RADTEST – Radiant Heating and Cooling Test Cases

RADTEST – Radiant Heating and Cooling Test Cases
RADTEST – Radiant Heating
and Cooling Test Cases
A Report of Task 22, Subtask C
Building Energy Analysis Tools
Comparative Evaluation Tests
July 2003
Supporting Documents
FHZ —> UNIVERSITY OF APPLIED SCIENCES OF CENTRAL SWITZERLAND
HTA —> LUCERNE SCHOOL OF ENGINEERING AND ARCHITECTURE
ZIG —> CENTER FOR INTERDISCIPILANY BUILDING TECHNOLOGY
RADTEST – Radiant Heating
and Cooling Test Cases
A Report of Task 22, Subtask C
Building Energy Analysis Tools
Comparative Evaluation Tests
April 2003
Matthias Achermann
Gerhard Zweifel
HTA LUZERN
T: 041-349-33-11
Technikumstrasse 21
F: 041-349-39-60
CH 6048 Horw
W: www.hta.fhz.ch
Acknowledgements
This work was a cooperative effort involving the members of the International Energy Agency (IEA)
Model Evaluation and Improvement Experts Group. The group was composed of experts from the IEA
Solar Heating and Cooling Programme (SHC), Task 22, Subtask C, chaired by R. Judkoff. The work
presented in this report was designed, evaluated and reported by Matthias Achermann and Gerhard
Zweifel from the University of Applied Sciences of Central Switzerland, Lucerne School of Engineering and Architecture on behalf of the Swiss Federal Office of Energy. We gratefully acknowledge the
contributions from the modellers and the authors of sections on each of the computer programs used in
this effort:
−
TRNSYS:
Clemens Felsmann and Gottfried Knabe, Dresden University of
Technology, Germany
−
DOE 2.1E:
Markus Dürig, HANS DÜRIG AG - Simulation für Gebäude
energie, Riggisberg, Switzerland (on behalf of HTAL)
−
IDA-ICE 3.0
Matthias Achermann, Lucerne School of Engineering and
Architecture (HTAL), University of Applied Science of Central
Switzerland, Horw, Switzerland
−
CLIM2000
Joseph Ojalvo, Electricité de France (EDF), Fontainebleau,
France
−
ESP-r/HOT3000
Kamel Haddad, CANMET Energy Technology Centre, Ottawa,
Canada
Also we highly appreciate the support and guidance of Michael Holtz, operating agent of Task 22, and
of Joel Neymark, J. Neymark & Associates.
The work would not have been possible without the funding from the Swiss Federal Office of Energy,
represented by Mark Zimmermann, Swiss Federal Laboratories for Materials Testing and Research
(EMPA), Dübendorf, Switzerland, and from the Lucerne School of Engineering and Architecture
(HTAL).
PREFACE
INTRODUCTION TO THE INTERNATIONAL ENERGY AGENCY
BACKGROUND
The International Energy Agency (IEA) was established in 1974 as an autonomous agency within the
framework of the Economic Cooperation and Development (OECD) to carry out a comprehensive
program of energy cooperation among its 24 member countries and the Commission of the European
Communities.
An important part of the Agency’s program involves collaboration in the research, development, and
demonstration of new energy technologies to reduce excessive reliance on imported oil, increase longterm energy security, and reduce greenhouse gas emissions. The IEA’s R&D activities are headed by
the Committee on Energy Research and Technology (CERT) and supported by a small Secretariat
staff, headquartered in Paris. In addition, three Working Parties are charged with monitoring the
various collaborative energy agreements, identifying new areas for cooperation, and advising the
CERT on policy matters.
Collaborative programs in the various energy technology areas are conducted under Implementing
Agreements, which are signed by contracting parties (government agencies or entities designated by
them). There are currently 40 Implementing Agreements covering fossil fuel technologies, renewable
energy technologies, efficient energy end-use technologies, nuclear fusion science and technology, and
energy technology information centers.
SOLAR HEATING AND COOLING PROGRAM
The Solar Heating and Cooling Program was one of the first IEA Implementing Agreements to be
established. Since 1977, its 21 members have been collaborating to advance active solar, passive solar,
and photovoltaic technologies and their application in buildings.
The members are:
Australia
Austria
Belgium
Canada
Denmark
European Commission
Finland
France
Germany
Italy
Japan
Mexico
Netherlands
New Zealand
Norway
Portugal
Spain
Sweden
Switzerland
United Kingdom
United States
A total of 30 Tasks have been initiated, 21 of which have been completed. Each Task is managed by
an Operating Agent from one of the participating countries. Overall control of the program rests with
an Executive Committee comprised of one representative from each contracting party to the
Implementing Agreement. In addition, a number of special ad hoc activities – working groups,
conferences, and workshops – have been organized.
The Tasks of the IEA Solar Heating and Cooling Programme, both completed and current, are as
follows:
Completed Tasks:
Task 1
Investigation of the Performance of Solar Heating and Cooling Systems
Task 2
Coordination of Solar Heating and Cooling R&D
Task 3
Performance Testing of Solar Collectors
Task 4
Development of an Insolation Handbook and Instrument Package
Task 5
Use of Existing Meteorological Information for Solar Energy Application
Task 6
Performance of Solar Systems Using Evacuated Collectors
Task 7
Central Solar Heating Plants with Seasonal Storage
Task 8
Passive and Hybrid Solar Low Energy Buildings
Task 9
Solar Radiation and Pyranometry Studies
Task 10
Solar Materials R&D
Task 11
Passive and Hybrid Solar Commercial Buildings
Task 12
Building Energy Analysis and Design Tools for Solar Applications
Task 13
Advanced Solar Low Energy Buildings
Task 14
Advanced Active Solar Energy Systems
Task 16
Photovoltaics in Buildings
Task 17
Measuring and Modeling Spectral Radiation
Task 18
Advanced Glazing and Associated Materials for Solar and Building Applications
Task 19
Solar Air Systems
Task 20
Solar Energy in Building Renovation
Task 21
Daylight in Buildings
Current Tasks and Working Groups:
Task 22
Building Energy Analysis Tools
Task 23
Optimization of Solar Energy Use in Large Buildings
Task 24
Solar Procurement
Task 25
Solar Assisted Cooling Systems for Air Conditioning of Buildings
Task 26
Solar Combisystems Working Group Materials in Solar Thermal Collectors
Task 27
Performance Assessment of Solar Building Envelope Components
Task 28
Solar Sustainable Housing
Task 29
Solar Crop Drying
Task 31
Daylight Buildings in the 21st Century
Task 32
Advanced Storage Concepts for Solar Thermal Systems in Low Energy Buildings
Task 33
Solar Heat for Industrial Process
TASK 22: BUILDING ENERGY ANALYSIS TOOLS
Goal and objectives of the task
The overall goal of Task 22 is to establish a sound technical basis or analyzing solar, low-energy
buildings with available and emerging building energy analysis tools. This goal will be pursued
by accomplishing the following objectives:
Assess the accuracy of available building energy analysis tools in predicting the performance of
widely used solar and low-energy concepts;
Collect and document engineering models of widely used solar and low-energy concepts for use
in the next generation building energy analysis tools; and
Assess and document the impact (value) of improved building analysis tools in analyzing solar,
low-energy buildings, and widely disseminate research results tools, industry associations, and
government agencies.
Scope of the task
This Task will investigate the availability and accuracy of building energy analysis tools and
engineering models to evaluate the performance of solar and low-energy buildings. The scope of
the Task is limited to whole building energy analysis tools, including emerging modular type
tools, and to widely used solar and low-energy design concepts. Tool evaluation activities will
include analytical, comparative, and empirical methods, with emphasis given to blind empirical
validation using measured data from test rooms of full scale buildings. Documentation of
engineering models will use existing standard reporting formats and procedures. The impact of
improved building energy analysis will be assessed from a building owner perspective.
The audience for the results of the Task is building energy analysis tool developers and national
building energy standards development organizations. However, tool users, such as architects,
engineers, energy consultants, product manufacturers, and building owners and managers, are the
ultimate beneficiaries of the research, and will be informed through targeted reports and articles.
Means
In order to accomplish the stated goal and objectives, the Participants will carry out research in
the framework of four Subtasks:
Subtask A:
Subtask B:
Subtask C:
Subtask D:
Tool Evaluation
Model Documentation
Comparative Evaluation
Empirical Evaluation
Participants
The participants in the Task are: Australia, Canada, Finland, France, Germany, Spain, Sweden,
Switzerland, United Kingdom, and United States. The United States serves as Operating Agent
for this Task, with Michael J. Holtz of Architectural Energy Corporation providing Operating
Agent services on behalf of the U.S. Department of Energy.
This report documents work carried out under Subtask C Comparative Evaluation.
