
This product has been assessed
against the test methods set
out in BS EN 778:2009*/BS
EN 1319:2009*/BS EN 483*
and certified as meeting those
minimum requirements by {insert
name or identification of Notified
Body}.
ii. Warm air unit alone
This product has been assessed
against the test method set out in
BS EN 778: 2009* or BS EN 1319:
2009* and certified as meeting
the minimum requirements by
{insert name and/or identification
of Notified Body}.
*Delete as appropriate
Supplementary
information
British standards
BS EN 778:2009 “Domestic
gas-fired forced convection
air heaters for space
heating not exceeding
a net heat input of
70 kW, without a fan to
assist transportation of
combustion air and/or
combustion products”.
BS EN 1319:2009
“Domestic gas-fired forced
convection air heaters
for space heating, with
fan-assisted burners not
exceeding a net heat input
of 70 kW”.
N
O
I
S
R
E
V
E
N
I
L
ON
BS EN 483:2000 “Gas-fired
central heating boilers.
Type C boilers of nominal
heat input not exceeding
70 kW”.
N
O
I
S
R
E
V
E
N
I
L
N
O
28 | Domestic Building Services Compliance Guide: 2010 Edition
Table 4: Recommended minimum standards for efficiency and installation for
gas-fired warm air heating systems (continued)
Gas-fired
warm air
heating
2.0
Installation
N
O
I
S
R
E
V
E
N
I
L
ON
New and replacement systems
a. The system should be installed in
accordance with BS 5864:2004.
b. Ductwork that is newly
installed or replaced should be
insulated in accordance with the
recommendations of BS 5422:2009.
Supplementary
information
BS 5864:2004 “Installation
and maintenance of gasfired ducted air heaters of
rated input not exceeding
70 kW net (second
and third family gases).
Specification”.
BS 5422:2009 “Method
for specifying thermal
insulating materials for
pipes, tanks, vessels,
ductwork and equipment
operating within the
temperature range of -40°C
to +700°C”.
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 2 Gas-fired space heating and hot water systems | 29
Table 5a: Recommended minimum standards for control of gas-fired warm air
heating without water heating
Gas-fired
warm air
heating
without
hot water
N
O
I
S
R
E
V
E
N
I
L
ON
New and replacement systems
1.0
a. Controls external to heater: time switch/programmer and room
Time and
thermostat, or programmable room thermostat; or
temperature b. controls integrated in the heater: time-switch/programmer and
control
room temperature sensor linked to heater firing and fan speed
control.
2.0
Zoning
a. New dwellings with a total usable floor area up to 150 m2 should
be divided into at least two space heating zones with independent
temperature controls, one of which is assigned to the living area.
b. New dwellings with a total usable floor area greater than 150 m2
should be provided with at least two space heating zones, each
having separate timing and temperature controls. Timing of the
separate space heating zones can be achieved by:
i. multiple heating zone programmers; or
ii. a single multi-channel programmer; or
iii. programmable room thermostats; or
iv. separate timers to each circuit; or
v. a combination of iii) and (iv) above.
c. The provisions for zoning for replacement systems in existing
dwellings should be as for new dwellings where practical.
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
30 | Domestic Building Services Compliance Guide: 2010 Edition
Table 5b: Recommended minimum standards for control of gas-fired warm air
heating with water heating
Gas-fired
warm air
heating
with hot
water
1.0
System
circulation
N
O
I
S
R
E
V
E
N
I
L
ON
New and replacement systems
a. Pumped primary circulation to the hot water cylinder.
a. Independent time control of both the space heating and hot water
2.0
Time and
circuits.
temperature b. Time control should be provided by use of either:
control
i. a full programmer with separate timing to each circuit; or
ii. two or more separate timers providing timing control to each
circuit; or
iii. programmable room thermostat(s) to the heating circuit(s), with
separate timing of the hot water; or
iv. a time switch/programmer (two channel) and room thermostat.
c. For new systems: Independent control of the hot water circuit
should be achieved by means of a cylinder thermostat and a timing
device, wired such that when there is no demand for hot water both
the pump and circulator are switched off.
d. For replacement systems: Independent control of the hot water
circuit should be achieved, where practicable, for circulator water
heaters of less than 6 kW output by means of a cylinder thermostat
and a timing device, wired such that when there is no demand for
hot water both the pump and circulator are switched off.
N
O
I
S
R
E
V
E
N
I
L
ON
3.0
Space
heating
zoning
a. New dwellings with a total usable floor area up to 150 m2 should
be divided into at least two space heating zones with independent
timing controls, one of which is assigned to the living area.
b. New dwellings with a total usable floor area greater than 150 m2
should be provided with at least two space heating zones, each
having separate timing and temperature controls.
c. The provisions for zoning for replacement systems in existing
dwellings should be as for new dwellings where practical.
N
O
I
S
R
E
V
2.5 Gas-fired fixed independent
space heating appliances
E
N
I
L
ON
Fixed independent space heating appliances may be installed as a means of primary or
secondary space heating.
Section 2 Gas-fired space heating and hot water systems | 31
Gas-fired fixed independent appliances for primary space heating
Gas-fired fixed independent space heating appliances in new and existing dwellings which
are provided as the primary heat source should meet the following conditions:
N
O
I
S
R
E
V
E
N
I
L
ON
a. the appliance should be one of the types described in Table 6
b. the efficiency of the appliance (gross calorific value) should be not less than
63 per cent (70% net)
c. the appliance manufacturer’s declaration of appliance performance should
include the following words:
The efficiency of this appliance has been measured as specified in {insert
appropriate entry from Table 6} and the result after conversion to gross using the
appropriate factor from Table E4 of SAP 2009 is [x] %. The test data has been
certified by {insert name and/or identification of Notified Body}. The efficiency
value may be used in the UK Government’s Standard Assessment Procedure
(SAP) for energy rating of dwellings.
N
O
I
S
R
E
V
E
N
I
L
ON
d. in new dwellings, each appliance should be capable, either independently or
in conjunction with room thermostats or other suitable temperature sensing
devices, of controlling the temperatures independently in areas that have
different heating needs (e.g. separate sleeping and living areas). In existing
dwellings, wherever practical, temperature controls should be upgraded to the
standards required for new dwellings.
Table 6: Acceptable types of natural gas and LPG-fired fixed independent
appliances for primary space heating
British Standard designation (appliance type)
BS EN 1266:2002 Independent gas-fired convection heaters incorporating a fan to assist
transportation of combustion air and/or flue gases.
BS 7977-1:2002 Specification for safety and rational use of energy of domestic gas
appliances. Radiant/convectors.
BS EN 613:2001 Independent gas-fired convection heaters.
BS EN 13278:2003 Open fronted gas-fired independent space heaters.
N
O
I
S
R
E
V
E
N
I
L
N
O
Gas-fired fixed independent appliances for secondary space heating
Gas-fired fixed independent space heating appliances which are provided as the secondary
heat source should meet the following conditions:
a. in new dwellings, the appliance efficiency (gross calorific value) should be not less
than 63 per cent (70% net)
32 | Domestic Building Services Compliance Guide: 2010 Edition
b. in existing dwellings, the appliance efficiency (gross calorific value) should be not
less than 45 per cent (50% net)
N
O
I
S
R
E
V
E
N
I
L
ON
c. the appliance manufacturer’s declaration of appliance performance should
include the following words:
The efficiency of this appliance has been measured as specified in {insert
appropriate entry from Table 7} and the result after conversion to gross using
the appropriate factor from Table E4 of SAP 2009 is [x]%. The test data has been
certified by {insert name and/or identification of Notified Body}. The efficiency
value may be used in the UK Government’s Standard Assessment Procedure
(SAP) for energy rating of dwellings.
Table 7: Acceptable types of natural gas and LPG-fired fixed independent
appliances for secondary space heating
BS EN 1266: 2002 Independent gas-fired convection heaters incorporating a fan to assist
transportation of combustion air and/or flue gases
N
O
I
S
R
E
V
E
N
I
L
ON
BS 7977-1: 2002 Specification for safety and rational use of energy of domestic gas
appliances. Radiant/convectors
BS EN 613: 2001 Independent gas-fired convection heaters
BS EN 13278: 2003 Open fronted gas-fired independent space heaters
Flueless
BS EN 14829: 2007 Independent gas-fired
flueless space heaters for nominal heat input
not exceeding 6 kW
BS EN 449: 2002 Specification for dedicated
liquefied petroleum gas appliances.
Domestic flueless space heaters (including
diffusive catalytic combustion heaters)
Thermal efficiency requirements for this
type of appliance are not specified as all
the heat produced by the combustion
process is released into the space to be
heated. In SAP 2009 the efficiency of
these appliances is classed as 90% and
an adjustment is made for ventilation
in the space heating requirement
calculation.
N
O
I
S
R
E
V
E
N
I
L
N
O
2.6 Gas-fired fixed decorative fuel-effect fires
This type of appliance is intended for decorative purposes and therefore a minimum
thermal efficiency is not specified. Note that for the purposes of SAP 2009 the efficiency of
decorative fuel-effect fires is classed as 20 per cent for use in the space heating requirement
calculation. See Table 4a of SAP 2009.
Gas-fired decorative fires in new and existing dwellings should:
a. meet the product standards in BS EN 509: 2000 Decorative fuel-effect gas
appliances; and
b. number not more than one appliance per 100 m2 of dwelling floor area.
Section 2 Gas-fired space heating and hot water systems | 33
2.7 Gas fires for secondary space heating provided as part
of a combined fire and back boiler unit
N
O
I
S
R
E
V
E
N
I
L
ON
Gas fires provided as a secondary heat source as part of a combined fire and back boiler
unit, when provided as a replacement system in existing dwellings, should meet the
following conditions:
a. the appliance should be one of the types described in Table 8
b. the efficiency (gross calorific value) of the appliance should be not less than the
value in Table 8 for that type of appliance
c. the appliance manufacturer’s declaration of appliance performance should
include the following words:
The efficiency of this appliance has been measured as specified in {insert
appropriate entry from Table 8} and the result after conversion to gross using the
appropriate factor from Table E4 of SAP 2009 is [x]%. The test data from which
it has been calculated has been certified by {insert name and/or identification
of Notified Body}. The efficiency value may be used in the UK Government’s
Standard Assessment Procedure (SAP) for energy rating of dwellings.
N
O
I
S
R
E
V
E
N
I
L
ON
Table 8: Minimum appliance efficiencies for gas fires in a combined fire and back
boiler unit
Minimum efficiency %
(Gross calorific value)
British Standard designation (appliance type)
Natural gas
LPG
Inset live fuel-effect
BS 7977-2:2003 Specification for safety and rational
use of energy of domestic gas appliances. Combined
appliances. Gas fire/back boiler.
45
46
All types except inset live fuel-effect
BS 7977-2:2003 Specification for safety and rational
use of energy of domestic gas appliances. Combined
appliances. Gas fire/back boiler.
63
E
N
I
L
N
O
N
O
I
S
R
E
V
64
34 | Domestic Building Services Compliance Guide: 2010 Edition
Table 8: Minimum appliance efficiencies for gas fires in a combined fire and back
boiler unit (continued)
N
O
I
S
R
E
V
E
N
I
L
ON
Supplementary information – further guidance on gas-fired heating
Energy Efficiency Best Practice in Housing publications:
• CE30 “Domestic heating by gas: boiler systems”
• CE51 “Central heating system specifications (CHeSS)”
• CE54 “Whole house boiler sizing method for houses and flats”.
SBGI publications on gas boilers and gas fires under development at the time of writing:
• See www.sbgi.org.uk for updates.
CORGI Domestic Manual Series:
• GID1 “Essential gas safety”
• GID2 “Gas cookers and ranges”
• GID3 “Gas fires and space heaters”
• GID5 “Water heaters”
• GID7 “Central heating wet and dry”
CORGI Design Guides:
• WCH1 “Wet central heating system design guide”
• WAH1 “Warm air heating system design guide”.
British Standards
BS 5440-1:2008 “Flueing and ventilation for gas appliances of rated input not exceeding
70 kW net (1st, 2nd and 3rd family gases). Specification for installation of gas appliances
to chimneys and for maintenance of chimneys”.
BS 5440-1:2009 “Flueing and ventilation for gas appliances of rated input not exceeding
70 kW net (1st, 2nd and 3rd family gases). Specification for the installation and
maintenance of ventilation provision for gas appliances”.
BS EN 12828:2003 “Heating systems in buildings. Design for water-based heating
systems”.
BS EN 12831:2003 “Heating systems in buildings. Method for calculation of the design
heat load”.
BS EN 14336:2004 “Heating systems in buildings. Installation and commissioning of
water-based heating systems”.
BS 6798:2009 “Specification for installation and maintenance of gas-fired boilers of
rated input not exceeding 70 kW net”.
BS 5871-1:2005 “Specification for the installation and maintenance of gas fires,
convector heaters, fire/back boilers and decorative fuel effect gas appliances. Gas fires,
convector heaters, fire/back boilers and heating stoves (2nd and 3rd family gases)”.
BS 5871-2:2005 “Specification for the installation and maintenance of gas fires,
convector heaters, fire/back boilers and decorative fuel effect gas appliances. Inset live
fuel effect gas fires of heat input not exceeding 15 kW, and fire/back boilers (2nd and
3rd family gases)”.
BS 5871-3:2005 “Specification for the installation and maintenance of gas fires,
convector heaters, fire/back boilers and decorative fuel effect gas appliances. Decorative
fuel effect gas appliances of heat input not exceeding 20 kW (2nd and 3rd family
gases)”.
BS 5871-4:2007 “Specification for the installation and maintenance of gas fires,
convector heaters, fire/back boilers and decorative fuel effect gas appliances.
Independent gas-fired flueless fires, convector heaters and heating stoves of nominal
heat input not exceeding 6 kW (2nd and 3rd family gases)”.
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 3 Oil-fired space heating and hot water systems | 35
Section 3
N
O
I
S
Oil-fired space heating and
hot water
R
E
systems
V
E
N
I
L
3.1 Scope of guidance
ON
This section provides guidance on the specification of oil-fired space heating and hot
water systems7 in dwellings to meet relevant energy efficiency requirements in building
regulations. The guidance applies to the following types of oil-fired heating system:
•
wet central heating systems
•
range cookers with integral central heating boilers
•
vaporising appliances providing secondary heating or hot water
•
fixed independent space heating devices.
N
O
I
S
R
E
V
3.2 Oil-fired wet central E
heating systems
IN
L
ON
Oil-fired central heating systems which are provided as new systems or replacement
systems in dwellings should meet the minimum standards for:
a. boiler efficiency, system circulation, hot water storage, system preparation and
commissioning in Table 9
b. boiler interlock, zoning, and time and temperature control of the heating and
hot water circuits in Table 10
N
O
I
S
R
E
V
E
N
I
L
N
O
c. pipework insulation in Table 11.
7
All gas appliances must be installed by a competent person in accordance with the current issue of the Gas Safety (Installation and
Use) Regulations. The installation should follow the manufacturerís instructions and should comply with all relevant parts of the
Building Regulations and, for wet systems, the Water Regulations.
d.
1.0
Efficiency
Oil-fired wet
heating
Supplementary information
The SEDBUK method for determining
efficiency has been revised in SAP
2009. SEDBUK 2009 values are
different from SEDBUK 2005. The
Boiler Efficiency Database at
www.sedbuk.com gives both,
together with separate winter and
summer (i.e. hot water) efficiencies
for boilers that are used by SAP
2009 to calculate the carbon dioxide
emission rate for dwellings. If the
SEDBUK efficiency given in a boiler
manufacturer’s literature does not give
a date, it should be assumed to be the
SEDBUK 2005 value.
The CLG “Guide to the condensing
boiler installation assessment
procedure for dwellings” sets out the
approved procedure for establishing
the exceptional circumstances in which
boilers may be of the non-condensing
type.
Replacement systems
Replacements not involving a fuel
or energy switch
a. The boiler seasonal efficiency
should be as defined for new
systems; and
b. not worse than two percentage
points lower than the seasonal
efficiency of the controlled service
being replaced. If the efficiency
of the system or appliance to be
replaced is not known, efficiency
values may be taken from Table 4a
or 4b of SAP 2009.
Replacements involving fuel or
energy switch
a. If the new heating system or
heat generating appliance uses a
different fuel, the efficiency of the
new service should be multiplied by
the ratio of the CO2 emission factor
of the fuel used in the service being
replaced to that used in the new
service before making the checks
in a and b above. The CO2 emission
factors should be taken from Table
12 of SAP 2009.
New systems
Boilers
a. The boiler should be of the
condensing type.
b. The boiler SEDBUK 2005 efficiency
should be not less than 90% (or
88% as rated by SEDBUK 2009).
c. In existing dwellings, compliance
with the requirements for boiler
efficiency can be demonstrated by
following the guidance in the CLG
Guide to the condensing boiler
installation assessment procedure
for dwellings.
Combination boilers
a. The boiler SEDBUK 2005 (or
SEDBUK 2009) efficiency should be
not less than 86%.
b. In existing dwellings, compliance
with the requirements for boiler
efficiency can be demonstrated by
following the guidance in the CLG
Guide to the condensing boiler
installation assessment procedure
for dwellings.
Table 9: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for oil-fired wet central heating systems
36 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
Range cooker boilers
a. The boiler efficiency for heating
boilers that are combined with
range cookers should be as defined
in Section 3.3 Oil-fired cookers with
integral central heating boilers.
a. Space heating systems and
domestic hot water primary
circuits should have fully pumped
circulation.
b. If the boiler manufacturer’s
instructions advise installation of
a bypass, an automatic bypass
valve should be provided and the
manufacturer’s instructions on
minimum pipe length followed.
2.0
System
circulation
New systems
1.0
Efficiency
(continued)
Oil-fired wet
heating
a. As for new systems.
b. When boilers are replaced,
existing systems with semi-gravity
circulation should be converted to
fully pumped circulation.
Replacement systems
Where condensing boilers are fitted
systems should be designed so as to
provide low primary system return
temperatures, preferably less than
55 degC, which maximise condensing
operation. Low temperature heat
emitters such as underfloor heating
and weather compensation are
examples of techniques which provide
low return water temperatures.
Supplementary information
Table 9: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for oil-fired wet central heating systems (continued)
Section 3 Oil-fired space heating and hot water systems | 37
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
3.0
Hot water
storage
Oil-fired wet
heating
Replacement systems
a. As for new systems, but
a. Vented copper hot water storage
cylinders should comply with the heat b. for replacement copper vented
cylinders and combination units,
loss and heat exchanger requirements
the standing loss should not exceed
of BS 1566:2002 Part 1.
