CIBSE TM44 Inspection of air conditioning systems 2012

CIBSE TM44 Inspection of air conditioning systems 2012
Inspection of air conditioning systems
CIBSE TM44: 2012
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© February 2012 (second edition) The Chartered Institution of Building Services
Engineers London
Registered charity number 278104
ISBN 978-1-906846-20-6
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Foreword
The Energy Performance of Buildings Directive (EPBD) was first adopted in 2002. The
recast Directive, adopted in May 2010, replaced the original Directive from 1 February
2012 and will be progressively implemented from January 2013. The Directive requires
Member States across Europe to put in place ‘measures to establish a regular inspection of
air conditioning systems of an effective rated output of more than 12 kW’. In the UK
separate legislation has been introduced in England and Wales, Scotland and Northern
Ireland that requires building owners or managers to undertake regular inspections of air
conditioning systems. The regulations and requirements relating to air conditioning
system inspections for England and Wales have now been in place for over three years, and
for a slightly shorter period for Northern Ireland and Scotland. The principle guidance for
the inspections is contained in CIBSE TM44: 2007.
CIBSE TM44 is used as the guidance for air conditioning inspections in the UK, the
Republic of Ireland, Malta and Gibraltar. The guidance is primarily intended to support
inspections which are carried out for compliance with the EPBD, but will also be useful to
anyone who wishes to assess the energy efficiency of an air conditioning system.
With the benefit of the experience gained over the past three years, and to clarify some of
the questions about air conditioning system inspections that have arisen over that period,
the TM has been revised. The revision also takes into account the reporting templates
produced by the Department for Communities and Local Government for the production
of reports in England and Wales. These templates will also form the basis for statutory
lodgement of air conditioning inspection reports, which will be required in England and
Wales as from 6th April 2012 under amendments to the Energy Performance of Buildings
Regulations 2007. The revision has also provided the opportunity to incorporate the
separate legislative requirements for Northern Ireland and Scotland in the main text of the
TM, rather than as separate addenda.
TM44 provides guidance on conducting an air conditioning inspection to satisfy the
requirements of the Directive as expressed in the various regulations in the UK. The focus
is on systems that use refrigerants to produce cooling. Some of the guidance may also be
applicable to elements of other forms of cooling systems, such as those that use pipes or
ducts built into the fabric of the building (e.g. cooled deck or ceiling slabs), or those which
use aquifers or local water sources to provide cooling solutions.
This TM does not address other statutory inspection requirements such as those required
for the purposes of preventing Legionella, including the associated test reports, or those
which cover any health and safety requirements for electrical installations and interlocks or
the provision of machinery guards on moving equipment. TM44 does not cover inspection
under the F-Gas Regulation and associated requirements. These requirements are all
outside the scope of the EPBD and of this TM.
Hywel Davies
Chairman, TM44 Working Group
Principal author
Roger Hitchin
TM44 Working Group
Simon Barnes (Sterling Accreditation)
Phil Beschizza (Department for Communities and Local Government)
Darren Bryant (Efficient Air Ltd.)
Mark Cousens (Department for Communities and Local Government)
Dr Hywel Davies (CIBSE) (Chairman)
Chris Dickson (EuroCool Ltd.)
Mike Duggan (Federation of Environmental Trade Associations)
Joe Glancy (Landmark)
Andy Hawes (Burgess Group)
Darren Jones (Low Carbon Europe LLP (Low Carbon UK))
Niraj Mistry (Stroma)
Dr Andy Pearson (Star Refrigeration and Institute of Refrigeration)
Carl Peat (Clouds Environmental Consultancy Ltd)
Michael Reeves (SummitSkills)
Catherine Simpson (Building Simulation Ltd./Quidos Ltd.)
Mike Smith (BSRIA)
Michael Tofts (NES Ltd.)
Bob Towse (Building & Engineering Services Association)
David Warriner (BRE)
Acknowledgements
The Institution acknowledges the contributions of Katherine Higley (Department for
Communities and Local Government), Jacob Andresen (Department for Food and Rural
Affairs) and Gerald Coulter (Department of Finance and Personnel (Northern Ireland)) to
the revision of TM44.
The Institution also acknowledges the contribution of Graham Manly OBE (Gratte
Brothers) in the production of the first edition of this guidance and to the members of the
working party for the first edition, including John Armstrong, Derrick Braham, Colin
Biggs, Geoffrey Brundrett, Paul DeCort, Terry Dix, Alan Green, Peter Grigg, Malcolm
Horlick, Steve Irving.
Production of this second edition of TM44 was supported by the CIBSE Research Fund.
Editor
Ken Butcher
CIBSE Technical Director
Hywel Davies
CIBSE Head of Knowledge
Nicolas Peake
Contents
1
2
3
4
5
Introduction
1
1.1
Purpose of air conditioning inspections
1
1.2
Purpose of this Technical Memorandum
1
1.3
Regulatory applications
2
1.4
Scope
2
1.5
Health and safety issues
3
The inspection process
4
2.1
Issues common to all systems
4
2.2
Packaged cooling systems: simple procedure
10
2.3
Centralised cooling systems: full procedure
13
Assessing system efficiency and sizing
21
3.1
Efficiency
21
3.2
Sizing
21
3.3
Assessment of ventilation performance
24
Factors relating to the provision of advice
24
4.1
Factors affecting air conditioning energy consumption
24
4.2
Cooling load reduction
25
4.3
Free cooling via condensers
26
4.4
Absorption cooling with CHP
26
Other sources of information
26
5.1
European standards
26
5.2
Empirical research results
26
5.3
European implementation lessons
27
References
27
Appendix A1: UK regulations for air conditioning systems
29
Appendix A2: Current accreditation arrangements for air conditioning
inspectors in the UK
30
Appendix A3: Explanatory notes for building owners and managers
30
1
Inspection of air conditioning systems
1
Introduction
1.1
Purpose of air conditioning
inspections
Air conditioning inspections are intended to identify ways
in which the energy consumption of existing air conditioning systems and associated costs may be reduced. They
differ from, for example, detailed energy audits by being
essentially non-invasive and from analysis of energy
consumption by being site-based. Experience shows that
they typically identify measures that can result in tangible
energy and running cost savings that require little or no
capital expenditure. However, these measures represent
only a small proportion of the savings that are technically
possible. Inspections can also confirm that some potential
sources of energy wastage are not actually present(1).
It should be recognised that other procedures beyond the
regulatory requirements, such as analysis of consumption
records or more detailed (and costly) inspections and
performance audits may identify additional savings
potential. Inspections may identify where these complementary procedures seem likely to identify further savings
and add value to an air conditioning inspection.
Inspection may be carried out at any time and for a variety
of purposes. It may, for example, be part of a routine
maintenance programme, though this might not include
every part of the guidance in this memorandum.
Throughout Europe there is a legal requirement for the
regular inspection of air conditioning systems with a
cooling capacity greater than 12 kW. In the UK this is
supported by regulatory structures that include the
accreditation of those who carry out inspections and the
quality assessment of inspections and inspection reports*.
Inspections only identify potential savings: achieving them
requires action by building managers and owners. It is
therefore important that inspection reports can be easily
understood by relatively non-technical readers and
expressed in terms that motivate relevant actions. It is
preferable for the results to be discussed with the owner or
manager. Before committing to major expenditure, building
owners should obtain more specific and detailed assessments
of likely savings and costs than are possible from an
inspection alone. Section 2.1.9 describes requirements for
* Within this document the words ‘must’ and ‘shall’ denote mandatory
requirements in England and Wales for inspections of air conditioning
under the Energy Performance of Buildings Directive(2,3) (EPBD). Where
the requirements differ in Scotland and Northern Ireland this is noted in
the text. They may not necessarily apply in other circumstances. Similarly,
rules on sampling, use of data collectors etc. are mandatory for EPBD
inspections in England and Wales but not necessarily for other inspections.
formal regulatory inspection reports. Section 2.1.10 gives
some guidance on the production of air conditioning
inspection reports that contain useful information for
building managers using appropriate non-technical
language.
1.2
Purpose of this Technical
Memorandum
This Technical Memorandum provides guidance on good
practice for inspection procedures. This guidance constitutes an approved inspection methodology for compliance
with regulatory inspections within the jurisdictions in the
UK. To be acceptable for regulatory purposes, compliance
with further specific requirements produced by the
responsible Departments in one or other of the
administrative areas of the UK may also be necessary. For
example, in England and Wales, inspectors must be
accredited and inspection reports must from 6 April 2012
be produced in specific formats using software that can
lodge the report in the specified format on the register of
energy certificates and air conditioning inspection reports.
The procedures described can be carried out largely
through visual observations of the plant and other visual
indicators such as refrigerant sight glasses and pressure,
temperature or filter gauges. Certain procedures require the
removal of access covers, the temporary isolation of
equipment, and the taking of test readings†. This shall only
be carried out when it is safe to do so, and with the building
manager’s permission. This approach distinguishes
‘inspection’ from, for example, technical performance
audits that typically require more intrusive investigation,
and from equipment servicing and maintenance activities.
An inspection may also identify aspects of performance
that are not directly energy-related, such as equipment
noise levels. All these possible outcomes are secondary and
are not the focus of the procedures described in this
memorandum.
Since the publication of the original version of TM44,
procedures for statutory lodgement of inspection reports
have been introduced in England and Wales, which come
into force on 6th April 2012. This edition of the TM reflects
these new requirements and also the experience gained by
inspectors and accreditation schemes more widely.
† Be aware that, for equipment using fluorinated gases like HFCs or ozone
depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect
measuring methods’) may be defined as leak checking for the purposes of
the F-Gas or Ozone Regulations and therefore subject to the requirement
of being appropriately certificated in accordance with these Regulations.
2
Inspection of air conditioning systems
1.3
Regulatory applications
1.3.1
Energy Performance of Buildings
Directive
The Energy Performance of Buildings Directive* (EPBD)
requires that across Europe
…Member States shall lay down the necessary measures to
establish a regular inspection of the accessible parts of air
conditioning systems of an effective rated output of more than
12 kW. The inspection shall include an assessment of the airconditioning efficiency and the sizing compared to the cooling
requirements of the building.
This requirement is implemented by separate legislation in
England and Wales, Scotland and Northern Ireland. For
details of the various regulations, see Appendix A.
Other EU member states including the Republic of Ireland
have similar inspection requirements, generally based on
European standard BS EN 15240: 2007: Ventilation for
buildings. Energy performance of buildings. Guidelines for
inspection of air-conditioning systems(4). Procedures in Malta
follow TM44.
Inspections must be undertaken by suitably qualified and
accredited persons, referred to in this document as
‘inspectors’. In England, Wales and Northern Ireland, they
are formally ‘Air Conditioning Energy Assessors’, accredited
by a scheme approved by the Department for Communities
and Local Government (DCLG). In Scotland assessors
must be members of an organisation with a protocol
agreement with the Scottish Government. For lists of
currently accredited schemes for air conditioning inspections, see Appendix A2.
The detailed advice contained in this TM specifically
describes the requirements of DCLG in England and Wales
(E&W). There are some differences in the regulatory
requirements in Scotland and Northern Ireland (NI). For
example, in E&W and NI, air conditioning inspection
reports must be produced at regular intervals not exceeding
five years, but in Scotland inspectors may require systems
that are assessed as being poorly maintained and inefficient
to be re-inspected as soon as three years after the initial
inspection (see section 2.1.9.1).
The quality assurance procedures operated by accreditation
schemes for air conditioning inspections will have to
become more structured and formal in response to the latest
changes to the Regulations and proposed Scheme Operating
Requirements in England and Wales. It is therefore
particularly important for regulatory inspections in
England and Wales to follow the guidance contained in this
TM.
1.3.2
Other inspection requirements
Since July 2007, EU Regulation 842/2006 on certain
fluorinated greenhouse gases, the ‘F-Gas Regulation’(5), has
required regular testing for leakage of fluorinated
greenhouse gas refrigerant from some systems. Refrigeration
systems containing CFC or HCFC refrigerants may already be
subject to regular leakage testing under Regulation (EC)
1005/2009 on substances that deplete the ozone layer (the
‘Ozone Regulation’(6)). Both the F-Gas Regulation and the
Ozone Regulation establish record keeping obligations for
certain air conditioning systems. An assessment to comply
with the EPB Regulations (or equivalents in Scotland and
Northern Ireland) may be combined with a leakage check
under the F-Gas and/or Ozone Regulations, so long as the
inspection addresses the minimum requirements of the
relevant frameworks as well as the EPB Regulations. Those
carrying out the inspections must comply with the relevant
regulatory certification requirements, and satisfy the
separate reporting requirements of each of the relevant
regulations†.
Some air conditioning installations fall under the scope of
the Pressure Systems Safety Regulations 2000(9), which
may apply to systems with an input power in excess of
25 kW.
In these cases it may be appropriate to combine visits or
inspections for these various purposes as long as the person
(or persons) undertaking the work are suitably qualified to
perform all the functions under each requirement.
1.4
Scope
This TM gives guidance on practical inspection procedures
for air conditioning systems, and broad guidance on how to
assess efficiency and sizing of the air conditioning system
compared to the cooling requirements of the building. It
does not give guidance on how to assess overall system
efficiency in absolute terms. The procedures described
focus on assessing how well a system is maintained,
controlled and operated, and whether it is fit for purpose.
† Fluorinated greenhouse gases (F-gases) are among the Kyoto Protocol
group of gases for which the EU has committed itself to reduce emissions.
EC Regulation 842/2006(5) on certain fluorinated greenhouse gases (the
F-Gas Regulation) is the legal instrument by which emissions reductions
are to be delivered. The framework set out by the Regulation and its
supplemental European Commission Regulations is underpinned in Great
Britain by the Fluorinated Greenhouse Gases Regulations 2009 (SI
2009/261)(7). Northern Ireland has similar domestic Regulations.
The aim of the F-gas regulatory framework is to minimise emissions
mainly through leak prevention and repair. Specific provisions include
leak checking obligations and the requirement that personnel and
companies must be appropriately certificated if they undertake work on
equipment such as air conditioning and plant containing HFCs, HCFCs or
CFCs. Air conditioning inspectors are not accredited under these
regulations.
Air conditioning systems are subject to other regulatory
inspection requirements, as follows.
EC Regulation 1005/2009(6) on ozone depleting substances also sets out
similar certification and leak checking requirements. It has been fully
implemented in Great Britain by the Ozone Depleting Substances
(Qualifications) Regulations 2009 (SI 2009/216)(8). Northern Ireland has
similar domestic regulations.
* A ‘recast’ of the Energy Performance of Buildings Directive, Directive
2010/31/EU(3) has been adopted, and requires that ‘Member States shall
adopt and publish, by 9 July 2012 at the latest, the laws, regulations and
administrative provisions necessary to comply with [the Directive]’.
Full details of all of the obligations can be found on the web pages and
information sheets of F-Gas Support, a government sponsored unit that
provides guidance to organisations and individuals affected by the
framework (http://www.defra.gov.uk/environment/quality/air/fgas)
Inspection of air conditioning systems
This TM also discusses the advice that is to be provided to
building owners and managers on possible improvement or
replacement of the air conditioning system.
Various definitions of the meaning of the term ‘air
conditioning’ exist in standards and regulatory and other
documents. In this document the term ‘air conditioning
system’ is used to represent both fixed self-contained
systems, such as split systems, and centralised systems. The
latter includes any water, air or other fluid distribution,
exhaust, heat recovery and humidification systems that
form part of the system. The term also includes the controls
that regulate systems. Mechanical ventilation systems that
provide no mechanical cooling themselves, but serve spaces
that are cooled by other mechanical means are included.
Any components contained in the systems that are only
intended to provide heating are excluded. The inspection
process described in this document is intended to include
all types of ‘comfort cooling’, i.e. cooling that is primarily
for the comfort of human occupants. However, the guidance
is generally appropriate for the inspection of air conditioning
systems for other purposes, such as server rooms. In the
case of systems that provide air conditioning for both
process and comfort purposes, it covers those parts of the
system that contribute to the comfort cooling. The guidance
is not intended to cover dedicated process cooling systems
or air conditioning of spaces where the principal purpose of
the air conditioning is not to provide comfort cooling, such
as those that serve chilled distribution warehouses or
production and manufacturing facilities.
Article 15 of the EPBD(3) applies to systems with a cooling
capacity of more than 12 kW, here taken to mean the
specified output under standard test conditions. In the UK
the term ‘system’ also includes groups of units that are
individually of less than 12 kW cooling capacity but have a
combined cooling capacity greater than 12 kW. For regulatory purposes the cooling capacity of an air conditioning
system is defined as ‘the sum of all individual cooling units
under the control of one building owner or operator’*.
1.5
Health and safety issues
Inspectors have a duty to comply with relevant health and
safety legislation including making a risk assessment of the
work. This includes a duty to draw the building owner or
manager’s attention to obvious instances of inadequate
maintenance or neglect, where these might have implications for the health and safety of building occupants or
the public. This document cannot list potential instances
but inspectors should be familiar with current guidance
concerning the health and safety implications of owning
and maintaining air conditioning systems, and shall ensure
that adequate precautions and maintenance practices are in
place to minimise such risks. The inspection report should
stress the aim of the inspection is to address energy issues,
but should also draw the attention of the owner or manager
to any such issues or concerns.
In particular, the assessor should be alert to Legionella risks
from standing water within equipment. HSE Approved
* The EPB Regulations define an air conditioning system as ‘a combination
of all the components required to provide a form of air treatment in which
the temperature is controlled or can be lowered, and includes systems
which combine such air treatment with the control of ventilation,
humidity and air cleanliness.’
3
Code of Practice and Guidance L8: Legionnaires disease —
The control of legionella in water systems(10) sets out detailed
guidance on risk assessment and control and on appropriate
maintenance requirements in cooling systems which pose a
risk of Legionella.
Assessors shall request copies of any reports on Legionella
related matters for cooling towers or evaporative coolers
report, which will focus on risks associated with Legionella
and and review these to check that any highlighted issues
or recommendations have been addressed. Cleaning and
disinfection records and logbooks shall be examined to
confirm that an appropriate risk assessment has been
carried out, an effective management strategy is in place for
controlling risks and that the required cleaning and dosing
regime is adhered to rigorously. These checks are important
for the safety of the assessor, who needs to ensure that the
inspection is carried out safely and does not place either the
assessor or any accompanying persons at risk. Where
practical, the cooling tower should be observed when
running in order to make a visual assessment of the overall
standard of care and maintenance. Issues that might raise
concern involving cooling towers would include:
—
leaks from the cooling tower
—
exterior damage to cladding
—
gaps in side screening or pond side walls
—
unscreened ponds
—
evidence of mould or moss growth
—
damaged drift eliminators
—
areas of rust which can be a source of food for
Legionella.
Issues that might raise concern involving air handling
units would include:
—
standing water in condensate trays
—
blocked condensate drains.