Table of Contents
1
Part I: Radiant Heating and Cooling Test Cases RADTEST
User’s Manual – Procedure and Specification .................................................................................5
1.1
Introduction ..........................................................................................................................5
1.2
Background ..........................................................................................................................5
1.3
General Description..............................................................................................................6
1.3.1
Overview of the Test Cases..............................................................................................6
1.3.2
How to use RADTEST.....................................................................................................9
1.3.3
Model Approach: Rules for Performing the Test .............................................................9
1.4
Specific Input Information .................................................................................................10
1.4.1
Case 800: Base Case ......................................................................................................10
1.4.1.1
Weather ......................................................................................................................10
1.4.1.2
Ground Coupling/ Adiabatic Zone .............................................................................10
1.4.1.3
Drawings and Plans ....................................................................................................11
1.4.1.4
Material specifications ...............................................................................................11
1.4.1.5
High conductance Wall / Opaque Window ................................................................12
1.4.1.6
Infiltration...................................................................................................................13
1.4.1.7
Internally Generated Heat (Casual Gains)..................................................................13
1.4.1.8
Exterior Combined Radiative and Convective Surface Coefficients .........................13
1.4.1.9
Interior Combined Radiative and Convective Surface Coefficients ..........................13
1.4.1.10
1.4.2
Mechanical System and Control.............................................................................14
Case 1800 .......................................................................................................................14
1.4.2.1
Ground Coupling/ Adiabatic Zone .............................................................................14
1.4.2.2
Drawings and Plans ....................................................................................................15
1.4.2.3
Material specifications ...............................................................................................15
1.4.2.4
Highly Conducting Wall / Opaque Window ..............................................................16
1.4.2.5
Infiltration...................................................................................................................16
1.4.2.6
Internally Generated Heat (Casual Gains)..................................................................16
1.4.3
Case 1805 .......................................................................................................................16
1.4.3.1
Infiltration...................................................................................................................17
1.4.3.2
Internally Generated Heat (Casual Gains)..................................................................17
1.4.4
Case 1810 ...................................................................................................................... 17
1.4.4.1
Constant Temperature Layer ..................................................................................... 17
1.4.4.2
Floor surface heat transfer ......................................................................................... 17
1.4.5
Case 1815 ...................................................................................................................... 18
1.4.5.1
1.4.6
Floor surface heat transfer ......................................................................................... 18
Case 1820 ...................................................................................................................... 19
1.4.6.1
1.4.7
Floor surface heat transfer ......................................................................................... 19
Case 1830 ...................................................................................................................... 19
1.4.7.1
Exterior Walls............................................................................................................ 19
1.4.7.2
Infiltration.................................................................................................................. 19
1.4.8
Case 1840 ...................................................................................................................... 19
1.4.8.1
High conductance Wall / Opaque Window ............................................................... 19
1.4.8.2
Internally Generated Heat (Casual Gains) ................................................................. 19
1.4.9
Case 1850 ...................................................................................................................... 19
1.4.9.1
Transparent Window ................................................................................................. 19
1.4.9.2
Interior Solar Distribution ......................................................................................... 20
1.4.10
Case 1860 ...................................................................................................................... 21
1.4.10.1
1.4.11
Case 1870 ...................................................................................................................... 21
1.4.11.1
1.4.12
Constant Temperature Layer ................................................................................. 22
Case 2800 ...................................................................................................................... 22
1.4.14.1
1.4.15
Constant Temperature Layer ................................................................................. 22
Case 1890 ...................................................................................................................... 22
1.4.13.1
1.4.14
Internally Generated Heat (Casual Gains) ............................................................. 21
Case 1880 ...................................................................................................................... 22
1.4.12.1
1.4.13
Internally Generated Heat (Casual Gains) ............................................................. 21
Detailed water loop................................................................................................ 22
Case 2810 ...................................................................................................................... 23
1.4.15.1
Detailed Water Loop Operation ............................................................................ 23
1.4.16
Summarised Input Values Table.................................................................................... 24
1.4.17
Required Outputs........................................................................................................... 24
1.5
1.4.17.1
Annual Outputs...................................................................................................... 24
1.4.17.2
Daily Hour Outputs ............................................................................................... 25
1.4.17.3
Excelsheet.............................................................................................................. 25
References ......................................................................................................................... 26
2
Part II: Production of Example Results..........................................................................................27
2.1
Participating Organisations ................................................................................................27
2.2
Interpretation of Results .....................................................................................................27
2.2.1
“Overall” and “Delta” Results (Section 2.4.1 and 2.4.2) ...............................................27
2.2.2
Detailed temperature values (Section 2.4.3 and 2.4.4)...................................................29
2.3
Conclusions ........................................................................................................................29
2.4
Graphical Results ...............................................................................................................30
2.4.1
Overall Results ...............................................................................................................30
2.4.1.1
Case 800 benchmark (correspond to ENVELOPE BESTEST case 800)...................30
2.4.1.2
Overall results case 800 to 2810.................................................................................31
2.4.1.3
2810)
Room temperatures: Active zone (case 800 to 2810) and basement (case 1800 to
33
2.4.1.4
Floor surface temperatures active zone (case 1830 to 2810)......................................35
2.4.1.5
Annual heat fluxes case 1820 to 2810........................................................................37
2.4.2
Delta results....................................................................................................................39
2.4.2.1
Delta Annual heating and cooling energy consumption - case 1800 to 2810 ............39
2.4.2.2
Delta room temperatures: active zone and basement (case 1800 to 2810).................41
2.4.2.3
Delta floor surface temperatures active zone (case 1805 to 2810).............................43
2.4.3
Detailed temperature values ...........................................................................................45
2.4.3.1
Temperatures summer period from July 27 to 30. .....................................................46
2.4.3.2
Winter cases from January 2 to 5 ...............................................................................49
2.4.3.3
Floor surface temperatures summer period ................................................................52
2.4.3.4
Floor surface temperatures winter period...................................................................55
2.4.4
Detailed water loop ........................................................................................................58
2.4.4.1
Room temperatures ....................................................................................................58
2.4.4.2
Floor surface temperature detailed water loop ..........................................................59
2.4.4.3
Return water temperature hydronic loop....................................................................60
2.5
2.5.1
Modeller Reports................................................................................................................61
Preliminary remark.........................................................................................................61
Executive Summary
This report describes the Radiant Heating and Cooling Test (RADTEST) project conducted by the
Model Evaluation and Improvement International Energy Agency (IEA) Experts Group. The group
was composed of experts from the Solar Heating and Cooling (SHC) Programme, Task 22, Subtask C.
This report documents a comparative diagnostic procedure for testing the ability of whole-building
simulation programs to model the performance of radiant heating and cooling systems. Results from
simulation programs that were used in field trials of the test procedure are also presented.
The test cases start from a case taken from the building envelope oriented suite BESTEST from IEA
Task 12 / Annex 21 (1995). The configuration of this base case building (Case 800) is a single
rectangular zone with heat transfer towards the outside through real construction building envelope.
The window is represented as a highly conductive opaque surface. Mechanical equipment
specification represents an idealised system without losses and a non proportional (on/off) control.
For the further cases, a second zone is added to this, and in order to isolate the relevant areas, the
primary zone is first simplified as near adiabatic. A constant temperature layer is introduced in the
floor between the two zones, representing the simplest way of modelling a radiative system. More
zone features are progressively added to show the interaction between the zone load and the system.
In this way, eleven cases (including the Envelope BESTEST base case) have been proposed for testing
the performance of radiant system models. Two more cases are defined to describe a radiant system in
detail, including water loop design and operation.
The specific test cases are designed to test the influence of the following issues:
−
Heat transmission through interior construction element
−
Presence of internal loads
−
Convective model
−
Radiation model
−
Distribution of radiation
−
More realistic zone load
−
Influence of highly conductive wall
−
Influence of incoming radiation
−
Influence of radiative heat source
−
Influence of convective heat source
The tests have been performed by five organisations using five different programs as shown in the
table below.
The results were produced in a first round as a “blind” test. According to the results of the first round,
some errors in the test specification were detected and the specification was modified and adjusted.
Obvious disagreement between results from different programs were discussed and improved in a
second round. In some cases a third round was necessary to eliminate program bugs or faults because
of misinterpretation of the specification. This helped adding diagnostic possibilities to the test suite.
At the final stage, the specification (part I: user’s manual) was restructured to improve clarity.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 3
Program
TRNSYS
Authoring organization
Transsolar/TUD
DOE 2.1E-116
LBNL / HTAL
IDA-ICE 3.0
EQUA AB, Sweden
CLIM2000
ESP-r/HOT3000
EDF
CANMET
Implemented by
TUD, Dresden University of
Technology
Germany
HANS DÜRIG AG - Simulation für
Gebäudeenergie
Riggisberg, Switzerland
Lucerne School of Engineering and
Architecture, University of Applied
Science of Central Switzerland
EDF, France
CANMET Energy Technology
Centre, Ottawa, Canada
Conclusions
The different approaches of modelling radiant heating and cooling systems lead to satisfying results.
The simple approach of an active temperature layer, to provide cooling or heating load to the active
zone shows a good agreement between the different programs. It is interesting to see that programs
like DOE-2.1E, which has not a special radiant heating system included, can be used and modified in a
way that leads to reasonable results (except for surface temperature calculations).
Over all, it may be said that all the participating programs calculate the radiant floor systems in the
same way. To use this approach to estimate floor temperatures and energy consumptions is a reasonable approach.
The aim of further tests should focus on:
−
- Different pipe configurations
−
- Different control strategies on different temperature levels.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 4
1 Part I: Radiant Heating and Cooling Test Cases RADTEST
User’s Manual – Procedure and Specification
1.1 Introduction
Radiant heating and cooling systems are known all over the globe. Radiant heating systems are in use
in residential buildings as floor heating systems. The majority of radiant cooling systems are in use in
commercial buildings, primarily as ceiling-based systems. In many cases, radiant systems are used for
heating and cooling purposes depending on the time of the year.
To take into account the behaviour of radiant heating and cooling in dynamic simulation programs,
specific models or modelling methods should be available. Some of these methods are well known,
but there is a need to validate these models and methods to improve confidence in them.
From this point of view, the following test cases were developed. To use synergies with former work,
the test cases are based on the ENVELOPE BESTEST from IEA Task 12 [1-1].
The goal of this work is to give a tool which can show if the tested programs are able to accurately
model radiant heating and cooling systems, and which gives some diagnostic hints to localise the
problem for the case where they don’t. Additionally, the relation between the simplified approaches
and the detailed floor heating and cooling models should be quantified.
1.2 Background
There are several types of radiant heating and cooling systems. The best known heating system is the
floor heating system with a water loop under a concrete slab. Through the thermal resistance of the
concrete slab, the heat transmission from the water loop in the floor to the room is delayed, and the
floor surface temperature is on a lower temperature level. This behaviour creates a comfortable room
climate and is probably the main reason for the widespread use of this type of system.
Frequently used cooling systems are cooling beams which are at least a small water cooled panel
placed on the bottom of the ceiling. Also, well known systems in Europe are thermally active building
elements. This system is similar to the floor heating, with the hydronic circuit in the center of a
massive concrete ceiling or floor. This concrete element is often cooled down during night time to a
lower temperature level than the adjacent space. During daytime the direct solar radiation and internal
radiative gains are stored in the concrete slab. Due to the massive concrete, the heat flux arrives with
delay in the middle of the concrete. In this way, the stored heat can be removed by the water loop
during night time. The big advantage of this operation is that the heat can be removed during night
time, when low temperature heat sink possibilities are available.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 5
1.3 General Description
1.3.1
Overview of the Test Cases
The purpose of this specification is to create a uniform set of unambiguous test cases for a software to
software diagnostic comparison. Not all the programs require exactly the same input data. Therefore,
the test description is given in a way that allows the use of many different simulation programs
(representing different degrees of modelling complexity).