Q = 1.28 x (0.2+0.051V2/3) kWh/day,
b. Copper hot water storage
where V is the volume of the
combination units should comply
cylinder.
with BS 3198:1981.
c. Primary storage systems should
meet the insulation requirements
of the Hot Water Association
Performance specification for
thermal stores.
d. Unvented hot water storage system
products should comply with BS
EN 12897: 2006 or an equivalent
standard as set by an accredited
test body such as the British Board
of Agrément, the Water Research
Council, or KIWA.
e. The standing heat loss for all hot
water storage vessels in a, b, c and d
above should not exceed Q = 1.15 x
(0.2+0.051V2/3) kWh/day, where V is
the volume of the cylinder.
New systems
N
O
I
S
R
E
V
E
N
I
L
ON
BS 3198 “Copper hot water storage
combination units for domestic
purposes”.
BS EN 12897 “Water supply.
Specification for indirectly heated
unvented (closed) storage water
heaters”.
British Standards
BS 1566: 2002 “Copper indirect
cylinders for domestic purposes. Open
vented copper cylinders. Requirements
and test methods”.
The HWA thermal storage specification
is available for free download from
www.hotwater.org.uk.
If a vented cylinder is made from an
alternative material to copper then
the heat loss and heat exchange
characteristics should be tested in
accordance with BS EN 12897:2006.
Supplementary information
Table 9: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for oil-fired wet central heating systems (continued)
38 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
3.0
Hot water
storage
(continued)
Oil-fired wet
heating
f. All hot water vessels should
carry a label with the following
information:
i. type of vessel (vented,
unvented, combination unit or
thermal store);
ii. nominal capacity in litres;
iii. standing heat loss in kWh/day;
iv. heat exchanger performance in
kW;
v. reference to product
compliance with relevant
standard (e.g. BS 1566,
BS 12897) and logos of
accreditation bodies as
required.
For labelling requirements for other
heat inputs, see relevant sections (e.g.
Section 11 for solar).
New systems
Replacement systems
Supplementary information
Table 9: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for oil-fired wet central heating systems (continued)
Section 3 Oil-fired space heating and hot water systems | 39
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
4.0
System
preparation
and water
treatment
Oil-fired wet
heating
Replacement systems
a. As for new systems.
New systems
a. Central heating systems should be
thoroughly cleaned and flushed
out before installing a new boiler.
b. During final filling of the system, a
chemical water treatment inhibitor
meeting the manufacturer’s
specification or other appropriate
standard should be added to the
primary circuit to control corrosion
and the formation of scale and
sludge.
c. Installers should also refer to the
boiler manufacturer’s installation
instructions for appropriate
treatment products and special
requirements for individual boiler
models.
d. Where the mains total water
hardness exceeds 200 parts per
million, and if required by the
manufacturer, provisions should
be made to treat the feed water to
water heaters and the hot water
circuit of combination boilers to
reduce the rate of accumulation of
limescale.
Inhibitors should as a minimum be
BuildCert approved.
Limescale can be controlled by the
use of chemical limescale inhibitors,
combined corrosion and limescale
inhibitors, polyphosphate dosing,
electrolytic scale reducers or water
softeners.
The relevant standard for water
treatment is BS 7593:2006 “Code
of practice for treatment of water in
domestic hot water central heating
systems”.
BS 7593 notes that soft water has
an increased potential for corrosion,
and this may influence the choice of
corrosion inhibitor. Where water is
artificially softened, it is advisable to
feed unsoftened water not only to
drinking water taps, but also to the
boiler primary circuit. In soft water
areas, the boiler manufacturer should
be consulted for advice.
Supplementary information
Table 9: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for oil-fired wet central heating systems (continued)
40 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
e. For solar thermal systems, see
Section 11.
a. On completion of the installation
of a boiler or a hot water
storage system, together with
associated equipment such as
pipework, pumps and controls,
the equipment should be
commissioned in accordance with
the manufacturer’s instructions.
These instructions will be specific
to the particular boiler or hot water
storage system.
b. The installer should give a full
explanation of the system and its
operation to the user, including the
manufacturer’s user manual where
provided.
5.0
Commissioning
New systems
4.0
System
preparation
and water
treatment
(continued)
Oil-fired wet
heating
a. As for new systems.
Replacement systems
N
O
I
S
R
E
V
E
N
I
L
ON
The Oil Controlled Document
System (as produced and managed
by OFTEC) can be used to show
that oil-fired appliances and related
systems have been installed and
commissioned satisfactorily by listing
and recording works and checks
which are deemed necessary for the
efficient operation of the appliance
and system in compliance with the
Building Regulations. A copy of
each completed form is left with
the householder or agent for record
and/or Building Control inspection
purposes, and a copy is retained by
the issuing installer and engineer.
In order to avoid loss and consequent
replacement of circulating fluid and
water treatment when removing
radiators for service or maintenance,
it is advisable to install radiator valves
that can isolate not only the heating
circuit but also seal off the radiators.
Supplementary information
Table 9: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for oil-fired wet central heating systems (continued)
Section 3 Oil-fired space heating and hot water systems | 41
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
N
O
I
S
R
E
V
E
N
I
L
N
O
5.0
Commissioning
(continued)
Replacement systems
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Oil-fired wet
heating
OFTEC branded forms are provided
for the use of OFTEC Registered
Competent Persons and nonOFTEC branded forms are available
for others carrying out oil-fired
installation and commissioning
works. To assist installers OFTEC oil
appliance manufacturing members
may provide forms CD/10 & CD/11
or equivalent “Boiler Passport” with
their equipment.
Controlled Document CD/10
Installing engineers should complete
OFTEC Form CD/10 to show that
they have compliantly completed
the installation of an oil-fired
appliance and controls, and wet
system commissioning prior to final
appliance commissioning.
Controlled Document CD/11
Commissioning engineers of oilfired appliances should complete
OFTEC Form CD/11 to record and
show that they have completed the
commissioning of the appliance and
that they have left it operating in a
safe and efficient manner.
Supplementary information
Table 9: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and
commissioning for oil-fired wet central heating systems (continued)
42 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
a. As for new systems.
a. Boiler-based systems should have a boiler control
interlock in which controls are wired so that when
there is no demand for either space heating or hot
water, the boiler and pump are switched off.
b. The use of thermostatic radiator valves (TRVs) alone does
not provide interlock.
a. Dwellings with a total usable floor area up to 150 m2
should be divided into at least two space heating
zones with independent temperature control, one of
which is assigned to the living area.
b. Dwellings with a total usable floor area greater than
150 m2 should be provided with at least two space
heating zones, each having separate timing and
temperature controls.
c. For single-storey open-plan dwellings in which the
living area is greater than 70% of the total floor area,
sub-zoning of temperature control is not appropriate.
a. All dwellings should have a separate hot water zone in
addition to space heating zones.
b. A separate hot water zone is not required if the hot
water is produced instantaneously, such as with a
combination boiler.
1.0
Boiler interlock
2.0
Space heating
zones
3.0
Water heating
zones
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
a. As for new systems.
a. As for new systems.
Replacement systems
New systems
Oil-fired wet
heating
Table 10: Recommended minimum standards for control of oil-fired wet central heating systems
Section 3 Oil-fired space heating and hot water systems | 43
N
O
I
S
R
E
V
E
N
I
L
N
O
4.0
Time control of
space and water
heating
Oil-fired wet
heating
Replacement systems
a. As for new systems unless only the hot water
cylinder is being replaced and separate time control
for the hot water circuit is not present. In this case it
is acceptable to have a single timing control for both
space heating and hot water.
New systems
a. Time control of space and water heating should be
provided by:
i. a full programmer with separate timing to each
circuit;
ii. two or more separate timers providing timing
control to each circuit; or
iii. programmable room thermostat(s) to the heating
circuit(s), with separate timing of the hot water
circuit.
b. For dwellings with a total usable floor area greater
than 150 m2, timing of the separate space heating
zones can be achieved by:
iv. multiple heating zone programmers; or
v. a single multi-channel programmer; or
vi. programmable room thermostats; or
vii. separate timers to each circuit; or
viii. a combination of (iii) and (iv) above.
c. Where the hot water is produced instantaneously,
such as with a combination boiler, time control is only
required for space heating zones.
Table 10: Recommended minimum standards for control of oil-fired wet central heating systems (continued)
44 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
Replacement systems
a. As for new systems.*
New systems
a. Separate temperature control of zones within the
dwelling should be provided using:
i. room thermostats or programmable room
thermostats in all zones; and
ii. individual radiator controls such as thermostatic
radiator valves (TRVs) on all radiators other than
in the reference rooms (with thermostat) and
bathrooms.
a. As for new systems for planned replacement of hot
a. Domestic hot water systems should be provided with
water cylinders on all fully pumped installations, and
a cylinder thermostat and a zone valve or three-port
on gravity circulation installations.
valve to control the temperature of stored hot water.
b. In dwellings with a total floor area greater than 150 m2 b. In exceptional circumstances, such as emergency
it would be reasonable to provide more than one
replacement or where the cylinder or installation is of a
hot water circuit, each with separate timing and
type that precludes the fitting of wired controls, either
temperature controls. This can be achieved by:
a wireless or thermomechanical hot water cylinder
i. multiple heating zone programmers; or
thermostat would be acceptable.
ii. a single multi-channel programmer; or
iii. separate timers to each circuit.
c. Non-electric hot water controllers should not be used.
Also, in some circumstances, such as with thermal
stores, a zone valve is not appropriate; a second pump
could be substituted for the zone valve.
5.0
Temperature
control of space
heating
6.0
Temperature
control of
domestic hot
water
Oil-fired wet
heating
Table 10: Recommended minimum standards for control of oil-fired wet central heating systems (continued)
Section 3 Oil-fired space heating and hot water systems | 45
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
New systems
Replacement systems
Supplementary information
More details on control systems can be found in manufacturers’ literature and on the The Association of Controls Manufacturers (TACMA)
website at
www.heatingcontrols.org.uk.
Oil-fired wet
heating
Table 10: Recommended minimum standards for control of oil-fired wet central heating systems (continued)
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
*When an individual system component – such as the boiler or a room thermostat – is being replaced, it is not necessary to upgrade the
whole system. However, while not essential for compliance with building regulations, in the case of a boiler replacement, because the
system has to be drained down, it would be good practice to install thermostatic radiator valves (or equivalent) on all radiators other than in
the room with the main thermostat, provided the radiators are suitable and pipework does not need to be altered.
Controls may be provided by any boiler management control system that meets the specified zoning, timing and temperature and boiler
interlock control requirements.
46 | Domestic Building Services Compliance Guide: 2010 Edition
Section 3 Oil-fired space heating and hot water systems | 47
Table 11: Recommended minimum standards for insulation of pipework in oil-fired wet
central heating systems
New systems
N
O
I
S
R
E
V
E
N
I
L
ON
Supplementary information
a. Pipes should be insulated to comply with the
maximum permissible heat loss indicated in the
Supplementary Information column, and labelled
accordingly, as follows:
i. Primary circulation pipes for heating and hot
water circuits should be insulated wherever
they pass outside the heated living space or
through voids which communicate with and are
ventilated from unheated spaces.
ii. Primary circulation pipes for domestic hot water
circuits should be insulated throughout their
length, subject only to practical constraints
imposed by the need to penetrate joists and
other structural elements.
iii. All pipes connected to hot water storage vessels,
including the vent pipe, should be insulated for
at least 1 metre from their points of connection
to the cylinder (or they should be insulated up to
the point where they become concealed).
iv. If secondary circulation is used, all pipes kept hot
by that circulation should be insulated.
Insulation of pipework in unheated
areas
Extra provision may need to be made to
protect central heating and hot water
pipework in unheated areas against
freezing. Guidance is available in:
• BS 5422:2009 “Method for specifying
thermal insulating materials for
pipes, tanks, vessels, ductwork and
equipment operating within the
temperature range -40°C to +700°C”.
• BRE Report No 262 “Thermal
insulation: avoiding risks”, 2002
Edition.
N
O
I
S
R
E
V
E
N
I
L
ON
Replacement systems
a. Whenever a boiler or hot water storage vessel
is replaced in an existing system, any pipes that
are exposed as part of the work or are otherwise
accessible should be insulated as recommended
above – or to some lesser standard where practical
constraints dictate.
Where insulation is labelled as complying
with this guide, it must not exceed the
following heat loss levels:
Pipe outside
diameter
8 mm
Maximum
heat loss*
7.06 W/m
10 mm
12 mm
15 mm
22 mm
28 mm
35 mm
42 mm
54 mm
7.23 W/m
7.35 W/m
7.89 W/m
9.12 W/m
10.07 W/m
11.08 W/m
12.19 W/m
14.12 W/m
N
O
I
S
R
E
V
E
N
I
L
N
O
*In assessing the thickness of insulation
required, standardised conditions
should be assumed in all compliance
calculations, based on a horizontal
pipe at 60°C in still air at 15°C. Further
guidance on converting heat loss limits to
insulation thickness for specific thermal
conductivities is available in TIMSA “HVAC
guidance for achieving compliance with
Part L of the Building Regulations”.
48 | Domestic Building Services Compliance Guide: 2010 Edition
3.3 Oil-fired range cookers with integral central heating
boilers
N
O
I
S
R
E
V
E
N
I
L
ON
This section provides guidance on the specification of oil-fired range cookers with integral
central heating boilers for space heating and hot water in dwellings.
Note that the guidance applies only to twin-burner cooker boilers, which should not be
confused with the type of range cooker described as a single burner “dry heat” range
cooker. The latter is intended only to provide a cooking function, is not included in SAP
2009 calculations, and does not come within the scope of building regulations energy
efficiency requirements.
Oil-fired range cookers with an integral central heating boiler which are provided as
new systems and as replacement systems should meet the following conditions:
a. the appliance should have two independently controlled burners (one for the
cooking function and one for the boiler)
N
O
I
S
R
E
V
E
N
I
L
ON
b. the integral boiler should have a seasonal efficiency (SEDBUK 2005 or SEDBUK
2009) in excess of 80 per cent
c. the manufacturer’s declaration of appliance performance and SEDBUK value
should include the following words:
i.
seasonal efficiency (SEDBUK) = xx%
ii. case heat emission value = yy kW
iii. heat transfer to water at full load = zz kW
iv. the efficiency values may be used in the UK Government’s Standard
Assessment Procedure (SAP) for the energy rating of dwellings. The test data
from which they have been calculated has been certified by {insert name
and/or identification of Notified body}. See www.rangeefficiency.org.uk.
N
O
I
S
R
E
V
E
N
I
L
N
O
If the integral boiler is a condensing boiler, the declaration should make clear
whether the efficiency has been calculated in accordance with SEDBUK 2005
or SEDBUK 2009. If it does not, then SEDBUK 2005 must be assumed.
d. the integral boiler should meet the minimum standards for oil-fired central
heating systems in Tables 9, 10 and 11 for system circulation, hot water storage,
system preparation, commissioning, controls and insulation.
Section 3 Oil-fired space heating and hot water systems | 49
3.4 Continually-burning oil-fired vaporising appliances
providing secondary heating or hot water
N
O
I
S
R
E
V
E
N
I
L
ON
This section provides guidance on the specification of oil-fired vaporising appliances
providing heating or hot water for dwellings.
The guidance does not apply to appliances which have been converted from another fuel
(for example from solid fuel to oil).
Oil-fired vaporising appliances provided as new systems or replacement systems
should meet the minimum standards for controls in Table 12:
Table 12: Recommended minimum standards for control of continually-burning
oil-fired vaporising appliances
Appliance type
New and replacement
systems
Supplementary
information
a. Manually operated
appliance, e.g. room
heater.
The integral manual controls
as provided by appliance
manufacturer.
b. Electrically operated
(modulating) appliance,
e.g. room heater.
The integral or remote
thermostatic controls as
provided (or specified) by the
appliance manufacturer.
Information about the
use of controls should
be clearly stated in
the manufacturer’s
literature.
N
O
I
S
R
E
V
E
N
I
L
ON
Automatic ON/OFF vaporising appliances
c. Room heater providing
(secondary) room space
heating.
The integral thermostatic
controls as provided by
appliance manufacturer.
d. Room heater providing
domestic hot water &
(secondary) room space
heating.
The integral or remote
thermostatic controls as
provided (or specified) by the
appliance manufacturer.
N
O
I appliances
S
3.5 Oil-fired fixed independent space
heating
R
E
V
E
N
I
L
N
O
This section provides guidance on the specification of oil-fired fixed independent space
heating appliances for dwellings.
Fixed independent space heating appliances may be installed as a means of primary or
secondary space heating.
50 | Domestic Building Services Compliance Guide: 2010 Edition
Oil-fired fixed independent appliances for primary heating
Oil-fired fixed independent space heating appliances in new dwellings which are provided
as the primary heat source should meet the following conditions:
N
O
I
S
R
E
V
E
N
I
L
ON
a. The efficiency of the appliance (gross calorific value) should be not less than
60%. The appliance manufacturer’s declaration of appliance performance
should include the following words:
The net efficiency of this appliance has been measured as specified in OFS
A102:2004 and the result after conversion to gross using the appropriate factor
from Table E4 of SAP 2009 is [x]%. The test data been certified by {insert name
and/or identification of Notified Body}. The efficiency value may be used in the UK
Government’s Standard Assessment Procedure (SAP) for energy rating of dwellings.
b. Each appliance should be capable, either independently or in conjunction with
room thermostats or other suitable temperature sensing devices, of controlling
the temperatures independently in areas that have different heating needs (e.g.
separate sleeping and living areas).
N
O
I
S
R
E
V
E
N
I
L
ON
Oil-fired fixed independent appliances for secondary heating
Oil-fired fixed independent space heating appliances in new dwellings which are provided
as the secondary heat source should have a minimum efficiency (gross calorific value) of
not less than 60 per cent.
Supplementary information
Further guidance on oil-fired heating systems is available in the following publications:
• Energy Efficiency Best Practice in Housing publications (see www.oftec.org)
• CE29 “Domestic heating by oil: boiler systems”
• CE51 “Central heating system specifications (CHeSS)”
• CE54 “Whole house boiler sizing method for houses and flats”
• OFTEC Technical Books 2, 3, 4 and 5 (see www.oftec.org)
• BS EN 12828
• BS 5410 Part 1.
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 4 Electric heating systems | 51
Section 4
N
O
I
S
Electric heating systemsR
E
V
E
N
I
L
N
O
4.1 Scope of guidance
This section provides guidance on the specification of fixed electric heating systems for
dwellings to meet relevant energy efficiency requirements in building regulations.
The guidance given in this section covers the following types of fixed electric heating
systems:
•
electric boilers serving central heating systems
N
O
I
S
R
E
V
E
N
I
L
4.2 Electric boilers
serving central heating systems
N
O
•
electric warm air systems
•
electric panel heaters
•
electric storage systems including integrated storage/direct systems.