Further guidance on controlling Legionella can be found in
CIBSE TM13(11).
Some of the required tasks (e.g. examining inside air
handling units (AHUs) or ducts) are likely to need to be
undertaken outside normal working hours. They shall be
carried out in collaboration with the building owner or
manager, and be subject to a proper risk assessment. Some
observations, such as the use of a smoke pencil to observe
airflows, may need the formal approval of the owner or
manager and, if considered necessary, isolation of any fire
detection systems. A method statement shall be provided
for the owner or manager to agree prior to the inspection
taking place. This should explicitly agree co-operation in
providing safe access to equipment as needed, at a mutually
convenient time, and approve the use of such simple, nonhazardous, techniques.
4
Inspection of air conditioning systems
2
The inspection process
2.1
Issues common to all systems
Specific guidance on inspection procedures for each of
these levels is given later in this document. Section 2
addresses issues that are common to both.
The inspection process can be divided into several stages:
2.1.1
General issues
—
collection of basic information, preferably before
visiting site.
Two forms of inspection procedure are described in this
document:
—
on-site system inspection
—
—
Reporting to the responsible person and providing
them with a hard copy of the final report.
—
Simple procedure: this may be used where systems do
not use chilled water for cooling distribution or
cooling coils and are not associated with a
centralised mechanical ventilation system. This
includes variable refrigerant flow (VRF) systems
that are not used in conjunction with centralised
mechanical ventilation systems.
Full procedure: for all other situations. These are
typically centralised systems that make use of plant
rooms, air handlers, and more complex controls.
The following situations are examples of situations where
the full procedure shall be used:
—
buildings that contain a series of rooms with
individual room air conditioners, where the rooms
are ventilated by a centralised mechanical
ventilation system that include a heating coil
(irrespective of whether the ventilation system
includes a cooling coil)
—
packaged rooftop units
—
water-loop heat pump systems (or those for other
fluids).
This distinction corresponds to levels of accreditation of
inspectors in England and Wales and in Northern Ireland,
where the full procedure may only be carried out by
inspectors with level 4 accreditation if the inspection is for
regulatory purposes.
From time to time unconventional systems may be
encountered, such as adsorption or desiccant systems.
These are unlikely to be suitable for inspection by the
simple procedure and may have features that are outside
the experience of some level 4 inspectors.
If a level 3 inspector is uncertain whether a system is a level
3 system, he/she shall advise the building manager that a
suitably experienced level 4 inspector is required.
Figure 1.1 illustrates the types of components likely to be
included in each type of system, to help decide which form
of inspection would be appropriate.
For EPBD inspections, in all cases, an accredited air
conditioning inspector shall be on site on the date of the
inspection for an appropriate period and shall visit and
inspect the property to ensure that data can be verified and
that the inspection report is accurate and the recommendations are appropriate.
The on-site inspection time will depend on the extent and
complexity of the system, typically ranging from 0.5 days
for a simple system to 3 days or more for larger complex
systems. Additional time will be required to assess preinspection information. If this is not readily available,
significant additional time will be needed to compile it.
2.1.2
Collection of basic information
The quality, extent and accessibility of relevant information
provided before an inspector visits an installation has
important consequences for the effectiveness and cost of an
inspection. Experience has shown that this information is
often missing and that inspectors need to spend time trying
to locate it. This is not an effective use of time spent on site
and without the information it is very difficult to estimate
the cost of an inspection properly.
The information can be divided into three categories:
—
That which defines the scope, size and layout of the
system(s) to be inspected. Much of this can be
obtained on-site (perhaps more reliably than from
design records), including BMS schematics for larger
systems. However, some elements of a system may
not be readily accessible and some information,
such as AHU duties, may not be easy to determine on
site.
—
That which provides information that can guide an
inspection. This could include records of maintenance or occupant complaints.
—
That which provides complementary information,
but which is not strictly necessary for an inspection.
Analysis of consumption records, for example, can
highlight areas of concern.
The inspector shall ask the building owner or his/her agent
for a list of relevant records, sight of the principal ones
before visiting site, and for site records to be made readily
available. In particular, the following information shall be
sought.
In some buildings, but by no means all, there should be
useful records of the air conditioning equipment installed,
its maintenance, and its energy consumption. In more
recent buildings these should be found in a building log
book, following the guidance contained in the documents
supporting Building Regulations and Standards. Most
larger buildings should have details, including commissioning results, included in building log books, operation and
maintenance (O&M) manuals and health and safety (H&S)
files. Records of maintenance may be held separately.
However in many buildings written records may be
incomplete or missing.
The minimum information required for the inspection is
listed in section 2.2 for packaged cooling systems and
section 2.3 for centralised cooling systems. The building
owner or manager shall be advised to make such information
available at the time of the inspection.
Inspection of air conditioning systems
Assessment
type
Delivery
terminals
5
System type
Air handling
Refrigeration
equipment
Heat rejection
equipment
Unitary packaged (’through the wall’) units — indoor and outdoor equipment housed in single casing
Simple
level 3
packaged
cooling
systems
Indoor
units/cassettes
Single split
packaged
Outdoor unit to single indoor unit
Multi-split
packaged
Outdoor unit to multiple indoor units
Variable refrigerant
flow (VRF) not
linked to an AHU
Outdoor unit to multiple indoor units
via manifold
Multiple
linked (VRF) not
linked to an AHU
Any air conditioning system serving any space that is also served by a mechanical air supply system is a level 4 complex system.
Assessment
type
Delivery
terminals
System type
Air handling
Refrigeration
equipment
Heat rejection
equipment
Grilles, slots,
diffusers
Distributed
cooled air only
AHU plus
refrigerant-to-air
heat exchanger
Refrigeration
plant delivering
chilled refrigerant
Air cooled
condenser
Distributed
cooled air with
terminal cooling
AHU plus
water-to-air
heat exchanger
Refrigeration
plant delivering
chilled water
Dry air cooler,
cooling tower or
adiabatic cooler
VAV boxes
Complex
level 4
centralised
systems
Induction units
Fan coil units
Chilled ceilings
and beams
Distributed
chilled water to
terminals only
Packaged air cooled chiller supplying
cold water
No cooling
in AHU
Room heat
pump
Temperate water
loop to local
reversible heat pump
(or other fluid)
Air handling unit (AHU): an assembly consisting of
sections containing a fan or fans and other necessary
equipment to perform one or more of the following
functions: air circulation, filtration, heating, cooling,
heat recovery, humidifying, dehumidifying and mixing
of air, and necessary controls functions.
Mechanical air supply: the process of supplying air
with the aid of powered air movement components,
usually fans.
Figure 1.1 Summary of system types and their component parts
6
Inspection of air conditioning systems
Having gathered together the information, building owners
should retain and update it, together with the inspection
report, for use in subsequent inspections
2.1.3
Access for Inspection
There are a number of reasons why access to equipment
may not be practicable. The inspector shall make all
reasonable attempts to obtain access, subject to health and
safety requirements. If access proves to be impossible this
shall be noted in the report with an explanation of the
reasons for lack of access (with evidence such as photographs
where possible) and recommendations qualified accordingly. Where the lack of access is significant or extensive, a
written confirmation from the client shall be sought.
2.1.4
Out-of-season inspection
It may be necessary to inspect a system during periods
when it not in operation. If it is possible and safe to do so,
plant shall be brought into operation on a temporary basis.
If this is not possible, the inspector shall note this in his
report and qualify recommendations accordingly, noting
that a revisit at a more suitable time is desirable.
2.1.5
2.1.5.2
Packaged systems
Where an installed system consists of a series of packaged
cooling plant components, then a 10% sample of the total
number of outdoor units must be inspected, with a
minimum of three units being sampled. In addition, an
equal number of indoor units must be inspected. Indoor
units for packaged systems may include fan coil units and
cassettes. Water loop heat pumps are to be treated as
terminals of centralised systems, as shown in Figure 1.1.
2.1.5.3
Terminal units for centralised systems
A 2% sample of the total number of terminal units must be
inspected, with a minimum of five units. For very large
systems where consistent conditions are found a maximum
of 20 units may be applied.
Sampling
The primary purpose of the air conditioning inspection is
to assess the relative energy efficiency of the installation,
and to identify where there may be scope for energy savings.
For larger installations it is not cost effective to inspect
every component, and so in these cases it may be appropriate
to inspect a sample number of components of certain types.
The following rules apply to the preparation of any
sampling programme for any air conditioning installation.
2.1.5.1
number is the greater, shall be inspected. If there are fewer
than ten units then they shall all be inspected. The
requirement also applies to any central air handling plant
which does not directly deliver cooling but which is a part
of a system which is capable of delivering cooling. Wherever
possible, the air volume and set points shall be determined
for all air handling units, and sampling is not permitted.
Central plant
All central chiller plant shall be inspected. For central air
handling plant a minimum of ten units or 30%, whichever
Terminal units for centralised systems may include VAV
terminals, fan coil units or chilled beams, local heat
recovery and ventilation units. Water-loop heat pumps
(‘Versatemp’-type systems) are subject to the same sampling
rules as terminals
An inspector must take a representative sample of the
installation on site, having regard to the age and size/
capacity of the components. While the minimum number
of components must always be inspected, an inspector may
choose to include a larger sample to improve the quality of
the air conditioning inspection report being provided.
If different makes of units are present on site then at least
one of each make must be inspected.
Energy consumption metering
Additional insight into system operation, beyond that from
a basic inspection may be obtained from input meters or
hours run meters that may have been installed to air
conditioning systems, particularly to larger individual items
of plant. For more recent buildings, this may have been
carried out to comply with the relevant Building Regulations
and Standards.
Where energy consumption has been recorded on a regular
annual basis it may be possible to deduce, from the rated
input power and the annual consumption record, whether
equipment has been in use for excessively long periods.
Where more frequent records are available these may allow
the onset and end of the ‘cooling season’ to be identified
and compared with expectation. Such simple checks may
help to identify whether controls are adequate and have
been used appropriately. More detailed energy analysis may
have been carried out by the energy manager or by specialist
consultants.
Where meters are installed, but no consumption records are
available, the owner or manager should be advised to take
and record meter readings on a regular basis. The inspection
process should include taking and recording any relevant
meter readings, together with the time and date of the
reading. This information should be provided to the building
owner or manager, to be kept available for the next
inspection.
Where no such metering is in place, a part of the advice
provided to the building owner or manager would be to
review the scope to install appropriate metering at least to
the more significant energy consuming air conditioning
plant, and subsequently to record the consumption on a
regular basis.
Regularly noting the readings of such meters can help assess
the operation of the air conditioning system, and could also
be helpful to the wider process of assessment needed to
provide an energy certificate. CIBSE TM31: Building log book
toolkit(13), CIBSE Guide F: Energy efficiency in buildings(14),
and CIBSE TM22: Energy assessment and reporting
method(15) include guidance on recording meter readings,
and on their interpretation. CIBSE TM39: Building energy
metering(16) provides guidance on developing a metering
plan.
Inspection of air conditioning systems
If observations of any unit type are found to be inconclusive
(where the inspection has identified a problem or area of
concern) then further units must be sampled where more
units of that type are available.
These sampling rules should ensure that a reasonable
minimum number of plant items are inspected. The
sampling required for larger items of plant is more stringent,
reflecting the fact that these items of plant will demand a
greater proportion of the energy used and are also more
likely to contain more refrigerant, depending upon the
nature of the equipment.
7
(d)
Evidence of supervision: the accredited air conditioning assessor must provide evidence of supervision
of the process. One way of demonstrating this
would be to use BS EN ISO 9001(17) procedures.
(e)
The suitability of any data gatherers used:
The inspector must confirm the sampling size chosen, the
reasons for selecting that sample size and that a
representative inspection has been carried out. A clear
record of the sampling applied and the justification for any
selections shall be prepared by the inspector and will be
used in an audit of their work. Where a sample inspection
has been carried out this must be recorded in the air
conditioning inspection report certificate.
2.1.6
Data gatherers are people who have a contractual
relationship with an accredited air conditioning assessor,
or the company employing the assessor, to provide
professional assistance to an assessor in gathering the
information needed to carry out an energy assessment of a
building for the purpose of issuing an air conditioning
inspection report.
The use of data gatherers working under the supervision of
an accredited air conditioning assessor enables the assessor
to produce the reports for larger and sometimes more
complex buildings and portfolios of buildings. It is
important that this procedure does not adversely affect the
quality of the report and the assessor needs to be in a
position to verify the data and to supervise how and by
whom it is collected.
The following conditions must be met:
(b)
(c)
The air conditioning assessor is responsible
for ensuring that any data gatherers used
are ‘fit and proper’ and suitably qualified to
at least level 3 (simple packaged air
conditioning system assessor) or through
membership of a recognised professional
body. The accredited air conditioning
assessor must be able to provide evidence to
support a data gatherer’s suitability to do
the work.
—
The air conditioning assessor must be able
to demonstrate that the contractual arrangement with the data gatherer allows for
sufficient supervision and quality control
by the assessor. Employment of data
gatherers by the same company as the air
conditioning assessor would be one way of
demonstrating this.
Data gatherers
An inspector may delegate tasks to data gatherers subject to
the conditions below, but remains responsible for the
accuracy of information thus collected.
(a)
—
Visiting the property: the air conditioning assessor
must inspect all properties for which he/she issues
an air conditioning report to ensure he/she can
verify any data provided and be sure that it is
appropriate for the building before the air conditioning report is submitted. This also enables the
air conditioning assessor to collect documents not
forthcoming from the client prior to the site
inspection.
Assistance: the accredited air conditioning assessor
may use data gatherers for level 3 or level 4 systems,
who are suitably competent to carry out data
collection, providing that the data gatherer is under
the supervision of the assessor. It is the assessor’s
responsibility to be present on site sufficiently to
ensure this.
Recording of data gatherers and data sources used: the
air conditioning assessor must record all the data
gatherers used and the provenance of all data that
has been used to produce the report.
Remote lodgement business models in which an accredited
inspector lodges a report that has been produced from data
that has not been collected or verified in the manner
described above by the accredited inspector are not
acceptable, since the accredited inspector is unable to fully
supervise the data gatherer to verify the data and how it was
collected.
2.1.7
Recommended naming convention*
The following methodology is to define an identification
reference of an air conditioning system that is standard,
consistent, and easily recognisable for all inspections.
2.1.7.1
Volume identifier (VOL)
The client is often not technical and identifies departments
by function. This is replicated in the ‘volume identifier’
(VOL ID). For example, in many old hospitals the
outpatients department is spread over a number of areas in
a number of buildings. Similarly, an office block may have
different departments on different floors.
The VOL ID enables energy assessors (EAs) to replicate this
logical group of air conditioning equipment by function, or
location within a building, or a group of equipment spread
across multiple buildings.
Each volume will be assigned a VOL ID in the form
VOL001, VOL002 ... VOLnnn
Examples:
—
VOL001: Outpatients
—
VOL002: Dermatology
—
VOL003: Optics
* The text of this section of TM44 is identical to that of the first issue of
the DCLG conventions document issued on 1st August 2011, which all
assessors in England and Wales are required to follow on inspections
carried out in England and Wales.
8
Inspection of air conditioning systems
—
VOL001: Gresham Building
—
VOL002: Turner Building
—
VOL003: Eastern Building
2.1.7.2
System identifier (SYS)
The ‘system identifier’ (SYS ID) identifies an air
conditioning subsystem. This SYS ID will contain all the
components that are within the air conditioning subsystem.
This will assist the EA to identify components that may be
affected by suggested changes to components within a
subsystem.
For example, if two packaged split units are serving the
same room, the performance of one will affect the
performance of the other in that if one were switched off,
the remaining unit would have to serve a higher load. In
this case the two independent split systems would be
described as being in the same air conditioning subsystem
and would both have the same SYS ID, even if their controls
are not linked.
If the same two packaged split units are serving two separate
rooms, the performance of one will not affect the performance of the other. In this case the two independent split
units would be described as being in different air conditioning subsystems and would have a different SYS IDs.
A common arrangement is to have a selection of packaged
split units and a centralised air conditioning system. The
split units could be grouped as one system or itemised
individually, and the centralised system would be regarded
as one system — the EA can decide what an appropriate
representation would be.
Each system will be assigned a SYS ID in the form SYS001,
SYS002, ... SYSnnn
Example:
—
—
SYS001: two split packaged units in canteen;
openable windows (no AHU)
—
SYS002: one split packaged unit in ground floor
reception plus air supply from AHU1
—
SYS003: twenty-four VRF packaged units serving
200 bedrooms plus air supply from AHU2 (heating
only).
Components
The components of an air conditioning system are those
items on which there is a series of questions in the Air
Conditioning Inspection Report:
—
Cooling plant: cooling plant
—
Air handling plant: air handling units
—
Terminal units: grilles, diffusers, fan coils, VAV boxes
etc.
—
Controls: control for chillers, AHUs and terminal units.
If there are three air handling units in system 1 (SYS001)
they can be referenced as AHU1, AHU2 and AHU3. If
there is a second system with air handling units they can be
referenced as AHU1, AHU2 and AHU3, or AHU4, AHU5
and AHU6 — the EA can decide. Each air conditioning
VOL002/SYS121/AHU14
Further examples are available in Appendix 1 to the first
issue of Air Conditioning System Conventions: AC CL 1.5
Appendix 1(18), which is issued to all accredited assessor by
the accreditation schemes.
2.1.8
Recognition of existing inspection
and maintenance regimes
Where there is clear documentary and physical evidence
that a good practice programme of inspection and
maintenance is in place and is being carried out, then
certain aspects of the inspection could be simplified or
reduced. In particular those aspects concerned with
observing filter or heat exchanger blockage should be
addressed adequately by good practice maintenance.
However, even though such maintenance should include
observations to test for refrigerant leakage, the relevant
observations described here shall be recorded as leakage
may begin at any time and the inspection provides an
additional opportunity for its early identification. In any
case visual signs of refrigerant leakage shall be noted and, if
present, evidence of attention to any leakage sought. If this
has not been attended to, then recommend prompt
maintenance by an appropriately qualified person.
(Appropriate qualifications for work on equipment using
HFCs must meet the minimum requirements of the F-Gas
Regulations(5); for equipment using HCFCs or CFCs they
must meet the minimum requirements of the EU Ozone
Regulation(6)*.)
2.1.9
Examples:
2.1.7.3
component has a unique reference by a combination of the
VOL/SYS/Component ID.
Formal reporting of air conditioning
inspections
A report of the air conditioning inspection shall be prepared
and signed by the inspector and given to the responsible
person†. It is important that the report contains
recommendations that a building manager can readily
understand and that the benefits of implementing them are
clearly explained using non-technical terms.
For all inspections, the reasoning and information leading
to recommendations shall be clear to those reading the
inspection report and also for quality assurance procedures.