The procedure is subdivided in two parts. In the first part, a simplified method with a constant
temperature layer is used. In the second part, a detailed hydronic system model is used. Look at tables
1-11 thru 1-13 to get an overview of the different test cases.
The RADTEST contains 14 runs. It starts with case 800 and proceeds to case 2810. Case 800 is a
rectangular single zone model with high thermal mass, an opaque window, without ground coupling.
At this stage the zone model corresponds to case 800 from the ENVELOPE BESTEST. The meaning
of this case is that the user has a benchmark for his model. If any results fail at this stage, the modeller
should run first the diagnostics cases from ENVELOPE BESTEST [1-1].
In cases 1800 to 1830 the active zone is modelled as a highly insulated zone and a second,
unconditioned, semi-adiabatic zone is inserted below the primary zone. In cases 1800 and 1805 the
heat flow between the zones is observed. From case 1810 upwards, a constant temperature layer is
placed within the floor construction (e.g. floor heating system, dummy zone with constant temperature
between floor constructions). The behaviour of the heat transfer to the active zone is observed in
detail. In case 1840 the insulated envelope is removed. An opaque window and afterwards a real
window are inserted in the model. At this model stage, several control strategies with different set
points and different schedules for the temperature layer are tested.
For all tests, the primary zone is held to constant set points with an ideal convective heating and
cooling system. The power and energy demand of these systems are observed parameters.
For diagnostics of the building envelope component models, the diagnostic test set from ENVELOPE
BESTEST [1-1] is adapted. For the system strategies, a new set of diagnostic cases is produced if
necessary.
The complex test case contains a description of a real floor heating system. At this stage, it is up to the
modeller to model this system in the most detailed way the program allows. The goal of this test is on
one hand to compare the complex case result with the simple one, and on the other hand to compare
the different modelling approaches.
Table 1-1 Simple Test Cases
CASE Graphic
Description
Test objective
800
Corresponds to case 800 from
ENVELOPE BESTEST. High mass
construction with opaque window.
Adiabatic floor with active storage
capacity.
Basic case
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 6
CASE Graphic
Description
Test objective
1800
Totally insulated 2 zone model.
- no infiltration
- no internal loads
Heat transmission
through interior
construction element
1805
Totally insulated 2 zone model.
- infiltration Ach=1.0 1/h
- internal loads 200 W from 1st may to
30 september. (purely convective)
Presence of internal
loads
1810
Tconst.
Constant temperature layer between the Convective model
concrete layer and the insulation
Surface coefficient on floor purely
convective
1815
Tconst.
Replace purely convective surface
coefficient by combined coefficient
Radiation model
Radiation from floor 100% to ceiling
1820
Tconst.
Normal distribution of radiation to all
surfaces
Distribution of
radiation
1830
Tconst.
Real constructions for walls and roof.
Internal gains purely convective 365
days.
Ach=0.5 1/h
More realistic zone
load
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 7
CASE Graphic
Description
Test objective
“Opaque window” is added.
Internal Loads set to case 800 values
Influence of highly
conductive wall
Real window is introduced
Influence of
incoming radiation
Tconst.
Equal to case 1850 but the internal
gains are only radiative
Influence of
radiative heat source
1870
Tconst.
Equal to case 1850 but the internal
gains are only convective
Influence of
convective heat
source
1880
Tconst.
Lower level of the constant layer
temperature
Setpoints for summer 18°C and winter
30°C
Influence of
temperature change
on heating and
cooling energy
demand
1890
Tconst.
Similar to case 1850, but during
summer time, the temperature layer
setpoint is only active from 8 pm to 6
am
Influence of
interrupted operation
on cooling energy
demand
1840
1850
1860
Tconst.
Tconst.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 8
Table 1-2 Detailed Model Case Descriptions
CASE Graphic
2800
Description
Det. water loop
Test objective
Real case with detailed water loop
model
Whole year 24h/d massflow
2810
Det. water loop
Real case with detailed water loop
model
During summer time massflow
provided only from 8 pm to 6am.
1.3.2
How to use RADTEST
RADTEST is built as a stand alone test suite. The basic case 800 is adapted from the ENVELOPE
BESTEST [1-1]. However, all specifications to run all cases are included in this paper.
Begin with case 800, which is a high mass building construction with an “opaque window” and
without ground coupling. Case 800 corresponds to case 800 from ENVELOPE BESTEST. If the
results appear reasonable, go to case 1800. If they do not correspond to reference results, go back to
the ENVELOPE BESTEST diagnostic test cases.
From 1800 run all cases up to 1850. For these cases, use the description 1.4.2 to 1.4.9. The tests 1860
to 1890 have a similar description to 1850, but with different internal gains and different control
strategies. If all the results appear reasonable – start with the design of the detailed cases 2800 and
2810. If these results show a good agreement, then the delta between the simplified cases 1850 and
1890 shall be compared with the cases 2800 and 2810 .
If anomalous results are observed, the reason for the disagreement should be located by evaluating the
last added feature or in an element depending on this added element.
1.3.3
Model Approach: Rules for Performing the Test
-
Use the most detailed level of modelling your program allows.
-
Do not use constant combined convective and radiative film coefficients if your program can
calculate surface radiation and convection in a more detailed or physically correct manner.
-
If your program allows for initialisation or preconditioning (iterative simulation of an initial
time period until temperatures and/or fluxes stabilize at initial values), then use that capability.
-
If your program includes the thickness of walls in a three-dimensional definition of the
building geometry, then wall, roof, and floor thickness should be defined such that the interior
air volume of the building remains as specified (6m x 8 m x 2.7m = 129.6m3). Make the
thicknesses extend exterior surfaces in addition to the currently defined internal volume.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 9
-
All references to time in this specification are to solar time, and assume that 1 hour equals the
interval from midnight to 1 a.m. Do not use daylight saving time or holidays for scheduling.
-
In some instances, the specification will include input values that do not apply to the input
structure of your program. For example, your program may not allow adjustment for infrared
emissivities. When this occurs, either use approximation methods suggested in your users
manual, or simply disregard the non applicable inputs, and continue. Such inputs are in the
specification for those programs that may need them.
1.4 Specific Input Information
1.4.1
1.4.1.1
Case 800: Base Case
Weather
Use the weather file (TMY) from disc supplied in the package. Site and weather characteristics are
summarized in Table 1-3.
Table 1-3. Site and Weather Summary
Weather Type
Weather format
Latitude
Longitude
Altitude
Time Zone
Ground reflectivity
Site
Mean annual wind speed
Ground temperature
Mean annual ambient dry-bulb temperature
Minimum annual ambient dry-bulb temperature
Maximum annual ambient dry-bulb temperature
Maximum annual wind speed
Heating degree days (base 18.3°C)
Cooling degree days (base 18.3°C)
Mean annual dew point temperature
Mean annual humidity ratio
Global horizontal solar radiation annual total
Direct normal solar radiation annual total
Direct horizontal solar radiation
Diffuse horizontal solar radiation
1.4.1.2
Cold clear winters / Hot dry summers
TMY
39.8° north
104.9° west
1609 m
7
0.2
Flat, unobstructed, located exactly at weather
station
4.02m/S
10°C
9.71°C
-24.39°C
35.00°C
14.89 m/S
3636.2°C-das
487.1°C-days
-1.44°C
0.0047
1831.82 kWh/m2 a
2353.58 kWh/m2 a
1339.48 kWh/m2 a
492.34 kWh/m2 a
Ground Coupling/ Adiabatic Zone
The floor insulation is made very thick to effectively decouple the floor thermally from the ground.
The ground temperature is set to 10°C.
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2.0 m
Drawings and Plans
6.0 m
0.2 m
2.7 m
1.4.1.3
0.5 m
3.0 m
1.0 m
3.0 m
0.5 m
8.0 m
N
Figure 1-1: Isometric Case 800
1.4.1.4
Material specifications
Table 1-4: Material Specifications; Heavyweight Case (Metric)
Floor (inside to ground)
ELEMENT
Int. Surf Coeff.
Concrete slab
Insulation
k
Thickness
U
(W/mK)
(m)
(W/m2K)
8.290
1.130
0.080
14.125
0.040
1.007
0.040
Total air-air
Total surf - surf
Exterior Wall (inside to outside)
ELEMENT
Int. Surf Coeff. (see note 2)
Concrete block
Foam Insulation
Wood Siding
Ext. Surf Coeff.
0.039
0.040
k
Thickness
U
(W/mK)
(m)
(W/m2K)
8.290
0.510
0.100
5.100
0.040
0.0615
0.651
0.140
0.009
15.556
29.300
Total air-air
Total surf - surf
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0.512
0.556
R
Density
CP
(m2K/W) (kg/m3) (J/kgK)
0.121
0.071
1400.000 1000.000
25.175
10.000
1400.000
25.366
25.246
R
(m2K/W)
0.121
0.196
1.537
0.064
0.034
Density
(kg/m3)
CP
(J/kgK)
1400.000 1000.000
10.000
1400.000
530.000 900.000
1.952
1.797
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Roof (inside to outside)
ELEMENT
k
Thickness
U
(W/mK)
(m)
(W/m2K)
8.290
0.160
0.010
16.000
0.040
0.1118
0.358
0.140
0.019
7.368
29.300
Int. Surf Coeff.
Plasterboard
Fiberglas quilt
Roofdeck
Ext. Surf. Coeff..