Portable, plug-in appliances are not covered by building regulations or by this guide.
Electric boilers serving wet central heating provided as new systems or replacement
systems in dwellings should meet the minimum standards for:
a.
system circulation, system preparation and commissioning in Table 13
b. boiler interlock, zoning, and time control and temperature control of heating and
N
O
I
S
R
E
V
E
N
I
L
N
O
hot water circuits in Table 14
c.
hot water storage systems in Table 15
d. pipework insulation in Table 16.
Replacement systems
As new systems.
When boilers are replaced, existing
systems with semi-gravity circulation
should be converted to fully pumped
circulation.
As for new systems.
New systems
a. Systems for space heating and
domestic hot water primary circuits
in new dwellings should have fully
pumped circulation.
b. If the boiler manufacturer’s
instructions advise installation of a
bypass, then an automatic bypass
valve should be used.
a. Central heating systems should be
thoroughly cleaned and flushed
before installing a new boiler.
b. During final filling of the system
a chemical water treatment
formulation should be added to the
primary circuit to control corrosion
and the formation of scale and
sludge. Reasonable provision
would be to follow the guidance
on how to prepare and commission
systems given in BS7593:2006.
1.0
System
circulation
2.0
System
preparation
and water
treatment
Electric wet
heating
Inhibitors should as a minimum be
BuildCert approved.
Limescale can be controlled by the
use of chemical limescale inhibitors,
combined corrosion and limescale
inhibitors, polyphosphate dosing,
electrolytic scale reducers or water
softeners.
The relevant standard for water
treatment is BS 7593:2006 “Code
of practice for treatment of water in
domestic hot water central heating
systems”.
Supplementary information
Table 13: Recommended minimum standards for system circulation, preparation and commissioning for electric wet central
heating systems
52 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
c. Installers should also refer to the
boiler manufacturer’s installation
instructions for appropriate
treatment products and special
requirements for individual boiler
models.
d. Where the mains total water
hardness exceeds 200 parts per
million, and if required by the
manufacturer, provisions should
be made to treat the feed water to
water heaters and the hot water
circuit of combination boilers to
reduce the rate of accumulation
of lime scale and the consequent
reduction in energy efficiency.
a. Manufacturers’ instructions for
commissioning should be followed
and a commissioning record should
be completed to show compliance.
b. The installer should give a full
explanation of the system and its
operation to the user, including the
manufacturer’s user manual where
provided.
3.0
Commissioning
New systems
2.0
System
preparation
and water
treatment
(continued)
Electric wet
heating
As for new systems.
Replacement systems
BS 7593 notes that soft water has
an increased potential for corrosion,
and this may influence the choice of
corrosion inhibitor. Where water is
artificially softened, it is advisable to
feed unsoftened water not only to
drinking water taps, but also to the
boiler primary circuit. In soft water
areas, the boiler manufacturer should
be consulted for advice.
In order to avoid loss and consequent
replacement of circulating fluid and
water treatment when removing
radiators for service or maintenance,
it is advisable to install radiator valves
that can isolate not only the heating
circuit but also seal off the radiators.
Supplementary information
Table 13: Recommended minimum standards for system circulation, preparation and commissioning for electric wet central
heating systems (continued)
Section 4 Electric heating systems | 53
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
As for new systems.
a. The boiler should be fitted with a flow temperature
control and be capable of modulating the power input
to the primary water depending on space heating
conditions.
a. If the boiler also supplies domestic hot water, the
system should have a boiler interlock in which controls
are wired so that when there is no call for heat from
either the space heating or hot water circuits then
the boiler and pump are switched off. The use of
thermostatic radiator valves (TRVs) alone does not
provide interlock.
a. Dwellings with a total usable floor area up to 150
m2 should be divided into at least two space heating
zones with independent temperature control, one of
which is assigned to the living area.
b. Dwellings with a total usable floor area greater than
150 m2 should be provided with at least two space
heating zones, each having separate timing and
temperature controls.
c. For single-storey open-plan dwellings in which the
living area is greater than 70% of the total floor area,
sub-zoning of temperature control is not appropriate.
1.0
Boiler
temperature
control
2.0
Boiler interlock
3.0
Zoning
N
O
I
S
R
E
V
E
N
I
L
ON
As for new systems.
As for new systems.
Replacement systems
New systems
Electric wet
heating
Table 14: Recommended minimum standards for control of electric wet central heating systems
54 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
As for new systems.*
a. Separate temperature control of zones within the
dwelling should be provided, using:
i. room thermostats or programmable room
thermostats in all zones; and
ii. individual radiator controls such as thermostatic
radiator valves (TRVs) on all radiators other than
in reference rooms (with a thermostat) and
bathrooms.
a. Time control of space and water heating should be
provided by:
i. a full programmer with separate timing to each
circuit;
i. two or more separate timers providing itiming
control to each circuit; or
iii. programmable room thermostat(s) to the heating
circuit(s), with separate timing of the hot water
circuit.
4.0
Temperature
control of space
heating
5.0
Time control of
space and water
heating
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
Supplementary information
More details on control systems can be found in manufacturers’ literature and on the The Association of Controls Manufacturers (TACMA)
website at
www.heatingcontrols.org.uk.
Controls may be provided by any boiler management control system that meets the specified zoning, timing and temperature and boiler
interlock control requirements.
*When an individual system component – such as the boiler or a room thermostat – is being replaced, it is not necessary to upgrade the
whole system. However, while not essential for compliance with building regulations, in the case of a boiler replacement, because the
system has to be drained down, it would be good practice to install thermostatic radiator valves (or equivalent) on all radiators other than in
the room with the main thermostat, provided the radiators are suitable and pipework does not need to be altered.
As for new systems.
Replacement systems
New systems
Electric wet
heating
Table 14: Recommended minimum standards for control of electric wet central heating systems (continued)
Section 4 Electric heating systems | 55
1.0
Vented systems
– including
cylinders heated
primarily by
electricity
Electric wet
heating
Supplementary information
British Standards
BS 1566: 2002 “Copper indirect cylinders for domestic
purposes. Open vented copper cylinders. Requirements
and test methods”.
BS 3198:1981 “Specification for copper hot water
storage combination units for domestic purposes”.
BS EN 12897 “Water supply. Specification for indirectly
heated unvented (closed) storage water heaters”.
New and replacement systems
a. Vented copper hot water storage vessels should
comply with BS 1566 or BS 3198.
b. Vented cylinders in materials other than copper
should also be labelled as complying with the heat loss
requirements of BS 1566.
c. For vented replacement systems, electrically heated
combination units should be insulated such that
the heat loss does not exceed the value Q = 1.28 x
(0.2+0.051V2/3) kWh/day, where V is the nominal
cylinder volume in litres. This applies to electrically
heated combination units as well as other electrically
heated cylinders.
d. For vented new systems, electrically heated
combination units should be insulated such that the
heat loss does not exceed the value
Q = 1.15 x (0.2+0.051V2/3) kWh/day, where V is the
nominal cylinder volume in litres. This applies to
electrically heated combination units as well as other
electrically heated cylinders.
Table 15: Recommended minimum standards for hot water storage in electric wet central heating systems
56 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
a. Products should either comply with BS EN 12897,
or be certified by the British Board of Agrément,
Water Research Council or other accredited body as
complying with building regulations.
b. Cylinders heated primarily by electricity should be
insulated such that their heat loss does not exceed
Q = 1.15 x (0.2+0.051V2/3) kWh/day, where V is the
nominal cylinder volume in litres. This applies to
electrically heated combination units as well as other
electrically heated cylinders.
a. Cylinders should either be factory fitted with, or have
provision for, two thermostatically controlled electrical
heating elements or immersion heaters.
b. The lower element should be capable of heating up at
least 85% of the cylinder contents.
c. The upper element should be capable of heating at
least 60 litres of water.
d. The lower element should be connected to utilise the
“off peak” electricity tariff and the upper for boost
operation.
e. The vessel should be designed such that following
reheating to 60°C from the off peak element, at least
80% of the contents can be drawn off at 45°C or
above at a flow rate of 0.25 l/s.
3.0
Vented and
unvented
systems
New and replacement systems
2.0
Unvented
systems –
including
cylinders heated
primarily by
electricity
Electric wet
heating
Supplementary information
Table 15: Recommended minimum standards for hot water storage in electric wet central heating systems (continued)
Section 4 Electric heating systems | 57
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
a. Primary storage systems should meet the insulation
requirements of the Hot Water Association
Performance specification for thermal stores.
b. Unvented hot water storage system products should
comply with BS EN 12897:2006 or an equivalent
standard as set by an accredited test body such as
the British Board of Agrément, the Water Research
Council, or KIWA
a. All hot water storage vessels should carry a label with
the following information:
i. type of vessel;
ii. nominal capacity in litres;
iii. standing heat loss in kWh/day;
iv. heat exchanger performance in kW.
b. Vented copper hot water cylinders should carry clear
labelling on the product such as a BSI Kitemark,
registered firm status or reference to an equivalent
quality control scheme.
c. Vented cylinders which are not of copper construction
should be labelled as complying with the heat loss and
heat exchanger requirements of BS 1566.
d. For labelling of hot water storage vessels in solar
thermal systems, see Section 11, Solar water heating.
5.0
Labelling
New and replacement systems
4.0
Primary stores
Electric wet
heating
Supplementary information
Table 15: Recommended minimum standards for hot water storage in electric wet central heating systems (continued)
58 | Domestic Building Services Compliance Guide: 2010 Edition
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 4 Electric heating systems | 59
Table 16: Recommended minimum standards for insulation of pipework in central heating
systems with electric boilers
New systems
N
O
I
S
R
E
V
E
N
I
L
ON
Supplementary information
a. Pipes should be insulated to comply with the
maximum permissible heat loss indicated in
the Supplementary Information column, and
labelled accordingly, as follows:
i. Primary circulation pipes for heating and hot
water circuits should be insulated wherever
they pass outside the heated living space or
through voids which communicate with and
are ventilated from unheated spaces.
ii. Primary circulation pipes for domestic
hot water circuits should be insulated
throughout their length, subject only to
practical constraints imposed by the need
to penetrate joists and other structural
elements.
iii. All pipes connected to hot water storage
vessels, including the vent pipe, should be
insulated for at least 1 metre from their
points of connection to the cylinder (or they
should be insulated up to the point where
they become concealed).
iv. If secondary circulation is used, all pipes kept
hot by that circulation should be insulated.
Insulation of pipework in unheated
areas
Extra provision may need to be made to
protect central heating and hot water
pipework in unheated areas against freezing.
Guidance is available in:
• BS 5422:2009 “Method for specifying
thermal insulating materials for pipes,
tanks, vessels, ductwork and equipment
operating within the temperature range
-40°C to +700°C”.
• BRE Report No 262 “Thermal insulation:
avoiding risks”, 2002 Edition.
Where insulation is labelled as complying
with this guide, it must not exceed the
following heat loss levels:
N
O
I
S
R
E
V
E
N
I
L
ON
Replacement systems
a. Whenever a boiler or hot water storage vessel
is replaced in an existing system, any pipes that
are exposed as part of the work or are otherwise
accessible should be insulated as recommended
above – or to some lesser standard where
practical constraints dictate.
Pipe outside
diameter
8 mm
Maximum
heat loss*
7.06 W/m
10 mm
12 mm
15 mm
22 mm
28 mm
35 mm
42 mm
54 mm
7.23 W/m
7.35 W/m
7.89 W/m
9.12 W/m
10.07 W/m
11.08 W/m
12.19 W/m
14.12 W/m
N
O
I
S
R
E
V
E
N
I
L
N
O
*In assessing the thickness of insulation
required, standardised conditions should
be assumed in all compliance calculations,
based on a horizontal pipe at 60°C in still air
at 15°C. Further guidance on converting heat
loss limits to insulation thickness for specific
thermal conductivities is available in TIMSA
“HVAC guidance for achieving compliance
with Part L of the Building Regulations”.
60 | Domestic Building Services Compliance Guide: 2010 Edition
4.3 Electric heating systems (other than electric boilers for
central heating)
N
O
I
S
R
E
V
E
N
I
L
ON
This section provides guidance on the following types of fixed electric heating systems:
•
electric warm air systems
•
electric panel heaters
•
electric storage systems including integrated storage/direct systems.
Portable, plug-in appliances are not covered by this guide.
Fixed electric heating systems (other than electric boilers) provided as new systems and
replacement systems should meet the minimum standards for time and temperature
control in Table 17.
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 4 Electric heating systems | 61
Table 17: Recommended minimum standards for control of primary and
secondary electric heating systems (other than with electric boilers)
Electric
heating
systems
Warm air
systems
N
O
I
S
R
E
V
E
N
I
L
ON
New and replacement systems
Supplementary
information
1.0
a. Time switch/programmer and
Time and
room thermostat; or
temperature b. programmable room thermostat .
control,
either
integral to
the heater
or external
2.0
Zone
control
a. Dwellings with a total usable
floor area up to 150 m2 should
be divided into at least two space
heating zones with independent
temperature control, one of which
is assigned to the living area.
b. Dwellings with a total usable floor
area greater than 150 m2 should
be provided with at least two
space heating zones, each having
separate timing and temperature
controls. Time control should be
provided by:
i. multiple heating zone
programmers; or
ii. a single multi-channel
programmer, or
iii. programmable room
thermostats, or
iv. separate timers to each circuit,
or
v. ia combination of (iii) and (iv)
above.
c. For single-storey open-plan
dwellings in which the living area is
greater than 70% of the total floor
area, sub-zoning of temperature
control is not appropriate.
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
62 | Domestic Building Services Compliance Guide: 2010 Edition
Table 17: Recommended minimum standards for control of primary and
secondary electric heating systems (other than with electric boilers) (continued)
Electric
heating
systems
N
O
I
S
R
E
V
E
N
I
L
ON
New and replacement systems
Supplementary
information
Panel
heaters
3.0
a. Time control by a programmable
Local
time switch integrated into the
time and
appliance or a separate time
temperature
switch.
control
b. Individual temperature control
by integral thermostats or by
separate room thermostats or
programmable room thermostats.
Panel heater
systems provide
instantaneous
heat.
Storage
heaters
4.0
Charge
control
Charge control
is the ability
to detect
the internal
temperature
and adjust
the charging
of the heater
accordingly.
a. Automatic control of input charge.
N
O
I
S
R
E
V
E
N
I
L
ON
5.0
a. Temperature control by adjusting
Temperature
the rate of heat release from the
control
appliance, using an adjustable
damper or other thermostaticallycontrolled method.
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 5 Solid fuel heating systems | 63
Section 5
N
O
I
S
Solid fuel heating systems
R
E
V
E
5.1 Scope of guidance
N
I
L
ON
This section provides guidance on meeting the energy efficiency standards in building
regulations for the following types of solid fuel heating appliances and systems used to
deliver primary and secondary heating:
•
batch-fed open fires
•
batch-fed and automatic-feed dry room heaters/stoves
•
batch-fed log and multi-fuel appliances
•
automatic-feed pellet stoves with and without boilers
•
batch-fed and automatic-feed room heaters with boilers
•
batch-fed cookers with boilers not exceeding 7.5 kW
•
batch-fed independent boilers and automatic-feed anthracite, wood pellet,
wood chip and wood log fired independent boilers
•
central heating systems using certain types of solid fuel appliances.
N
O
I
S
R
E
V
E
N
I
L
ON
The guidance covers the following types of solid fuel: coal, anthracite, manufactured
smokeless fuel, dual-fuel, wood logs, wood pellets and wood chips.
5.2 Solid fuel appliances for primary heating
N
O
I
S
R
E
V
E
N
I
L
N
O
Solid fuel appliances provided as new systems and replacement systems in dwellings
for primary heating should have an efficiency (gross calorific value) not less than specified
in Table 18 for that category of appliance.
64 | Domestic Building Services Compliance Guide: 2010 Edition
Table 18: Solid fuel appliance categories and recommended minimum
efficiencies
N
O
I
S
R
E
V
E
N
I
L
ON
Category Appliance description
Minimum efficiency
(gross calorific value)
Feed
B1
Simple open fire – Inset
37%
Batch
B2
Open fire – freestanding convector 47%
Batch
B3
Open fire inset convector
45% (mineral fuels)
43% (wood fuels)
C1/2
Open fire and boiler(inset or
freestanding)
50%
Batch
D1/2/3
Open fire + high output boiler
(trapezium and rectangular grates)
63%
Batch
D4
Open fire + high output boiler
(rectangle)
63%
Batch
E1
Dry room heater (often known as
dry stove)
65%
Batch/
Automatic
E2
Dry room heater – logs only
65%
Batch
E3
Dry room heater – multi-fuel
65%
Batch
E4
Dry room heater – pellet stove
65% part load
70% nominal load
Auto
F
Room heater with boiler
67%(mineral fuels and
logs)
70% (wood pellets –
part load)
75% (wood pellets –
nominal load)
Batch/
Automatic
G1
Cooker without boiler not
exceeding 3.5 kW
65% (mineral fuels)
55% (wood fuels)
Batch
G2
Cooker with heating boiler
exceeding 3.5 kW
65% (mineral fuels)
60% (wood fuels)
Batch
J2
Independent boiler (batch-fed)
wood logs only
75%
Batch
J3
Independent boiler (batch-fed)
multi-fuel
65% (mineral fuels)
75% (wood logs)
Batch
J4
Independent boiler – anthracite
70% up to 20.5 kW
75% above 20.5 kW
Automatic
J5
Independent boiler –
wood/pellets/chips
75% nominal load
70% part load
Automatic
Slow heat release appliances
65%
Batch
One-off tiled/mortared stoves
70%
Batch
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 5 Solid fuel heating systems | 65
Supplementary information on solid fuel appliances
Minimum efficiencies
Minimum efficiencies for solid fuel appliances are published in the HETAS “Official guide
to approved solid fuel products and services”, and on the website www.hetas.co.uk.
Manufacturers’ efficiency figures may be higher than those indicated and should be used
where independently certified against the harmonised European Standards now in place.
Carbon emission factors
Solid fuels include wood in various forms, different types of coal, and manufactured
solid fuels, and consequently there is a range of associated CO2 emission factors. These
factors are as important as appliance efficiency when selecting a boiler. Table 19 shows
the CO2 emission factors for generic types of solid fuel recognised in SAP.