Clear record-keeping, including photographs shall be
included in the supporting information for inspection
reports. Where sampling has been used, there shall be clear
identification of units sampled
* Be aware that, for equipment using fluorinated gases like HFCs or ozone
depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect
measuring methods’) may be defined as leak checking for the purposes of
the F-Gas or Ozone Regulations and therefore subject to the requirement
of being appropriately certificated in accordance with these Regulations.
† The term ‘responsible person’ is defined in the relevant regulations. For
inspections to comply with the Regulations in England and Wales as from
6th April 2012, the report must be lodged with an accreditation scheme of
which the inspector is a full member, using a standard template and
associated software.
Inspection of air conditioning systems
This shall include at least the following details.
Details of the property and the inspector:
9
The following shall be considered when setting an
inspection frequency of less than five years:
(a)
inefficiency of system
—
the address, name, or other unique identifier of the
property
(b)
significantly oversized in relation to the cooling
requirements
—
the name of the owner or manager of the building
(c)
evidence that the design is not fit for purpose
—
the inspector’s name, affiliation, and status (e.g.
‘approved by [name of accreditation body]’)
(d)
evidence of poor installation
—
the date of the inspection.
(e)
evidence of lack of maintenance
(f)
control system out of adjustment
(g)
age of system.
Details of the systems inspected including sampling:
—
—
physical descriptions of the systems inspected,
including the type of system (e.g. unitary, split,
multi-split)
an inventory of equipment inspected, including
makes, models and serial numbers (if readily
accessible) and their ratings, the locations of the
outdoor equipment and the areas served (including
the locations of indoor equipment).
Details of the results of the inspection:
—
the results of any measurements or calculations
reviewed or made for the inspection
—
comments on the likely efficiency of the installation
and any suggestions made for improvement
—
comments on any faults identified during the
inspection and suggested actions
—
comments on the adequacy of equipment maintenance and any suggestions made for improvement
—
comments on the adequacy of installed controls and
control settings and any suggestions made for
improvement
—
comments on the size of the installed system in
relation to the cooling load and any suggestions for
improvement
—
comments concerning alternative solutions
—
summary of the findings and recommendations of
the inspection.
2.1.10
A hard copy of the inspection report should be provided to
the person who commissioned the report, who may be
referred to under certain regulations as ‘the responsible
person’, and is likely to be the building owner or manager.
The formal reporting requirements for EPBD inspections
are described in section 2.2.3.5.
2.1.10.1
sources of good practice publications on the ownership and efficient operation of air conditioning
systems
—
sources of funding that might support further
investigations and improvements in efficiency.
2.1.9.1
The inspector should review his/her findings and form an
opinion on the appropriate recommendations. It is
important that these recommendations and any associated
benefits such as any potential energy and cost savings are
expressed in terms of actions that the building manager can
readily understand.
It is important to remember that the building manager may
not be familiar with the technical jargon or the technicalities
of air conditioning systems. Therefore, it is important that
the report is written with a lay reader in mind. The advice
given in the report shall be clear and concise.
Two simple examples would be:
‘It would be useful to have a notice in each room served by the
packaged cooling subsystems reminding occupants to close the
windows when cooling is on. This will reduce the cooling load
and save energy. This measure could be implemented now in
order to achieve immediate energy savings.’
or
‘It would be useful to have a lower heating set-point and a higher
cooling set-point. [The inspector should suggest suitable setpoints.] This will save energy by enabling the heating and cooling
systems to operate for a shorter period of time and at a lower
output. This measure could be implemented via the BMS now in
order to achieve immediate energy savings”
Date of next inspection
The report should include the date by which the next
inspection should be carried out.
In England, Wales and Northern Ireland, the next inspection must be carried out within five years.
In Scotland, the inspector has discretion to set the frequency
of subsequent inspection at between three years for poorly
maintained and inefficient systems and five years for those
systems that are well maintained and demonstrate excellent
levels of efficiency.
Presentation
The objective of the inspection is to advise the building
manager on how the energy consumption of the air
conditioning (AC) subsystems could be reduced now and
possibly in the future.
Additional advice:
—
Reporting to the owner, building
manager or responsible person
2.1.10.2
Content
When writing the report, it is useful to consider each
subsystem in terms of the following aspects:
—
AC
AC subsystem efficiency: Consider ways in which the
technical efficiency of the existing AC subsystem
10
Inspection of air conditioning systems
could be improved in order to reduce energy
consumption. Consider whether airflow rates could
be reduced.
—
—
—
—
—
Impact of maintenance on energy consumption: Consider
what aspects of maintenance could be improved and
how they could benefit the building owner. Where it
is lacking, the adoption of a schedule of good
practice inspection and maintenance shall be
recommended. This may involve more frequent
routine inspection than is required to satisfy the
requirements of the EPB Regulations(19), as part of
an industry good practice maintenance regime.
contains the refrigerant compressor, a refrigerant-tooutdoor air heat exchange coil (the condenser where heat is
removed from the refrigerant) and a condenser cooling fan.
Packaged heat pumps have an indoor unit (or evaporator)
that contains a refrigerant-to-air heat exchange coil (the
evaporator) and a room air circulation fan. The indoor and
outdoor units can be integrated into one item of equipment
or exist as separate items of equipment connected by
refrigerant pipework. These systems are usually described
as follows:
—
Impact of controls on energy consumption: Consider
whether set-points could be adjusted and whether
there is any potential conflict between set-points,
particularly when heat recovery is present or where
heating and cooling could operate simultaneously.
Unitary packaged units: the indoor and outdoor units
are both contained in a self-contained ‘unitary’
housing, often installed as a ‘through the wall’ unit.
The unit may be reversible allowing operation as a
heat pump or electric resistance heating may be
included.
—
Impact of the how the AC subsystem is managed:
Consider whether energy consumption could be
improved if staff had a greater understanding of
how to control and operate the AC subsystems or
perhaps set-points could be modified without
affecting occupant comfort.
Split packaged units: a single indoor unit is connected
by refrigerant pipework to a single outdoor unit.
The indoor unit may be floor, wall or ceiling
mounted. The unit may be reversible allowing
operation as a heat pump, or electric resistance
heating may be included.
—
Multi-split packaged units: a number of indoor units
are connected to a common outdoor unit by their
own dedicated refrigerant pipework. The indoor
units may be floor, wall or ceiling mounted. The
system may be reversible allowing operation of all
the indoor units as heaters in heat pump mode, or
electric resistance heating may be included.
—
Variable refrigerant flow (VRF) systems: a number of
indoor units are connected to a common outdoor
unit by refrigerant pipework on a common
distribution network. The indoor units may be
floor, wall or ceiling mounted. Systems may be
‘cooling only’ or each indoor unit may operate to
provide either cooling or heating. Some VRF systems
enable heat transfer between zones operating in
cooling or heating mode as necessary to meet the
net demand. In some systems, the outdoor units
may also be linked together to enable greater heat
transfer within the building (see below for
externally linked VRF systems).
Scope to reduce the cooling load: The building owner
may not be aware of how elements of the building
fabric affect the energy consumption of the
building. Consider aspects of the building fabric
that appear to be near the end of their life and
advise on the benefits of replacement. For example,
early solar control glazing had poor daylight transmission properties compared to modern solar
control glazing. Early consideration of replacement
windows may enable daylight optimisation to be
viable thereby reducing cooling loads and energy
consumption associated with lighting and cooling.
The fresh air supply might be generous, especially
where smoking is no longer permitted.
Future options for improvement of the energy efficiency of
the AC subsystem: Many modern air conditioning
components, such as chillers and split systems, are
substantially more efficient than older models.
Where there are components that may require
replacement before the next AC inspection, planning
for higher efficiency equipment rather than likefor-like replacement provides an opportunity for
saving energy. AC systems that are better suited to
the occupational patterns or alternative types of
system could benefit the building owner. Examples:
3-pipe VRF systems or water-loop heat pumps are
particularly suitable to buildings with simultaneous
heating and cooling requirements; CO2 control
may be a cost effective means of ensuring appropriate ventilation rates.
2.2
Packaged cooling systems:
simple procedure
2.2.1
Application
The procedure (see section 2) relates to inspections by level
3 assessors and would generally be applied where cooling is
provided to conditioned spaces using packaged air-to-air
heat pumps (also referred to as direct expansion (DX) units).
These packaged heat pumps have an outdoor unit that
Such packaged units or systems usually include selfcontained ‘on-board’ controls for temperature, and may
include a timer control function.
2.2.2
Checklist of basic inspection
information
The building owner or manager shall be asked to provide
any available documentation for the cooling systems in
readiness for the inspection. This would include, for
example, catalogue information and details provided
during the installation, commissioning and maintenance of
the equipment. This information, see Table 2.1, will help to
minimise the time and cost of the subsequent inspection
process. High levels of submetered energy consumption
indicate the possibility of poor control. Where a building
owner has not made the relevant documentation available
at the time of the inspection, then the information noted in
the Table 2.1 as ‘essential’ must be prepared as part of the
inspection procedure. If the documentation is not available,
a minimum portfolio of relevant information (which may
be done partly on site) forms part of the inspection
procedure.
Inspection of air conditioning systems
11
Table 2.1 Packaged systems: checklist of basic-inspection information
Level
Information required for the subsystem and components
to be inspected
Essential
Itemised list of installed packaged cooling systems
including at least name of manufacturer, model, age,
refrigerant, cooling capacity and location of equipment.
Record and comment on the frequencies and scope
of maintenance in relation to industry guidelines.
This information, along with the dates and activity
schedule of the most recent maintenance, may also
need to be referred to during the on site inspection.
(b)
Compare system sizes with likely loads. Section 4
contains basic procedures for assessing whether the
systems are likely to be oversized.
(c )
If the packaged systems are sub metered and their
energy consumption identified then compare the
actual use with the expected use or compare with
appropriate benchmarks. The basis for any comparison must be noted in the inspection report.
Description of method of compressor capacity control.
Description of method of control of periods of
operation.
Desirable
Reports from earlier inspections of air conditioning
systems, and for the generation of an energy
performance certificate or display energy certificate.
Records of maintenance operations carried out
including filter changing, cleaning indoor and outdoor
coils, refrigerant leakage tests, repairs to refrigeration
components or replenishing with refrigerant.
Records of calibration and maintenance operations
carried out on control systems and sensors
2.2.3.2
(a)
Locate and check the condition and operation of
the outdoor unit or the outdoor part of ‘through the
wall’ units.
(b)
Note whether the area near the equipment shows
signs of oily stains that could indicate refrigerant
leakage. If oily stains are present, check whether
any attention to this is noted in the maintenance
records. Visual signs of refrigerant leakage must be
noted and, if present, evidence of attention to any
leakage sought*. If this has not been attended to,
then recommend prompt maintenance by an
appropriately qualified person(9).
(c)
If an enclosure has been constructed to provide
additional weather-proofing around the outdoor
equipment, check that this does not obstruct the
flow of air to and from the equipment, and that
there are adequate openings for the free passage of
air into and out of the enclosure. Check that the
openings are not themselves obstructed either by
proximity to adjacent structures, or by damage or
debris.
(d)
Check that the condenser coil surfaces are free from
debris and reasonably undamaged.
Records of sub-metered air conditioning plant use.
Records of any issues or complaints that have been
raised concerning the indoor comfort conditions
achieved in the treated spaces.
An estimate of the design cooling load for each system
(if available). Otherwise, a brief description of the
occupation of the cooled spaces, and of power
consuming equipment normally used in those spaces.
2.2.3
Inspection process for packaged
cooling systems: general
The items to be examined, and subsequent actions or advice
that might be recommended, are described in the following
paragraphs and summarised in the checklists shown below
as Tables 2.2 to 2.4.
2.2.3.1
System documentation
The minimum information that should be available in
readiness for the inspection or which the inspector must
compile is indicated as ‘essential’ in section 2.1 above. The
inspector shall examine the relevant documentation and
subsystems as far as possible to check that the installed
equipment is as described.
(a)
Record whether there is evidence of a regular
inspection and planned maintenance regime.
Outdoor units
* Be aware that, for equipment using fluorinated gases like HFCs or ozone
depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect
measuring methods’) may be defined as leak checking for the purposes of
the F-Gas or Ozone Regulations and therefore subject to the requirement
of being appropriately certificated in accordance with these Regulations.
Table 2.2 Packaged cooling systems: checklist for system documentation
Item
Inspection topic
Advice
PS1.1
Review available documentation in particular
records of installed plant and schedule of the
maintenance activity actually carried out
If missing or unsatisfactory then certain basic information will need to be prepared;
see section 2.1 for preparation of information.
PS1.2
Locate the plant and compare details
Prepare revised information as necessary and note any discrepancies.
PS1.3
Review current inspection and maintenance
schedules
Compare with, and recommend, ‘industry norm’ maintenance regime. Record
frequencies, scope and dates of maintenance and the specification to which it was
carried out.
PS1.4
Compare size with imposed cooling loads
(see section 3 for estimation and comparison
procedure)
Report result of comparison; see section 4 for potential recommendations.
PS1.5
Compare any records of use of the package,
or sub-metered energy consumption with
expected hours of use per year for the plant,
or with appropriate energy benchmarks
Excessive energy consumption could indicate either a control problem or an installation/
maintenance issue affecting the efficiency of the system.
12
Inspection of air conditioning systems
Table 2.3 Packaged cooling systems: checklist for outdoor and indoor units
Item
Inspection topic
Advice
PS2.1
Locate and check condition of unit
Note general condition and any significant observations.
PS2.2
Check for signs of refrigerant leakage
Visual signs of refrigerant leakage shall be noted and, if present, evidence of attention to
any leakage sought. If this has not been attended to, then recommend prompt
maintenance by an appropriately qualified engineer (note mandatory qualification
requirements for work on plant containing HFCs, HCFCs, or CFCs)*.
PS2.3
Check for obstructions to airflow through
any external enclosure around the outdoor
equipment, and that there are adequate
openings for airflow
Check that air flow through coils is unimpeded. Recommend appropriate action if air
flow could be improved.
Check that grilles are clean and unobstructed. Recommend appropriate action as
required. Deliberately obstructed grilles may indicate occupants are not comfortable
with the system.
Check that filters are clean. Recommend that filters are cleaned/replaced as appropriate.
outdoor and indoor coils. Check condition of indoor and outdoor grilles. Check
condition of filters.
PS2.4
Check that the condenser coil surfaces are
free from debris and reasonably undamaged;
the inspection evidence used to comment
on the unit operation must be entered into
the ‘Notes and Recommendations’ within
the report
State whether the unit is in heating or cooling mode. Assess correct operation, for
example by determining whether the temperature difference across the coils in the
indoor unit is appropriate for the conditions under which the unit is operating.
PS2.5
Check location of outdoor unit for proximity
to local sources of heat, such as discharge
air from other units or warm air exhausts
Comment on whether there is the potential for warmer than ambient air to be drawn
across the outdoor coil thereby reducing cooling efficiency. Recommend appropriate
action as required.
PS2.6
Check condensate drain and pipework,
including lagging, for condition and evidence
of deterioration or faulty operation
Comment on the state and condition of the drain and associated pipework and lagging.
Note where coils may be partially blocked. Recommend cleaning as appropriate.
Note any evidence of icing or excessive condensation.
* Be aware that, for plant using fluorinated gases like HFCs or ozone depleting substances like CFCs or HCFCs, checks involving more than just looking
for visual signs of leakage such as when using ‘direct or indirect measuring methods’ may be defined as leak checking for the purposes of the F gas or
Ozone Regulations and therefore subject to the requirement of being appropriately certificated in accordance with those Regulations.
Table 2.4 Packaged cooling systems: checklist for system controls
Item
Inspection topic
Advice
PS3.1
Identify and assess zone heating and cooling
sensors
Comment on the type and location of sensors in relation to the position of heating
and cooling grilles and diffusers and the room load, taking note of potential for direct
solar gain onto sensors.
PS3.2
Assess zoning in relation to factors such as
local levels of internal gain, orientation and
exposure to solar radiation
Comment on zoning and recommend further investigation if unclear and specialist
advice if inappropriate.
PS3.3
Note the current indicated weekday and time
of day on controllers against the actual day
and time.
Recommend resetting if incorrect.
PS3.4
Note the set on and off periods (for weekday
and weekend if this facility is available with
the timer)
Note any shortfall in the control timer capabilities, and recommend resetting if current
settings are inappropriate.
PS3.5
Note the temperature set-points in each zone
in relation to the needs of the zone and the
building manager’s intent
Note the suitability of the heating and cooling set-points and recommend alternative
set-points as appropriate or which more adequately reflect the building manager’s
intent. If appropriate, recommend a notice with suggested temperature set-point(s).
PS3.6
Note provision of controls or guidance to
maximise natural ventilation for cooling and
to reduce the risk of open windows when
cooling is operational
Recommend that management provides signs to ask occupants to use windows to
provide cooling where possible and to close the windows when the cooling units are
switched on.
PS3.7
Note the type, age and method of compressor
capacity control
Compare with current good practice control of the equipment.
Inspection of air conditioning systems
(e)
Note the general state of the equipment and the
space immediately around them. Check whether
the outdoor units are located close to a source of
heat such as discharged air from other units or
warm air exhausts. Check whether heat rejected
from the unit can enter the building for example by
open windows.
13
of inhibiting the simultaneous operation of the
heating and cooling equipment in the same zone.
(e)
Locate and check the condition and operation of
the indoor units within the treated spaces.
Note whether the cooling units are installed to
provide cooling in spaces with opening windows.
Note whether there is any provision to disable
operation of the equipment when windows are
open, or whether there is visible guidance for the
local user to open windows for cooling and when
cooling equipment is needed to ensure that the
window is closed
(f)
(b)
Assess the condition of the evaporator coil. Note
whether coil surfaces are significantly damaged, or
blocked by debris or dust. Note any evidence of
icing or excessive condensation.
Determine, if possible, the type of compressor
capacity control. Comment on the likely efficiency
compared to current good practice.
2.2.3.5
(c)
Check the condition of air filters. Note the usual
filter changing or cleaning frequency, and the
elapsed time since the last change or clean, in
relation to industry guidance.
2.2.3.3
(a)
Indoor units
(d)
Note any evidence that occupants find the air
distribution arrangements unacceptable, e.g. by
taping over grilles or otherwise modifying the
designed flow distribution.
(e)
Note whether there are any signs of refrigerant
leakage*.
(f)
Check condensate drain and pipework, including
lagging, for condition and evidence of deterioration
or faulty operation.
2.2.3.4
(a)
System controls
Locate and examine the controls responsible for
the operation of the cooling units, the heating
system controls and their associated temperature
sensors.
(b)
Assess the suitability of the zoning in relation to
factors such as local levels of internal gain,
orientation and exposure to solar radiation.
(c)
Observe any control timers and note the current
indicated weekday, and time of day against the
actual day and time. Recommend resetting if
incorrect.