Total air-air
Total surf - surf
0.318
0.334
R
(m2K/W)
0.121
0.063
2.794
0.136
0.034
Density
CP
(kg/m3) (J/kgK)
950.000 840.000
12.000 840.000
530.000 900.000
3.147
2.992
Surface Summary
Component
Area
(m2)
63.6
48.0
48.0
12.0
Wall
Floor - near adiabatic
Roof
South “window” (highly
conductive wall)
Infiltration
ACH
0.5
UA
(W/K)
32.580
1.892
15.253
36.000
18.440
(see Note 1)
VOLUME
(m3)
129.6
Altitude
(m)
1609.000
Note 1: Infiltration derived from: ACH*Volume*(specific heat of air)*(air density at specific altitude)
Note 2: The interior film coefficient for floors and ceilings is a compromise between upward and
downward heat flow for summer and winter.
1.4.1.5
High conductance Wall / Opaque Window
An element that may be thought of as a highly conductive wall or an opaque window is used. The
properties of this element are as follows:
−
Short wave transmittance = 0
−
Interior and exterior infrared emissivities are the same as for the normally insulated
wall
−
Interior combined surface coefficient is 8.29 W/m2K and exterior combined surface
coefficient is 21 W/m2K for cases were infrared emissivity is 0.9
−
Exterior solar absorption is the same as for normally insulated walls
−
Conductance, density, specific heat, and surface texture (very smooth) are the same as
for the transparent window (See section 1.4.9.1)
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1.4.1.6
Infiltration
The infiltration air exchange rate in the primary zone is set to 0.5.
If the program does not use barometric pressure from the weather data, or other automatic correction
for the change in air density due to altitude, then adjust the specific infiltration rates to yield mass flow
equivalent to what would occur at the specific altitude as shown in Table 1-5.
Table 1-5 Air changes for the primary zone
Altitude adjustment algorithm
Input air changes per Adjustment factor
hour (ACH)
Programs with automatic altitude adjustment
0.50
1
Programs with fixed assumption that site is at 0.41
0.822 *
sea level (no automatic adjustment)
Specified rate * 0.822 = (altitude adjusted rate)
1.4.1.7
Internally Generated Heat (Casual Gains)
The internal heat is used to take into account heat gains from people, lights and equipment. For all
cases the internal heat is 100% sensible and 0% latent.
Table 1-6 Internal Gain
Case
800
1.4.1.8
Gain (W)
200
Radiative portion
60 %
Convective portion
40%
Exterior Combined Radiative and Convective Surface Coefficients
If the program calculates exterior surface radiation and convection automatically, this section may be
disregarded. If the program does not calculate this effect, use the information given in Table 1-7.
Table. 1–7 Exterior Surface Coefficient
Surface texture
Specified Emissivity
E = 0.9
Brick or rough plaster ( all walls and roof)
29.3 W/m2K
Glass or very smooth surface (Window and high 21.0 W/m2K
conductive wall)
The exterior combined radiative and convective surface conductance for the glass and very smooth
opaque surface are specified as equivalent for the convenience of input, even though the infrared
emissivity for common window glass is usually 0.84.
Rain causes the surface temperature to rapidly approach the water temperature. Provide documentation
if your program treats rain as a special case.
1.4.1.9
Interior Combined Radiative and Convective Surface Coefficients
If the program calculates interior surface radiation and convection, disregard this section. If the program does not calculate these effects, use the following American Society of Heating, Refrigerating,
and Air-Conditioning Engineers (ASHRAE) constant combined radiative and convective coefficients
as shown in Table 1-8.
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Table 1-8 Interior surface coefficient
Orientation of surface and heat flow
Specified Emissivity
E = 0.9
Combined
Radative
Horizontal heat transfer on vertical 8.29 W/m2K 5.13 W/m2K
surfaces
Upward heat transfer on horizontal 9.26 W/m2K 5.13 W/m2K
surfaces
Downward heat transfer on horizontal 6.13 W/m2K 5.13 W/m2K
surfaces
1.4.1.10 Mechanical System and Control
An ideal mechanical system is used to control the temperature of the primary zone. This means that
the equipment has a 100% efficiency, with no duct losses and no capacity limitations. It has the
following characteristics:
−
Heat capacity = 1000 kW (effectively infinite)
Purely convective
−
Cooling capacity = 1000 kW (effectively infinite)
Purely convective, sensible cooling only; no latent load calculation
The thermostat is non proportional in the sense that when the air temperature exceeds the thermostat
cooling set point, the heat extraction rate is assumed to equal the maximum capacity of the cooling
equipment. Likewise, when the air temperature drops below the thermostat heating set point, the heat
addition rate equals the maximum capacity of the heating equipment. A proportional thermostat model
can be made to approximate a non proportional thermostat model by setting a very small throttling
range (the minimum allowed by your program). The set points are:
Heating = on if temp < 20°C
Cooling = on if temp > 27°C
1.4.2
Case 1800
Case 1800 is the same as the base case 800 except for the following specifications.
1.4.2.1
Ground Coupling/ Adiabatic Zone
A second “basement” zone is specified. This zone is a nearly adiabatically insulated box except for the
top of this box which is connected to the floor of the primary zone. Walls and floor of the basement
face to ground with a constant temperature of 10 °C.
The basement is a free floating zone with no system equipment and without any control.
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1.4.2.2
Drawings and Plans
2.7 m
Primary Zone
2.7 m
Secondary Zone - Basement
Tground 10°
Figure 1-2 Cross Section
1.4.2.3
Material specifications
Table 1-9 Material Specifications (Metric)
Exterior Wall (inside to outside)
ELEMENT
k
(W/mK)
Int. Surf Coeff. (see note 2)
Concrete block
0.510
Foam Insulation
0.040
Wood Siding
0.140
Ext. Surf Coeff.
Thickness
U
(m)
(W/m2K)
8.290
0.100
5.100
1.004
0.651
0.009
15.556
29.300
Total air-air
Total surf - surf
Roof (inside to outside)
ELEMENT
Int. Surf Coeff.
Plasterboard
Foam Insulation
Roofdeck
Ext. Surf. Coeff..
0.039
0.039
k
Thickness
U
(W/mK)
(m)
(W/m2K)
8.290
0.160
0.010
16.000
0.040
1.004
0.0398
0.140
0.019
7.368
29.300
Total air-air
Total surf - surf
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0.039
0.040
R
(m2K/W)
0.121
0.196
25.1
0.064
0.034
Density
(kg/m3)
CP
(J/kgK)
1400.000 1000.000
10.000
1400.000
530.000 900.000
25.515
25.360
R
Density
CP
(m2K/W) (kg/m3) (J/kgK)
0.121
0.063
950.000 840.000
25.1
10.000
1400.000
0.136
530.000 900.000
0.034
25.454
25.299
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Floor (inside to basement)
ELEMENT
Int. Surf Coeff.
Concrete slab
Insulation
Reinforced concrete
Int. Surf Coeff.
k
Thickness
U
(W/mK)
(m)
(W/m2K)
8.290
1.130
0.080
14.125
0.040
0.050
0.800
1.800
0.200
9.000
8.290
Total air-air
Total surf - surf
0.597
0.698
R
(m2K/W)
0.121
0.071
1.250
0.111
0.121
Density
(kg/m3)
CP
(J/kgK)
1400.000 1000.000
10.000
1400.000
2400.000 1100.000
1.674
1.432
Wall basement (inside to ground)
ELEMENT
k
Thickness
U
R
Density
CP
(W/mK)
(m)
(W/m2K) (m2K/W) (kg/m3) (J/kgK)
Int. Surf Coeff.
8.290
0.121
Insulation
0.040
1.007
0.040
25.175
10.000
1400.000
Total air-air
Total surf - surf
0.040
0.040
25.296
25.175
Surface Summary
Component
Wall
Floor
Roof
- 3 Layer
Basement Floor
Basement Wall
1.4.2.4
Area
(m2)
75.6
48.0
48.0
UA
(W/K)
38.727
28.656
15.253
48.0
75.6
1.892
2.988
Highly Conducting Wall / Opaque Window
The highly conducting wall is removed.
1.4.2.5
Infiltration
Infiltration is set to 0.
1.4.2.6
Internally Generated Heat (Casual Gains)
Internal gains are set to 0.
1.4.3
Case 1805
Case 1805 is the same as case 1800 except for the following specifications.
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1.4.3.1
Infiltration
Infiltration is set to 1.0, with the same adjustment as for the base case (see section 1.4.1.6).
1.4.3.2
Internally Generated Heat (Casual Gains)
Table 1-10 Internal Gain
Case
1805
Gain (W)
200
1.4.4
Radiative portion
0%
Convective portion
100%
Case 1810
Case 1810 is the same as case 1805 except for the following specifications.
1.4.4.1
Constant Temperature Layer
A constant temperature layer is inserted in the floor construction between the top concrete slab and the
insulation layer.
Its temperature is maintained constantly at the following values:
Winter Period (from October 1 to April 30):
40°
Summer Period (from May 1 to September 30): 20°
1.4.4.2
24 hours/day
24 hours/day
Floor surface heat transfer
If your program allows it, the surface coefficients for the heated/cooled floor and ceiling shall be
specified by the method developed by EMPA [1-2] as follows:
For floor heating systems the combined surface coefficient is a function of the difference between the
mean floor temperature and the room-temperature.
hs = 8.92*(υTfloor – υTra)0.1
Total combined interior surface coefficient [W/m2K]
hs
υTfloor Mean floor heat layer temperature [°C]
Room temperature [°C]
υTra
Diagram 1-1 Combined interior surface coefficient for floor heating system
12.0
hs [W/m2K]
11.0
10.0
9.0
8.0
7.0
6.0
0
1
2
3
4
5
6
7
(υT floor – υTra) [K]
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For the cooling case, the surface coefficient depends on the convective fraction of the heat sources.
The dependency is shown in Diagram 1-2
Combined interior surface coefficient for radiant cooling systems with
(υTra- υTfloor) =1K
Total combined interior surface coefficient hs [W/m2K]
Diagram 1-2
12
10
only Floor
8
Ceiling
6
Floor
4
2
vra- vf
Factor
1.0
1.00
2.0
1.07
3.0
1.12
4.0
1.15
0
0
20
40
60
80
100
Convective part of the internal heat source [%]
Only floor:
One conditioned surface (either floor or ceiling). Use this function for the Radtest
Ceiling:
Combined surface coefficient for ceiling if the floor is conditioned at the same time.