N
O
I
S
R
E
V
E
N
I
L
ON
Table 19: CO2 emission factors for generic types of solid fuel
Solid fuel
Solid Fuel CO2 emission
factors
(kg CO2/kWh)
Notes
House Coal
0.301
Traditional British coal. It
burns with smoky flame
0.318
A mineral fuel with high
carbon content. Burns very
cleanly
Manufactured smokeless
fuel
0.347
Mineral fuel usually made
from anthracite
Wood logs
0.008
Renewable wood logs
either purchased or from
own land
Wood pellets in bags
0.028
Mechanically compressed
sawdust
Bulk wood pellets
0.028
As above, delivered in bulk
Wood chips
0.009
Chipped wood, processed
on site
Anthracite
Dual-fuel
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
0.206
A UK “typical blend” of
logs and mineral fuel
as burnt by a typical
householder on a dual-fuel
stove
Smoke Control Areas
Within local authority Smoke Control Areas only anthracite or other Authorised
Smokeless Fuels may be used, unless the property is fitted with an Exempted Appliance.
An exempted appliance is one that has been approved by Parliamentary Statutory
Instrument for installation in smoke control areas and prospective purchasers should
check that the appliance and intended fuel are permitted. A list of currently authorised
fuels and exempted appliances is given on the web site
www.uksmokecontrolareas.co.uk.
66 | Domestic Building Services Compliance Guide: 2010 Edition
Supplementary information on solid fuel appliances (continued)
Outside a smoke control area house coal or wood can be burnt on non-exempted
appliances. Wood should always be seasoned to a moisture content appropriate to the
design and performance of the appliance, for example log wood not exceeding 20% to
ensure maximum performance and limit the occurrence of condensation and deposits in
the chimney system.
All solid fuel appliances require appropriate soot-fire resistant chimneys discharging at
high level locations as defined within building regulations. Details of HETAS-approved
chimney products independently tested and approved to accepted standards can be
found on the HETAS website. The natural ventilation rates of these chimneys may be less
than the default values listed within SAP 2009; the use of these more accurate values will
reduce SAP values.
N
O
I
S
R
E
V
E
N
I
L
ON
5.3 Central heating systems using certain types of solid fuel
appliances
N
O
I
S
R
E
V
E
N
I
L
ON
This section provides guidance on the following types of solid fuel appliance used to deliver
primary heating as part of a central heating system:
•
batch-fed open fires with high output boilers (appliance types D1 to D4 in
Table 18)
•
batch-fed and automatic-feed room heaters and stoves with boilers (appliance
type F in Table 18)
•
batch-fed cookers with boilers (appliance type G2 in Table 18)
•
batch-fed independent boilers and automatic-feed anthracite, wood log,
wood pellet and wood chip fired independent boilers (appliance types J1 to J5 in
Table 18).
Unless stated otherwise, the guidance applies equally to appliances that burn wood, wood
pellets, house coal, manufactured smokeless fuels and anthracite.
N
O
I
S
R
E
V
E
N
I
L
N
O
For central heating systems with a solid fuel appliance installed as a new system or
replacement system in dwellings:
a. the appliance should be from HETAS categories D, F, G and J in Table 18 and
have a minimum efficiency (gross calorific value) which is not less than the value
specified for its category
b. the ratio of room heat to water heat should be appropriate for the room and
total property. This will require reference to installation practice guidelines and
calculation of room and property heat loss. Advice on this is given in the HETAS
Guide and website
Section 5 Solid fuel heating systems | 67
c. circulation, fuel storage, hot water storage, system preparation, water treatment
and commissioning should be to the standards in Table 20
N
O
I
S
R
E
V
E
N
I
L
ON
d. control of heating and hot water circuits should be to the standards in Table 21
e. pipework should be insulated to the standards in Table 22.
Supplementary information
Turn-down values (i.e. the ratio of high to low output)
a. Turn-down ratios are generally very good (>10:1) for automatic-feed appliances with
small firebeds.
b. Turn-down ratios are less good with large batch-fed appliances unless the latter are
used in conjunction with a hot water accumulator.
c. Automatic appliances are likely to require less frequent refuelling. Automatic
(e.g. electric or gas) ignition is now available for certain designs and reduces energy
usage at times of low demand allowing boiler interlock.
d. Some boilers have both auto-ignition and fire-extinguishing features.
N
O
I
S
R
E
V
E
N
I
L
ON
Link-up systems
It is possible to connect together two or more heating appliances with boilers (at least
one of which can be solid fuel-fired), to maximise flexibility and efficiency. For example,
an oil or gas boiler could be combined with a wood burning stove with boiler sited in the
living room. This combination with wood burning appliances will reduce overall carbon
emissions. Both systems should be designed to appropriate installation codes.
N
O
I
S
R
E
V
E
N
I
L
N
O
Most solid fuel central heating systems require a heat
leak radiator to dissipate heat from the smouldering
fire bed. This is commonly the bathroom towel-rail and
a thermosiphon system may be used for this circuit. In
some cases a fully pumped system reduces efficiency and
should not be used.
a. Where boiler interlock is available, fully pumped
1.0
System
circulation
circulation should be chosen.
b. The manufacturer’s instructions on the sizing and
positioning of heat leak radiators should be followed.
c. Solid fuel appliances should not be fitted to sealed
heating systems with expansion vessels, except where
specifically permitted by the manufacturer or where a
thermal storage interface device is used.
Supplementary information
New and replacement systems
Solid fuel
heating
Table 20: Recommended minimum standards for system circulation, fuel storage, hot water storage, system preparation and
commissioning for solid fuel central heating
quantities of fuel in a convenient and dry location. The
size of the storage will depend upon the requirement
of the house.
N
O
I
S
R
E
V
E
N
I
L
ON
No minimum quantity of fuel is specified for solid mineral
fuel but bunkers greater than 250 kg are preferred
as below this householders are likely to pay a delivery
premium.
N
O
I
S
R
E
V
E
N
I
L
ON
a. Provision should be made for storage of reasonable
N
O
I
S
R
E
V
E
N
I
L
N
O
2.0
Fuel storage
68 | Domestic Building Services Compliance Guide: 2010 Edition
Supplementary information
Primary hot water stores
These can have a major role to play in the installation of
solid fuel. The main reason for their use is to store the heat
generated during slumber periods, but where unvented
storage cylinders are used they also provide mains pressure
hot water and possible frost protection (via electric
immersion heaters) for the solid fuel system. Domestic hot
water outlet temperature is to be controlled at a safe level.
Because of the higher than normal storage temperatures it
is very important that stores are well insulated.
The HWA thermal storage specification is available for
free download from
www.hotwater.org.uk.
New and replacement systems
a. Vented copper hot water storage vessels should
Solid fuel
heating
3.0
Hot water
storage
Table 20: Recommended minimum standards for system circulation, fuel storage, hot water storage, system preparation and
commissioning for solid fuel central heating (continued)
N
O
I
S
R
E
V
E
N
I
L
N
O
f.
e.
d.
c.
b.
N
O
I
S
R
E
V
E
N
I
L
ON
British Standards
BS 1566: 2002 “Copper indirect cylinders for domestic
purposes. Open vented copper cylinders. Requirements and
test methods”.
BS 3198:1981 “Specification for copper hot water storage
combination units for domestic purposes”.
BS EN 12897 “Water supply. Specification for indirectly
heated unvented (closed) storage water heaters”.
N
O
I
S
R
E
V
E
N
I
L
ON
comply with the heat loss and heat exchanger
requirements of BS 1566-1:2000 or BS 3198.
Vented cylinders in materials other than copper
should comply with the heat loss and heat exchanger
requirements of BS 1566.
Unvented hot water storage system products should:
i. comply with BS EN 12897 ; or
ii. be certified by the British Board of Agrément, the
Water Research Council; or
iii. be certified by another accredited body as
complying with building regulations.
Unvented systems should not be used with gravity
circulation.
Primary storage systems should meet the insulation
requirements of section 4.3.1 or 4.3.2 of the Hot
Water Association Performance specification for
thermal stores.
Combination cylinders should comply with BS 3198
and in addition have a heat loss not exceeding 1.6 x
[0.2 + 0.51V2/3] kWh/day where V is the volume of the
hot water part of the cylinder.
Section 5 Solid fuel heating systems | 69
Solid fuel
heating
the following information:
i. type of vessel;
ii. nominal capacity in litres;
iii. standing heat loss in kWh/day;
iv. type of vessel;
v. heat exchanger performance in kW.
h. Vented copper hot water cylinders should carry clear
labelling on the product such as a BSI Kitemark,
registered firm status or reference to an equivalent
quality control scheme.
g. All hot water storage vessels should carry a label with
New and replacement systems
N
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R
E
V
E
N
I
L
ON
BS 7593 notes that soft water has an increased potential
and flushed out before installing a new boiler.
for corrosion, and this may influence the choice of
b. During final filling of the system a chemical water
corrosion inhibitor. Where water is artificially softened, it
treatment formulation should be added to the primary is advisable to feed unsoftened water not only to drinking
circuit to control corrosion and the formation of scale
water taps, but also to the boiler primary circuit. In soft
and sludge. Reasonable provision would be to follow
water areas, the boiler manufacturer should be consulted
the guidance on how to prepare and commission
for advice on the choice of inhibitor.
systems given in BS 7593:2006.
c. Installers should also refer to the boiler manufacturer’s In order to avoid loss and consequent replacement of
installation instructions for appropriate treatment
circulating fluid and water treatment when removing
products and special requirements for individual boiler radiators for service or maintenance, it is advisable to
models.
install radiator valves that can isolate not only the heating
circuit but also seal off the radiators.
N
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E
N
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ON
a. Central heating systems should be thoroughly cleaned
N
O
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E
V
E
N
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L
N
O
4.0
System
preparation and
water treatment
Supplementary information
Table 20: Recommended minimum standards for system circulation, fuel storage, hot water storage, system preparation and
commissioning for solid fuel central heating (continued)
70 | Domestic Building Services Compliance Guide: 2010 Edition
Solid fuel
heating
d. Where the mains total water hardness exceeds 200
New and replacement systems
Only persons who are competent should carry out
the installation, e.g. installers who are registered with
HETAS. Such persons will certify that they have carried
out installation and commissioning in accordance
with requirements in building regulations and in the
manufacturer’s instructions (which may be more
stringent).
Note that the delivery of wood or coal without
appropriate documentation into a smoke-control area is
an offence under the Clean Air Act.
Supplementary information
Table 20: Recommended minimum standards for system circulation, fuel storage, hot water storage, system preparation and
commissioning for solid fuel central heating (continued)
N
O
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R
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V
E
N
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L
ON
N
O
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R
E
V
E
N
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L
N
O
a. On completion of the installation of a boiler or hot
5.0
water storage system, together with associated
Commiss-sioning
equipment such as pipework, pumps and controls, the
equipment should be commissioned in accordance
with the manufacturer’s instructions. These
instructions will be specific to the particular boiler or
hot water storage system used.
b. The installer should give a full explanation of the
system and its operation to the user, including the
manufacturer’s user manual where provided.
parts per million, and if required by the manufacturer,
provision should be made to treat the feed water to
water heaters and the hot water circuit to reduce the
rate of accumulation of lime scale and the consequent
reduction in energy efficiency
Section 5 Solid fuel heating systems | 71
N
O
I
S
R
E
V
E
N
I
L
ON
Replacement systems
a. Thermostatic control of the
New systems
1.0
Burning rate
a. Thermostatic control of the burning rate.
All appliances, except open fires
Solid fuel
heating
Table 21: Recommended minimum standards for control of solid fuel central heating systems
N
O
I
S
R
E
V
E
N
I
L
N
O
but, as far as it is
practicable and economic
to do so, controls should
be upgraded to the levels
defined for new systems.
a. No minimum requirement
a. Time control of space and water heating should
3.0
Time control of
be provided by:
space and water
i. a full programmer with separate timing to
each circuit; or
heating
ii. two or more separate timers providing
timing control to each circuit; or
iii. programmable room thermostat(s) to the
heating circuit(s), with separate timing of
the hot water circuit.
a. No minimum requirement
but, as far as it is
practicable and economic
to do so, controls should
be upgraded to the levels
defined for new systems.
a. Dwellings with a total usable floor area up to
The level of sophistication
should generally be
appropriate to and compatible
with that of the appliance.
The highest levels are only
appropriate to appliances with
automatic ignition.
N
O
I
S
R
E
V
E
N
I
L
ON
150 m2 should be divided into at least two space
heating zones with independent temperature
control, one of which is assigned to the living
area.
b. Dwellings with a total usable floor area greater
than
150 m2 should be provided with at least two
space heating zones, each having separate
timing and temperature controls.
c. For single-storey, open-plan dwellings in which
the living area is greater than 70% of the total
floor area, sub-zoning of temperature control is
not appropriate.
2.0
Zoning
Automatic-feed appliances
N
O
I
S
R
E
V
E
N
I
L
ON
burning rate.
Supplementary
information
72 | Domestic Building Services Compliance Guide: 2010 Edition
control should be provided
to prevent excessive tap
water temperatures.
b. As far as it is practicable
and economic to do
so, controls should be
upgraded to the levels
defined for new systems.
In some circumstances, such
as with thermal stores, a
zone valve is not appropriate;
a second pump could be
substituted for the zone valve.
Controls may be provided by any boiler management control system that meets the specified zoning, timing and temperature, and boiler
interlock control requirements.
Some automatic solid fuel systems can be fitted with weather compensation, and incorporate multi-zone control. It is important to seek
guidance from the manufacturer, especially if the heating package is to include other fuels.
In most solid fuel systems the room thermostat will switch off the pump, which in turn will cause the boiler to operate at minimum output.
In some simple batch-fed or automatic appliances (without heat stores or without automatic ignition), it is not possible to switch off the heat
output completely, but the appliance output can be lowered to a minimum to reduce fuel consumption.
Boiler interlock, provided by a wiring arrangement, to prevent the system from operating when there is no demand for heat, should only be
fitted if recommended by the manufacturer.
Supplementary information on controls for solid fuel central heating
a. A method of temperature
three-port valve should be fitted to control the
temperature of stored hot water.
b. Non-electric hot water controllers should not be
used.
c. Where permitted by the manufacturer, the
cylinder thermostat should be wired to provide
a boiler interlock.
N
O
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S
R
E
V
E
N
I
L
ON
a. A cylinder thermostat and a zone valve or
N
O
I
S
R
E
V
E
N
I
L
N
O
5.0
Temperature
control of
domestic hot
water
Supplementary
information
N
O
I
S
R
E
V
E
N
I
L
ON
but, as far as it is
practicable and economic
to do so, controls should
be upgraded to the levels
defined for new systems.
a. No minimum requirement
a. Separate temperature control of zones within
4.0
Temperature
control of space
heating
the dwelling should be provided using:
i. room thermostats or programmable room
thermostats in all zones; and
ii. individual radiator controls such as
thermostatic radiator valves (TRVs) on all
radiators other than in reference rooms and
bathrooms.
Replacement systems
New systems
Solid fuel
heating
Table 21: Recommended minimum standards for control of solid fuel central heating systems (continued)
Section 5 Solid fuel heating systems | 73
74 | Domestic Building Services Compliance Guide: 2010 Edition
Table 22: Recommended minimum standards for insulation of pipework in solid fuel
central heating systems
New systems
N
O
I
S
R
E
V
E
N
I
L
ON
Supplementary information
a. Pipes should be insulated to comply with the
maximum permissible heat loss indicated in the
Supplementary Information column, and labelled
accordingly, as follows:
i. Primary circulation pipes for heating and hot
water circuits should be insulated wherever
they pass outside the heated living space or
through voids which communicate with and
are ventilated from unheated spaces.
ii. Primary circulation pipes for domestic hot
water circuits should be insulated throughout
their length, subject only to practical
constraints imposed by the need to penetrate
joists and other structural elements.
iii. All pipes connected to hot water storage
vessels, including the vent pipe, should be
insulated for at least 1 metre from their points
of connection to the cylinder (or they should
be insulated up to the point where they
become concealed).
iv. If secondary circulation is used, all pipes kept
hot by that circulation should be insulated.
Insulation of pipework in unheated
areas
Extra provision may need to be made to
protect central heating and hot water
pipework in unheated areas against
freezing. Guidance is available in:
• BS 5422:2009 “Method for specifying
thermal insulating materials for pipes,
tanks, vessels, ductwork and equipment
operating within the temperature range
-40°C to +700°C”.
• BRE Report No 262 “Thermal insulation:
avoiding risks”, 2002 Edition.
Where insulation is labelled as complying
with this guide, it must not exceed the
following heat loss levels:
N
O
I
S
R
E
V
E
N
I
L
ON
Replacement systems
a. Whenever a boiler or hot water storage vessel
is replaced in an existing system, any pipes that
are exposed as part of the work or are otherwise
accessible should be insulated as recommended
above – or to some lesser standard where
practical constraints dictate.
Pipe outside
diameter
8 mm
Maximum
heat loss*
7.06 W/m
10 mm
12 mm
15 mm
22 mm
28 mm
35 mm
42 mm
54 mm
7.23 W/m
7.35 W/m
7.89 W/m
9.12 W/m
10.07 W/m
11.08 W/m
12.19 W/m
14.12 W/m
N
O
I
S
R
E
V
E
N
I
L
N
O
*In assessing the thickness of insulation
required, standardised conditions should
be assumed in all compliance calculations,
based on a horizontal pipe at 60oC in still
air at 15oC. Further guidance on converting
heat loss limits to insulation thickness for
specific thermal conductivities is available
in TIMSA “HVAC guidance for achieving
compliance with Part L of the Building
Regulations”.
Section 5 Solid fuel heating systems | 75
5.4 Solid fuel appliances for secondary heating
N
O
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S
R
E
V
E
N
I
L
ON
Solid fuel appliances in new and existing dwellings that are provided for secondary heating
and are not part of a central heating system should have an efficiency (gross calorific value)
not less than specified in Table 18 for that category of appliance.
Supplementary information on solid fuel appliances providing secondary
heating
Minimum efficiencies
Minimum efficiencies for solid fuel appliances are published in the HETAS “Official guide
to approved solid fuel products and services”, and on the website www.hetas.co.uk.
Manufacturers’ efficiency figures may be higher than those indicated and should be
used where independently certified against the harmonised European Standards now
in place.
Appliance types
Appliances which are most suitable for secondary space heating are summarised in
Table 23.
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R
E
V
E
N
I
L
ON
Table 23: Appliance types
Appliance type
Notes
Open fire with high
output boiler, when
used with “link-up”.
Small solid fuel room
heaters (stoves),
especially wood-fired.
These can be a dedicated wood burner or burn logs in a multifuel appliance or use pellets. They can be matched with a main
heating system fired by the same or a different primary fuel
or off-peak electricity to reduce carbon emissions, especially
wood-fired, with or without thermostatic control. Many
designs can provide heating during power cuts. Mineral fuel
appliances can be chosen but the attention of designers is
drawn to the probable need to supply additional measures, as
the carbon emission values of these tend to be high. Mineral
fuel appliances may often have slightly higher efficiencies than
their wood burning counterparts. Multi-fuel room heaters
can enable the user to burn renewable wood as well as an
alternative to mineral fuels outside smoke control areas.