Note the set times of on and off periods (for weekday
and weekend if this facility is available with the
timer). Comment on the suitability of the timers
and the suitability of the set periods in use.
(d)
Determine, if possible, the set temperatures in each
relevant zone for heating and cooling. Comment on
the suitability of the heating and cooling
temperature set-points in relation to the activities
and occupancy of the zones and in relation to the
building manager’s intent. A change of 1 °C in the
temperature set-point can significantly affect
energy use.
Comment on the dead-band between the heating
and cooling temperature set-points, or other means
* Be aware that, for equipment using fluorinated gases like HFCs or ozone
depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect
measuring methods’) may be defined as leak checking for the purposes of
the F-Gas or Ozone Regulations and therefore subject to the requirement
of being appropriately certificated in accordance with these Regulations.
Reporting
The reporting of inspection results serves two purposes:
—
as a formal record that regulatory requirements
have been met
—
as a means of communication with building
managers and owners about the opportunities
available to reduce energy consumption; this may
usefully be complemented by discussion with the
building manager.
Sections 2.1.9 and 2.1.10 address reporting needs for both
purposes. Checking reports will also form part of quality
assurance procedures.
2.3
Centralised cooling systems:
full procedure
2.3.1
Application
This procedure applies to more extensive and more complex
systems that are generally characterised by the use of fluid
distribution systems to deliver cooling to conditioned
spaces using a variety of active (i.e. containing air moving
fans) or passive terminal devices. These systems generally
include more complex controls that may divide the
conditioned spaces into zones where different control
parameters can be applied, and that could be located
remotely from the equipment, or incorporated into a
building management system (BMS). In addition, some
areas may be served by separate packaged, split and multisplit packaged comfort cooling equipment, including
variable refrigerant flow (VRF) equipment. Such equipment
can be inspected using the procedure described in section
2, with the observations and advice on the equipment
reported either separately or combined in the centralised
system report.
Section 2.1.1 defines the scope of application of inspection
procedures for regulatory purposes.
Centralised systems include the following:
—
Centralised air systems: cooled air is produced by a
cooling heat exchanger in an air handling unit
(AHU) and distributed to conditioned spaces
through ductwork to grilles or diffusers, or to other
terminal units, in the conditioned spaces. The
cooled air distribution systems may also include
floor or ceiling plenums.
14
Inspection of air conditioning systems
This category includes systems where air distributed through a centralised ducted system may also
be cooled at active or passive terminal devices in
the conditioned spaces. This cooling may be
provided by the indoor units of split packaged and
VRF systems where these are installed within the air
distribution ducts.
—
—
2.3.2
Table 2.5 Centralised cooling systems: checklist of basic inspection
information
Level
Information required
Essential
Itemised list of installed air conditioning and
refrigeration plant including product makes, models and
identification numbers, together with cooling capacities,
with locations of the indoor and outdoor components of
each plant. Include refrigerant and age.
Centralised cooled water systems: cooled water is
produced centrally and distributed to active or
passive terminal devices in the conditioned spaces.
Active terminal units would include fan coil units,
and fan assisted chilled beams. Passive units would
include chilled beams (without fans) and chilled
ceiling panels. Terminal units may transfer cooling
to recirculated room air, to air drawn locally from
outdoors, or to air supplied through centralised
ducted systems.
Water loop/reversible heat pump systems: systems with
individual reversible water-to-air heat pumps in
the treated space that draw or return heat from or to
a common temperature-controlled water loop
(sometimes known as ‘Versatemp’-type). Excess
heat in the water loop is dissipated as necessary by
a cooling tower (often a dry cooler), and an overall
requirement for heat in the loop similarly provided
by a central heat generator (fossil fuel boiler, electric
flow boiler, or other central heat exchanger).
Description of system control zones, with schematic
drawings or sketches.
Description of method of condenser capacity control of
temperature.
Description of method of control of periods of
operation.
Floor plans and schematics of air conditioning systems
or sketches.
Desirable
Records of maintenance operations carried out on
refrigeration systems, including cleaning indoor and
outdoor heat exchangers, refrigerant leakage tests,
repairs to refrigeration components or addition or
removal of refrigerant.
Records of maintenance operations carried out on air
delivery systems, including filter cleaning and changing,
and cleaning of heat exchangers.
Records of calibration and maintenance operations
carried out on control systems and sensors, or BMS
systems and sensors.
Checklist of basic inspection
information
Records of sub-metered air conditioning plant use or
energy consumption.
The building owner or manager shall be asked to provide
any available documentation for the air conditioning
systems in readiness for the inspection. This would include,
for example, catalogue information and details provided
during the installation, commissioning and maintenance of
the equipment. The assembly of this information will help
to minimise the time and cost of the subsequent inspection
process. Where the owner has not made the relevant
documentation available at the time of the inspection, then
the information noted in Table 2.5 as ‘essential’ must also
be prepared as part of the inspection procedure.
2.3.3
For relevant air supply and extract systems,
commissioning results of measured absorbed power at
normal air delivery and extract rates, and
commissioning results for normal delivered delivery and
extract airflow rates (or independently calculated
specific fan power for the systems).
An estimate of the design cooling load for each system
(if available). Otherwise, a brief description of the
occupation of the cooled spaces, and of power
consuming equipment normally used in those spaces.
Records of any issues or complaints that have been
raised concerning the indoor comfort conditions
achieved in the treated spaces.
Inspection process for centralised air
conditioning systems
Where a BMS is used the manager should arrange for a
short statement to be provided describing its
capabilities, the plant it is connected to control, the set
points for the control of temperature, the frequency with
which it is maintained, and the date of the last
inspection and maintenance.
The items to be examined, and subsequent actions or advice
that might be recommended, are described in the following
paragraphs and summarised in checklists in section 2.3.5.
2.3.3.1
System documentation (Table 2.6)
Where a monitoring station, or remote monitoring
facility, is used to continually observe the performance
of equipment such as chillers, the manager should
arrange for a statement to be provided describing the
parameters monitored, and a statement reviewing the
operating efficiency of the equipment.
The inspector shall examine the relevant documentation
and systems as far as possible to check that the installed
equipment is as described. If the documentation is not
available, then the inspector must locate the equipment
and assemble a portfolio of relevant documentation.
The minimum content for the information that should be
available in readiness for the inspection, or be produced as
part of the inspection, is listed in section 2.3.2 above.
(a)
For each component inspected compare the
inspection documentation with the equipment and
record any discrepancies. Note the general condition of the equipment and whether it is operational.
Reports from earlier inspections of air conditioning
systems, and for the generation of an energy
performance certificate.
This item will appear in each checklist as an aidememoire.
(b)
Record whether there is evidence of a regular
inspection and maintenance regime, including the
frequencies and scope of maintenance to the air
conditioning equipment and systems in relation to
Inspection of air conditioning systems
15
Table 2.6 Centralised cooling systems: checklist for system documentation
Item
Inspection topic
Advice
CS1.1
Review/compile basic inspection
documentation
If missing or unsatisfactory then certain basic information will need to be prepared;
see section 2.3.2 above for preparation of information.
CS1.2
Locate relevant plant and compare details
Prepare revised information as necessary for all components inspected.
CS1.3
Review current inspection and maintenance
regime, including frequency
Compare with, and recommend ‘industry norm’ maintenance schedules.
CS1.4
Compare system size with imposed cooling
loads (see section 3 for estimation and
comparison procedure)
See section 3.2 for recommendations.
CS1.5
Estimate specific fan power of relevant
air movement systems (see section 3.1.2.2
for calculation procedure)
If commissioning flowrates are not available, recommend that these are measured. If
the result is significantly higher than, for example, the current Building Regulations*
recommendations, the assessor shall seek during the inspection to form a view of the
reason. For example: likely efficiency of fan and drive; air velocities in ductwork;
degree of closure of balancing dampers.
CS1.6
Compare any records of air conditioning plant
usage or sub metered energy consumption with
expected hours of use per year for the plant, or
with appropriate energy benchmarks
Excessive hours of use could indicate a control problem. Excessive energy consumption
could indicate either a control problem or an installation/maintenance issue affecting
the efficiency of the system.
* See for example Non-domestic building services compliance guide(20)
industry guidelines. This, and the dates of most
recent maintenance, may also need to be referred to
during the ‘physical’ inspection.
(c)
(d)
For each subsystem, compare the cooling capacity
with estimated cooling loads and assess whether
the system appears to be correctly sized. Section 3
contains basic procedures for assessing whether
refrigeration systems and air supply systems are
likely to be oversized.
Estimate the specific fan power (SFP) of air
movement systems, provided that this can be done
simply from existing records of the installed fan
capacities and the flow rates and pressure drops
noted in commissioning records, for comparison
with local requirements associated with Building
Regulations and Standards, for example the Nondomestic Building Services Compliance Guide(20).
(e)
Estimate the outdoor air ventilation provision and
compare to appropriate guidelines.
(f)
If the systems are sub metered and their energy
consumption identified then compare the actual
use with the expected use or compare with appropriate benchmarks. The basis for any comparison
must be noted in the inspection report.
2.3.3.2
DX and chilled water refrigeration
equipment (Table 2.7)
(a)
Locate equipment and compare data to documentation, comment on general condition of equipment
(b)
If installed as separate plant, note the general state
of the refrigeration equipment and the space
immediately around it. Note whether the area near
the equipment (wherever installed) shows signs of
oily stains that could indicate refrigerant leakage. If
Table 2.7 Centralised cooling systems: checklist for direct expansion (DX) and chilled water refrigeration plant
Item
Inspection topic
Advice
CS2.1
Locate refrigeration plant and check operation
Note whether there are any discrepancies between actual and documented plant. Note
whether plant is operational.
CS2.2
Visual appearance of refrigeration plant and
immediate surrounding area
Note whether the plant appears clean and unobstructed. If dirty and cluttered, then
regular inspection and maintenance is unlikely and this should be noted; recommend
the plant is kept clear and properly maintained. Visual signs of refrigerant leakage shall
be noted* and, if present, evidence of attention to any leakage sought. If this has not
been attended to, then recommend prompt maintenance by an appropriately qualified
engineer (note mandatory qualification requirements for work on plant containing
HFCs, HCFCs, or CFCs). Visual signs of refrigerant leakage should be noted and, if
present, evidence of attention to any leakage sought. If this has not been attended to,
then recommend prompt skilled maintenance*.
CS2.3
Check that refrigeration plant is capable of
providing cooling by assessing temperature
difference, and observing the refrigerant
sight glass, and/or refrigerant temperature
or pressure gauges (where readily visible and
accessible)
Note where plant appears to contain no, or insufficient, refrigerant and recommend
prompt skilled maintenance*. Note where evaporator or condenser may be partially
blocked, or undersized. If no problems are apparent in subsequent visual inspection,
then recommend prompt skilled maintenance. Recommend cleaning evaporator or
condenser as appropriate. Note any evidence of icing or excessive condensation. Note
excessive noise or vibration from the plant.
CS2.4
Check water flow and pressure drop through
condenser and evaporator
* Be aware that, for equipment using fluorinated gases like HFCs or ozone depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect measuring methods’) may be defined as leak checking for the purposes of the
F-Gas or Ozone Regulations and therefore subject to the requirement of being appropriately certificated in accordance with these Regulations.
16
Inspection of air conditioning systems
present, check whether any attention to this is
noted in the maintenance records. A leakage check
may be carried out using an electronic leak
detector*. Visual signs of refrigerant leakage shall
be noted and, if present, evidence of attention to
any leakage shall be sought. If this has not been
attended to, then recommend prompt maintenance
by an appropriately qualified person.
(c)
In operation observe the temperature difference
across the refrigeration compressor. Compared
with the ambient temperature in the plant room (or
indoors or outdoors), one side of the refrigeration
circuit should be cold and the other warm while the
compressor is working. These differences in
temperature should be apparent when flow and
return water pipework or refrigerant pipes to and
from the refrigerant plant are measured using one
or two surface temperature probes. If, while the
refrigeration plant is operating, both flow and
return appear to be at the same temperature, or
warmer than the surroundings, then it may be that
the equipment has lost its refrigerant charge,
although this may not be the only cause.
If the refrigeration equipment includes a readily
visible liquid sight glass, intended to show the state
of the refrigerant in the system, this shall be
observed while the equipment is operating. If there
is a reasonable difference between flow and return
temperatures, but gas bubbles can be seen passing
through the sight-glass, or a distinct liquid level
line can be seen across the sight glass, then it may
be that there is insufficient refrigerant in the
system, although this may not be the only cause.
If the refrigeration equipment includes readily
visible refrigerant temperature or pressure gauges,
then the readings when the equipment is operating
shall be compared with the evaporating and/or
condensing temperatures or pressures expected for
the current indoor and outdoor temperatures.
Evaporating pressure or temperature readings that
are significantly lower than expected may indicate
that the evaporator is partially blocked, or undersized. Condensing pressure or temperature readings
that are significantly higher than expected may
indicate that the condenser is partially blocked, or
undersized. Either of these situations indicate the
partial loss of refrigerant. Pressures or temperatures
that deviate significantly from design values may
indicate that the system may contain insufficient
refrigerant. This may be due to insufficient initial
charging or to leakage, although this may not be
the only cause.
(d)
(e)
If the refrigeration equipment includes water
chillers check that adequate water flows are
available through the condensers and evaporators
to achieve efficient heat transfer. Also check that
the water pressure drops across them are in
accordance with design or commissioning data if
gauges or test points are available and accessible.
The procedures described apply primarily to
electrically driven vapour compression refrigeration, but most observations also apply generally to
other forms of refrigeration equipment including
engine-driven systems, and direct or heat powered
absorption refrigeration plant.
2.3.3.3
Air and water cooled heat rejection
equipment (Table 2.8)
(a)
Locate and check the condition and operation of
heat rejection units, comment upon findings and
record in the inspection report. Also note whether
the equipment is running
(b)
If there is an enclosure around the heat rejection
equipment, check that this does not obstruct the
flow of air to and from the equipment, and that
there are adequate openings for the free passage of
air into and out of the enclosure. Check that the
openings are not themselves obstructed either by
proximity to adjacent structures, or by damage or
debris. Check for the possibility of air shortcircuiting, in which exhaust air that has passed
through the coils is subsequently re-admitted to
the coil air inlet. Check that the condenser coil
surfaces are free from debris and reasonably
undamaged.
(c)
Check for oily stains on direct expansion coil
surfaces that might indicate leakage of refrigerant.
If present, check whether this is noted in the
maintenance records. Visual signs of refrigerant
leakage shall be noted and, if present, evidence of
attention to any leakage sought. A leakage check
may be carried out using an electronic leak
detector*. If this has not been attended to, then
recommend prompt maintenance by an appropriately qualified engineer.
(d)
In operation, check the rotation and control of
condenser fans to ensure that fan operation varies
with the heat rejection loads.
(e)
If cooling towers or evaporative coolers are used
refer to the cooling tower inspection report and, if
not, ensure that the water distribution is even
across the surfaces and all sprays and nozzles are
free flowing, evenly adjusted and not causing
excessive water loss through splashing or overflow.
If a cooling tower inspection report is available, it
should cover these issues. There should also be a
record of regular cleaning of the tower.
(f)
Check that there is no restriction to water flow from
any cooling tower bund or enclosure and that outlet
pipes and strainers appear clear. (Note: this may not
be possible with the plant running and the operator
must be consulted if detailed inspection is considered necessary.) If a cooling tower inspection report
is available, it should cover these issues.
(g)
Check that the route and condition of any cooling
water system linking the refrigeration plant with the
heat rejection units are satisfactory and ensure that
the system is adequately insulated and efficiently
controlled, especially on part load, and not subject to
extraneous heat gains, such as pipe runs exposed to
the sun.
* Be aware that, for equipment using fluorinated gases like HFCs or ozone depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect measuring methods’) may be defined as leak checking for the purposes of the
F-Gas or Ozone Regulations and therefore subject to the requirement of being appropriately certificated in accordance with these Regulations.
Inspection of air conditioning systems
17
Table 2.8 Centralised cooling systems: checklist for air and water cooled heat rejection equipment
Item
Inspection topic
Advice
CS3.1
Visual check of the condition and operation
of outdoor heat rejection units and compare
observations with documentation
Note whether units have adequate free access to outdoor air. Recommend removal of
debris, or increasing openings in enclosures, as appropriate.
CS3.2
Check that there is free flow of air around and
through the condenser coils and that they are
clean and free from damage and debris; assess
potential for recirculation of discharge air
Note whether units have adequate free access to outdoor air. Recommend removal of
debris, or increasing openings in enclosures, as appropriate.
CS3.3
Check for signs of refrigerant leakage
Visual signs of refrigerant leakage shall be noted* and, if present, evidence of attention to
any leakage sought. If this has not been attended to, then recommend prompt
maintenance by an appropriately qualified engineer (note mandatory qualification
requirements for work on plant containing HFCs, HCFCs, or CFCs).
CS3.4
Check for the correct rotation of fans. If
possible, observe the modulation of multiple
fans in response to load changes
Note whether fan rotates in the correct sense, and whether speed control or modulation
is operational. If incorrect or defective, recommend skilled rectification or maintenance.
CS3.5
Check that water flow through cooling towers
or evaporative coolers is even and efficient,
and there is no loss of water
Observe signs of poor water distribution or excessive overflow and recommend action
or maintenance.
CS3.6
Check that water tanks or bunds are free of
debris and outlets are running free
Recommend maintenance as appropriate.
CS3.7
Check the route and condition of all heat
rejection pipework and the efficiency of
its operation
Note whether pipework attracts avoidable heat gain and whether water circulation varies
with load and recommend suitable action.
CS3.8
Check whether the heat rejection equipment
and pipework circuitry provide a free cooling
facility under certain conditions
Advise that operation of such a system should be verified under low ambient
temperature conditions.
CS3.9
Check for dosing and Legionella risk
Advise on any requirements related to legislation.
* Be aware that, for equipment using fluorinated gases like HFCs or ozone depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect measuring methods’) may be defined as leak checking for the purposes of the
F-Gas or Ozone Regulations and therefore subject to the requirement of being appropriately certificated in accordance with these Regulations.
(h)
If the plant and heat rejection controls provide a
free cooling facility with low ambient temperatures,
check that this is operating and controlled correctly.
(i)
Legionella risk and dosing regime issues: if a cooling
tower inspection report is available, it should cover
these issues.
2.3.3.4
When units are supplied with chilled and hot water
check that the controls are correctly set to ensure
that the units are not receiving both simultaneously.
(Air-side control of fan coil units, mixing heated
and cooled air, is inherently inefficient although it
can provide rapid control.
(h)
In the case of local heat pump units (such as
Versatemp units) check the operation of the compressors to ensure adequate charge of refrigerant,
and that cycling and frosting are not occurring.