Floor:
Combined surface coefficient for floor if the ceiling is conditioned at the same time.
For other temperature differences hs is multiplied with the factor in Diagram 1-2 or with the calculated
value with:
hs,eff = hs(υTra- υTfloor)0.1
hs,eff
hs
υTfloor
υTra
Corrected Total combined interior surface coefficient [W/m2K]
Total combined interior surface coefficient [W/m2K]
Mean floor heat layer temperature [°C]
Room temperature [°C]
As a deviation from the above description, for case 1810 the heat transfer on the top surface of the
floor shall be assumed to be purely convective, but using the values for the combined coefficient.
1.4.5
Case 1815
Case 1815 is the same as case 1810 except for the following specifications.
1.4.5.1
Floor surface heat transfer
The heat transfer on the top surface of the floor is assumed to be combined radiative and convective
according to the program’s assumptions. If there is a need for a definition, assume 45 % to be
convective. The radiative portion is connected only to the ceiling.
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1.4.6
Case 1820
Case 1820 is the same as case 1815 except for the following specifications.
1.4.6.1
Floor surface heat transfer
The radiative portion of the floor surface heat transfer is connected to all surfaces according to the
program’s normal assumptions.
1.4.7
Case 1830
Case 1830 is the same as case 1820 except for the following specifications.
1.4.7.1
Exterior Walls
The wall and roof constructions of the primary zone are replaced by the ones from case 800 (see
section 1.4.1.4).
1.4.7.2
Infiltration
The infiltration air exchange rate in the primary zone is set to 0.5 with the same assumptions as in case
800 (see section 1.4.1.6).
1.4.8
Case 1840
Case 1840 is the same as case 1830 except for the following specifications.
1.4.8.1
High conductance Wall / Opaque Window
The high conductance wall / opaque window from case 800 is introduced in the south (see section
1.4.1.5).
1.4.8.2
Internally Generated Heat (Casual Gains)
The internal heat gains are set to the values of case 800 (see section 1.4.1.7).
1.4.9
Case 1850
Case 1850 is the same as case 1840 except for the following specifications.
1.4.9.1
Transparent Window
The high conductance wall / opaque window is replaced by a real transparent window.
Many programs use different algorithms to calculate window transmittance, and therefore require
different inputs. Therefore, a great deal of information about the window properties is provided so that
equivalent input for the window will be possible for these programs. The basic properties of the
window are provided in Table 1-11. The angular dependence of direct beam transmittance is given in
Table 1-12. Additional information can be found in the glazing tables that were derived from Snell’s
Law, Bouger’s Law , and the Fresnel Equation ( Appendix E). For Programs that need transmittance
or reflectance at other angles of incidence, calculate them using equations given with the glazing
tables, or interpolate between the values in the glazing tables. Where other unspecified data is needed,
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then values that are consistent with those tabled will have to be calculated. For more information on
glazing optical properties see Appendix E of ENVELOPE BESTTEST [1-1].
Tab. 1-11 Window properties
Property
Extinction coefficient
Number of panes
Pane thickness (standard 1/8” glass under the inchpound [IP] system)
Air-gap thickness
Index of refraction
Normal direct-beam transmittance through one pane in
air
Conductivity of glass
Conductance of each glass pane
Combined radiative and convective coefficient of air
gap (hs)
Exterior combined surface coefficient (ho)
Interior combined surface coefficient (hi)
U-value from interior air to ambient air
Hemispherical infrared emittance of ordinary uncoated
glass
Value
0.0196/mm
2
3.175 mm
13 mm
1.526
0.86156
1.06 W/mK
333 W/m2K (R- 0.003 m2K/W)
6.297 W/m2K (R- 0.1588 m2K/W)
21.00 W/m2K (R- 0.0476 m2K/W)
8.29 W/m2K (R- 0.1206 m2K/W)
3.00 W/m2K (R- 0.3333 m2K/W)
0.84 (use 0.9 for simplicity of input. If your
program must use 0.84, this is acceptable
because the effect on outputs will be less
than 0.5%.)
Density of glass
2500 kg/m3
Specific heat of glass
750 J/kgK
Curtains, blinds, frames, spacers; mullions, obstructions None
inside the window
Double pane shading coefficient (at normal incidence) 0.916
Double pane solar heat gain coefficient (at normal 0.787
incidence)
Table 1-12 Angle Dependence of direct-beam transmittancea for double pane window
Angle of
incidence
Transmittance
0
10
20
30
40
50
60
70
80
0.74745 0.74682 0.74465 0.73989 0.72983 0.70733 0.65233 0.51675 0.26301
a
Transmittance is defined as total direct-beam transmittance through the window assembly (no other
solar absorbtance or reflectance, or transmission of radiation reflected from the room back out the
window is included in these values)
1.4.9.2
Interior Solar Distribution
If your program does not calculate this effect internally, but requires distribution fractions from the
user, assume that 100% of the incoming radiation strikes the floor first, and that all reflections are
diffuse. Table 1-13 presents an approximate calculation of solar distribution fractions. Only use these
approximations if your program does not provide a more detailed approach.
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Table 1-13 Interior Solar distribution fraction versus window orientation and interior short-wave
absorbance
Surface
Floor
Ceiling
North wall
East Wall
South Wall
West Wall
Solar lost through window
Fraction [-]
0.642
0.168
0.053
0.038
0.026
0.038
0.035
Appendix F of ENVELOPE BESTEST [1-1] has a detailed description of the algorithm used for
calculating these solar fractions. Briefly, the calculations assume that:
−
No solar radiation is directly absorbed by the zone air.
−
All incident solar radiation initially hits the floor
−
The fraction or radiation initially absorbed by the floor is the interior short-wave
absorbance
−
The remaining solar radiation is diffusely reflected such that it is distributed over the
other surfaces in proportion on their shape factors (Kreith and Bohn 1993)
−
The fraction of radiation absorbed by these surfaces is the interior short-wave
absorbance.
−
The remaining amount of the original as sunlight (after the second “bounce”) is then
assumed to be absorbed by all surfaces in proportion to their area-absorbance
products.
Fractional values for the walls with windows include the portion of the solar radiation absorbed by the
glass (as it passes back out the window) and conducted into the zone. Solar radiation absorbed by the
glass (and conducted inwards) as it passes into the buildings is treated by most programs in their
window transmissivity algorithms, and is therefore not included in the values in Table 1-8.
1.4.10 Case 1860
Case 1860 is the same as case 1850 except for the following specifications.
1.4.10.1 Internally Generated Heat (Casual Gains)
The internal heat gains are assumed to be 100 % radiative.
1.4.11 Case 1870
Case 1870 is the same as case 1850 except for the following specifications.
1.4.11.1 Internally Generated Heat (Casual Gains)
The internal heat gains are assumed to be 100 % convective.
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1.4.12 Case 1880
Case 1880 is the same as case 1850 except for the following specifications.
1.4.12.1 Constant Temperature Layer
The temperatures of the constant temperature layer are set to the following values:
Winter Period (from October 1 to April 30):
30°
Summer Period (from May 1 to September 30): 18°
24 hours/day
24 hours/day
1.4.13 Case 1890
Case 1890 is the same as case 1850 except for the following specifications.
1.4.13.1 Constant Temperature Layer
The constant temperature layer is operated in the following manner:
Winter Period (from October 1 to April 30):
40°
Summer Period (from May 1 to September 30): 20°
24 hours/day
on from 20:00 to 6:00
1.4.14 Case 2800
Case 2800 is the same as case 1850 except for the following specifications.
1.4.14.1 Detailed water loop
The most detailed possible model shall be used with the following data:
0.30
0.30
0.30
Return Temp. 35/25°C
6.00
Supply Temp. 40/20°C
8.00
Figure 1-3: Floor plan for detailed cooling system: Case 2800/2810
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Table 1-14: System parameters
Design Cooling Power
Massflow
Design supply temperature Winter/Summer
Design return temperature Winter/Summer
3500 W
0.167 kg/s
40/20 °C
35/25 °C
Table 1-15: Water pipe specifications
Material
Outside diameter
Inner diameter
Total pipe length
Roughness
Density
Conductivity
PEX
0.025 m
0.020 m
139.2 m
0.007 mm
938 kg/m3
0.35 W/mK
The flow temperatures of the detailed water loop (floor heating and cooling system) are set as follows:
Winter Period (from October 1 to April 30):
40°
Summer Period (from May 1 to September 30): 20°
24 hours/day
24 hours/day
1.4.15 Case 2810
Case 2810 is the same as case 2800 except for the following specifications.
1.4.15.1 Detailed Water Loop Operation
Winter Period (from October 1 to April 30):
40°
Summer Period (from May 1 to September 30): 20°
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
24 hours/day
on from 20:00 to 6:00
Matthias Achermann
Gerhard Zweifel
Page 2 3
1.4.16 Summarised Input Values Table
Table 1-16 Summarised input values table
Case Setp.