N
O
I
S
R
E
V
E
N
I
L
N
O
Small solid fuel stoves
with boilers.
The efficiency of these can be higher than that of dry
appliances. They can be integrated with the primary wet
heating system. Multi-fuel appliances enable the householder
to burn renewable wood outside smoke control areas.
76 | Domestic Building Services Compliance Guide: 2010 Edition
Table 23: Appliance types (continued)
Appliance type
Range cookers.
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R
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V
E
N
I
L
ON
Notes
Typically appliances which are installed in a “living area” and
are designed to provide some useful heat from their case into
the space in which they are located. They are available in a
variety of shapes and sizes and can incorporate a boiler which
can be connected to dual-fuel integrated systems (e.g. linkup). Multi-fuel versions are also available.
Where requested,
open fires (HETAS
categories B1, B2 and
B3) can be fitted.
These do not have thermostatic control of the burning rate
and have lower efficiencies. However, they are able to burn
wood logs with correspondingly low net carbon emissions.
It must be stressed that large open fires with large free face
areas (see Note 1) usually have a need for ventilation well in
excess of that available in a property built to modern standards
of air tightness. This is likely to lead to severe operational
problems unless special steps are taken to provide the required
air supply. The use of such large (simple) open fires is penalised
in the SAP calculations.
Note 1: The free face area of an open fire is its opening width
times its opening height.
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O
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R
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V
E
N
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ON
N
O
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R
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V
E
N
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N
O
Section 5 Solid fuel heating systems | 77
Controls for solid fuel appliances providing secondary heating
Wherever possible, solid fuel appliances should have thermostatic control (these are
usually integral to appliances in categories E, F and G). Controls should be appropriate
to the level of sophistication of the appliance; automatic appliances can benefit from
advanced controls.
Provision of fuel storage for solid fuel appliances providing secondary heating
The quantity of fuel consumed by secondary heating appliances is likely to be less than
1 tonne per year. However it should be stored in a dry and convenient location.
Smoke control areas
The location of the appliance within or without a smoke control area is critical to the
process of optimising the choice of appliance and fuel.
For further information on solid fuel appliances see CE47 “Energy Efficiency Best Practice
in Housing – Domestic heating by solid fuel: Boiler systems”.
Guidance and standards
EN 12809:2001/A1:2004/AC:2006/2007 “Residential Independent boilers fired by solid
fuel – Nominal output up to 50kW – Requirements and test methods”.
EN 12815:2001/A1:2004/2006/2007 “Residential cookers fired by solid fuel –
Requirements and test methods”.
EN 13229:2001/A1:2003/A2:2004/AC:2006/2007 “Inset appliances including open
fires fired by solid fuel – Requirements and test methods”.
EN 13240:2001/A2:2004 /AC2006/2007 “Room heaters fired by solid fuel –
Requirements and test methods”.
EN 15250:2007 “Slow heat release appliances fired by solid fuel – Requirements and test
methods”.
EN 15544 “One-off tiled/mortared stoves – Calculation method”.
EN 14785:2006 “Residential space heating appliances fired by wood pellets”.
Solid biofuels quality standards: CEN/TS 14588:2004; CEN/TS 14774-1:2004; CEN/TS
14774-2:2004; CEN/TS 14774-3:2004; CEN/TS 14775:2004; CEN/TS 14778-1:2005;
CEN/TS 14778-2:2005; CEN/TS 14779:2005; CEN/TS 14780:2005; CEN/TS 14918:2005;
CEN/TS 14961:2005; CEN/TS 15103:2005; CEN/TS 15148:2005; CEN/TS 151491:2006; CEN/TS 15149-2:2006; CEN/TS 15150:2005; CEN/TS 15210-1:2005; CEN/TS
15234:2006; CEN/TS 15289:2006; CEN/TS 15290:2006; CEN/TS 15296:2006.
N
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ON
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V
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N
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ON
N
O
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V
E
N
I
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N
O
78 | Domestic Building Services Compliance Guide: 2010 Edition
Section 6
N
O
I
S
Community heating systems
R
E
V
6.1 Scope of guidanceINE
L
N
O
This section provides guidance on the specification of community heating systems for
dwellings to meet relevant energy efficiency requirements in building regulations.
A community heating system is one that supplies heat to a number of dwellings from
a common heat source. A system may heat a small block of flats or a large number of
buildings.
The guidance in this section applies to systems that:
N
O
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E
V
E
N
I
L
6.2 New and existing
ON community heating schemes
•
supply 15 or more dwellings from a central boiler, or from a low carbon source
such as combined heat and power (CHP), biofuels, heat pumps and solar panels
•
distribute heat from the central source using a wet radiator system (although
warm air heating and underfloor heating systems may also be used).
The central heat source should comply with the requirements in the Non-domestic building
services compliance guide except where specified in this section.
Guidance is provided for two scenarios:
•
connecting dwellings to a new community heating scheme
•
connecting dwellings to an existing community heating scheme.
N
O
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S
R
E
V
E
N
I
L
N
O
Connecting dwellings to a new community heating scheme
New community heating systems for both new and existing dwellings should meet the
minimum standards for:
a. energy efficiency in Table 24
b. low-carbon heat sources in Table 25
c. system control in Table 26
Section 6 Community heating systems | 79
d. hot water production, storage and treatment, heat metering and commissioning
in Table 27
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N
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ON
e. insulation of pipework in Table 28.
Connecting dwellings to an existing community heating scheme
When existing community heating systems are connected to new or existing dwellings, the
minimum requirements are:
a. if the existing community heating system is in need of replacement or
improvement, a study should be carried out to assess the economic and
environmental benefits of a range of options, including the use of CHP and other
low carbon heat sources, especially where individual heating systems are being
considered as an alternative to continuing with the community heating system
b. replacement boilers should meet the minimum standards for boiler efficiency
in the Non-domestic building services compliance guide (available from
www.planningportal.gov.uk/approveddocuments > Part L > Associated
documents)
N
O
I
S
R
E
V
E
N
I
L
ON
c. if thermal energy is purchased from an existing district or community heating
system, an assessment of the carbon intensity of the scheme should be carried
out. Emission factors should be determined based on the particular details of
the scheme, but should take account of the annual average performance of the
whole system – that is, of the distribution circuits and all the heat generating
plant, including any CHP, and any waste heat recovery or heat dumping. The
calculation of the Dwelling CO2 Emission Rate should be carried out by a suitably
qualified person, who should explain how the emission factors were derived
d. controls should meet the minimum standards in Table 26
e. pipework insulation should meet the minimum standards in Table 28.
N
O
I
S
R
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V
E
N
I
L
N
O
80 | Domestic Building Services Compliance Guide: 2010 Edition
Table 24: Recommended minimum standards for the design of new community
heating systems to maximise efficiency of heat generation and minimise
energy use by pumps
N
O
I
S
R
E
V
E
N
I
L
ON
Community
heating
New systems
Supplementary information
1.0
Boilers
a. Boiler-only community
heating systems for new
dwellings may be used
provided that the Target
carbon dioxide Emission
Rate (TER) for the dwelling
is not exceeded.
b. Boilers should be selected
to comply with the boiler
efficiency requirements of
the Non-domestic building
services compliance guide.
When calculating the carbon emission
rate, the type and quantity of fuel
used and also the electricity needed to
operate the central plant and pumps
should be taken into account.
For systems using condensing boilers:
• To achieve high boiler efficiency,
return temperatures from radiator
circuits should be selected lower
than 50°C.
• Where instantaneous plate heat
exchangers are used to produce
hot water in individual dwellings
the return temperature selected
should be less than 40°C.
• Where hot water cylinders are used
the coil size should be such as to
require a flow rate that results in
a nominal return temperature of
less than 40°C whilst meeting the
required heat-up time.
• Where hot water is produced
centrally (e.g. in each block of
dwellings) return temperatures
lower than 40°C should be
achieved.
a. Controls for boilers should
meet the requirements of
the Non-domestic building
services compliance guide,
except optimum start is
not required.
Setting occupation times is not
generally possible for a group of
dwellings and so optimum start
controls are not a requirement.
N
O
I
S
R
E
V
E
N
I
L
ON
2.0
Controlling
the
sequencing
and firing of
boilers
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 6 Community heating systems | 81
Table 24: Recommended minimum standards for the design of new community
heating systems to maximise efficiency of heat generation and minimise
energy use by pumps (continued)
Community
heating
3.0
Minimising
energy use
by pumps
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Supplementary information
a. For new community
heating systems, the
design temperature
difference for the
community heating
primary circuit should be
greater than 20ºC.
b. Variable volume control
systems should be used
to reduce the volume of
water and the pressure
difference required from
the pumps under part
load.
Pumping energy can be minimised by
optimising operating temperatures
and pipe sizes to reduce installed
pump power.
To take full advantage of variable
volume systems, variable speed pumps
should be installed and controlled
to deliver the required pressure
difference to suit the load.
Further guidance is provided in BSRIA
Application Guide AG 16/2002
“Variable-flow water systems: design,
installation and commissioning
guidance”.
N
O
I
S
R
E
V
E
N
I
L
ON
Table 25: Recommended minimum standards for design of low-carbon heat
sources where these are included in community heating systems
Community
heating
1.0
Low carbon
heat
sources
New systems
Supplementary information
a. No minimum standard,
Community heating systems can be
designed to use low-carbon heat
sources to meet all or part of the heat
demand, which may enable some
relaxation of the U-values that would
otherwise be required.
but see Supplementary
Information.
N
O
I
S
R
E
V
E
N
I
L
N
O
82 | Domestic Building Services Compliance Guide: 2010 Edition
Table 25: Recommended minimum standards for design of low-carbon heat
sources where these are included in community heating systems (continued)
N
O
I
S
R
E
V
E
N
I
L
ON
Community
heating
New systems
Supplementary information
2.0
Biofuels
a. No minimum standard,
Biofuels can be used to provide heat
from boiler systems or as a fuel for CHP
systems.
Consideration should be given to
operation and maintenance of the
plant to ensure a long life and to
prevent a later replacement by a
conventional fuel system.
Where a biofuel boiler is to be used
in conjunction with conventionally
fuelled heating boilers or electric
heating, a reasonable minimum
proportion of the annual heat supply
from biofuels would be 45% of the
annual heat demand (space, domestic
hot water and process heating).
Further guidance is provided in “Low or
zero carbon energy sources: strategic
guide”, ODPM 2006.
3.0
Combined
heat and
power
(CHP)
but see supplementary
information.
N
O
I
S
R
E
V
E
N
I
L
ON
a. Where CHP is used in
conjunction with boiler
plant, the control system
should ensure that, as far
as is practicable, the CHP
plant operates as the lead
heat source.
CHP capacity should be optimised
to meet the required economic and
environmental objectives.
A reasonable minimum proportion
of the annual heat supply from CHP
would be 45% of the annual heat
demand (space, domestic and hot
water heating).
To maximise the use of CHP heat over
the year, consideration should be given
to the use of thermal storage to meet
peaks, especially in the early morning
period.
The procedure given in SAP 2009
should be used to calculate the carbon
emissions from CHP systems.
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 6 Community heating systems | 83
Table 25: Recommended minimum standards for design of low-carbon heat
sources where these are included in community heating systems (continued)
Community
heating
4.0
Heat Pumps
5.0
Solar
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Supplementary information
a. No minimum standard,
Heat pumps can be used as a heat
source for community heating
systems. Selection of operating
temperatures to optimise the
efficiency of the community heating
system and achieve high COPs is
important if carbon emissions are
to be reduced. This may involve the
use of underfloor heating and the
provision of domestic hot water by
other means.
Where heat pumps are installed in
conjunction with heating boilers, a
reasonable minimum proportion of
the annual heat supply from the heat
pump would be 45% of the annual
space heating demand.
but see Supplementary
Information.
N
O
I
S
R
E
V
E
N
I
L
ON
a. No minimum standard,
but see Supplementary
Information.
Solar thermal panels can be used
as the heat source for a centralised
domestic hot water system.
Table 26: Recommended minimum standards for control of systems within
dwellings for community heating
Community
heating
New systems
Supplementary information
1.0
Zoning
a. Dwellings with a total
usable floor area up to
150 m2 should be divided
into at least two zones with
independent temperature
control, one of which is
assigned to the living area.
b. Dwellings with a total usable
floor area greater than
150 m2 should be provided
with at least two space
heating zones, each
having separate timing and
temperature controls.
In single-storey open-plan dwellings
in which the living area is greater
than 70% of the total floor area,
sub-zoning of temperature control
is not appropriate.
N
O
I
S
R
E
V
E
N
I
L
N
O
84 | Domestic Building Services Compliance Guide: 2010 Edition
Table 26: Recommended minimum standards for control of systems within
dwellings for community heating (continued)
N
O
I
S
R
E
V
E
N
I
L
ON
Community
heating
New systems
Supplementary information
2.0
Time control
of space
heating
a. Time control of space
heating should be provided
by:
i. a full programmer;
ii. two or more separate
timers providing timing
control to each zone; or
iii. programmable room
thermostat(s) to the
heating circuit(s).
b. For dwellings with a total
usable floor area greater
than 150 m2, time control for
the separate space heating
zones can be achieved by:
i. multiple heating zone
programmers; or
ii. a single multi-channel
programmer.
Where the hot water is produced
instantaneously, such as with a plate
heat exchanger, time control is only
required for space heating zones.
Time control of domestic hot
water heating using a cylinder
is not considered essential for
community heating and could be
a disadvantage with CHP-based
systems, increasing the morning
peak demand and hence causing
more use of the boiler than
necessary.
N
O
I
S
R
E
V
E
N
I
L
ON
3.0
a. Separate temperature
control of zones within the
Temperature
control
dwelling should be provided
using:
of space
i. room thermostats or
heating
programmable room
thermostats in all zones;
ii. a room thermostat or
programmable room
thermostat in the main
zone, and individual
radiator controls such
as thermostatic radiator
valves (TRVs) on all
radiators in the other
zones; or
iii. a combination of (i) and
(ii) above.
Control valves and TRVs should be
two-port type to reduce flow rates
under part load.
Differential pressures across control
valves and TRVs should be limited to
ensure that the control valves work
effectively and maintain shut-off.
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 6 Community heating systems | 85
Table 26: Recommended minimum standards for control of systems within
dwellings for community heating (continued)
Community
heating
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
a. Temperature control of the
4.0
domestic hot water service
Temperature
control of
should be provided by means
domestic
of two-port control valves
hot water
either electrically operated or
direct-acting.
Supplementary information
Where instantaneous heat
exchangers are used the control
valve should be selected to maintain
steady temperatures (<+/- 5ºC) for a
range of draw-off rates and primary
differential pressures. To reduce
the incidence of scaling, the control
valve should shut off the primary
flow when there is no domestic hot
water draw off.
A small intermittent flow is
an advantage to maintain the
temperature within the heat
exchanger so as to provide more
rapid heat up.
N
O
I
S
R
E
V
E
N
I
L
ON
5.0
a. The maximum design
Limitation
flow rate into the dwelling
heating system should be
of maximum
limited by suitable control
flow rate
and balancing valves to
into building
maintain the overall balance
or dwelling
in the network and to avoid
excessive pumping energy.
N
O
I
S
R
E
V
E
N
I
L
N
O
86 | Domestic Building Services Compliance Guide: 2010 Edition
Table 27: Recommended minimum standards for domestic hot water
production, storage and water treatment, heat meters and commissioning
for community heating
Community
heating
1.0
DHW
production
and storage
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Supplementary information
a. The hot water system
should be controlled
using variable volume
control principles and
be designed to maintain
low return temperatures
in the primary
community heating
circuit.
Hot water can be produced in four
ways in community heating systems:
• in individual dwellings using
indirect storage cylinders;
• in individual dwellings using
instantaneous plate heat
exchangers;
• centrally using storage calorifiers
with either an indirect coil or an
external plate heat exchanger;
• centrally using an instantaneous
plate heat exchanger.
• In selecting the system,
consideration should be given to:
• the impact on return temperatures
in the community heating system;
• the impact on flow rates in the
community heating system;
• the impact on heat demand
profiles and compatibility with the
heat source;
• standing losses from storage
cylinders/calorifiers and the impact
on energy use;
• the quality of service provided in
terms of flow rate and temperature
control;
• the advantages of having local
storage in terms of security of
supply.
Where the network is extensive and
hot water production is centralised,
a two stage water heating system
can be used to deliver low return
temperatures. In this design the return
water from the space heating circuit is
used to pre-heat the cold feed to the
domestic hot water.
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 6 Community heating systems | 87
Table 27: Recommended minimum standards for domestic hot water
production, storage and water treatment, heat meters and commissioning
for community heating
Community
heating
2.0
Water
treatment
3.0
Heat meters
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Supplementary information
a. A suitable system for
introduction of water
treatment chemicals
into the community
heating system in a
controlled manner with
facility for monitoring of
water quality should be
provided.
A suitable long-term programme of
water treatment is essential to preserve
the life of the community heating
system by limiting internal corrosion.
Additional chemical and physical
treatment should be evaluated
especially for larger systems, including:
• removal of oxygen by physical
means;
• softened water supply;
• side-stream filtration;
• biocide.
N
O
I
S
R
E
V
E
N
I
L
ON
a. Provision should be
made in the design for
including heat meters
either at the time of
installation or at a later
date without major
pipework changes.
4.0
a. The community heating
Commissioning
system should be
commissioned so that
the design volume flow
rates are supplied to
each dwelling and there
is no excessive bypassing
of water that would
lead to higher pumping
energy use.
b. The flow rates in
individual heat emitters
should be balanced
using appropriate return
temperatures or by using
calibrated control valves.
c. The systems within the
dwellings should be
demonstrated to the
resident and suitable
information provided
on the operation of the
controls
Where the central heat source
includes a low-carbon heat source,
the control system should be proven
by demonstrating that the low-carbon
heat source will normally act as the
lead heat source.
N
O
I
S
R
E
V
E
N
I
L
N
O
88 | Domestic Building Services Compliance Guide: 2010 Edition
Table 28: Recommended minimum standards for insulation of internal and external
pipework for community heating systems
N
O
I
S
R
E
V
E
N
I
L
ON
Standards for internal pipework in new
systems
Supplementary information
a. Pipes should be insulated to comply with the
maximum permissible heat loss indicated in
the Supplementary Information column, and
labelled accordingly, as follows:
i. Primary circulation pipes for heating and hot
water circuits should be insulated wherever
they pass outside the heated living space or
through voids which communicate with and
are ventilated from unheated spaces.
ii. Primary circulation pipes for domestic hot
water circuits should be insulated throughout
their length, subject only to practical
constraints imposed by the need to penetrate
joists and other structural elements.
iii. All pipes connected to hot water storage
vessels, including the vent pipe, should be
insulated for at least 1 metre from their points
of connection to the cylinder (or they should
be insulated up to the point where they
become concealed).
iv. If secondary circulation is used, all pipes kept
hot by that circulation should be insulated.