(i)
Check for staining on direct expansion heat
exchanger surfaces that might indicate leakage of
refrigerant. If present, check whether this is noted
in the maintenance records. Visual signs of
refrigerant leakage shall be noted and, if present,
evidence of attention to any leakage sought*. If this
has not been attended to, then recommend prompt
maintenance by an appropriately qualified person.
Water- or refrigerant-based terminal
units (Table 2.9)
(a)
Check that the route and condition of any cooling
or chilled water system serving local cooling units
(e.g. fan coils or chilled beams) is satisfactory.
(b)
Check equipment data against documentation and
make general comment on condition. Locate and
check the condition and operation of the terminal
units serving treated spaces.
(c)
Check that the coil surfaces are free from debris and
reasonably undamaged and reasonably unobstructed.
(d)
Check the condition of room air filters and
condensate tray/drain where fitted.
(e)
Check that supply and return air grilles (where
appropriate) are not damaged or obstructed by
proximity to adjacent structures, lighting, furniture,
occupant belongings or debris.
(f)
(g)
In operation, check the rotation and control of
terminal unit fans. Note whether there is any
facility to vary the speed in response to changes in
room loads.
2.3.3.5
(a)
Air supply and extract terminal units
(Table 2.10)
Compare with documentation and comment on
general condition. Locate the supply and return air
openings, grilles or diffusers in the treated spaces,
* Be aware that, for equipment using fluorinated gases like HFCs or ozone
depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect
measuring methods’) may be defined as leak checking for the purposes of
the F-Gas or Ozone Regulations and therefore subject to the requirement
of being appropriately certificated in accordance with these Regulations.
18
Inspection of air conditioning systems
Table 2.9 Centralised cooling systems: checklist for water- and refrigerant-based terminal units
Item
Inspection topic
Advice
CS4.1
Visually inspect the route and condition of the
cooling system pipework serving local areas
Advise whether pipework is subject to unwanted heat transfer and energy losses and the
flow is efficiently controlled.
CS4.2
Locate and compare the terminal unit data
with the documentation, describe unit and
comment on general condition and operation
Note any variance between documentary records and installed units. Note whether units
have adequate free access to air and are free of debris.
CS4.3
Check for obstructions to airflow through heat
exchangers and check that coils are free from
debris and reasonably undamaged
Recommend cleaning or repair as appropriate. Note any evidence of icing or excessive
condensation.
CS4.4
Check condition of intake air filters
Recommend cleaning or replacement as appropriate.
CS4.5
Check air inlets and outlets for obstruction
Note whether units have adequate free access to indoor air. Recommend removal of
debris or blockage as appropriate.
CS4.6
Check for the correct rotation of fans. If
possible, observe any facility to modulate
their speed in response to load changes.
Note whether fans rotate in the correct sense, and whether speed control or modulation
is operational. If incorrect or defective, recommend skilled rectification or maintenance.
CS4.7
Check that chilled and hot water are not
being supplied to terminals simultaneously
Advise that controls equipment requires checking for faulty components or the control
strategy needs to be revised.
CS4.8
Check that local heat pumps are running
correctly with no cycling or frosting of coils.
Incorrect operation is likely to be caused by loss of refrigeration.
CS4.9
Check for signs of refrigerant leakage.
Visual signs of refrigerant leakage shall be noted* and, if present, evidence of attention to
any leakage sought. If this has not been attended to, then recommend prompt
maintenance by an appropriately qualified engineer (note mandatory qualification
requirements for work on plant containing HFCs, HCFCs, or CFCs).
* Be aware that, for equipment using fluorinated gases like HFCs or ozone depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect measuring methods’) may be defined as leak checking for the purposes of the
F-Gas or Ozone Regulations and therefore subject to the requirement of being appropriately certificated in accordance with these Regulations.
Table 2.10 Centralised cooling systems: checklist for air handling terminal units
Item
Inspection topic
Advice
CS5.1
Compare with documentation and comment on Locate and compare the terminal unit data with the documentation, describe unit
general condition; review air delivery openings, and comment on general condition. Note whether these appear to provide good
grilles or diffusers, and route by which air is
distribution.
extracted from the spaces
CS5.2
Review any evidence that occupants find the
air delivery arrangement unacceptable
If present, recommend more detailed assessment by ventilation specialist.
CS5.3
Assess the positioning and geometry of air
supply openings in relation to extract openings,
and assess potential for short circuiting
Note where there may be potential that air might short circuit from supply to extract.
If suspected, this might be checked visually using a smoke pencil. Where relative
positioning of inlet and extract is sure to cause direct short circuit, recommend that
alternatives are sought.
CS5.4
Observe if partitioning or furniture is affecting
performance
Suggest modifications to improve performance.
CS5.5
Assess the controllability and effective air
delivery of a sample number of terminal units
including some at the extremities of the system
Comment on the adequacy of control and operation, and any conflicts with other forms
of heating
identifying the airflow arrangement for all unique
situations and any potential for short-circuiting. If
ceilings or other access routes are easily accessible,
note any signs of air leakage from visible ducts.
(b)
(c)
Note any evidence that occupants find the air
distribution arrangements unacceptable, e.g. by
taping over grilles, or otherwise modifying the
designed flow distribution by such means as closing
dampers, blocking air paths with furniture or
similar obstructions, or wedging doors open.
Assess the positioning of the air supply terminals
and comment of the potential for short circuiting
with return air flows and the air distribution taking
account of potential obstructions such as light
fittings, partitioning, furniture etc.
(d)
Observe whether building modifications, partitioning or fitted furniture are likely to be affecting the
performance of the system through obstruction or
otherwise.
(e)
Using a random sample as indicated in section
2.1.5, but preferably towards the extremity of the
system, check that supply air is apparent through
the terminal units.
(f)
Where the airflow to separate spaces is subject to
individual temperature and volume control, check
a random sample to ensure that they are functioning
satisfactorily and are not in conflict with other
forms of heating within the space.
Inspection of air conditioning systems
2.3.3.6
19
Air handling units and associated
ductwork (Table 2.11)
(f)
Where DX cooling is used, note whether refrigeration
coils show signs of oily stains that could indicate
refrigerant leakage. If present, check whether any
attention to this is noted in the maintenance
records. Visual signs of refrigerant leakage shall be
noted and, if present, evidence of attention to any
leakage sought*. If this has not been attended to,
then recommend prompt maintenance by an
appropriately qualified person.
(g)
Note the fan type and method of speed control and,
if possible, the direction of rotation. Compare with
current good practice and identify opportunities
for improvement.
(h)
Identify whether the systems have any energy
conservation facilities, e.g. heat recovery, free
cooling sequence, and check for evidence that such
facilities are/have been functioning and record
temperature set points in the inspection report.
(i)
Observe the air handling plant and visible air
containment including ductwork, floor or ceiling
plenums and builders’ work shafts for signs of
excessive leakage and energy loss.
(j)
Where these may be visible to the inspector, note
the setting and functioning of any dampers that
modulate the proportions of outside and return air.
(k)
Check that condensate drip trays are clean and
clear of standing water. Advise the client if they are
not, as this poses an immediate Legionella risk.
For safety reasons, it will be necessary for air handling fans
in air distribution systems to be turned off in order to gain
access inside air handling units (AHUs) or ductwork. The
building manager shall arrange safe access for the inspector.
(a)
(b)
Review records of air handling units and make a
comment on the condition of each AHU inspected
Note the usual filter changing or cleaning frequency,
and the elapsed time since the last change or clean,
in relation to industry guidance.
Assess the state of cleanliness, damage or blockage
of filters. Filter housings may be fitted with a
differential pressure gauge to indicate blockages
while the system is in operation. If the gauge is
inoperable or missing, this shall be noted and a
measurement shall be made of the filter resistance
where this is reasonably practical. Access the
interior of the air handling unit to observe filter
condition and check the fit and sealing of the filter
and housing within the duct.
(c)
Assess the condition of filter pressure differential
gauges and recommend replacement or repair as
appropriate.
(d)
Assess the fit and sealing of filters and housings and
recommend skilled maintenance if ill-fitting or
damaged.
(e)
Assess the condition of coils. Note whether any coil
surfaces are significantly damaged, or blocked by
debris or dust. Where reasonably practical, and
where suitable information is available for comparison, the air path resistance across the coil shall be
measured and compared with the design resistance.
* Be aware that, for equipment using fluorinated gases like HFCs or ozone
depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect
measuring methods’) may be defined as leak checking for the purposes of
the F-Gas or Ozone Regulations and therefore subject to the requirement
of being appropriately certificated in accordance with these Regulations.
Table 2.11 Centralised cooling systems: in air handling units and ducts
Item
Inspection topic
Advice
CS6.1
Review documentation and make general
comment about condition of unit; review
filter changing or cleaning frequency
Note any variance between documentary records and installed units. Recommend
adopting good practice industry guidance on cleaning and replacement if not in place.
CS6.2
Assess the current state of cleanliness or
blockage of filters
Recommend replacement if appropriate, and adopting good practice industry guidance
on cleaning and replacement.
CS6.3
Note the condition of filter differential
pressure gauge
Recommend rectification if inoperable.
CS6.4
Assess the fit and sealing of filters and
housings
Recommend skilled maintenance if visibly poorly fitted.
CS6.5
Examine coils for damage, or significant
blockage by debris or dust
Recommend cleaning or skilled maintenance as appropriate.
CS6.6
Where DX is present examine refrigeration
coils for signs of refrigerant leakage
Visual signs of refrigerant leakage shall be noted* and, if present, evidence of attention
to any leakage sought. If this has not been attended to, then recommend prompt
maintenance by an appropriately qualified engineer (note mandatory qualification
requirements for work on plant containing HFCs, HCFCs, or CFCs).
CS6.7
Note fan type and method of air speed control
Compare with current good practice and identify opportunities for improvement.
CS6.8
Note the type of energy conservation facilities
incorporated in the system.
Recommend maintenance if not functioning and additional facilities if beneficial and
appropriate.
CS6.9
Inspect air handling units and associated air
paths for signs of leakage
Recommend reasonable action to reduce the air and energy losses.
CS6.10
Check the setting and operation of any outdoor
air/return air dampers
Comment on the appropriateness of the settings and performance.
CS6.11
Check that condensate drip trays are clean
If not, advise of Legionella risk.
* Be aware that, for equipment using fluorinated gases like HFCs or ozone depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect measuring methods’) may be defined as leak checking for the purposes of the
F-Gas or Ozone Regulations and therefore subject to the requirement of being appropriately certificated in accordance with these Regulations.
20
2.3.3.7
Inspection of air conditioning systems
Outdoor air intakes (Table 2.12)
(a)
Locate inlets for outdoor air, compare with records
and comment on general condition. Note any
significant obstructions or blockages to inlet grilles,
screens and pre-filters.
(b)
Note where inlets may be affected by proximity to
local sources of heat, or to air exhausts or warm
extracts.
2.3.3.8
(a)
(b)
(c)
Note the set times of on and off periods (for weekday
and weekend if this facility is available with the
timer). Form a view of the suitability of the timers
and the suitability of the set periods in use. Where
timing and set temperatures are part of the function
of a BMS, the building manager or maintenance
agent should interrogate the BMS or otherwise
provide documentation, to demonstrate the current
values of these timers and temperatures.
(d)
Note the locations of zone heating and cooling
temperature control sensors. Form a view of the
appropriateness of the type and location of sensors
in relation to the heating and cooling emitters, heat
flows or likely temperature distributions in the
zone or space, and the intended function of the
sensors.
(e)
Determine, if possible, the set temperatures in each
zone for heating and cooling. Form a view on the
suitability of the set temperatures in relation to the
activities and occupancy of the zones and spaces, in
relation to the building manager’s intent, and in
relation to each other.
(f)
Note particularly whether there is a set dead-band
between the need for cooling and the need for
heating.
System controls (Table 2.13)
Locate and examine the controls responsible for
the operation of the air conditioning and heating
system and their associated temperature sensors.
Compare to documentation and comment on
condition. Review documentation or other sources
of information to determine the individual control
zones for heating and cooling. Form a view of the
effectiveness of zoning in relation to factors such as
local levels of internal gain, orientation and
exposure to solar radiation.
Observe any control timers and note the current
indicated weekday, and time of day against the
actual day and time.
Table 2.12 Centralised cooling systems: checklist for outdoor air intakes
Item
Inspection topic
Advice
CS7.1
Locate and compare to records and comment
on condition; check for obstructions or
blockages to inlet grilles, screens and pre-filters
Note any variance between documentary records and installed units. Recommend
clearing or cleaning as appropriate.
CS7.2
Check location of inlets for proximity to local
sources of heat, or to air exhausts.
Comment on location of air inlets and recommend seeking skilled advice if these appear
compromised.
Table 2.13 Centralised cooling systems: checklist for system controls
Item
Inspection topic
Advice
CS8.1
Review documentation and compare, comment
on general condition; assess zoning in relation
to factors such as local levels of internal gain,
orientation and exposure to solar radiation
Note any variance between documentary records and installed units. Comment on
appropriateness of zoning and recommend further investigation if unclear and
specialist advice if inappropriate.
CS8.2
Note the current indicated weekday and time
of day on controllers against the actual day and
time
Recommend resetting if incorrect.
CS8.3
Note the set on and off periods (for weekday
and weekend if this facility is available with
the timer).
Note any shortfall in the control timer capabilities, and recommend resetting if
inappropriately set.
CS8.4
Identify and locate the zone heating and
cooling temperature control sensors in each
zone and assess appropriateness
Note the appropriateness of the type and location of sensors in relation to the heating
and cooling emitters, heat flows or likely temperature distributions in the zone or space,
and the intended function of the sensors. Recommend further investigation if unclear
and specialist advice on replacement if inappropriate.
CS8.5
Note the set temperatures in each zone for
heating and cooling in relation to the activities
and occupancy of the zones and spaces, in
relation to the manager’s intent
Note the suitability of the set temperatures and recommend re-setting as appropriate.
Recommend further investigation if unclear.
CS8.6
Note whether a dead-band is or can be set
between heating and cooling
Recommend resetting as appropriate. Recommend further investigation if unclear.
CS8.7
Assess the refrigeration compressor(s) and
the method of refrigeration capacity control
Provide a view of the likely efficiency compared to good current practice, and
recommend further investigation if there appears to be significant potential for
improvement.
CS8.8
Assess means of modulating or controlling
airflow rate through air supply and exhaust
ducts
Provide a view of the likely efficiency compared to good current practice, and
recommend further investigation if there appears to be significant potential for
improvement.
Inspection of air conditioning systems
(g)
(h)
2.3.4
Determine, if possible, the type and age of the
refrigeration compressor(s) and method of refrigeration capacity control. Form a view of the likely
efficiency compared to good current practice.
Determine, where applicable, the method used to
set, modulate or control airflow rate through air
supply and exhaust ducts. Form a view of the likely
efficiency compared to good current practice. If
available, the BMS may also indicate air supply and
exhaust flow rates.
Reporting
The reporting of inspection results serves two purposes:
—
as a formal record that regulatory requirements
have been met
—
as a means of communication with building
managers and owners about the opportunities
available to reduce energy consumption; this may
usefully be complemented by discussion with the
building manager.
Sections 2.1.9 and 2.1.10 address reporting needs for both
purposes. Checking reports will also form part of quality
assurance procedures
3
Assessing system
efficiency and sizing
3.1
Efficiency
3.1.1
Packaged cooling systems
Efficiency ratings for room air conditioners of less than
12 kW have been mandatory since 2003 and efficiency
figures from voluntary third-party rating for many products
are accessible from Eurovent Certification for products
from 1995(21). From 2013 mandatory energy labelling will
be based on seasonal performance. Up to that date it is
based on efficiency at rated output: other things being
equal, products with variable speed compressors will have
better seasonal efficiencies than those without.
3.1.2
Centralised systems
3.1.2.1
Efficiency of cooling provision
Estimating the overall efficiency of a centralised system is
much more difficult than for self-contained packaged
systems. Eurovent voluntary third-party performance data
are available for chillers from 1996. For recent years both
seasonal and nominal performance figures are reported.
Realistic opportunities to improve technical efficiency will
come from improving maintenance and (re-)commissioning,
and from the replacement of system elements such as
chillers when they reach the end of their lives.
21
3.1.2.2
Air handling
Specific fan power (SFP) is a measure of the efficiency of a
ventilation system. It is defined as the sum of the design
total circuit-watts, including all losses through switchgear
and controls such as inverters, of all fans that supply air and
exhaust it back to outdoors (i.e. the sum of the total circuitwatts for supply and extract fans), divided by the design
ventilation rate through that system.
The SFP of the supply and extract installation shall be
determined. It can be compared with the current level
recommended in local guidance such as the Non-domestic
building services compliance guide(20). The result of an SFP
calculation for the air supply and extract system may have
been provided as part of the information supplied prior to
the inspection (see section 2.1), or may be provided in the
building log book. If a calculation result has not been
provided, then the inspector may be able to calculate the
SFP from the installed fan capacities and airflow rates.
Guidance on estimating the SFP is contained in the box on
page 22.
3.2
Sizing
3.2.1
General sizing issues
Although regulatory requirements and other recommendations call for inspectors to assess system sizing, this is not
easy to do and the relationship between sizing and energy
efficiency is complex. The EPBD Recast(3) does not require
a new assessment of sizing if the system has not been altered
since the previous inspection. Assessment is not the same
as detailed calculation and the effort put into the assessment
of the cooling load should be proportionate to the size of
the system being assessed.
What is intended for the purposes of an inspection report is
an estimate of the current loads and an indication of
whether the system is of an appropriate size. This will
inform building owners of the current state of the building
and system, and is intended to assist them in making
decisions about future maintenance, replacement or
upgrading of the system. If detailed design information is
available, this will form a good basis but, commonly, such
information will not be available.
The assessment should serve two purposes:
—
it should identify significant oversizing based, if
possible, on actual operational experience, and
—
it should inform users of appropriate levels of
cooling and ventilation for consideration when
planning replacements.
Owners are unlikely to act on a 5-year-old system that is
20% over the optimum size but they may be prompted to
take early action to replace a 10-year-old system that is
twice the required size.
The sizing of cooling and of air supply offer different
energy saving opportunities. Chiller capacity in excess of
peak demand may result from design redundancy — if a
chiller is installed but rarely operates, this is unlikely to
have a major impact on annual energy use. Replacement of
chillers is unlikely to be economic unless they are nearing
the end of their useful life. The most recently manufactured
22
Inspection of air conditioning systems
Estimating specific fan power
Extract motor capacity: 4 kW
inverter is in use, absorbed fan powers may be indicated on
the inverter’s display. Where this is not available, commissioning data should be consulted (if available) to establish
the designer’s intended operational frequency. These data
can then be used in conjunction with installed motor
capacity to establish the anticipated absorbed power of the
system. When the operational motor frequency differs from
the commissioned value, air flow rates shall be recalculated
accordingly.