H,C
INTGEN
W
800 20, 27 200
1800 20, 27
0
ACH
INT IR EXT IR
INT SW
EXT SW
RAD CONV INFIL EMISS EMISS ABSORP ABSORP
0.6
0.4
GLASS
0.5
0.9
0.9
NA
0.6
m2
ORIENT
HC-W / S
LAYER
CONS
AD
NA
SCHED NEXT
LOC TEMP
h
TO
NA
NA
AD
BA
0
0
0
0.9
0.9
NA
0.6
0
3L
Mid
NA
NA
1805 20, 27 200
0
1.0
1.0
0.9
0.9
NA
0.6
0
3L
Mid
NA
NA
BA
1810 20, 27 200
0
1.0
1.0
0.9
0.9
NA
0.6
0
3L
Mid
40/20
24
BA
1815 20, 27 200
0
1.0
1.0
0.9
0.9
NA
0.6
0
3L
Mid
40/20
24
BA
1820 20, 27 200
0
1.0
1.0
0.9
0.9
NA
0.6
0
3L
Mid
40/20
24
BA
1830 20, 27 200
0
1.0
0.5
0.9
0.9
NA
0.6
0
3L
Mid
40/20
24
BA
1840 20, 27 200
0.6
0.4
0.5
0.9
0.9
0.6
0.6
HC-W / S
3L
Mid
40/20
24
BA
1850 20, 27 200
0.6
0.4
0.5
0.9
0.9
0.6
0.6
12 / S
3L
Mid
40/20
24
BA
1860 20, 27 200
1.0
0.0
0.5
0.9
0.9
0.6
0.6
12 / S
3L
Mid
40/20
24
BA
1870 20, 27 200
0.0
1.0
0.5
0.9
0.9
0.6
0.6
12 / S
3L
Mid
40/20
24
BA
1880 20, 27 200
0.6
0.4
0.5
0.9
0.9
NA
0.6
12 / S
3L
Mid
30/18
24
BA
1890 20, 27 200
0.6
0.4
0.5
0.9
0.9
NA
0.6
12 / S
3L
Mid
40/20
24/10
BA
2800 20, 27 200
0.6
0.4
0.5
0.9
0.9
0.6
0.6
12 / S
3L
Mid
40/20
24
BA
2810 20, 27 200
0.6
0.4
0.5
0.9
0.9
0.6
0.6
12 / S
3L
Mid
40/20
24/10
BA
Abbreviations
H, C
INTGEN
ACH INFIL
INT / EXT IR EMISS
INT / EXT SW ABSORP
ORIENT
HC-W / S
NA
Heating and Cooling
Internal gains
Air changes per hour infiltration
Internal /external infrared emissivity
Internal/external short-wave absorption
Orientation S = south
Highly conductive wall / south
Not active. No input value required
LAYER
- CONS
- LOC
- TEMP
SCHED
NEXT TO
Active temperature layer
Floor construction AD= adiabatic,
1L = 1layer, 3L = 3 layers
Location of active layer
Temperature of active layer
Schedule of active layer
Boundary from the floor of active zone
Adiabatic floor, BA = Basement
1.4.17 Required Outputs
All results should be inserted in the pre-formatted EXCEL sheet (RAD_RES.xls) on the enclosed CD.
Instructions for using the spreadsheet are included at the top of the sheet and in Section 6.
1.4.17.1 Annual Outputs
The annual outputs are as follows:
Primary zone
− Annual Heating and Cooling loads for all cases (MWh).
− Annual hourly integrated peak heating and cooling loads (kW) with the data and hour
when they occur.
− Annual hourly integrated maximum and minimum room temperature (°C) with date
and hour when they occur.
− Annual hourly integrated maximum and minimum floor surface temperature (°C) with
date and hour when they occur.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 2 4
AD
=
Secondary Zone (Basement)
Annual hourly integrated maximum and minimum room temperature (°C) with date and hour when
they occur.
Detailed water loop
Annual hourly integrated maximum and minimum return water temperature (°C)
1.4.17.2 Daily Hour Outputs
If the program can produce hourly outputs, produce the hourly values for the specific day periods as
shown in Table 1-17. To produce this output, run the program for normal annual run. Do not just run
the required days because your result could contain temperature history errors.
Table 1-17 Hourly output files
Hourly outputs
Hourly room temperatures (°C) (Primary zone and basement)
Hourly floor surface temperature of primary zone
Hourly heating(+) and cooling (-) (kWh) (designate cooling with
a (-) sign)
Upward heat (+) and cool (-) flow from temperature layer
Downward heat (+) and cool (-) flow from temperature layer
Return water temperature (°C)
Case number
all
1820 to 2810
all
Day
Jan 2-5./July 27-30
Jan 2-5./July 27-30
Jan 2-5./July 27-30
1810 to 2810
1810 to 2810
2800 to 2810
Jan 2-5./July 27-30
Jan 2-5./July 27-30
Jan 2-5./July 27-30
Table 1-18 Required Outputs
Case
Zone 1
T room
T floor
Q heat
Q cool
Zone 2
L to Z*
Water loop
T room
Heat flux
Return water
temperature
UP
DOWN
800
1800
1805
1810
1815
1820
1830
1840
1850
1860
1870
1880
1890
2800
2810
Description
Opaque window basic case 800 from
ENVELOPE-BESTEST
Fully insulated 2 zone model
Internal and external loads
Active layer only convective
Radiation only to ceiling
Normal distribution to all surfaces
Normal insulated construction
Opaque window
Real Window
Influence of internal gains 100% rad.
Influence of internal gains 100% conv.
Lower temp. level case
Schedule for summer 8pm to 6am
Detailed water loop
Detailed water loop
* Active layer to zone
1.4.17.3 Excelsheet
Pre-formatted EXCEL sheet for required output data. Please fill the generated yearly hourly values in
the predefined folder (case number) in the EXCEL sheet called RAD_RES.xls. The daily output will
automatically be extracted from the yearly values.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 2 5
1.5 References
[1-1] Judkoff R., Neymark J. (1995) ENVELOPE BESTEST: Building Energy Simulation Test and
Diagnostic Method. International Energy Agency, Solar Heating and Cooling Programm -Task
12 and Buildings and Community Systems Annex 21, NREL/TP-472-6231
[1-2] Koschenz M., Lehmann B. (2000): Thermoaktive Bauteile; EMPA, Zentrum für Energie und
Nachhaltigkeit (ZEN), 8600 Dübendorf, Switzerland, ISBN 3-905594-19-6
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 2 6
2 Part II: Production of Example Results
2.1 Participating Organisations
The final results of the participant of the IEA Task 22 RADTEST are presented in this report. The
interpretation of the results refer to the programs listed in table 2-1.
Table 2-1: Participating programs and authors
Authoring organization
Implemented by
TRNSYS
Transsolar/TUD
TUD, Dresden University of
Technology
Germany
DOE 2.1E
LBL
IDA-ICE 3.0
EQUA Sweden
HANS DÜRIG AG - Simulation für
Gebäudeenergie
Riggisberg, Switzerland
Lucerne School of Engineering and
Architecture, University of Applied
Science of central Switzerland
CLIM2000
EDF
EDF, France
ESP-r/HOT3000
CANMET
CANMET Energy Technology
Centre, Ottawa, Canada
The results were produced in a first round as a blind test. This is a good solution to improve the test
specification. According the results of the first round, some errors in the test specification were
detected and the specification was modified and adjusted. Obvious disagreement between results from
different programs were discussed and improved in a second round. In some cases a third round was
necessary to eliminate program bugs or faults because of misinterpretation of the specification. Bugs
and modelled errors are listed in section 2.5 “modeller reports”.
2.2 Interpretation of Results
2.2.1
“Overall” and “Delta” Results (Section 2.4.1 and 2.4.2)
The final results from the participating programs are presented in tables and diagrams. There are no
maximum and minimum ranges set for the diagnostic cases, because diagnostics will be performed by
specialists for whom such simplifications will not be necessary. The ranges of the participating
programs do not represent truth. They do represent the best current state-of-the-art in whole building
simulation predictions for radiant heating and cooling systems. There is no truth standard in this type
of exercise. For any given case, a program that yields values in the middle of the range should not be
perceived as better or worse than a program that yields values at the border of the range. The range
represents algorithmic differences in the current state-of-the-art as defined by the group of
international experts from IEA TASK 22. Investigating the source(s) of the difference(s) is
worthwhile, but the existence of a difference does not necessarily mean a program is faulty. The
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 2 7
experience in that field shows, that when programs show a major disagreement with a range, often a
bug or questionable algorithms can be found. The results show a certain amount of disagreement
among the programs for many of the cases. The reference ranges reflect this disagreement.
There is a large amount of output data. Not all results can be described in detail. Some trends are
apparent as evidence in the section overall results (Section 2.4.1 and 2.4.2). Observing the results from
cases 1800 up to 2810, the results are not varying extremely. The criteria to judge the deviation of the
results is the deviation from case 800, which correspond to the boundaries of case 800 from
ENVELOPE BESTEST. It presents the spread of more than the five participating programs. All cases
without the radiant floor system (case 800 to 1810) show a good agreement with the deviation
boundaries from ENVELOPE BESTEST.
Observing the results from case 1815 up to 2810, the results are not varying extremely. The deviation
of the room and surface temperatures shows an almost homogeneous behaviour. As listed in Table 22, the values are lying all in a range of 10% or less.
Table 2-2: Deviation of room and surface temperatures from mean value in %
Temperatues - mean % differences
100.00
90.00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
800
1800
1810
1820
1830
1840
1850
1860
1870
1880
1890
2800
3.67
2.48
1.00
1.17
0.60
1.81
2.24
1.96
2.64
3.90
1.81
3.24
3.25
Tbase Mean
10.07
10.07
10.07
9.50
12.26
12.26
12.26
12.26
10.32
15.67
6.35
5.50
Tbase Max
11.30
11.30
11.30
10.53
10.53
10.53
10.53
10.53
9.42
10.53
2.13
1.98
Tbase Min
4.56
4.56
14.94
Tactive Mean
2810
4.56
6.88
16.06
16.06
16.06
16.06
12.55
29.63
16.25
Tsurf Mean
1.07
0.58
1.73
2.60
2.69
2.41
1.95
2.69
5.72
6.38
Tsurf Max
1.49
2.09
4.33
12.32
12.14
12.15
12.39
12.25
22.14
22.40
Tsurf Min
0.90
1.07
2.80
3.73
3.32
3.56
3.81
4.77
4.01
3.49
The highest variation is seen for the basement temperature. This is due to the free floating temperature
in that space, and that the basement is semi-adiabatic so that small variations in heat flows to the
basement can easily result in large basement temperature variations. Also, on this graph case 1890 is
the one with the highest spread of the deviation. It is the one with the lower set points. This means that
the influence of the floor heating system is not as strong as on a higher temperature level. The heating
and cooling equipment are out of control and the temperatures are free floating in between the dead
band.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 2 8
2.2.2
Detailed temperature values (Section 2.4.3 and 2.4.4)
To compare the behaviour of the room conditions, the temperatures are compared for several days
under winter and summer conditions. Different trends are apparent.
-
Case 1810, which has a purely convective heat transfer coefficient for the floor, shows a wide
spread over the three participating programs. If the combined coefficient is used, the results
are much closer. If the radiation part is distributed to all surfaces, the results are even closer.