Insulation of pipework in unheated
areas
Extra provision may need to be made to
protect central-heating and hot water
pipework in unheated areas against
freezing. Guidance is available in:
• BS 5422:2009 “Method for specifying
thermal insulating materials for pipes,
tanks, vessels, ductwork and equipment
operating within the temperature range
-40°C to +700°C”.
• BRE Report No 262 “Thermal insulation:
avoiding risks”, 2002 Edition.
N
O
I
S
R
E
V
E
N
I
L
ON
Standards for internal pipework in
replacement systems
a. Whenever a boiler or hot water storage vessel
is replaced in an existing system, any pipes that
are exposed as part of the work or are otherwise
accessible should be insulated as recommended
above – or to some lesser standard where
practical constraints dictate.
Where insulation is labelled as complying
with this guide, it must not exceed the
following heat loss levels:
Pipe outside
diameter
Maximum
heat loss*
8 mm
7.06 W/m
10 mm
7.23 W/m
12 mm
7.35 W/m
15 mm
7.89 W/m
N
O
I
S
R
E
V
E
N
I
L
N
O
22 mm
9.12 W/m
28 mm
10.07 W/m
35 mm
11.08 W/m
42 mm
12.19 W/m
54 mm
14.12 W/m
*In assessing the thickness of insulation
required, standardised conditions should
be assumed in all compliance calculations,
based on a horizontal pipe at 60oC in still air
at 15oC. Further guidance on converting heat
loss limits to insulation thickness for specific
thermal conductivities is available in TIMSA
“HVAC Guidance for achieving compliance
with Part L of the Building Regulations”.
Section 6 Community heating systems | 89
Table 28: Recommended minimum standards for insulation of internal and external
pipework for community heating systems (continued)
N
O
I
S
R
E
V
E
N
I
L
ON
Standards for insulation of external distribution Supplementary information
pipework
a. Community heating pipework should be
insulated to the standards defined in EN 253
for pre-insulated pipes or to an equivalent
performance for conventionally insulated pipes.
Community heating pipework typically uses
pre-insulated buried pipe systems. Minimum
insulation thicknesses are defined in European
standards. Where pipework is run above
ground the pipe insulation performance
should be at least as high as that used in
the buried part of the system. Enhanced
insulation standards should be evaluated
where community heating is supplied only
from fossil-fuelled boilers or where flow
temperatures over 100ºC are being used.
Designing for minimum heat losses
Heat losses can be reduced by optimising
operating temperatures in conjunction
with the need to minimise pumping energy.
Variable volume control systems will assist
in maintaining low return temperatures.
Whilst some bypasses may be needed to
maintain the system in a hot condition
ready to meet the demand these should be
controlled to the minimum flow needed. The
use of temperature-controlled bypass valves
where the bypass only operates when flow
temperature has dropped below a set level is
recommended.
N
O
I
S
R
E
V
E
N
I
L
ON
Further guidance and standards
Good Practice Guide GPG234 “Guide to community heating and CHP – Commercial, public and
domestic applications”. Available from the Carbon Trust.
BS EN 13941:2003 “Design and installation of pre-insulated bonded pipe systems for direct
heating”.
BS EN 14419:2003 “District heating pipes. Pre-insulated bonded pipe systems for directly buried hot
water networks. Surveillance systems”.
BS EN 253:2003 “District heating pipes. Pre-insulated bonded pipe systems for directly buried hot
water networks. Pipe assembly of steel service pipe, polyurethane thermal insulation and outer
casing of polyethylene”.
BS EN 448:2003 “District heating pipes. Pre-insulated bonded pipe systems for directly buried hot
water networks. Fitting assemblies of steel service pipes, polyurethane thermal insulation and outer
casing of polyethylene”.
BS EN 488:2003 “District heating pipes. Pre-insulated bonded pipe systems for directly buried hot
water networks. Steel valve assembly for steel service pipes, polyurethane thermal insulation and
outer casing of polyethylene”.
BS EN 489:2003 “District heating pipes. Pre-insulated bonded pipe systems for directly buried hot
water networks. Joint assembly for steel service pipes, polyurethane thermal insulation and outer
casing of polyethylene”.
N
O
I
S
R
E
V
E
N
I
L
N
O
90 | Domestic Building Services Compliance Guide: 2010 Edition
Section 7
N
O
I
S
Underfloor heating systems
R
E
V
7.1 Scope of guidanceINE
L
N
O
This section provides guidance on the specification of underfloor heating systems in new
dwellings to meet relevant energy efficiency requirements in building regulations.
The guidance covers systems that use both hot water pipes and electric heating elements
as the underfloor heat source.
7.2 Underfloor heating in new dwellings
N
O
I
S
R
E
V
E
N
I
L
ON
Underfloor heating in new dwellings should meet the minimum standards for:
a. system control and safe operating temperatures in Table 29
b. floor insulation and system design to minimise distribution losses in Table 30; and
c. in the case of electric underfloor heating systems in new dwellings, construction and
controls in Table 31.
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 7 Underfloor heating systems | 91
Table 29: Recommended minimum standards for control of wet and electric
underfloor heating systems
Underfloor
heating
1.0
System
temperature
controls:
Wet and
electric
underfloor
heating
systems
2.0
Room
temperature
control:
Wet and
electric
underfloor
heating
systems
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Supplementary
information
a. All underfloor heating systems, whether
warm water or electrical types, should be
fitted with controls to ensure safe system
operating temperatures:
i. A separate flow temperature highlimit thermostat is required for warm
water systems connected to any high
water temperature heat supply (i.e.
operating at more than 60°C).
ii. Mixed systems containing both
radiators and floor heating,
connected to a common high water
temperature supply (i.e. operating at
more than 60°C), should be provided
with a separate means of reducing
the water temperature to the floor
heating system.
N
O
I
S
R
E
V
E
N
I
L
ON
a. Each room should have its own
temperature control device; however,
it may be acceptable for adjacent rooms
with similar function – e.g. kitchens and
utility rooms – to share a thermostat or
sensor.
b. Bathrooms or en-suites which share a
heating circuit with an adjacent bedroom
will provide heat only when the bedroom
thermostat is activated. In such cases, the
bathroom or en-suite areas should be
fitted with an independent towel rail or
radiator.
c. Weather compensating controllers
should be installed.
N
O
I
S
R
E
V
E
N
I
L
N
O
92 | Domestic Building Services Compliance Guide: 2010 Edition
Table 29: Recommended minimum standards for control of wet and electric
underfloor heating systems (continued)
Underfloor
heating
3.0
Time control:
Wet and
electric
underfloor
heating
systems
4.0
Boiler control:
Wet
underfloor
heating
systems only
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Supplementary
information
a. Dwellings with a total usable floor area
up to 150 m2 should be divided into
at least two zones with independent
temperature control, one of which is
assigned to the living area.
b. Dwellings with a total usable floor area
greater than 150 m2 should be provided
with at least two space heating zones
each having separate on/off timing
controls and temperature controls.
c. For single storey open-plan dwellings in
which the living area is greater than 70%
of the total floor area, sub-zoning of
temperature control is not appropriate.
d. Thick screed floor heating systems
(>65 mm) should have facilities for
automatic setback of room temperature
to a lower level at night or during
unoccupied periods.
Facilities for
automatic setback of
room temperature
to a lower level at
night or during
unoccupied periods
are recommended
for both electric and
warm water systems.
N
O
I
S
R
E
V
E
N
I
L
ON
a. Warm-water floor heating system
controls should be interlocked with the
boiler and stored hot water temperature
control to ensure that the boiler does not
fire when there is no demand for heat for
either space or water heating.
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 7 Underfloor heating systems | 93
Table 30: Recommended minimum standards for floor insulation and
minimising distribution losses in wet and electric underfloor heating systems
Underfloor
heating
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Supplementary
information
a. Ground floors on earth, or suspended
floors in contact with outside air, should
be insulated to limit downward heat
loss to not more than 10 W/m2 resulting
from thermal resistance of the applied
floor finish.
b. When heat output is not known, but
the floor finish is specified, the extra
amount of system thermal insulation
may be calculated using the sum of the
thermal resistance of the floor finish
and the thermal resistance of the
underlying heated layer, all multiplied by
a factor of 10.
c. Supplementary floor heating system
thermal insulation may be supplied
independently, or added to the statutory
insulation requirement.
d. Floor heating systems intended for
cyclical operation or installed over
unheated rooms should be separated
from the structural floor by a layer
of thermal insulation of at least 1.25
(m2.K)/W thermal resistance, and
installed below the heated plane.
The specifier
should confirm
that insulation
levels comply
with Approved
Document L1A
standards.
2.0
Intermediate
floors with
heated rooms
below: wet
systems
a. Intermediate floors with heated rooms
below should have a separating layer
of system thermal insulation to comply
with either 1b above or BS EN1264
Part 4, where the minimum thermal
resistance is given as not less than
R = 0.75 (m2.K)/W.
Thermal insulation
of party floors is
essential because
the floor or ceiling
is directly coupled
to the heating
elements.
3.0
Intermediate
floors with
heated rooms
below: electric
systems
a. Intermediate floors with heated rooms
below should either comply with 1.0 b.
above or have a separating layer of
system thermal insulation where the
minimum thermal resistance is not less
than R = 0.5 (m2.K)/W.
1.0
Exposed ground
floors
N
O
I
S
R
E
V
E
N
I
L
ON
N
O
I
S
R
E
V
E
N
I
L
N
O
94 | Domestic Building Services Compliance Guide: 2010 Edition
Table 30: Recommended minimum standards for floor insulation and
minimising distribution losses in wet and electric underfloor heating systems
(continued)
Underfloor
heating
4.0
System design
to minimise
distribution
losses
5.0
System
commissioning
and corrosion
protection
N
O
I
S
R
E
V
E
N
I
L
ON
New systems
Supplementary
information
a. Underfloor heating distribution boards
or warm water distribution manifolds
should be located centrally between the
rooms being heated, thus minimising
the length of interconnecting services.
b. Service pipes carrying hot water to
more distant rooms should be insulated
or routed through conduits to reduce
distribution losses and the risk of
overheating the room or floor finish.
a. Commissioning warm water floor
heating systems should be carried out
in accordance with BS EN 1264 Part 4.
Even where plastic tubes contain oxygen
gas barriers, the control of corrosion in
mixed product heating systems must be
addressed carefully.
Control of
b. After testing and flushing with clean
oxidation,
water, the system circulating fluid
biofilm, scale and
should be treated with a suitable
sludge in warm
corrosion inhibitor approved by the tube
water heating
manufacturer and complying with
systems
BS 7593:2006 or DIN 4725/6, and
applied strictly in accordance with the
additive manufacturer’s instructions.
British Standards
BS 7593:2006
“Code of practice
for treatment of
water in domestic
hot water central
heating systems”.
N
O
I
S
R
E
V
E
N
I
L
ON
Inhibitors should
as a minimum be
BuildCert approved.
Note should also be
made of advice in
the manufacturer’s
instructions.
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 7 Underfloor heating systems | 95
Table 31: Recommended minimum standards for construction and control of
electric underfloor heating systems
N
O
I
S
R
E
V
E
N
I
L
ON
Underfloor heating
New systems
Electric
1.0
a. Electric cable underfloor heating
storage
Construction
low tariff night energy storage
systems with
systems should have a 65 mm
minimum thickness screed for
individual
correct operation.
room or
programmable
b. Principal rooms containing 80%
thermostats
floor area should be assigned
and low tariff
to low tariff heating cables and
anticipatory
20% of the floor area should be
controls
assigned to either direct-acting
perimeter heating cables or
systems such as ceiling or panel
heaters in order to maximise
energy efficiency.
N
O
I
S
R
E
V
E
N
I
L
ON
2.0
Controls
Electric cable,
direct-acting
(non-storage)
systems with
individual
room timer or
thermostat
control in
screeded
floors
a. Anticipatory controllers should
be installed controlling low
tariff input charge with external
temperature sensing and floor
temperature sensing.
b. Programmable room
thermostats with an override
feature should be provided for all
direct-acting zones of the system
with air and floor temperature
sensing capabilities to be used
individually or combined.
3.0
a. Direct-acting electric underfloor
Construction
heating cables should be
installed within screeds of
thickness not exceeding 60 mm.
b. All heated floors should be
insulated in accordance with
Table 30.
N
O
I
S
R
E
V
E
N
I
L
N
O
4.0
Controls
a. Programmable room
thermostats with a manual
override feature for all
heating zones with air or floor
temperature sensing capabilities
should be used individually or
combined.
Supplementary
information
Other areas
should be
assigned as low
tariff heating
cables only
(subject to heat
requirements).
Bathrooms
and separate
kitchens
may have
direct-acting
heating cables
(subject to heat
requirements).
Anticipatory
controllers
(i.e. weather
compensators)
reduce night
energy storage
as a function
of external
temperature.
96 | Domestic Building Services Compliance Guide: 2010 Edition
Table 31: Recommended minimum standards for construction and control of
electric underfloor heating systems (continued)
N
O
I
S
R
E
V
E
N
I
L
ON
Underfloor heating
Electric cable,
direct-acting
systems with
individual
room timer or
thermostat
control in
timber floors
Under-tile
electric floor
heating
systems
New systems
Supplementary
information
5.0
a. Direct-acting electric underfloor
Construction
heating cables installed below
floor boards in voids between
floor joists should be insulated in
accordance with Table 30.
6.0
Controls
a. Programmable room
thermostats with a manual
override feature should be
provided to control space
temperature and limit floor
void temperature for safety and
comfort in each area.
N
O
I
S
R
E
V
E
N
I
L
ON
7.0
a. Direct-acting electric underfloor
Construction
heating cables should be
provided with a pre-fabricated
mattress, or equivalent IEC
60800 approved heating cable
product, of thickness less than 4
mm encapsulated in tile bedding
adhesive or mortar, below a
ceramic or other equivalent floor
finish on a thermally resistive
insulation layer as defined in
Table 30(1.0 b.).
8.0
Controls
a. Programmable room
thermostats with a manual
override feature should be
provided to control space
temperature and limit floor
temperature for safety and
comfort in each area.
N
O
I
S
R
E
V
E
N
I
L
N
O
Section 8 Mechanical ventilation systems | 97
Section 8
N
O
I
S
Mechanical ventilation systems
R
E
V
E
8.1 Scope of guidance
N
I
L
ON
This section provides guidance on the specification of mechanical ventilation systems in
dwellings to meet relevant energy efficiency requirements in building regulations.
The guidance covers the following types of mechanical ventilation:
•
intermittent mechanical extract ventilation
•
continuous mechanical extract ventilation
N
O
I
S
R
E
8.2 Energy efficiency of mechanical
ventilation systems
V
E
N
I
L
ON
•
continuous mechanical supply ventilation
•
continuous mechanical supply and extract with heat recovery.
Mechanical ventilation systems should:
a. follow the guidance in:
i.
GPG 268 Energy efficient ventilation in dwellings – a guide for specifiers; and
ii. the CLG publication Domestic ventilation compliance guide (available from
www.planningportal.gov.uk/approveddocuments > Part L > Associated
documents); and
N
O
I
S
R
E
V
E
N
I
L
N
O
b. meet the minimum standards for specific fan power, heat recovery efficiency and
controls in Table 32.
98 | Domestic Building Services Compliance Guide: 2010 Edition
Table 32: Recommended minimum standards for mechanical ventilation
systems
N
O
I
S
R
E
V
E
N
I
L
ON
New and replacement systems
1.0
Fan power
a. Mechanical ventilation systems should be
designed to minimise electric fan power.
Specific fan power (SFP) should not be worse
than:
i. 0.5 W/(l/s) for intermittent extract
ventilation systems;
ii. 0.7 W/(l/s) for continuous extract
ventilation systems;
iii. 0.5 W/(l/s) for continuous supply
ventilation systems;
iv. 1.5 W/(l/s) for continuous supply and
extract with heat recovery ventilation
systems.
2.0
Heat
recovery
efficiency
a. The heat recovery efficiency of balanced
mechanical ventilation systems
incorporating heat recovery should not be
worse than 70%.
3.0
Controls
a. Intermittent mechanical extract ventilation
systems should be operated by local manual
switches or automatically by a presence
sensor.
b. All other mechanical ventilation systems
should have manual or automatic control of
the boost facility.
Supplementary
information
N
O
I
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British Standards
BS EN 15232:2007
“Energy
performance
of buildings –
Impact of building
automation,
controls and
building
management”.
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Section 9 Heat pump systems | 99
Section 9
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Heat pump systems
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9.1 Scope of guidance
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This section provides guidance on the specification of heat pump systems in dwellings for
the provision of space heating and domestic hot water to meet relevant energy efficiency
requirements in building regulations.
A heat pump is a device which takes heat energy from a low temperature source and
upgrades it to a higher temperature at which it can be usefully employed for heating or
hot water. Heat pumps may supply all or part of the heating load.
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The guidance in this section applies to the types of electrically-driven heat pump in
Table 33.
Table 33: Heat pump technologies
Heat pump type
Ground source systems (GSHP)
Heat energy is extracted from the ground using closed
pipe loops buried horizontally in trenches or in vertical
boreholes that are connected back to the GSHP. The fluid
circulating in the closed loop is normally a water/propylene
glycol antifreeze mixture or accepted equivalent but some
direct expansion GSHPs use refrigerant. Open loops may
also be used to collect water from an aquifer and discharge
via a separate aquifer downstream of the water table
flow; systems of this type normally require permits from
the Environment Agency. Heat extracted from the ground
may be supplied to a dwelling either by a water-based
heating system (ground-to-water heat pump) or by an air
distribution system (ground-to-air heat pump).
Warm
water and
hot water
systems
Warm air
systems
Ground-towater
Ground-toair
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100 | Domestic Building Services Compliance Guide: 2010 Edition
Table 33: Heat pump technologies (continued)
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Heat pump type
Water source systems (WSHP)
Heat energy is extracted indirectly from a water source
using closed pipe loops as a heat exchanger. The closed
loop is connected back to the water to water heat pump.
The water source may be a lake, pond or river or other
stable water source. The fluid circulating in the closed
loop will normally be water but a water/propylene glycol
or accepted equivalent antifreeze mixture may be used,
depending on operating temperatures. Open loops may
also be used subject to the permits being obtained from
the Environment Agency. Heat may be supplied to the
dwelling either by a water-based heating system (water-towater heat pump) or by an air distribution system (waterto-air heat pump).