Step 1
Step 3
Calculate the sum of the installed supply and extract motor
capacities:
Express the installed motor capacity in watts:
Example
Supply volume: 5 m3·s–1 (5000 litre·s–1)
Extract volume: 4 m3·s–1 (4000 litre·s–1)
Supply motor capacity: 7.5 kW
7.5 + 4.0 = 11.5 kW
Step 2
The sum of the motor capacities is then multiplied by 0.7 to
give 70% of the installed motor capacity, which allows for
typical design tolerances:
11.5 ¯ 0.7 = 8.05 kW
The 0.7 multiplier is to reflect the typical difference between
nominal motor power and actual energy absorbed. For an
ideally-matched motor and load, the factor would be 1. The
absorbed power would be slightly above the nominal power
because motors are not 100% efficient. The SFP could
therefore be higher than this approximate figure.
8.05 kW = 8050 W
Step 4
This figure is then divided by the greater of either the supply
or extract volumes:
8050 ÷ 5000 = 1.61 W/(litre·s–1)
Where specific airflow rates are unavailable, they can be
estimated by multiplying the cross-sectional area of the
cooling coil by its design face velocity (typically 2.5 m·s–1).
For example, an AHU cooling coil having width of 2.0 m and
a height of 1.5 m would have an estimated airflow rate as
follows:
Cross sectional area = 2.0 m ¯ 1.5 m = 3 m2
Note: it may be possible to determine power input more
directly by using a non-contact meter. Where a frequency
chillers are appreciably more efficient than older ones. The
energy saving penalty of oversizing is more complex, not
least because modern chillers (and room units) are often
more efficient at part-load than at full load. Care may be
needed to distinguish between apparent oversizing to
provide redundancy (with one of a series of chillers perhaps
rarely being used) and over-provision. Replacement of
other major components such as air handling units and
ductwork is also unlikely. On the other hand, if air handling
equipment is oversized relative to the need, it is almost
certainly using additional energy. Energy savings may be
obtained by reducing the volume of air that is handled.
A sizing assessment will help to inform the owner about the
cost-saving and energy-saving opportunities that may be
available by replacing system components by those of lower
capacity. It may indicate that there is a specific and localised
load, for example a server room, that requires special
cooling measures.
3.2.2
Estimating cooling loads: general
There are two components to assessing whether the cooling
provision of a subsystem is appropriately sized: estimating
the peak load for the air conditioning subsystem, and
determining the installed capacity for the air conditioning
subsystem. Where a subsystem contains multiple cooling
plant components the assessment may be undertaken for
the air conditioning subsystem as a whole and reported in
the checklist for the first cooling component.
Estimated flow rate = 3 m2 ¯ 2.5 m·s–1 = 7.5 m3·s–1
Air conditioning systems commonly cool supply air below
its dew point temperature, and this should be borne in
mind when assessing system sizing. The nominal cooling
capacity of packaged units is for total cooling, which
includes a degree of latent heat. But if this is not included
in the estimated cooling load (or the apparent system
cooling capacity adjusted), it may contribute to apparent
oversizing.
Where humidity control is required the consequent latent
load shall be included. When the cooling capacity of
equipment is considered (see section 3.2.3) the ‘inadvertent’
latent load resulting from cooling coils operating below the
dew-point shall be taken into account.
Existing cooling load design calculations should be sought
and, if available, used. If they are not available, or appear to
be no longer applicable, estimates shall be made (though
these will be less reliable). In the time available for the
inspection it will not be possible to estimate the cooling
load accurately, and so the estimate will need to be based on
quickly observable factors and information that could be
obtained readily from the building manager such as floor
areas, the numbers of occupants, and the use of computers
and other heat producing equipment.
CIBSE Guide A: Environmental design(22) contains helpful
information and tables of data for estimating heat gains and
hence cooling loads.
Table 3.1, based on the 5th edition of BSRIA’s Rules of
thumb — Guidelines for building services(23), and earlier
Inspection of air conditioning systems
23
Table 3.1 Approximate cooling loads for various building types
Type of building
Total cooling load
(W·m–2 gross internal floor
area unless stated otherwise)
Banks
160
Hotels
150
Offices:
— perimeter zones
— core zones
100 to 160
75
Restaurants
200
Retail establishments
140
Residential
70
editions, provides estimates of total cooling load per square
metre of floor area. Highly glazed buildings will have
higher loads and newer buildings (i.e. those constructed
since 2006) are likely to have lower loads.
The source of cooling load information used in the
assessment must be clearly recorded in the report checklist.
Typical values of heat gains from lighting, people and small
power (but not solar radiation) in offices, from BSRIA’s
Rules of thumb — Guidelines for building services(23), are shown
in Table 3.2. These figures are based on an occupancy
density of 1 work space per 10 m2. When diversified over an
area of 1000 m2 or more, small power consumption rarely
exceeds 15 W/m2. These are design rules of thumb and
older buildings with less efficient lighting systems may
experience higher gains.
Equipment (nameplate) loads have been found to be related
to the occupant density(24). Figure 3.1 shows that for an area
of occupation of 5 m2 per person, nameplate power loads
are typically between 60 and 100 W·m–2. At a density of
12 m2 per person, gains are between 30 and 50 W·m–2. Using
these data may provide a quick estimate of loads in a large
air conditioned building on a floor-by-floor basis. However,
Table 3.2 Typical heat gains for lighting,
people and small power(23)
Source of heat gain
Heat gain (W·m–2)
25
Lighting
12
Occupants
12
Heat gains / W·m–2 total floor area
Small power
120
110
100
90
80
70
60
50
40
30
20
10
4
6
8
10
12
14
16
18
20
22
Total floor area per person / m2 per person
care must be taken to identify any special sources of heat
gains such as server rooms, areas with display lighting,
catering areas or clusters of large office equipment, which
may add to the typical loads indicated in this graph.
3.2.3
Assessment of cooling capacity
3.2.3.1
Packaged systems
For packaged systems the rated cooling capacity should be
given on the equipment rating plate. Electrically driven
vapour compression systems installed within the last few
years should also be clearly identifiable. Note that the
nominal capacity includes both latent and sensible cooling
and the sensible heat ratio shall be taken into account.
Performance data for these systems, may be available via
the Eurovent online database(21).
Where the cooling output is not stated, then it may be
calculated from the electrical input power and an estimate
of the energy efficiency ratio (EER). Where it is not possible
to obtain specific information from the inspection, this
shall be reported.
Where there is no available information about the cooling
capacity, it may be possible for an experienced inspector to
provide an estimate of the likely cooling capacity based on
the size and likely age of the equipment. The key recommendation under these circumstances should be to review the
cooling needs carefully prior to specifying a replacement, to
ensure that it is appropriately sized for the requirements,
and not merely to specify a like-for-like replacement of the
existing equipment.
3.2.3.2
Centralised systems
The electrical input and the rated capacity or output of the
plant should be available from rating plates. If these are
missing then the O&M manual should be consulted,
although if the rating plates are missing the O&M manual
may also be incomplete, out of date, or difficult to access.
Performance data may be available via the Eurovent online
database(21).
In the absence of clear evidence about the cooling capacity,
the inspector will need to form a view about the likely
capacity of the system, based on what can be observed and
experience of other installations. Where it is not possible to
obtain specific information from the inspection, this should
be reported. Inadequate information about the plant may
indicate that other aspects of the maintenance regime could
be improved, and this shall also be noted.
24
Figure 3.1 Variation of calculated heat gains with area of occupationper
person (source: CIBSE Guide A(22))
Where it is not possible for the inspector to form a
reasonable view on the cooling capacity and compare it to
the estimates of cooling requirements, then the report shall
indicate this, and may recommend that further work is
undertaken to establish the capacity in relation to the actual
load. As with packaged systems, the key recommendation
under these circumstances should be to review the cooling
needs carefully prior to specifying a replacement, to ensure
that it is appropriately sized for the requirements, and not
merely to specify a like-for-like replacement of the existing
equipment.
24
3.3
3.3.1
Inspection of air conditioning systems
Assessment of ventilation
performance
Table 3.3 Yardstick installed fan capacities
(source: BSRIA AG1/2000(26))
General considerations
Offices (general)
Retail
Halls and theatres
Restaurants
The energy consumed by the ventilation system is
important, as it can be a significant proportion of overall
building energy use. Energy used for ventilation may
increase because of changes in the way the building is used
compared to the design intent. For an air conditioning
inspector, the key is to assess how the building is currently
used, rather than how it was designed to be used. The two
major considerations in assessing the efficiency of an air
distribution system are the volume of air being circulated,
or ventilation rate through the building, and the total
power required by the various supply and extract fans.
3.3.2
Airflow rates
The inspector should note the airflow rates provided by the
fans in relation to the likely ventilation requirements of the
building. Indicators of the ventilation requirements include
the number of occupants, the volume treated, and any
particular sources of contamination, heat gains or odours
(such as kitchens).
Fan duties should be available from O&M manuals or
building log books, failing which nameplate information
may need to be inspected although this will invariably
require the plant to be isolated and hence the user’s
authority obtained (see section 1.5). The airflow rate being
supplied at any particular time will depend on the
ventilation control system, which the inspector shall assess
before comparisons with the estimated requirement or any
recommendations are made.
It is important to note that these ventilation rates and those
given in the documents supporting the Building Regulations
and Standards, are the rates deemed necessary to supply
sufficient ventilation air for human occupants. If the
ventilation system is also required to cool some or all of the
spaces served, then there is a need for additional airflow
above that required purely for ventilation. The total volume
of air supplied is a function of the duty of the equipment
and its control facility. Inspectors shall therefore take note
of these aspects of the system during the inspection
procedure. Oversupply of air is particularly likely where
the system was designed in anticipation of smoking taking
place, but is no longer permitted.
The ventilation air volume requirements of various types of
building are listed in chapter 1 of CIBSE Guide A(22), which
takes account of the building use and occupancy. They are
also set out in the documents supporting the Building
Regulations and Standards. In the particular case of office
ventilation the documents supporting the Building
Regulations and Standards indicate a whole building
ventilation air supply rate of 10 litre·s–1 per person. Some
general yardsticks for installed fan capacity, in litre·s–1 per
m3 of treated space, are indicated in Table 3.3(26).
Where an inspector considers that the ventilation rate is
insufficient to provide an adequate air supply, that should
be noted in the inspection report.
Building type
4
Yardstick capacity
(litre·s–1 per m3)
1.4
2.1
2.1
3.5
Factors relating to the
provision of advice
This section provides an outline of issues that relate to the
provision of advice. Accredited inspectors should already
be familiar with most of the content. The report shall
identify and explain simple and cost effective opportunities
to reduce cooling loads.
The benefit of the inspection to the manager is that it
provides appropriate advice on ways of reducing air
conditioning energy consumption. Regulations require the
provision of advice, but do not impose any requirement on
the system owner or manager to act on that advice.
For advice to have any real potential to be adopted on a
voluntary basis, it should indicate improvement options
that are cost-effective over a relatively short period, or are
otherwise evidently needed for the system to work
effectively. Advice based on this assessment is not expected
to involve detailed consideration of the individual system
component costs nor their use in the particular building, or
detailed cost benefit analysis. However, where less
immediately apparent opportunities for improvement are
identified as a result of the inspection, the advice provided
shall include the recommendation for the potential costs
and benefits to be examined in more detail.
4.1
Factors affecting air conditioning
energy consumption
The energy consumption of an air conditioning system
depends on the loads placed upon it, its technical efficiency
and the quality of its management and operation. Inspection
procedures focus on the system efficiency and management,
but opportunities to reduce loads shall also be sought.
The operating efficiency of an air conditioning system
depends on a number of factors concerning:
—
the inherent efficiency of the system (especially at
part load)
—
its state of maintenance, and
—
its effective control.
The inherent efficiency of the system is affected by the
efficiencies of:
—
the refrigeration equipment that removes heat
—
the refrigerant fluid chosen, and its charge in the
system
—
heat rejection to atmosphere
—
the delivery of cooled air or water to, or other means
of absorbing heat from, the treated spaces
Inspection of air conditioning systems
—
4.2
any associated ventilation air supply and/or extract
system.
Cooling load reduction
The effect on energy consumption of reduced cooling loads
is straight forward: energy will be saved. The savings will
be greatest where equipment is inherently able to operate
reliably and efficiently at reduced loading. This depends on
the type and form of capacity control. The least efficient
situation is where cooling is provided by an individual unit
with basic on/off control. However, there will also be
instances where reducing cooling loads may allow
mechanical cooling systems to be turned off altogether for
longer periods of the year.
Cooling loads generally are influenced by:
—
solar gains through glazing
—
heat gains from artificial lighting
—
heat gains from the occupants
—
heat gains from IT and other equipment
—
heat gains from ventilation air which depends on
the amount of outdoor air provided for ventilation
—
the temperature set-points for heating and cooling
—
the temperature set-points on heat recovery systems
(where applicable)
—
the temperature set-point for free cooling via
ventilation air (where applicable).
Provided that the air conditioning system is considered
suitable to benefit from the reduction of cooling load, then
opportunities shall specifically be sought in each of these
areas
4.2.1
Reducing solar gain
Large areas of glazing can make a significant, and in some
cases the largest, contribution to cooling load, particularly
in perimeter spaces where glazing areas exceed 40%.
External shading and solar control glazing are the most
effective ways to reduce solar gain but both measures can be
costly, disruptive to retrofit and may require planning
permission.
Internal blinds improve occupant comfort but do not
reduce the cooling load as effectively as external shading or
solar control glazing because the solar gain is able to enter
the building. To be effective, they need to be used before
overheating occurs.
Solar film applied to glazing can also reduce solar gains.
Films with a low daylight transmittance should be avoided
as these may increase the use of artificial lighting.
4.2.2
25
illumination levels can be simply measured using a lux
meter, and the result compared with current guidance for
the particular activity in the Society for Light and
Lighting’s Code for lighting(27). The type of lamp and
luminaire predominantly in use shall also be identified,
and the efficiency compared with the guidance contained
in the documents supporting the Building Regulations and
Standards. Switching and lighting control arrangements
shall also be assessed and compared with current guidance,
as there may be significant opportunities to reduce average
loads through localised switching and/or occupancy or
daylight level controls. Guidance is provided in CIBSE
Lighting Guide LG10: Daylighting and window design(29).
4.2.3
Heat gains from equipment
Old IT equipment is not as efficient as new equipment and
therefore consideration should be given to upgrading.
Most IT equipment, such as personal computer monitors,
printers and copiers, is now available with a ‘sleep’ facility
to reduce energy use, and hence heat gains, when not in use
for significant periods. Modern equipment is also designed
to consume less energy when in use.
There may be opportunities to move certain heat generating
equipment, such as printers and copiers, away from the
general work areas into separate rooms where the heat gains
may be dealt with either by the use of opening windows or
by providing extract ventilation.
Advice for specific sectors is available free of charge in
various publications from the Carbon Trust (http://www.
carbontrust.co.uk).
4.2.4
Outdoor air
Where cooling systems are used in spaces with access to
opening windows, the inspector shall ensure that the
building owner or manager is made aware that windows
should normally be closed (although trickle vents should
be open as necessary) when the cooling equipment is in use.
The inspector should ensure that windows are used for
cooling as far as possible and are then closed when
mechanical cooling is needed. It can be the case that
mechanical cooling is used in preference to opening the
windows.
The manager shall be advised to ensure that occupants are
made aware of this need, or to consider installing interlocks
between windows and cooling equipment in the associated
spaces. Where outdoor air is provided by mechanical
ventilation, the effect of over-provision on fan energy use
has been raised elsewhere in this document (section 3.3.2).
The inspector shall make the building owner aware that
providing significantly more ventilation air than necessary
during hot weather will increase the cooling loading and
the heating load.
Heat gains from lighting
Older lighting systems may be relatively inefficient and
may also provide higher illumination levels than are
recommended in current guidance. Such systems may
contribute a significant proportion of the cooling load, and
could be improved relatively easily. The appropriateness of
Where outdoor air is provided purely for ventilation, the
inspector should ensure that the air supply temperature is
appropriate for the heating and cooling set-points in the
treated areas. Outdoor air should be supplied at a temperature that will not contribute to the heating or cooling loads
of the building for the majority of the year.
26
4.2.5
Inspection of air conditioning systems
Temperature set-points for heating
and cooling
Lowering the heating set-point or to raising the cooling set
point in the treated spaces by 1 °C will have a significant
and immediate impact on the energy consumption of the
air conditioning system. The inspector shall ensure that
the building manager and occupants are aware of this
straightforward and effective measure.
4.2.6
Temperature set-points on heat
recovery systems (where applicable)
The temperature set-points on heat recovery systems need
to be checked against the set-points for central plant
components to ensure that the heat recovery system is
working at its maximum efficiency and is not contributing
to cooling or heating loads.
5
Other sources of
Information
5.1
European standards
The guidance given here is consistent with the principles
for inspection of air conditioning systems set out in BS EN
15240(4).
5.2
Empirical research results
Two recent European projects have examined aspects of air
conditioning inspections: AuditAC(32) and HarmonAC(1).
The HarmonAC project included analysis of 400
inspections, many of which were in the UK. It assessed the
time taken for each inspection item, the frequency with
which it identified potential savings and the estimated
magnitude of the savings.
Key findings included:
4.2.7
Temperature set-point for free cooling
via ventilation air (where applicable)
The temperature set-points and volume modulation for free
cooling using ventilation air need to be checked against the
operating parameters of central plant components to ensure
that the benefits of ventilation air free cooling are maximised
and that cooling and heating loads are not increased.
4.3
Pre-inspection data is rarely available: complete
data were not available for any of the inspections.
—
The actual inspection process including reportwriting typically took around 1 day for a small
system and up to 3 days for larger systems.
—
Taking into account frequency of occurrence and
potential savings, the most effective parts of an
inspection relate to operation and maintenance and
are:
Free cooling via condensers
Larger, centralised, systems using a cooling tower or dryair cooler may be suitable for conversion to employ free
cooling techniques for some proportion of the time. In
mid-season conditions, such as in spring and autumn, air
temperatures may be sufficiently low that heat may be
rejected from the chilled water circuit to atmosphere,
through the cooling tower or dry-air cooler, without
operating mechanical cooling plant. One method involves
the introduction of an intermediary heat exchanger to the
chilled water circuit, transferring heat to a separate water
circuit which rejects heat through the cooling tower or dryair cooler. Guidance on the potential use of such free cooling
techniques is provided in chapter 4 of CIBSE Guide B(30).
Further information and guidance is also available in
BSRIA BG 8/2004: Free cooling systems(31).
4.4
—
Shut off equipment when not needed.
—
Clean or replace filters regularly.
—
Maintain proper system set-points.
—
The inspectors who participated found these easier
to identify in small systems (typically room units)
than in larger, central systems.
—
Detailed monitoring and analysis of a smaller
number of systems highlighted substantial potential
savings from load reduction and system modification (beyond those identified by inspection).