In contrast with the room temperature, the floor surface temperatures correspond for all cases
almost perfectly.
-
For all cases the floor surface temperatures show good agreement, except for DOE-2, which
has a serious problem. In the real window case, the floor surface temperatures from DOE-2 are
much lower (less sensitive on radiation) than the other programs.
-
The detailed water loop results are in good agreement.
-
The influence of the 100% convective or radiative fraction of the internal gains has no big
influence on the room and surface temperatures. This statement is only valid for these special
cases – if the fractions of internal and external loads are different, the result can vary much
more.
2.3 Conclusions
The different approaches of modelling radiant heating and cooling systems lead to satisfying results.
The simple approach of an active temperature layer, to provide cooling or heating load to the active
zone shows a good agreement between the different programs. It is interesting to see that programs
like DOE-2.1E, which has not a special radiant heating system included, can be used and modified in a
way that leads to reasonable results (except for surface temperature calculations). Some questions
should be cleared concerning cases 1810 to 1830. An analytical comparison between the convective
heat surface coefficient should clarify if the deviation between the results comes from different
algorithms or if they are affected by the modeller’s modifications.
Over all, it may be said that all the participating programs calculate the radiant floor systems in the
same way. To use this approach to estimate floor temperatures and energy consumptions is a reasonnable approach.
If the investigations go much deeper in detail, a detailed water loop system is necessary. In that field
the RADTEST should provide more test cases in a future work. The aim of further tests should focus
on:
−
Different pipe configurations
−
Different control strategies on different temperature levels.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 2 9
2.4 Graphical Results
2.4.1
2.4.1.1
Overall Results
Case 800 benchmark (correspond to ENVELOPE BESTEST case 800)
All programs
are in the
range of case
800 from IEA
Task 12
ENVELOPE
BESTEST
Annual heating energy
8.000
7.000
6.000
5.000
[MWh] 4.000
3.000
2.000
1.000
0.000
CASE 800
ESP-UKDMU
BLASTUS/IT
DOE2-USA
4.868
5.953
7.228
SRES/SUN- SERIRESUSA
UK-BRE
6.611
6.600
S3PASSPAIN
TRNSYSBEL/UK
TASEFINLAND
IDA-SUI
CLIM2000F
ESP-CAN
6.161
5.940
5.86
5.160
7.236
4.875
CLIM2000 is
on the edge
of the
boundaries.
But still ok.
Annual cooling energy
0.350
0.300
0.250
0.200
[MWh]
0.150
0.100
0.050
0.000
CASE 800
ESP-UKDMU
BLASTUS/IT
DOE2-USA
0.113
0.224
0.055
SRES/SUN- SERIRESUSA
UK-BRE
0.272
0.222
S3PASSPAIN
TRNSYSBEL/UK
TASEFINLAND
IDA-SUI
CLIM2000F
ESP-CAN
0.195
0.207
0.33
0.298
0.038
0.209
S3PASSPAIN
T RNSYSBEL/UK
T ASEFINLAND
IDA-SUI
CLIM2000F
ESP-CAN
3.902
3.786
3.94
3.586
3.984
3.370
S3PASSPAIN
TRNSYSBEL/UK
TASEFINLAND
IDA-SUI
CLIM2000F
ESP-CAN
1.028
0.983
1.36
0.928
0.833
0.810
P eak h eatin g load
4.500
4.000
3.500
3.000
[MW h]
2.500
2.000
1.500
1.000
0.500
0.000
CASE 800
ESP-UKDMU
BLAST US/IT
DOE2-USA
3.227
3.793
3.909
SRES/SUN- SERIRESUSA
UK-BRE
4.138
4.188
Peak cooling load
1.600
1.400
1.200
1.000
[MWh] 0.800
0.600
0.400
0.200
0.000
CASE 800
ESP-UKDMU
BLASTUS/IT
DOE2-USA
0.585
0.967
0.743
SRES/SUN- SERIRESUSA
UK-BRE
1.352
1.382
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 3 0
2.4.1.2
Overall results case 800 to 2810
The annual additional
heating consumption is
reduced by the heat
emitted by the active
floor.
Annual heating demand
[MWh]
8.000
7.000
6.000
5.000
4.000
3.000
2.000
1.000
0.000
800
1800
1805
TRNSYS
1810
DOE
IDA
1815
CLIM2000
1820
1830
ESP
The cooling energy
demand is increased
by the influence of the
heated floor in the
intermediate season.
Annual cooling demand
[MWh]
14.000
12.000
10.000
6
8.000
6.000
4.000
2.000
0.000
800
1800
1805
TRNSYS
1810
DOE
IDA
1815
CLIM2000
1820
1830
1820
1830
1820
1830
ESP
Max. heating power
[kW]
4.500
4.000
3.500
3.000
2.500
2.000
1.500
1.000
0.500
0.000
800
1800
1805
TRNSYS
1810
DOE
IDA
1815
CLIM2000
ESP
Max. cooling power
[kW]
4.000
3.500
3.000
2.500
2.000
1.500
1.000
0.500
0.000
800
1800
1805
TRNSYS
1810
DOE
IDA
1815
CLIM2000
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
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Gerhard Zweifel
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Annual heating demand
[MWh]
1.400
1.200
1.000
0.800
0.600
0.400
0.200
0.000
1840
1850
1860
TRNSYS
1870
DOE
1880
IDA
1890
CLIM2000
2800
2810
2800
2810
2800
2810
2800
2810
ESP
Annual cooling demand
[MWh]
16.000
14.000
12.000
10.000
8.000
6.000
4.000
2.000
0.000
6
1840
1850
1860
TRNSYS
1870
DOE
1880
IDA
CLIM2000
1890
ESP
Max. heating power
[kW
2.500
2.000
1.500
1.000
0.500
0.000
1840
1850
1860
TRNSYS
1870
DOE
1880
IDA
CLIM2000
1890
ESP
Max. cooling power
[kW]
9.000
8.000
7.000
6.000
5.000
4.000
3.000
2.000
1.000
0.000
1840
1850
1860
TRNSYS
1870
DOE
1880
IDA
CLIM2000
1890
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 3 2
2.4.1.3
Room temperatures: Active zone (case 800 to 2810) and basement (case 1800 to 2810)
The room
temperatures cannot
vary extremely due to
the small dead band.
Annual mean room temperature active zone
[°C]
30.0
25.0
20.0
15.0
10.0
5.0
0.0
800
1800
1805
TRNSYS
1810
DOE
IDA
1815
CLIM2000
1820
1830
ESP
Annual mean room temperature basement
[°C]
The free floating
basement temperatures
show a wider range.
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
800
1800
1805
TRNSYS
1810
DOE
IDA
1815
CLIM2000
1820
1830
1820
1830
1820
1830
ESP
Maximum room temperature basement
[°C]
50.0
40.0
30.0
20.0
10.0
0.0
800
1800
1805
TRNSYS
1810
DOE
IDA
1815
CLIM2000
ESP
Minimum room temperature basement
[°C]
25.0
20.0
15.0
10.0
5.0
0.0
800
1800
1805
TRNSYS
1810
DOE
IDA
1815
CLIM2000
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 3 3
Annual mean room temperature active zone
The room
temperatures cannot
vary extremely due to
small dead band.
[°C]
30.0
25.0
20.0
15.0
10.0
5.0
0.0
1840
1850
1860
TRNSYS
1870
DOE
1880
IDA
CLIM2000
1890
2800
2810
ESP
Annual mean room temperature basement
[°C]
40.0
The free floating
basement temperatures
show a wider range.