Warm
water and
hot water
systems
Water-towater
Warm air
systems
Water-to-air
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Air-to-water Air-to-air
Air source systems (ASHP)
Air source heat pumps extract heat directly from the
ambient air. Heat is supplied to the dwelling either by a
water-based heating system (air-to-water heat pump) or by
an air distribution system (air-to-air heat pump). Air-to-air
heat pumps may be single package or split systems.
All heat pump systems are at their most efficient when the source temperature is as
high as possible, the heat distribution temperature is as low as possible and pressure
losses in air and water systems are kept to a minimum. If installed in a new dwelling, heat
pumps should use refrigerants complying with the provisions of EU Directive 2037:2000.
Heat pumps should be CE marked in accordance with applicable EU Directives: e.g. the
machinery safety, low voltage, pressure equipment and electromagnetic compatibility
directives. If summer cooling is provided by the heat pump, it is recommended that
condensate drainage from the indoor units is provided.
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Section 9 Heat pump systems | 101
9.2 Key terms
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Coefficient of performance (CoP) is a measure of the efficiency of heat pumps.
Heating CoP = heat output/power input.
% CoP (CoP x 100) is the heat generator efficiency.
Seasonal performance factor (SPF) is the operating performance of an electric heat
pump over the season. It is the ratio of the heat delivered and the total energy supplied
over the season.
9.3 Warm water and hot water heat pumps
Electrically-driven heat pumps used as the heat generator in, e.g. underfloor, warm air and
medium temperature radiator heating systems should:
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a. have a coefficient of performance not less than 2.28 when used for space heating
b. have a coefficient of performance not less than 2.0 when used for heating domestic
hot water
c. have a seasonal performance factor not worse than the minimum required by
BS EN 15450 Table C1 for new build and Table C2 for existing build
d. meet the minimum standards for supply temperature, wet system radiator efficiency,
installation and commissioning, hot water and controls in Table 34 for warm water and
hot water heat pumps
e. meet the minimum standards for installation and controls in Table 35 for warm air
heat pumps.
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CoP to be measured according to procedures in BS EN 14511-4:2007.
102 | Domestic Building Services Compliance Guide: 2010 Edition
Table 34: Recommended minimum standards for warm water and hot water
heat pumps (ground-to-water, water-to-water and air-to-water systems)
Warm and
hot water
heat pumps
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New and replacement systems
1.0
Underfloor heating
Supply
a. Supply water temperatures to the
water
underfloor heating system should
temperatures
be in the range 30°C to 40°C for
and
new buildings and 30°C to 55°C
efficiency
for existing systems.
Supplementary
information
Section 7 of this guide on
underfloor heating.
Radiators
a. High-efficiency radiators with high
water volume should be utilised.
b. Supply water temperature to the
radiators should be in the range
40°C to 55°C.
Space heating may be sized to
meet all or part of the space
heating load. Secondary
heating will be required if the
heat pump is sized to meet
part of the space heating load.
Fan coil units
a. Supply water temperature to the
fan coil units should be in the
range 35°C to 45°C.
Fan coil units may be utilised
for heating only or for winter
heating and summer cooling.
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Section 9 Heat pump systems | 103
Table 34: Recommended minimum standards for warm water and hot water
heat pumps (ground-to-water, water-to-water and air-to-water systems)
(continued)
Warm and
hot water
heat pumps
2.0
Installation
and
commissioning
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New and replacement systems
a. The water distribution system
should be arranged for reverse
return operation or arranged
with a low loss manifold system
to maximise efficiency and
ease commissioning and future
maintenance.
b. Pipework not contributing to the
space heating should be insulated
to prevent heat loss following the
guidance in the TIMSA guide.
c. If summer cooling is provided
by the heat pump, all water
distribution pipework should be
insulated to prevent condensation
following the guidance in the
TIMSA guide.
d. External pipework between the
dwelling and the ground heat
exchanger should be insulated
following the TIMSA guidance.
e. The ground loop water circuit
should be protected with an anti
freeze solution and inhibitor as
recommended by the heat pump
manufacturer.
f. Ground loops should be cleaned
with a cleaning fluid and biocide
as part of the commissioning
process.
Supplementary
information
Design
A pressurised water
distribution system
with expansion vessel is
recommended.
Constant water flow should be
maintained through the heat
pump.
Pipe sizes should be
in accordance with
the manufacturer’s
recommendations.
Installation
Installation should be carried
out by an installer approved by
the manufacturer.
If during installation access
to the refrigeration circuit
is needed, a competent
refrigeration and air
conditioning engineer (with
a valid refrigerant handling
certificate or an Engineering
Services Skillcard) should carry
out the work.
Exposed refrigeration
pipework should be insulated
and enclosed in protective
trunking to limit accidental
damage.
Installation of the dwelling’s
water distribution system
should be undertaken by a
competent central heating
specialist.
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104 | Domestic Building Services Compliance Guide: 2010 Edition
Table 34: Recommended minimum standards for warm water and hot water
heat pumps (ground-to-water, water-to-water and air-to-water systems)
(continued)
Warm and
hot water
heat pumps
2.0
Installation
and
commissioning
(continued)
3.0
Domestic
hot water
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New and replacement systems
Supplementary
information
g. The internal water distribution
circuit should contain an inhibitor
and may be protected by an anti
freeze solution as recommended
by the heat pump manufacturer.
h. Ground loops should be filled
with a heat transfer fluid. Installers
should also refer to the equipment
manufacturer’s installation
instructions for appropriate
treatment products and special
requirements for individual
appliance models.
Guidance and standards
TIMSA “HVAC guidance for
achieving compliance with
Part L of the Building
Regulations”.
BS EN 378 “Specification for
refrigerating systems and heat
pumps”.
TR30 “Guide to good practice
– heat pumps”,
HVCA July 2007.
MIS 3005 “Requirements for
contractors undertaking the
supply, design, installation, set
to work, commissioning and
handover of microgeneration
heat pump systems”,
BERR 2008.
a. For full heating, the heat pump
and any supplementary domestic
hot water heating should be
capable of supplying water in
the range 60°C to 65°C. This is
applicable to ground-to-water,
water-to-water and air-to-water
type heat pumps.
b. If the heat pump is not capable
of supplying water at these
temperatures, supplementary
heating should be provided and
controlled as described in other
sections of this guide. Controls
should include an auxiliary heating
regime to 60°C or more for
disinfection purposes.
c. The domestic hot water (DHW)
system should include a tank
thermostat and a time clock to
optimise the time taken to heat
the water.
The heat pump may be utilised
for all or part of the DHW
load. During the DHW heating
period the heat pump may
not necessarily be providing
heated water to the space
heating system.
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Section 9 Heat pump systems | 105
Table 34: Recommended minimum standards for warm water and hot water
heat pumps (ground-to-water, water-to-water and air-to-water systems)
(continued)
Warm and
hot water
heat pumps
4.0
Controls
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New and replacement systems
a. Heat pump unit controls should
include:
i. control of water pump
operation (internal and
external as appropriate);
ii. control of water temperature
for the distribution system;
iii. control of outdoor fan
operation for air-to-water
units;
iv. defrost control of external
airside heat exchanger for airto-water systems;
v. protection for water flow
failure;
vi. protection for high water
temperature;
vii. protection for high refrigerant
pressure;
viii. protection for air flow failure
on air-to-water units.
b. External controls should include:
i. room thermostat to regulate
the space temperature and
interlocked with the heat
pump unit operation;
ii. timer to optimise operation of
the heat pump.
Supplementary
information
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106 | Domestic Building Services Compliance Guide: 2010 Edition
Table 35: Recommended minimum standards for warm air heat pumps (groundto-air, water-to-air and air-to-air systems)
Warm air
heat pumps
1.0
Installation
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New and replacement systems
a. Minimum clearances adjacent to
all airflow paths, as recommended
by the manufacturer, should be
maintained.
b. Pipe sizes should be in accordance
with the manufacturer’s
recommendations.
c. The refrigerant pipework on
split systems should be insulated
in line with the manufacturer’s
recommendations.
d. If summer cooling is provided by
the heat pump, provision should
be made for condensate drainage
from the indoor terminal units.
e. For ground-to-air and water-toair systems all external pipework
between the dwelling and the
external heat exchanger should
be insulated by following TIMSA
guidance.
f. For ground-to-air and water-toair systems constant water flow
should be maintained through the
heat pump.
Supplementary
information
Installation should be carried
out by an installer approved by
the manufacturer.
Installation that requires access
to the refrigeration circuit,
or the connection of split
systems, should be carried out
by a competent refrigeration
and air conditioning engineer
holding a refrigerant handling
certificate and, preferably, an
Engineering Services Skillcard.
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TIMSA “HVAC guidance
for achieving compliance
with Part L of the Building
Regulations”.
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Section 9 Heat pump systems | 107
Table 35: Recommended minimum standards for warm air heat pumps (groundto-air, water-to-air and air-to-air systems) (continued)
Warm air
heat pumps
2.0
Controls
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New and replacement systems
Supplementary
information
a. Heat pump unit controls should
include:
i. control of room air temperature
(if not provided externally);
ii. control of outdoor fan
operation for air-to-air units;
iii. defrost control of external
airside heat exchanger for airto-air systems;
iv. control for secondary heating (if
fitted) on air-to-air systems;
v. control of external water pump
operation for ground-to-air and
water-to-air systems;
vi. protection for high water
temperature;
vii. protection for high refrigerant
pressure;
viii. protection for indoor air flow
failure;
ix. protection for external air flow
failure on air-to-air units;
x. protection for water flow failure
on ground-to-air and water-toair systems.
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108 | Domestic Building Services Compliance Guide: 2010 Edition
Table 35: Recommended minimum standards for warm air heat pumps (groundto-air, water-to-air and air-to-air systems)
Warm air
heat pumps
2.0
Controls
(continued)
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New and replacement systems
Supplementary
information
b. External controls should include:
i. room thermostat (if not
provided internal to the heat
pump) to regulate the space
temperature, and interlocked
with the heat pump unit
operation;
ii. timer to optimise operation of
the heat pump.
Supplementary information – further guidance on heat pumps
EU Directives for machinery safety, low voltage, pressure equipment, electromagnetic
compatibility.
SAP 2009.
Defra/Carbon Trust Energy Technology List – Heat Pumps.
BS EN 14511 “Air conditioning, liquid chilling packages and heat pumps with electrical
driven compressors for space heating and cooling”. Parts 1-4.
BS EN 15450 “Heating systems in buildings. Design of heat pump heating systems”.
BS EN 15316 “Heating systems in buildings. Method for calculation of system energy
requirements and system efficiencies”. Part 4.2: “Space heating generation systems,
heat pump systems”.
ISO 13256 “Water-source heat pumps – testing and rating for performance”: Part 1 –
“Water-to-air and brine-to-air heat pumps” and Part 2 – “Water-to-water and brine-towater heat pumps”.
CE 82 Energy Efficiency Best Practice in Housing: “Domestic ground source heat pumps:
design and installation of closed-loop systems”.
BS EN 378 “Specification for refrigerating systems and heat pumps. Safety and
environmental requirements and system efficiencies”. Part 4-2: “Space heating
generation systems, heat pump systems”.
Microgeneration Certification Scheme MIS 3007 “Product certification scheme
requirements – heat pumps”.
Microgeneration Certification Scheme MIS 3005 “Requirements for contractors
undertaking the supply, design, installation, set to work, commissioning and handover
of microgeneration heat pump systems”, BERR 2008.
EU Ecolabel “Establishing the ecological criteria for the award of the Community ecolabel to electrically-driven, gas-driven or gas absorption heat pumps”.
Heat Pump Association data sheet “Air-to-water heat pumps”.
HVCA TR30 “Guide to good practice: Heat pumps”.
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Section 10 Comfort cooling systems | 109
Section 10
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Comfort cooling systems
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10.1 Scope of guidance
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This section provides guidance on the specification of fixed mechanical comfort cooling
systems in dwellings to meet relevant energy efficiency requirements in building
regulations.
(Dwellings should always be designed to avoid or minimise the need for cooling through
the appropriate use of solar control, secure ventilation and thermal mass.)
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10.2 Air-cooled and water-cooled air conditioners
Cooling systems in new and existing dwellings should:
a. meet the minimum standards for efficiency in Table 36; and
b. be controlled to prevent simultaneous heating and cooling of the same space
within the dwelling.
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Table 36: Recommended minimum standards for comfort cooling
Comfort
cooling
1.0
Efficiency
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New and replacement systems
Supplementary information
a. Air-cooled air conditioners
working in cooling mode should
have an EER greater than 2.4.
b. Water-cooled air conditioners
working in cooling mode should
have an EER greater than 2.5.
c. Fixed air conditioners should
have an energy efficiency
classification equal to or better
than Class C in Schedule 3 of
the labelling scheme adopted
under The Energy Information
(Household Air Conditioners) (No.
2) Regulations, SI 2005/1726.
Installation should be carried out
by an installer approved by the
manufacturer or supplier. The
installer should be a competent
refrigeration and air conditioning
engineer with a valid refrigerant
handling certificate.
Exposed refrigeration pipework
should be insulated and enclosed
in protective trunking to limit
accidental damage.
www.eurovent-certification.com
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Supplementary information
British Standards
BS EN 14511-2 “Air conditioners, liquid chilling packages and heat pumps with
electrically driven compressors for space heating and cooling – Test conditions”.
BS EN 14511-4 “Air conditioners, liquid chilling packages and heat pumps with
electrically driven compressors for space heating and cooling – Requirements”.
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Section 11 Solar water heating | 111
Section 11
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Solar water heating
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11.1 Scope of guidance
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This section provides guidance on the specification of solar water heating for dwellings to
meet relevant energy efficiency requirements in building regulations.
The guidance in this section covers indirect solar systems with a collector area of less than
20 m2 and solar heated water storage of less than 440 litres. It does not cover “direct”
solar systems9 or systems intended to contribute exclusively to space heating or systems
providing heat exclusively to heat swimming pools. It should be used in conjunction with
the guidance on water heating contained in the fuel-based sections of this guide.
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Indirect solar heating systems installed as new systems and replacement systems should
meet the minimum standards for:
a. collector certification, identification and testing, collector primary loop transfer
fluid, circulation pump power, heat-exchanger sizing, system control, solar preheated water storage, and system preparation in Table 37
b. system labelling and commissioning in Table 38
c. insulating pipes in a solar primary system in Table 39.
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Supplementary information
When work is carried out on an existing indirect solar hot water system, it is
recommended that the system controls and insulation should be upgraded in line with
the standards for new and replacement systems.
9
The Microgeneration Certification Scheme Standard MIS3001 Issue 1.7, January 2010, gives guidance on solar heating systems with
a dedicated solar volume that is below the minimum recommended for indirect systems. SAP 2009 Appendix H sets out rules for
estimating the annual energy performance of solar heating systems, including direct systems.
112 | Domestic Building Services Compliance Guide: 2010 Edition
Table 37: Recommended minimum standards for indirect solar water heating
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Solar water
heating
New and replacement systems
Supplementary information
1.0
Allowance
for collector
shading
a. No minimum provision.
Solar collectors should be sited
in unshaded locations wherever
possible. Where this is unavoidable
or in cases of significant or heavy
shading or significant variance
to the optimum orientation
and tilt (i.e. normal pitch roofs
facing between SE and SW),
then an allowance for the loss
of performance should be made
when sizing the collector area
according to the factors indicated
in SAP 2009 Appendix H.
a. Collectors should be
2.0
independently certified to comply
Solar
with all required tests for safety
collector
and thermal performance, and
certification
for reporting and identification
according to BS EN 12975.
Copies of the full test report should
be made available upon request.
3.0
Primary
circuit fluid
a. The transfer fluid in the collector
primary loop should be chosen
so as not to deposit limescale,
sludge, ice or other solids that
could either restrict circulation or
impair the rate of heat transfer
within the absorber.
In secondary systems, measures to
reduce the formation of limescale
should be considered so that
performance is not significantly
affected.
4.0
Circulation
pump
power
a. The electrical input power of
the primary pump in the solar
system should be less than 50 W
or 2% of peak thermal power of
collector, whichever is the higher.
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Section 11 Solar water heating | 113
Table 37: Recommended minimum standards for indirect solar water heating
(continued)
Solar water
heating
5.0
Heatexchanger
sizing
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New and replacement systems
Supplementary information
a. The heat exchanger between
a solar primary and secondary
system should be sized so that not
less than 0.1 m2 or equivalent of
heat exchanger area is provided
per 1 m2 of solar collector net
absorber area.
A heat exchanger reduces the
possibility of clogging and
deposition due to dirt, scale or
similar impurities that could
reduce the system performance.
Heat exchangers and store
connections should be sized and
located to promote a low return
temperature to the solar collector.
Solar heat exchangers are often
sized larger than those usually
used on gas- or oil-based primary
systems owing to the lower
temperature of transfer.
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Table 37: Recommended minimum standards for indirect solar water heating
(continued)
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Solar water
heating
New and replacement systems
6.0
System
control
a. Solar domestic hot water (DHW)
system controls should be fitted
to:
i. maximise the useful energy
gain from the solar collectors
into the system’s dedicated
storage;
ii. minimise the accidental
loss of stored energy by the
solar DHW system, whether
originating from solar
collectors, cold intake or
auxiliary heat sources;
iii. ensure that hot water
produced by back-up
(auxiliary) heat sources is not
used when adequate grade
solar pre-heated water is
available;
iv. provide a means of control
consistent with the solar
system being hydraulically
(inherently) secure against the
adverse affects of excessive
primary temperatures and
pressures;
v. where a separate DHW
heating appliance is preheated by a solar system,
control the appliance where
possible such that no extra
heat is added if the target
temperature is already
satisfied from the pre-heat
vessel;
vi. inform the end user of the
system’s correct function and
performance at all times.
Supplementary information
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Section 11 Solar water heating | 115
Table 37: Recommended minimum standards for indirect solar water heating
(continued)
Solar water
heating
7.0
Solar preheated
water
storage
8.0
Volume
of solar
pre-heated
water
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New and replacement systems
Supplementary information
a. Vented copper hot water storage
vessels should comply with the
heat loss and back-up heating
heat exchanger requirements of
BS 1566-1:2002.
b. Unvented hot water storage
system products should:
i. comply with BS EN 12897; or
ii. be certified by the British
Board of Agrément, the Water
Research Council or other
accredited body as complying
with building regulations.
c. Primary storage systems should
meet the insulation requirements
of sections 4.3.1 or 4.3.2 of
the Hot Water Association
Performance specification for
thermal stores.