—
These additional opportunities are typically more
difficult and expensive to implement than changes
to operation and maintenance.
—
The most important opportunities to reduce
consumption through changes to systems or loads
(again taking account of frequency of occurrence
and scale of potential savings) were:
Absorption cooling with CHP
Where buildings are provided with combined heat and
power (CHP) systems to generate electricity and to service
winter heating loads, and where ‘waste heat’ temperatures
are suitable, there may be opportunities to employ
absorption cycle refrigeration systems. These make use of
the heat generated by the CHP plant in summer, when there
is little or no heat demand, to provide cooling. This would
offset the use of electric vapour compression refrigeration
systems and may increase the proportion of the year where
the CHP might usefully be operated. Guidance on the
potential to use absorption cooling in CHP applications is
provided in chapter 4 of CIBSE Guide B(30).
—
—
Consider applying
ventilation.
demand-controlled
—
Replace or upgrade items of equipment.
—
Introduce daylight or occupancy controls
on lighting.
—
Upgrade glazing systems.
The project also defined three levels of inspection based on
the empirical findings:
—
HarmonAC full version: this version of the
methodology presents all the information derived
about the air conditioning inspection elements
Inspection of air conditioning systems
27
from the HarmonAC project. It contains a number
of inspection items that may not lead directly to
energy savings but will provide a greater insight
into the interaction of the building and the air
conditioning system.
z
z
z
—
HarmonAC preferred version: this contains all those
inspection elements that the HarmonAC partners
think in practice might lead to worthwhile energy
savings.
—
HarmonAC short version: this contains the bare
minimum information needed to be obtained
during an inspection to identify the most likely
sources of energy inefficiency in an air conditioning
system. It is designed to identify only those energy
conservation opportunities that provide the largest
savings and are the most frequently occurring. It is
intended that this version should act as a guide to
the minimum set of inspection items that should be
required by EU Member States.
Weaknesses
Strengths
z
Verification of actual
status
Concrete observation
Creating awareness
z
z
z
Provide figures from
measurements
Threats
Opportunities
z
z
z
The inspection should
include advice to improve
the system
Benchmarking with respect
to the best systems will be
very effective
The inspection may create
business
z
z
z
z
Training material and analysis tools developed by the
project and the full report can be found at HarmonAC
website(1).
5.3
European implementation
lessons
Figure 5.1
on-site inspections should represent the last step in
a graded scheme: pre-audit, audit, inspection
—
maintenance data are useful and probably reliable
enough for the pre-inspection phase
—
inspections are a good opportunity to give specific
advice while visiting the end-user
—
the inspection report should be understandable by
non-technicians and provide building specific
advice, focusing primarily on low-cost measures.
—
energy consumption data could be used for
benchmarking; member states should ensure that
utilities are obliged to supply energy data to users
when they install smart meters
—
obligations to install energy meters on systems are
desirable.
The application of advice
may not meet the
expectations
Mistakes can occur with
measurement and advice
Inspections could be
perceived as useless, or
as a ‘fiscal check’
Possible commercial
exploitation
analysis resulting from Concerted Action EPBD
3
Directive 2010/31/EU of the European Parliament and of the
Council of 19 May 2010 on the energy performance of buildings
(recast) Official J. of the European Union L153/13 (18.6.2010)
(Brussels: Commission for the European Communities) (2010)
(available at http://eur-lex.europa.eu/JOHtml.do?uri=OJ:L:201
0:153:SOM:EN:HTML) (accessed September 2011)
4
BS EN 15240: 2007: Ventilation for buildings. Energy performance of
buildings. Guidelines for inspection of air-conditioning systems
(London: British Standards Institution) (2007)
5
Regulation (EC) No. 842/2006 of the European Parliament and
of the Council of 17 May 2006 on certain fluorinated greenhouse
gases (‘the F-Gas Regulation’) Official J. of the European Union
L161/1 (14.6.2006) (Brussels: Commission for the European
Communities) (2006) (available at http://eur-lex.europa.eu/
LexUriServ/LexUriServ.do?uri=OJ:L:2007:333:0004:01:EN:H
TML) (accessed September 2011)
6
Regulation (EC) No 1005/2009 of the European Parliament and
of the Council of 16 September 2009 on substances that deplete
the ozone layer (recast) (‘the Ozone Regulation’) Official J. of the
European Union L161/1 (14.6.2006) (Brussels: Commission for
the European Communities) (2006) (available at http://eur-lex.
europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32010R0744:
EN:NOT) (accessed September 2011)
7
The Fluorinated Greenhouse Gases Regulations 2009 Statutory
Instruments No. 261 2009 (London: The Stationery Office)
(2010) (available at http://www.legislation.gov.uk/uksi/2009/261)
(accessed September 2011)
8
The Ozone-Depleting Substances (Qualifications) Regulations
2009 Statutory Instruments No. 216 2009 (London: The
Stationery Office) (2010) (available at http://www.legislation.gov.
uk/uksi/2009/216) (accessed September 2011)
‘Concerted Action EPBD’(33) is a forum where Member
States discuss EPBD implementation issues. The discussions are not published but conclusions are available(34,35).
In summary the main conclusions are that:
—
SWOT
Possible high cost
Measuring equipment is
required
Skills are missing, even
for advice
A ‘SWOT’ analysis was reported, see Figure 5.1. This relates
to the EU as a whole, with varying degrees of relevance to
the UK.
References
1
HarmonAC (website) (http://www.harmonac.info) (accessed
September 2011)
9
2
Directive 2002/91/EC of the European Parliament and of the
Council of 16 December 2002 on the energy performance of
buildings (‘The Energy Performance of Buildings Directive’)
Official J. of the European Communities L1/65 (4.1.2003) (Brussels:
Commission for the European Communities) (2003)
The Pressure Systems Safety Regulations 2000 Statutory
Instruments 2000 No. 128 (London: The Stationery Office)
(2000) (available at http://www.legislation.gov.uk/uksi/2000/128)
(accessed September 2011)
10
Legionnaires disease — The control of legionella in water systems
HSE Approved Code of Practice and guidance L8 (Sudbury:
HSE Books) (2000)
28
Inspection of air conditioning systems
11
Minimising the risk of Legionnaires’ disease CIBSE TM13 (London:
Chartered Institution of Building Services Engineers) (2002)
12
Conservation of fuel and power in new buildings other than dwellings
Building Regulations Approved Document L2A (London:
NBS/RIBA Enterprises) (2010) (available at http://www.
planningportal.gov.uk/buildingregulations/approveddocuments/
partl) (accessed September 2011)
24
Knight I and Dunn G UK Office Air Conditioning Energy Profiling
Study — Final Monitoring Report, Toshiba Carrier UK Ltd. (Cardiff:
Welsh School of Architecture) (2003)
25
Means of ventilation Building Regulations Approved Document
F1 (London: NBS/RIBA Enterprises) (2010) (available http://
www.planningportal.gov.uk/buildingregulations/approveddocuments/partf/approved) (accessed September 2011)
13
Building log book toolkit CIBSE TM31 (London: Chartered
Institution of Building Services Engineers) (2006)
26
Crozier B Enhancing the performance of oversized plant BSRIA
AG1/2000 (Bracknell: BSRIA) (2000)
14
Energy efficiency in buildings CIBSE Guide F (London: Chartered
Institution of Building Services Engineers) (2004)
27
SLL Code for lighting (London: Society for Light and Lighting)
(2012)
15
Energy assessment and reporting method CIBSE TM22 (London:
Chartered Institution of Building Services Engineers) (2006)
28
16
Building energy metering CIBSE TM39 (London: Chartered
Institution of Building Services Engineers) (2009)
Conservation of fuel and power in existing buildings other than
dwellings Building Regulations Approved Documents L2B
(London: NBS/RIBA Enterprises) (2010) (available at http://
www.planningportal.gov.uk/buildingregulations/approveddocu
ments/partl) (accessed September 2011)
17
BS EN ISO 9001: 2008: Quality management systems. Requirements
(London: British Standards Institution) (2007)
29
Daylighting and window design CIBSE Lighting Guide LG10
(London: Chartered Institution of Building Services Engineers)
(1999)
18
Air Conditioning Conventions Issue 1 — AC CL 1.5 Appendix 01
(Air Conditioning Technical Steering and Conventions Group)
(2011) (available at http://www.cibseenergycentre.co.uk/
assessor-area/ac-conventions.html) (accessed December 2011)
30
Heating, ventilating, air conditioning and refrigeration CIBSE Guide
B (London: Chartered Institution of Building Services
Engineers) (2001–2)
31
19
The Energy Performance of Buildings (Certificates and
Inspections) (England and Wales) Regulations 2007 Statutory
Instruments 2007 No. 991 (London: The Stationery Office)
(2007) (available at http://www.legislation.gov.uk/uksi/2007/900999) (accessed September 2011)
De Saulles T Free cooling systems BSRIA BG 8/2004 (Bracknell:
BSRIA) (2004)
32
AuditAC (website) (Cardiff: Welsh School of Architecture) (http://
www.cardiff.ac.uk/archi/research/auditac) (accessed September
2011)
33
Concerted Action — Energy Performance of Buildings (website)
(European Commission Directorate-General for Energy and
Transport) (http://www.epbd-ca.org) (accessed September 2011)
34
Executive summary report on the interim conclusions of the concerted
action supporting transposition and implementation of the Directive
2002/91/EC (Brussels, Belgium: Concerted Action EPBD)
(available at http://www.epbd-ca.eu/ca-outcomes/2005-2007)
(accessed January 2012)
35
Implementing the Energy Performance of Buildings Directive featuring
country reports 2010 (Brussels, Belgium: Concerted Action
EPBD) (2011) (available at http://www.epbd-ca.eu/archives/498)
(accessed January 2012)
20
Non-domestic building services compliance guide (London: NBS/
RIBA Enterprises) (2010) (available at http://www.planning
portal.gov.uk/uploads/br/non-domestic_building_compliance_
guide_2010.pdf) (accessed September 2011)
21
Eurovent Certification (website) (Paris, France: Eurovent
Certification Company) (http://www.eurovent-certification.
com)(accessed September 2011)
22
Environmental design CIBSE Guide A (London: Chartered
Institution of Building Services Engineers) (2006)
23
Hawkins G Rules of thumb — Guidelines for building services 5th.
edn. BSRIA BG 9/2011 (Bracknell: BSRIA) (2011)
Inspection of air conditioning systems
29
Appendix A1: UK Regulations for air conditioning inspections
A1.1
England and Wales
The Energy Performance of Buildings (Certificates and
Inspections) (England and Wales) Regulations 2007(A1.1)
(hereafter referred to as the EPB Regulations) set out the
requirements in England and Wales. There are several sets
of amendments, although these do not amend Part 4 of the
original regulations, which cover air conditioning
inspections.
The Energy Performance of Buildings (Certificates and
Inspections) (England and Wales) (Amendment)
Regulations 2011(A1.2) introduce the requirement for the
statutory lodgement of air conditioning inspection reports
in England and Wales.
A1.2
(a)
The Building (Scotland) Act 2003(A1.3)
(b)
The Building (Scotland) Amendment Regulations
2006 Scottish Statutory Instrument 2006 No.
534(A1.4).
(d)
(e)
A1.3
The Building (Procedure) (Scotland) Regulations
2004 Scottish Statutory Instrument 2004 No
428(A1.5).
Technical Handbook:
A1.1
The Energy Performance of Buildings (Certificates and
Inspections) (England and Wales) Regulations 2007 Statutory
Instruments 2007 No. 991 (London: The Stationery Office)
(2007) (available at http://www.legislation.gov.uk/uksi/2007/991)
(accessed September 2011)
A1.2
The Energy Performance of Buildings (Certificates and
Inspections) (England and Wales) (Amendment) Regulations
2011 Statutory Instruments 2011 No. 2452 (London: The
Stationery Office) (2007) (available at http://www.legislation.gov.
uk/uksi/2011/2452) (accessed September 2011)
A1.3
Building (Scotland) Act 2003 Elizabeth II 2003 asp 8 (London:
The Stationery Office) (2003) (available at http://www.
legislation.gov.uk/asp/2003/8) (accessed September 2011)
A1.4
The Building (Scotland) Amendment Regulations 2006 Scottish
Statutory Instrument 2006 No. 534 (London: The Stationery
Office) (2006) (available at http://www.legislation.gov.uk/
ssi/2006/534) (accessed September 2011)
A1.5
The Building (Procedure) (Scotland) Regulations 2004 Scottish
Statutory Instrument 2004 No. 428 (London: The Stationery
Office) (2004) (available at http://www.legislation.gov.uk/
ssi/2004/428) (accessed September 2011)
A1.6
Building Standards Technical Handbook: Non-domestic (London:
The Stationery Office) (2010) (available at http://www.scotland.
gov.uk/Topics/Built-Environment/Building/Building-standards/
publications/pubtech) (accessed September 2011)
A1.7
Building Standards Technical Handbook: Domestic (London: The
Stationery Office) (2010) (available at http://www.scotland.gov.
uk/Topics/Built-Environment/Building/Building-standards/publications/pubtech) (accessed September 2011)
A1.8
The Energy Performance of Buildings (Certificates and
Inspections) Regulations (Northern Ireland) 2008 Statutory
Rules of Northern Ireland 2008 No. 170 (London: The
Stationery Office) (2008) (available at http://www.legislation.gov.
uk/nisr/2008/170) (accessed September 2011)
A1.9
The Energy Performance of Buildings (Certificates and
Inspections) (Amendment) Regulations (Northern Ireland)
2008 Statutory Rules of Northern Ireland 2008 No. 241 (London:
The Stationery Office) (2008) (available at http://www.legislation.
gov.uk/nisr/2008/241) (accessed September 2011)
Non-domestic(A1.6):
—
Section 0: Regulation 17 (Continuing
requirements) and guidance clauses
—
Section 3: Environment
—
Section 6: Energy
Technical Handbook: Domestic(A1.7):
—
Section 0: Regulation 17 (Continuing
requirements) and guidance clauses
—
Section 3: Environment
—
Section 6: Energy
Northern Ireland
The legislation relevant to air conditioning inspections in
Northern Ireland is:
(a)
The Energy Performance of Buildings (Certificates
and Inspections) Regulations (Northern Ireland)
2008 Statutory Rules of Northern Ireland 2008 No.
170(A1.8).
The Energy Performance of Buildings (Certificates
and Inspections) (Amendment) Regulations
(Northern Ireland) 2008 Statutory Rules of
Northern Ireland 2008 No. 241(A1.9).
References (Appendix A1)
Scotland
The legislation relevant to air conditioning inspections in
Scotland is:
(c)
(b)
30
Inspection of air conditioning systems
Appendix A2: Current accreditation arrangements for air conditioning
inspectors in the UK
For lists of currently accredited schemes or protocol
organisations see the following links (correct as at January
2012):
England and Wales:
http://www.communities.gov.uk/
planningandbuilding/sustainability/
energyperformance/existingdwellings/
accreditation
Northern Ireland:
http://www.dfpni.gov.uk/index/buildings-energyefficiency-buildings/energy-performance-ofbuildings/content_-_energy_performance_of_
buildings-energy_assessors_schemes.htm
Scotland:
http://www.scotland.gov.uk/Topics/BuiltEnvironment/Building/Building-standards/
profinfo/techguide/inspectaircon
Appendix A3: Explanatory notes for building owners and managers
A3.1
Background
Inspection, maintenance and cleaning programmes to
maintain efficiency and to alleviate potential health hazards
should be part of the normal activities associated with the
ownership and operation of air conditioning systems, and
should be carried out more frequently air conditioning
inspections. Owners and managers are reminded of their
statutory obligations and duties of care in the operation
and maintenance of air conditioning systems, and their
attention is also drawn to the legislation and guidance
mentioned in this section.
The major reasons for undertaking maintenance are to
maintain the ability of the system to provide a healthy and
comfortable environment for building occupants, limit
escape of refrigerant gases, ensure the safety of equipment,
minimise energy use and maintain the value of the capital
asset. The practices and procedures needed to achieve these
aims will be more extensive for complex systems than for a
single unit air conditioner. It is outside the scope of this
document to describe such procedures in detail, but an
introduction to available professional and industry good
practice guidance is included in section A3.6.
It should be noted that a good practice inspection and
maintenance regime would not normally include all of the
issues addressed by the Energy Performance of Buildings
Regulations 2007(A3.1), in particular the aspect relating to
the sizing of the system in relation to the cooling load.
A3.2
The inspection process
The inspection process required under the EPBD (for
example, the EPB Regulations(A3.1)) will examine the refrigeration equipment and air movement systems that are part
of air conditioning systems, including their controls. It will
also examine any documentation that helps understand the
systems, or indicates the extent to which the systems have
been maintained. The inspector is also required to estimate
whether the system is suitably sized for the cooling loads in
the treated spaces, and to provide advice on ways in which
improvement might be made to the energy efficiency of the
system.
Access will be required to equipment that may be located in
plant rooms, or outside the building including on rooftops
or in other positions with limited provision for access. In
all cases the building owner or manager should agree the
means for safe access, in conjunction with the inspector,
following a health and safety risk assessment of the
individual situation. The inspector may need to be
accompanied by the responsible building manager or
maintenance agent at all times.
Some additional access is likely to be needed, for example
to the inside of AHUs or ducts, which must be provided and
supervised by the responsible building manager or
maintenance agent with due regard to the safety of the
inspector and to building occupants. As this would require
the system to be turned off to allow safe access, arrangements may need to be made for this outside normal working
hours to avoid disruption to business. Similarly, the
inspector may need to access a sample of components, such
as fan coil units, which may be hidden above suspended
ceilings where access should again be provided by the
responsible building manager.
Owners and managers should not expect the inspector to
routinely alert them to all hazards or aspects of the
installation, operation or maintenance of systems that are
unsafe. If owners or managers require this service then they
should ensure that the need is clearly specified in their
invitation to tender for the work, assure themselves that the
inspector is competent to undertake such additional
inspections*, and ensure that such aspects are clearly
expressed in the contract or agreement with the contractor.
* For example, that they hold the appropriate mandatory qualifications for
work on systems using a hydrofluorocarbon (HFC), hydrochlorofluorocarbon
(HCFC) or chlorofluorocarbon (CFC) refrigerant.
Inspection of air conditioning systems
A3.3
The inspection report
The purpose of the inspection and the resulting report are
to ensure that building owners or managers are provided
with basic information that gives an indication of the likely
efficiency of the air conditioning systems for which they
have responsibility, together with some initial advice on
how energy efficiency or effectiveness might be improved.
The inspection and report will benefit the owner or manager
only if its findings are acted upon. All of the organisations
involved in the preparation of this guidance recommend
that the advice be considered, and that appropriate
rectification or improvement be made where this is
attractive and cost effective. Following up the advice in the
inspector’s report could often result in immediate
improvements to the effectiveness of air conditioning
systems and/or to reduction in the operating costs. In some
cases the costs of providing both heating and cooling may
be reduced, where it may have been identified that these
two systems are unnecessarily in use at the same time due
to inappropriate controls or settings.