Vented copper hot water cylinders
should carry clear labelling on the
product such as a BSI Kitemark,
registered firm status or reference
to an equivalent quality control
scheme.
a. The ratio of solar heated water
storage volume to collector area
should be as follows:
i. The dedicated solar storage
volume, Vs, should be at least
25 litres (or equivalent heat
capacity) per net square metre
of the solar collector absorber
area.
ii. Alternatively, Vs should be a
volume (or equivalent heat
capacity) which is equivalent
to at least 80% of the daily hot
water demand, Vd (as defined
by SAP 2009).
Collector area is measured as
effective aperture or net absorber
area, whichever is smaller.
Vented cylinders which are not
of copper construction should
be labelled as complying with
the heat loss and heat exchanger
requirements of BS 1566.
Due to the higher than normal
storage temperatures in primary
stores, it is very important that
they are well insulated.
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A separate pre-heat storage vessel
should be considered wherever
possible.
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116 | Domestic Building Services Compliance Guide: 2010 Edition
Table 37: Recommended minimum standards for indirect solar water heating
(continued)
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Solar water
heating
New and replacement systems
Supplementary information
9.0
System
preparation
and water
treatment
New build
a. Solar primary circuits should
be thoroughly cleaned with an
appropriate cleaner and flushed
through with solar heat transfer
fluid before filling with the solar
heat transfer fluid.
b. Systems should be filled with a
heat transfer fluid containing
a volatile inhibitor package,
capable of protecting the system
from frost and corrosion at all
operating temperatures.
c. Installers should refer to the
equipment manufacturer’s
installation instructions for
appropriate treatment products
and special requirements for
individual appliance models.
d. Where mains water is used to fill
the solar primary circuit and the
total water hardness exceeds
200 parts per million, provisions
should be made to reduce the
limescale.
Existing installations
a. Solar thermal systems should
be cleaned with an appropriate
cleaner formulated to remove
build-up of degradation films
from exhausted heat transfer
fluids, then flushed through with
fresh solar heat transfer fluid.
b. Systems should be filled with a
heat transfer fluid containing
a volatile inhibitor package,
capable of protecting the system
from frost and corrosion at all
operating temperatures.
c. Installers should refer to the
equipment manufacturer’s
installation instructions for
appropriate treatment products
and special requirements for
individual appliance models.
Parts of BS 7593:2006 “Code of
practice for treatment of water
in domestic hot water central
heating systems” may assist in
flushing and cleaning procedures.
“Legionnaire’s disease: The control
of legionella bacteria in water
systems”. Approved code of
practice and guidance, HSE Books.
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Section 11 Solar water heating | 117
Table 38: Recommended minimum standards for labelling, commissioning and
documentation for solar hot water systems
Solar water
heating
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New and replacement systems
1.0
Labelling of
solar
collectors and
hot water
stores
a. All solar collectors should have a
visible and durable label displaying
all information required according to
BS EN 12975, and including at least
the following:
i. name of manufacturer;
ii. collector type;
iii. serial number;
iv. year of production;
v. gross area of collector;
vi. aperture area of collector;
vii. net absorber area of collector;
viii. maximum operation pressure;
ix. stagnation temperature at 1000
W/m2 and 30°C ambient;
x. volume of heat transfer fluid;
xi. weight of empty solar collector.
b. All hot water storage vessels should
carry a label with the following
information:
i. manufacturer’s name;
ii. nominal overall capacity in litres;
iii. dedicated solar capacity in litres;
iv. standing heat loss in kWh/day;
v. type of vessel;
vi. back-up heating heat exchanger
performance in kW (where
present);
vii. solar heating heat exchanger
performance in kW.
Supplementary
information
In addition to the
minimum provision for
labelling of hot water
storage vessels, labelling
with the following
information is also
recommended:
• Total net fluid content
of secondary volume
normally heated by
each heat exchanger,
where present (+/- 1.0
litre).
• The type, fluid
content, maximum
pressure and surface
area of all heat
exchangers.
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118 | Domestic Building Services Compliance Guide: 2010 Edition
Table 38: Recommended minimum standards for labelling, commissioning and
documentation for solar hot water systems (continued)
Solar water
heating
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New and replacement systems
Supplementary
information
2.0
a. A signed and dated commissioning
Commissioning
certificate should be completed to
confirm the equipment has been
correctly installed and to record key
safety and operational features.
b. As a minimum, the commissioning
certificate should record the
following details of the solar system:
i. net or aperture area of solar
collector;
ii. minimum ambient temperature
without freeze damage to
components;
iii. location of device and method
for controlling over-pressure;
iv. location of the electrical isolating
switch;
v. type of circulation fluid;
vi. circulation rate of collector
circuit;
vii. location of device for protecting
against overheating of solar
heated water.
A signed commissioning
certificate, certifying
that the equipment is
safe, legal and fit for its
intended purpose, should
be handed over to the
dwelling owner or user as
applicable.
A separate certificate is
required to cover
the installation and
commissioning of the hot
water storage vessels and
appliances within a solar
DHW system.
A commissioning
engineer
should be a competent
person who can
personally testify by
signature and date that
the equipment has been
commissioned.
3.0
a. No minimum standard.
Documentation
Information concerning
the solar DHW system
should be provided to
the dwelling owner or
user as applicable. The
documentation should
include:
• user’s manual;
• warranty information;
• a recommended
maintenance
schedule;
• commissioning
certificate;
• full contact details of
the installer.
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Section 11 Solar water heating | 119
Table 39: Recommended minimum standards for insulation of pipework in solar
hot water systems
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New and replacement systems
Supplementary information
a. All pipes of a solar primary system
should be insulated throughout the
length of the circuit.
b. All other pipes connected to hot
water storage vessels, including the
vent pipe, should be insulated for
at least 1 metre from their points
of connection to the cylinder, or
insulated up to the point where they
become concealed.
c. Pipes should be insulated with
materials labelled as complying
with the Domestic building services
compliance guide and in line with
the guidance in the TIMSA guide.
The insulation should be suitably rated for
the maximum foreseeable pipe temperature
applicable, and where external also be
resistant to vermin attack and climatic
degradation.
In a dwelling that already has a solar hot
water system, it is recommended that the
insulation should be upgraded in line with
these minimum provisions where significant
work, such as change of solar storage, is
carried out.
A fully-filled or drainback solar hot water
system can have a pipe service temperature
of 150°C. Therefore an insulation material
should be specified to accommodate this
temperature. An EPDM based rubber would
normally be a minimum requirement for such
an application. Any insulation specified must
be better than 0.044 W/m.K at 40°C mean
and the insulation diameter must be 87% of
the pipe diameter.
Where insulation is labelled as complying
with this guide, it must not exceed the
following heat loss values:
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Pipe outside
diameter
Maximum heat
loss
8 mm
7.06 W/m
10 mm
7.23 W/m
12 mm
7.35 W/m
15 mm
7.89 W/m
22 mm
9.12 W/m
28 mm
10.07 W/m
35 mm
11.08 W/m
42 mm
12.19 W/m
54 mm
14.12 W/m
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120 | Domestic Building Services Compliance Guide: 2010 Edition
Table 39: Recommended minimum standards for insulation of pipework in solar
hot water systems (continued)
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New and replacement systems
Supplementary information
Further guidance on converting heat loss
limits to thicknesses of insulation for specific
thermal conductivities is available in the
TIMSA “HVAC guidance for achieving
compliance with Part L of the Building
Regulations”.
Insulation for pipework in unheated
areas
Extra provision may need to be made to
protect water-carrying pipework in unheated
areas against freezing. Further guidance is
available in:
• BS 5422:2009 “Method for specifying
thermal insulating materials for pipes,
tanks, vessels, ductwork and equipment
operating within the temperature range
of -40°C to +700°C”.
• BRE Report No 262 “Thermal insulation:
avoiding risks”, 2002 Edition.
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Section 11 Solar water heating | 121
Supplementary information
Guidance and standards
Microgeneration Certification Scheme MIS3001 “Requirements for contractors undertaking
the supply, design, installation, set to work, commissioning and handover of solar heating
microgeneration systems”, January 2010.
Energy Efficiency Best Practice in Housing CE131 “Solar water heating systems. Guidance for
professionals”.
CIBSE “Solar heating design and installation guide”. ISBN 978-1-903287-84-2.
CE 51/GIL59 “Central Heating System Specifications (CHeSS)”, 2005.
BS 7431:1991 “Method for assessing solar water heaters. Elastomeric materials for absorbers,
connecting pipes and fittings”.
BS 6785:1986 “Code of practice for solar heating systems for swimming pools”.
prCEN/TS 12977-3:2006 “Performance characterisation of stores for solar heating systems”.
prCEN/TS 12977-2:2005 “Thermal solar systems and components. Custom built systems. Test
methods”.
TS 12977-1:2001 “Thermal solar systems and components. Custom built systems. General
requirements”.
BS EN ISO 9488:2000 “Solar energy. Vocabulary”.
BS EN 12976-2:2006 ”Thermal solar systems and components. Factory made systems. Test
methods”.
BS EN 12976-1:2006 “Thermal solar systems and components. Factory made systems. General
requirements”.
BS EN 12975-2:2006 “Thermal solar systems and components. Solar collectors. Test methods”.
BS EN 12975-1:2006 “Thermal solar systems and components. Solar collectors. General
requirements”.
ISO 9553:1997 “Solar energy-Methods of testing preformed rubber seals and sealing
compounds used in collectors”,
BS 3734-1: 1997 “Rubber – Tolerances for products – Part 1: Dimensional tolerances”.
BS 903-0:2003 “Physical testing of rubber – Part 0: General”.
BS 6920:2000 “Suitability of non-metallic products for use in contact with water intended for
human consumption with regard to their effect on the quality of water”.
ISO/TR 10217:1989 “Solar energy water heating systems guide”.
to material selection with regard to internal corrosion
BS 8000 “Workmanship on building sites”.
BS EN 12897:2006 “Water supply. Specification for indirectly heated unvented (closed) storage
water heaters”.
BS 7671:2008 “Requirements for electrical installations”.
BS 1566 “Copper indirect cylinders for domestic purposes”.
BS 4814:1990 “Specifications for expansion vessels using an internal diaphragm for sealed hot
water heating systems”.
BS 7074 “Application, selection and installation of expansion vessels and ancillary equipment
for sealed water systems”.
BS 5422:2009 “Methods of specifying thermal insulation materials on pipes, ductwork and
equipment in the temperature range of –40ºC to 700ºC”.
BS 5449:1990 “Specification of forced circulation hot water central heating systems for
domestic premises”.
BS 6701:2010 “Telecommunications equipment and telecommunications cabling”.
BS 5970:2001 “Code of practice for thermal insulation of pipes and equipment”.
BS 6700:2006 “ Specification and design, installation, testing and maintenance of services
supplying water for domestic uses within buildings and their curtilages”.
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122 | Domestic Building Services Compliance Guide: 2010 Edition
Section 12
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Lighting
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12.1 Scope of guidance
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This section provides guidance on the specification of fixed internal and external lighting
for new and existing dwellings to meet relevant energy efficiency requirements in building
regulations.
12.2 Key terms
Circuit-watt means the power consumed in lighting circuits by lamps and, where
applicable, their associated control gear (including transformers and drivers) and power
factor correction equipment.
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Light fitting means a fixed light or lighting unit that can comprise one or more lamps and
lampholders, control gear and an appropriate housing. The control gear may be integrated
in the lamp or located elsewhere in or near to the fixed light.
Fixed external lighting means lighting fixed to an external surface of the dwelling
supplied from the occupier’s electrical system. It excludes lighting in common areas of
blocks of flats and in other communal accessways.
12.3 Internal and external lighting
Fixed internal and external lighting should meet the minimum standards for efficacy and
controls in Table 40.
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Section 12 Lighting | 123
Table 40: Recommended minimum standards for fixed internal and external
lighting
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Lighting New and replacement systems
Fixed
internal
lighting
Supplementary information
a. In the areas affected by the building
Light fittings may be either:
work, provide low energy light
• dedicated fittings which will
fittings (fixed lights or lighting units)
have separate control gear and
that number not less than three per
will take only low energy lamps
four of all the light fittings in the
(e.g. pin based fluorescent or
main dwelling spaces of those areas
compact fluorescent lamps); or
(excluding infrequently accessed
• standard fittings supplied
with low energy lamps with
spaces used for storage, such as
cupboards and wardrobes).
integrated control gear (e.g.
b. Low energy light fittings should
bayonet or Edison screw base
have lamps with a luminous efficacy
compact fluorescent lamps).
greater than 45 lamp lumens per
Light fittings with GLS tungsten
circuit-watt and a total output
filament lamps or tungsten
halogen lamps would not meet the
greater than 400 lamp lumens.
c. Light fittings whose supplied
standard.
power is less than 5 circuit-watts are The Energy Saving Trust publication
excluded from the overall count of
GIL 20, “Low energy domestic
the total number of light fittings.
lighting”, gives guidance on
identifying suitable locations for
fixed energy efficient lighting.
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Fixed
Where fixed external lighting is
external installed, provide light fittings with the
lighting following characteristics:
a. Either:
i. lamp capacity not greater than
100 lamp-watts per light fitting;
and
ii. all lamps automatically controlled
so as to switch off after the
area lit by the fitting becomes
unoccupied; and
iii. all lamps automatically controlled
so as to switch off when daylight
is sufficient.
b. Or
i. lamp efficacy greater than 45
lumens per circuit-watt; and
ii. all lamps automatically controlled
so as to switch off when daylight
is sufficient; and
iii. light fittings controllable
manually by occupants.
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124 | Domestic Building Services Compliance Guide: 2010 Edition
Table 40: Recommended minimum standards for fixed internal and external
lighting (continued)
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British Standards
BS EN 15193:2007 “Energy performance of buildings – Energy requirements for lighting”.
Other related documents
CE80 “Domestic lighting innovations”, Energy Efficiency Best Practice in Housing.
CE61 “Energy efficient lighting – guidance for installers and specifiers”, Energy Saving
Trust.
EP84 “Housing for people with sight loss”, Thomas Pocklington Trust Design Guide.
IP412 “Making the most of your sight: Improve the lighting in your home”, RNIB and
Thomas Pocklington Trust.
Energy Saving Trust best practice standards
The Energy Saving Trust sets best practice “Energy Saving Recommended (ESR)” standards
for lamps that cover not only energy efficiency, but also other aspects of quality including
colour rendering, warm-up time, product life and power factor. It is advisable to install only
ESR low energy lamps in dwellings.
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Section 13 Micro-combined heat and power packages | 125
Section 13
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Micro-combined heat and
power
R
E
packages
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13.1 Scope ofN
guidance
O
This section provides guidance on the specification of micro-combined heat and power
(micro-CHP) packages for dwellings to meet relevant energy efficiency requirements in
building regulations.
The guidance covers micro-CHP systems with an electrical output less than 5 kWe
which are:
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N
13.2 Key terms LI
ON
•
heat-led
•
capable of exporting electricity to the grid, and
•
controlled in such a way as to avoid heat dumping.
Heating plant emission rate (HPER) is the annual CO2 emissions from fuel and power
consumed by the heating plant, offset by the emissions saved as a result of any electricity
generated by the heating plant, divided by the heat output over a year. It is measured in
units of kg of CO2 per kWh. To calculate HPER it is necessary to know the plant size ratio.
Note: The HPER includes any auxiliary space and water heating that may be necessary,
i.e. it represents the performance of all heating plant needed to provide space and water
heating service to the building, assuming a standard demand pattern.
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Plant size ratio (PSR) is defined as the nominal heat output of the heating plant
divided by the design heat loss (the average heat loss of the building on a cold day with a
temperature differential of 24.2oC). Note: For a given heat demand, the PSR determines
the part-load condition for the heating plant.
126 | Domestic Building Services Compliance Guide: 2010 Edition
13.3 Micro-CHP systems
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a. For new systems and replacement systems, the HPER of the micro-CHP
package (calculated as in c. below) should be no greater than the carbon
emission factor for the fuel divided by the minimum efficiency for a regular boiler
using that fuel, at the PSR determined as in b. below. The design heat loss of the
dwelling should be calculated using the Energy Saving Trust’s Whole house boiler
sizing method for houses and flats 10.
b. The PSR for the micro-CHP system when operating in the intended dwelling
should be calculated as defined in 13.2 above.
c. The HPER of the micro-CHP system should be calculated at the PSR determined
in c. above, using the methodology set out in DECC’s Annual Performance
Method (APM)11, and the performance data for the micro-CHP package
establied by testing according to BSI PAS 6712.
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Supplementary information
British Standards
BS EN 15316-4-4:2007 “Heating systems in buildings – method for calculation of system
energy requirements and system efficiencies – Heat generation systems, buildingintegrated cogeneration systems”.
Other documents
Appendix N of SAP 2009 “Method to evaluate the annual energy performance of
micro-cogeneration heating systems in dwellings”.
BSRIA BG 2/2007 “CHP for existing buildings: Guidance on design and installation”.
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10
Energy Saving Trust CE54 Whole house boiler sizing method for houses and flats. This is an interactive calculator available from the
Energy Saving Trust at www.energysavingtrust.org.uk/housingbuildings/publications. The design heat loss in kW is the basic design
heat loss in box U (from the 2010 edition).
11
Method to evaluate the annual energy performance of micro-cogeneration heating systems in dwellings (APM), SAP 2009 revision,
DECC. Available from www.bre.co.uk/sap2009.
12
BSI PAS 67: 2008 Laboratory tests to determine the heating and electrical performance of heat-led micro-cogeneration packages
primarily intended for heating dwellings.
Section 14 Heating system circulators | 127
Section 14
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Heating system circulators
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14.1 Scope of guidance
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This section provides guidance on the specification of stand-alone, glandless heating
system circulators to meet relevant energy efficiency requirements in building regulations.
The guidance does not apply to circulators supplied as integrated units within the casing
of boilers.
14.2 Circulators
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Heating system circulators provided as part of new systems or replacement systems in
dwellings should meet the minimum standards for energy efficiency in Table 41.
Table 41: Recommended minimum standards for stand-alone, glandless heating
system circulators
New and replacement systems
Supplementary information
a. Stand-alone glandless circulators should be
labelled for energy efficiency in accordance
with the Europump Labelling Scheme, and have
a rating in the range A to G.
Further information and
guidance, including a list of
approved glandless domestic
circulators, is available at
www.bpma.org.uk.
The EuP Directive will introduce
a requirement for all circulators
placed on the market from
January 2013 to have a minimum
Energy Efficiency Index (EEI),
initially equivalent to an A-rating
under the Europump Labelling
Scheme, and later equivalent
to an A* rating. To meet these
standards, over the next three to
five years the circulator industry
will have to switch from using
induction motors to permanent
magnet motors.
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