In some buildings it will be clear that the building and
systems are already well understood and well maintained,
and records may be available showing that the equipment
has been well commissioned and is already being regularly
maintained to a good standard. In such cases the
recommendations may be brief with the main content
advising on opportunities for load reduction or on
alternative solutions that may not have been previously
considered. However, in other cases the inspector may find
it necessary to suggest relatively basic maintenance such as
cleaning or repairs to equipment the efficiency of which has
evidently suffered through neglect.
It should be noted that cleaning operations or adjustment
to controls do not form part of the inspection procedure,
even where they might be carried out simply and with
significant immediate effect in improving efficiency. This
is because the inspection itself is not intended, or expected,
to carry out any physical work of this nature and to do so
would change the level of professional risk to the inspector.
Authority to carry out such work would need to be given
specifically, as part of a separate arrangement by the
responsible person, and would be appropriate only where
the inspector is competent to carry it out. The owner or
manager or their representative may be able to carry out
such alterations themselves as the inspection is carried out,
provided they agree with the inspector’s observations and
are competent to undertake the work.
Most reports are likely to contain advice between the two
extremes described above, and to recommend a combination
of low- or no-cost measures along with some investment,
either in more detailed investigation or in modifications or
replacements to elements of the system.
The manager should be provided with, or advised how to
obtain, access to advice on the ongoing management of the
systems, particularly that contained in existing free publications such as the Carbon Trust’s Good Practice Guides
(available from http://www.carbontrust.co.uk).
31
A3.4
Exchanging information with
other inspection or
certification procedures
The inspector’s report should be kept in a safe place so that
it can be used to inform subsequent inspections. An ideal
location would be to keep the report together with ongoing
maintenance and/or energy records in a building log book.
The more recent buildings may already be provided with a
building log book satisfying the provisions required by the
Building Regulations and Standards. CIBSE TM31:
Building log book toolkit(A3.3) provides guidance and a
template for the preparation of the log book, and also on its
subsequent use by the building manager. The building log
book would be the most suitable place to keep records of
the air conditioning inspection, together with other such
inspection results. Where such a log book has not already
been prepared, it would be most helpful to begin a file in
which to keep and use these records.
In addition to the requirement to undertake regular
inspection of air conditioning systems, the Energy
Performance of Buildings Directive(A3.4) also includes
requirements for the preparation of a building Energy
Performance Certificate (EPC) for certain building types.
This is to be made available to prospective buyers or leasers
of buildings, and is intended to inform them of the energy
efficiency properties of the building. The Energy
Performance Certificate will need to be prepared following
an inspection of the building to identify key characteristics
that influence the energy efficiency. These would include
the building fabric properties (walls and glazing), details of
the installed heating, ventilation and cooling systems, and
factors influencing the loading on heating and cooling
systems such as the likely heat gain from occupants and the
use of energy consuming equipment in the building. Some
of this information is also needed for the air conditioning
inspection, and so it would be of benefit to share information
between the inspections wherever possible.
Since July 2007, EU Regulation 842/2006 on certain
fluorinated greenhouse gases, the ‘F-Gas Regulation’(A3.5),
has required regular testing for leakage of fluorinated
greenhouse gas refrigerant from some systems. Refrigeration
systems containing CFC or HCFC refrigerants may already be
subject to regular leakage testing under Regulation (EC)
1005/2009 on substances that deplete the ozone layer (the
‘Ozone Regulation’(A3.6)). Both the F-Gas Regulation and
the Ozone Regulation establish record keeping obligations
for certain air conditioning systems. An assessment to
comply with the EPB Regulations (or equivalents in
Scotland and Northern Ireland) may be combined with a
leakage check under the F-Gas and/or Ozone Regulations,
so long as the inspection addresses the minimum
requirements of the relevant frameworks as well as the EPB
Regulations. Those carrying out the inspections must
comply with the relevant regulatory certification requirements, and satisfy the separate reporting requirements of
the relevant regulations*.
Some air conditioning installations fall under the scope of
the Pressure Systems Safety Regulations 2000(A3.7), which
may apply to systems with an input power in excess of
25 kW.
* See footnote on page 2
32
Inspection of air conditioning systems
The information that would be helpful to keep in the
building log book, or in a separate file if a formal log book
is not available, includes:
under the action of its low temperature or pressure cut-out,
often without satisfying the building cooling load.
—
the preparatory details listed in sections 2.2:
Packaged cooling systems or 2.3: Centralised cooling
systems
A3.5.2
—
a copy of the inspector’s full signed report from the
air conditioning inspection
—
the preparatory details and report from any
inspection carried out to provide the building
energy performance certificate, and
—
the reports of any other regular inspections (such as
inspections for refrigerant leakage) involving the
building’s air conditioning or heating systems
—
any reports required related to Legionella risk
assessments.
Any future inspections can then be provided with this
information easily, and the time needed to carry out future
inspections can be minimised.
A3.5
The scope of the inspection
A3.5.1
Refrigeration
Refrigeration equipment and its associated heat exchange
systems are checked only briefly. The inspection looks
primarily for indicators of damage or lack of maintenance
that would significantly reduce efficiency from the ‘as new’
state, and does not provide a high level of detail*.
Effective heat rejection is necessary to maintain the
efficiency of the refrigeration system. If outdoor heat
rejection equipment is damaged, or its access to adequate
flow of air is otherwise reduced by blockage due to dirt and
debris, its effectiveness in rejecting heat is reduced and its
temperature will be unnecessarily high. The consequent
increased temperature at the outdoor unit increases the
temperature difference that the refrigeration system has to
maintain, which has the effect of reducing refrigeration
efficiency and reducing the cooling capacity of the system.
It may cause the refrigeration equipment to turn off and on
under the action of its own high temperature or pressure
cut-out, often without satisfying the building cooling load.
Similarly, effective indoor heat exchange is necessary to
maintain the efficiency of the refrigeration system. If this
heat exchange equipment is damaged, or its access to
adequate airflow is otherwise reduced, its effectiveness in
transferring heat to the refrigeration system is reduced and
its temperature will be unnecessarily low. The consequent
reduced temperature at the indoor unit increases the
temperature difference that the refrigeration system has to
maintain, which has the effect of reducing refrigeration
efficiency, and reducing the cooling capacity of the system.
It may cause the refrigeration equipment to turn off and on
* Be aware that, for equipment using fluorinated gases like HFCs or ozone
depleting substances like CFCs or HCFCs, checks involving more than just
looking for visual signs of leakage (such as when using ‘direct or indirect
measuring methods’) may be defined as leak checking for the purposes of
the F-Gas(A3.5) or Ozone Regulations(A3.6) and therefore subject to the
requirement of being appropriately certificated in accordance with these
Regulations.
Air movement systems
Where installed as part of the system to provide cooling, air
movement systems are an important aspect of the inspection. The contribution that fans make to the total annual
energy consumption of the combined cooling system is
likely to be higher than that of the refrigeration plant itself,
and there may be a greater potential for improvement.
The effectiveness of delivery of air can play a part in
determining the overall efficiency of the air conditioning
system. Where delivery systems are ineffective, plant that is
otherwise efficient may operate for longer periods than
necessary. However, the reverse may also be true, in that
some delivery systems may interact unfavourably with
occupants or with control sensors, leading to reduced
operation and consequent lack of adequate cooling.
Improving some systems, even at good efficiency, could
increase annual energy use.
Important factors to observe are the condition of, damage
to, or blockage of filters and heat exchangers, and the fan
type and method of control. Ventilation air delivery systems
need free access to outdoor air. Where grilles, screens or
pre-filters are obscured by damage or debris, additional
energy will be needed to overcome the extra resistance
caused by the restriction to flow, or the system may
underperform in other ways due to reduced airflow rates.
Where systems provide cooled air, then admitting air from
locations where the local air temperature may be higher
than ambient will add to the energy required to achieve
cooling to the required temperature. Such locations might
include positions near busy roads, in car parks, or where
exhaust air from the building could be drawn into the air
inlet.
A3.5.3
Controls
System controls are inspected in more detail. There could
be considerable scope to identify inefficiency due to
inappropriate control methods, incorrect control settings
and poorly located sensors, and there could be much
potential for improvement at low cost. Although discovered
‘faults’ may only be time switches or cooling or heating
sensors being incorrectly set, the inspector would not have
any authority to reset them but only to report to the
manager.
An investigation of the realised effectiveness of system
controls over any significant period of operation would be
outside the scope of a simple inspection regime, but a series
of physical observations of their layout and operation could
give an indication of potential inefficiency, ineffectiveness
or misuse.
It may not be possible to investigate all aspects of the layout
and operation of controls, particularly in more complex
systems. However, some or all of the following important
issues might be accessible to a brief examination:
—
the set temperatures to which the treated spaces are
to be conditioned
Inspection of air conditioning systems
—
the time periods during which they are to be
conditioned
—
the appropriateness of the control zones, control
sensors and their locations
—
the potential for cooling to be operating at the same
time as heating
—
the method of refrigeration capacity control
—
the method of airflow rate control.
Where systems are controlled by a building management
system (BMS), it may be necessary for the building manager
to arrange for relevant aspects of this information to be
extracted from the BMS prior to the inspection.
A3.5.4
Maintenance
Evidence is sought of any existing planned maintenance
schedule, or of other recent maintenance activities. Where
documentation clearly shows that equipment and systems
are already the subject of regular good practice checking
and maintenance procedures, a number of aspects of the
required inspection and provision of advice may be omitted.
A3.5.6
A3.6
Advice on improvement options
Three levels of practice are likely to be encountered when
systems are inspected:
—
systems where efficiency is clearly impaired due to
faults, neglect or misuse
—
systems where efficiency is likely to be lower than
currently ‘accepted’ due to aspects of design or use
—
systems that are acceptably efficient.
Corresponding to these, there are three ‘levels’ at which
advice might be given, for example:
(a)
to advise on the rectification of faults in any system
that would have impaired its efficiency from the
design intent
(b)
to offer improvement advice to bring existing
systems broadly to a standard of ‘inherent’
efficiency consistent with the current minimum
provisions of Building Regulations or Standards
(c)
to offer best practice improvement advice to raise
standards even where systems are fully compliant
with the current minimum provisions of Building
Regulations or Standards.
EPBD-compliant inspections address a combination of
aspects of (a) and (b) only. However, best practice aspects
may be provided on a generalised basis by providing
reference to other published guidance sources.
Good practice inspection and
maintenance of air
conditioning equipment
The CIBSE, in common with other professional and
industry bodies, recommends that air conditioning
equipment be regularly inspected and maintained to good
practice standards. This is considered necessary for a
variety of important reasons, including:
—
maintaining healthy and comfortable conditions
for building occupants
—
minimising loss of refrigerant gases that may
damage the atmosphere or contribute to global
warming; be aware that leak checking and leak
prevention obligations in the F-Gas Regulation(A3.5)
(for systems using HFCs) and Ozone Regulation(A3.6)
(for systems using HCFCs and CFCs) may apply.
—
ensuring the continued safe and efficient operation
of the equipment and extend its life.
Documentation
A number of the issues to be assessed as part of the procedure
may be found by examining documentation describing the
installed systems and their commissioning results. As an
example, the specific fan power (SFP) of air supply and
exhaust systems may be calculated from details of the
installed plant and commissioning flowrates, for comparison
with current guidance.
A3.5.5
33
To support these aims, a number of industry and professional
bodies have developed guidance on good practice for the
inspection and maintenance of most air conditioning
equipment, and support training schemes to provide the
technical skills necessary to carry out the work. Among
these bodies, the CIBSE, the Heating and Ventilation
Contractors’ Association (HVCA)*, the Institute of
Refrigeration (IoR), the Air Conditioning and Refrigeration
Industry Board (ACRIB) and the Sector Skills Council
(SummitSkills) are widely recognised as setting industry
standards.
The frequency with which air conditioning equipment
should be inspected and maintained is another important
factor. Manufacturers will normally recommend the
particular intervals they consider appropriate for their own
equipment, although this may sometimes be considered on
the conservative side and others might recommend longer
intervals. The F-Gas(A3.5) and Ozone Regulations(A3.6) also
set minimum frequency levels for inspections of equipment
using HFC, HCFC, or CFC refrigerants. HVCA’s Standard
Maintenance Specification for Services in Buildings(A3.8)
provides detailed guidance on maintenance schedules.
It must be stressed that the inspection and assessment
procedures described in this document provide only an
initial survey of equipment designed to alert the owner or
manager to the more obvious needs to maintain or modify
air conditioning systems. These inspections will only be
capable of identifying instances where performance is
likely to have been significantly affected, based on fairly
superficial inspection and observation, and are intended to
fulfil the requirements of the EPB Regulations(A3.1). These
are not a substitute for the fuller inspection and maintenance
regimes recommended by the CIBSE and others that are
considered necessary for the safe and correct operation of
equipment. Neither are they a substitute for inspection and
maintenance regimes required by other regulatory
frameworks such as the F-Gas(A3.5) and Ozone
Regulations(A3.6) or for Legionella risks.
* From March 2012 the HVCA will become the Building Engineering
Services Association
34
Guidance on good and best practice inspection and
maintenance of air conditioning equipment, and controls,
has been published by the CIBSE and the HVCA. It
includes both strategic advice for the building owner or
operator, and specific detailed advice for the maintenance
contractor.
CIBSE Guide M: Maintenance engineering and
management(A3.9) covers most aspects of building services
maintenance both from the standpoint of the services
designer and of the building owner or operator. It reviews
the procurement of maintenance services and legal issues as
well as providing an overview of the maintenance needs of
building services systems including air conditioning
systems and their controls.
Inspection of air conditioning systems
conditioning systems may specify more simply by asking
organisations to quote for maintenance to the HVCA’s
Standard Maintenance Specification for Services in
Buildings(A3.9), for the relevant equipment. Organisations
should also be asked to demonstrate that their personnel
are suitably qualified to undertake work of that nature.
References (Appendix A3)
A3.1
The Energy Performance of Buildings (Certificates and
Inspections) (England and Wales) Regulations 2007 Statutory
Instruments 2007 No. 991 (London: The Stationery Office)
(2007) (available at http://www.legislation.gov.uk/uksi/2007/991)
(accessed September 2011)
A3.2
The Building Regulations 2010 Statutory instruments No. 2214
2010 (London: The Stationery Office) (2010) (available at http://
www.legislation.gov.uk/uksi/2010/2214) (accessed September
2011)
A3.3
Building log book toolkit CIBSE TM31 (London: Chartered
Institution of Building Services Engineers) (2006)
A3.4
Directive 2010/31/EU of the European Parliament and of the
Council of 19 May 2010 on the energy performance of buildings
(recast) Official J. of the European Union L153/13 (18.6.2010)
(Brussels: Commission for the European Communities) (2010)
(available at http://eur-lex.europa.eu/JOHtml.do?uri=OJ:L:201
0:153:SOM:EN:HTML) (accessed September 2011)
A3.5
Regulation (EC) No. 842/2006 of the European Parliament and
of the Council of 17 May 2006 on certain fluorinated greenhouse
gases (‘the F-Gas Regulation’) Official J. of the European Union
L161/1 (14.6.2006) (Brussels: Commission for the European
Communities) (2006) (available at http://eur-lex.europa.eu/
LexUriServ/LexUriServ.do?uri=OJ:L:2007:333:0004:01:EN:H
TML) (accessed September 2011)
A3.6
Also relevant is BS 8210: Guide to building maintenance
management(A3.10), which addresses the whole range of
building fabric and services equipment and include some
general guidance on simple inspections that would be
carried out as part of asset and condition surveying, and
maintenance planning.
Regulation (EC) No 1005/2009 of the European Parliament and
of the Council of 16 September 2009 on substances that deplete
the ozone layer (recast) (‘the Ozone Regulation’) Official J. of the
European Union L161/1 (14.6.2006) (Brussels: Commission for
the European Communities) (2006) (available at http://eur-lex.
europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32010R0744:
EN:NOT) (accessed September 2011)
A3.7
Another source of guidance regarding maintenance is the
Institute of Refrigeration’s RealZero campaign (http://
www.realzero.org.uk/NCN552738712).
The Pressure Systems Safety Regulations 2000 Statutory
Instruments 2000 No. 128 (London: The Stationery Office)
(2007) (available at http://www.legislation.gov.uk/uksi/2000/128)
(accessed December 2011)
A3.8
Maintenance engineering and management CIBSE Guide M (London:
Chartered Institution of Building Services Engineers) (2008)
A3.9
Standard maintenance specification for building services HVCA
SFG20 (London: Heating and Ventilating Contractors
Association) (2008)
A3.10
BS 8210: 1986: Guide to building maintenance management
(London: British Standards Institution) (1986)
A3.11
Harris J and Hastings P Business focused maintenance toolkit
BSRIA BG 7/2004 (Bracknell: BSRIA) (2004)
A3.12
Nanayakkara R and Smith MH Operation and maintenance audits
BSRIA AG 24/97 (Bracknell: BSRIA) (1997)
A3.13
Fletcher J HVAC troubleshooting — a guide to solving indoor
environmental and energy consumption problems AG 13/99
(Bracknell: BSRIA) (1999)
The HVCA’s Standard Maintenance Specification for Services
in Buildings(A3.8), provides advice on the maintenance of a
wide range of engineering services from the standpoint of
the building services engineer. It provides advice, in
checklist form, indicating the specific components that
should be inspected, and the recommended frequencies of
inspection for each component. It is divided into equipment
categories that include the whole range of air conditioning
system components and controls.
Both documents are extensive, and it is not suggested that a
building owner or manager should read them entirely.
However, they provide useful sources of reference in
planning a maintenance strategy and selecting a suitable
contractor to undertake the work. They do not supplant
equipment suppliers’ own recommendations for inspection
and maintenance, which may be more demanding and
which the owner or manager may consider need to be
carried out in order to preserve equipment guarantees.
They do provide a consensus view of standards that are
appropriate to the safe working and efficiency of systems
where manufacturer guidance may be absent.
Other information supporting the operation and
maintenance of building services include BSRIA
publications BG 7/2004: Business focused maintenance
toolkit(A3.11), AG 24/97: Operation and maintenance audits(A3.12)
and AG 13/99: HVAC troubleshooting — a guide to solving
indoor environmental and energy consumption problems(A3.13).
It is not possible, in this document, to specify the content
or frequency of good practice inspection and maintenance.
Such a specification should ideally be arrived at as an
individual decision for the owner or manager, based on the
good practice guidance described above, additional relevant
guidance that may have been provided by particular
equipment suppliers, and the specific aims and needs of the
organisation. However, at a minimum, the owner or
manager seeking good practice maintenance of air
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