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
1840
1850
1860
TRNSYS
1870
DOE
1880
IDA
CLIM2000
1890
2800
2810
2800
2810
2800
2810
ESP
Maximum room temperature basement
[°C]
50.0
40.0
30.0
20.0
10.0
0.0
1840
1850
1860
TRNSYS
1870
DOE
1880
IDA
CLIM2000
1890
ESP
Minimum room temperature basement
[°C]
30.0
25.0
20.0
15.0
10.0
5.0
0.0
1840
1850
1860
TRNSYS
1870
DOE
1880
IDA
CLIM2000
1890
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 3 4
2.4.1.4
Floor surface temperatures active zone
(case 1830 to 2810)
Maximum surface temperature active zone
[°C]
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
800
1800
1805
TRNSYS
1810
DOE
IDA
1815
CLIM2000
1820
1830
ESP
Minimum surface temperature active zone
[°C]
25.0
20.0
15.0
10.0
5.0
0.0
800
1800
1805
TRNSYS
1810
DOE
IDA
1815
CLIM2000
1820
1830
1820
1830
ESP
Mean surface temperature active zone
[°C]
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
800
1800
1805
TRNSYS
1810
DOE
IDA
1815
CLIM2000
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 3 5
Maximum surface temperature active zone
[°C]
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
1840
1850
1860
TRNSYS
1870
DOE
1880
IDA
CLIM2000
1890
2800
2810
2800
2810
2800
2810
ESP
Minimum surface temperature active zone
[°C]
25.0
20.0
15.0
10.0
5.0
0.0
1840
1850
1860
TRNSYS
1870
DOE
1880
IDA
CLIM2000
1890
ESP
Mean surface temperature active zone
[°C]
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
1840
1850
1860
TRNSYS
1870
DOE
1880
IDA
CLIM2000
1890
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
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Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 3 6
2.4.1.5
Annual heat fluxes case 1820 to 2810
Annual upward heat flux from active layer
[MWh]
25.000
20.000
15.000
10.000
5.000
0.000
1810
1815
1820
TRNSYS
DOE
1830
IDA
CLIM2000
1840
1850
ESP
Annual downward heat flux from active layer
[MWh]
1.000
0.800
0.600
0.400
0.200
0.000
1810
1815
1820
TRNSYS
DOE
1830
IDA
CLIM2000
1840
1850
ESP
Max. upward heat flux from active layer
[kW]
25.000
20.000
15.000
10.000
5.000
0.000
1810
1815
TRNSYS
1820
DOE
1830
IDA
CLIM2000
1840
1850
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 3 7
Annual upward heat flux from active layer
[MWh]
25.000
20.000
15.000
10.000
5.000
0.000
-5.000
1860
1870
1880
TRNSYS
DOE
1890
IDA
CLIM2000
2800
2810
ESP
Annual downward heat flux from active layer
[MWh]
3.000
2.500
2.000
1.500
1.000
0.500
0.000
1860
1870
1880
TRNSYS
DOE
1890
IDA
CLIM2000
2800
2810
ESP
Max. upward heat flux from active layer
[kW]
25.000
20.000
15.000
10.000
5.000
0.000
1860
1870
TRNSYS
1880
DOE
1890
IDA
CLIM2000
2800
2810
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 3 8
2.4.2
Delta results
2.4.2.1
Delta Annual heating and cooling energy consumption - case 1800 to 2810
[MWh]
Delta - Annual heating load
4.000
3.000
2.000
1.000
0.000
-1.000
-2.000
-3.000
-4.000
1805- 1810- 1815- 1820- 1830- 1850- 1860- 1870- 1880- 1890- 2800- 28101800 1805 1810 1815 1820 1840 1850 1850 1850 1850 1850 2800
TRNSYS
3.076 -3.467 0.016 0.012 0.035 -0.181 0.025 -0.032 0.303
DOE
2.921
IDA
2.679 -3.064 0.016 0.017 -0.010 -0.064 0.028 -0.033 0.139 -0.047 -0.002 -0.043
0.027 -0.223 0.007 0.001 0.489 -0.115 -0.151 -0.031
-0.324 0.022 -0.032 0.720 -0.218 -0.194 -0.078
CLIM2000
ESP-r
-0.046 -0.071
3.093 -3.332 0.026 0.002 -0.029 -0.133 0.031 -0.036 0.235 -0.075
Delta -Annual cooling load
[MWh]
10.000
5.000
0.000
-5.000
-10.000
-15.000
1805- 1810- 1815- 1820- 1830- 1850- 1860- 1870- 1880- 1890- 2800- 28101800 1805 1810 1815 1820 1840 1850 1850 1850 1850 1850 2800
TRNSYS
0.028 5.255 1.627 3.164 -0.896 3.090 -0.217 0.329 -8.193
DOE
0.009
IDA
0.044 6.605 0.926 2.988 -0.852 3.643 -0.224 0.346 -8.714 0.493 -4.742 0.203
CLIM2000
ESP-r
-5.598 1.178
-2.498 5.402 -0.059 -0.010 -9.149 0.864 -3.780 0.743
4.144 -0.085 0.127 -11.38 0.495 -8.357 0.615
0.075 7.008 2.903 0.227 -0.562 3.071 -0.232 0.358 -9.124 0.434
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 3 9
Delta - Peak heating load
[kW]
2.000
1.500
1.000
0.500
0.000
-0.500
-1.000
-1.500
1805- 1810- 1815- 1820- 1830- 1850- 1860- 1870- 1880- 1890- 2800- 28101800 1805 1810 1815 1820 1840 1850 1850 1850 1850 1850 2800
TRNSYS
1.557 -1.295 0.009 0.016 0.202 -0.148 0.042 -0.064 0.323
DOE
1.471
IDA
1.345 -1.196 0.030 0.023 0.152 -0.003 0.041 -0.071 0.217 -0.071 0.087 -0.076
-0.151 0.022 -0.034 0.485 -0.110 -0.155 -0.034
CLIM2000
ESP-r
0.001 0.000
0.416 -0.067 0.013 0.003 0.454 -0.056 -0.353 -0.050
1.530 -1.240 0.010 0.000 0.050 -0.170 0.050 -0.070 0.340 -0.090
Delta - Peak cooling load
[kW]
4.000
3.000
2.000
1.000
0.000
-1.000
-2.000
-3.000
-4.000
1805- 1810- 1815- 1820- 1830- 1850- 1860- 1870- 1880- 1890- 2800- 28101800 1805 1810 1815 1820 1840 1850 1850 1850 1850 1850 2800
TRNSYS
0.358 1.567 0.310 0.618 0.071 1.929 -0.041 0.062 -2.097
DOE
0.277
IDA
0.341 1.747 0.171 0.587 0.250 2.835 -0.034 0.062 -2.437 -0.025 -0.319 0.066
CLIM2000
ESP-r
-0.869 0.005
0.319 3.152 -0.011 0.062 -2.220 0.054 -0.183 0.003
3.300 0.000 0.062 -3.240 0.000 -1.130 0.010
0.410 1.860 0.560 0.040 0.140 2.110 -0.030 0.062 -2.390 0.000
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 4 0
2.4.2.2
Delta room temperatures: active zone and basement (case 1800 to 2810)
Delta - Annual mean room temperature active zone
[°C]
5.0
4.0
3.0
2.0
1.0
0.0
-1.0
-2.0
1805- 1810- 1815- 1820- 1830- 1840- 1850- 1860- 1870- 1880- 1890- 2800- 28101800 1805 1810 1815 1820 1830 1840 1850 1850 1850 1850 1850 2800
TRNSYS
1.4
3.5
-0.4
-0.1
0.2
DOE
1.3
IDA
0.0
0.3
0.1
0.6
0.0
0.0
-1.3
0.6
0.3
0.4
1.3
3.9
-0.7
-0.2
0.2
0.1
0.5
-0.1
0.1
-1.2
0.3
0.0
0.3
0.4
0.0
0.0
-1.5
0.6
-0.1
0.4
0.9
3.2
-0.3
0.0
0.2
0.0
0.5
-0.1
0.2
-1.2
0.7
CLIM2000
ESP
0.5
-0.1
0.1
-1.4
0.1
0.8
Delta - Annual mean roomtemperature basement
[°C]
15.0
10.0
5.0
0.0
-5.0
-10.0
1805- 1810- 1815- 1820- 1830- 1840- 1850- 1860- 1870- 1880- 1890- 2800- 28101800 1805 1810 1815 1820 1830 1840 1850 1850 1850 1850 1850 2800
TRNSYS
1.2
9.7
0.0
0.0
0.0
DOE
1.2
IDA
0.0
0.0
0.1
0.0
0.0
0.0
-5.7
-0.1
-1.3
0.8
1.1
8.8
0.0
0.0
0.2
0.1
0.0
0.0
0.0
-5.8
0.9
-1.8
0.5
0.0
0.0
0.0
-7.0
1.0
-3.7
0.6
0.7
10.3
0.0
0.0
0.1
0.0
0.0
0.0
0.0
-6.6
1.4
CLIM2000
ESP
0.0
0.0
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
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Task 22: Building Energy Analysis Tools, Subtask C
0.0
-6.2
-2.6
1.8
Matthias Achermann
Gerhard Zweifel
Page 4 1
Delta - Max. roomtemperatue basement
[°C]
15.0
10.0
5.0
0.0
-5.0
-10.0
1805- 1810- 1815- 1820- 1830- 1840- 1850- 1860- 1870- 1880- 1890- 2800- 28101800 1805 1810 1815 1820 1830 1840 1850 1850 1850 1850 1850 2800
TRNSYS
5.1
DOE
4.6
13.0
0.0
IDA
4.1
12.0
0.0
3.2
13.7
0.0
0.0
0.0
0.0
0.0
0.0
0.0
-9.4
0.0
0.0
0.0
0.0
0.0
-8.7
0.0
-3.4
0.0
0.0
0.3
0.0
0.0
0.0
0.0
-8.7
0.0
-4.1
0.0
0.0
0.0
0.0
-10.0
0.0
-7.6
0.0
0.0
0.0
0.0
0.0
0.0
0.0
-10.0
0.0
CLIM2000
ESP
-5.6
0.1
Delta - Min. roomtemperatue basement
[°C]
3.0
2.0
1.0
0.0
-1.0
-2.0
-3.0
1805- 1810- 1815- 1820- 1830- 1840- 1850- 1860- 1870- 1880- 1890- 2800- 28101800 1805 1810 1815 1820 1830 1840 1850 1850 1850 1850 1850 2800
TRNSYS
0.0
DOE
0.0
0.3
0.0
IDA
0.0
0.5
0.0
0.0
1.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
-1.3
0.0
0.0
0.0
0.0
0.0
-1.8
-0.8
1.2
1.3
0.0
0.1
0.0
0.0
0.0
0.0
-1.7
1.4
1.2
1.4
0.0
0.0
0.0
-2.8
2.2
1.5
1.2
0.0
0.6
0.0
0.0
0.0
0.0
-2.0
2.4
CLIM2000
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
1.4
1.3
Matthias Achermann
Gerhard Zweifel
Page 4 2
2.4.2.3
Delta floor surface temperatures active zone (case 1805 to 2810)
Delta - Max surface temperatureactive zone
[°C]
15.0
10.0
5.0
0.0
-5.0
-10.0
1805- 1810- 1815- 1820- 1830- 1840- 1850- 1860- 1870- 1880- 1890- 2800- 28101800 1805 1810 1815 1820 1830 1840 1850 1850 1850 1850 1850 2800
TRNSYS
5.8
DOE
6.6
IDA
5.0
10.4
10.2
-0.5
-0.3
-0.9
-0.9
-0.1
0.2
2.9
0.0
-0.1
-6.6
-0.1
-0.3
0.0
0.1
0.0
-5.6
0.0
-4.4
0.0
0.1
0.0
3.5
0.0
-0.1
-6.3
0.0
-1.4
0.1
4.1
0.0
0.0
-5.4
0.0
3.1
0.0
-0.1
-6.3
0.0
CLIM2000
3.4
ESP
9.9
-0.8
-0.1
0.0
0.2
-2.5
0.0
Delta - Minimum surface temperatureactive zone
[°C]
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
TRNSYS
1805- 1810- 1815- 1820- 1830- 1840- 1850- 1860- 1870- 1880- 1890- 2800- 28101800 1805 1810 1815 1820 1830 1840 1850 1850 1850 1850 1850 2800
0.0
DOE
0.0
IDA
-0.7
0.4
0.0
0.0
-0.3
-0.1
0.1
0.0
0.7
0.0
0.0
0.0
-0.1
-0.4
-0.3
-0.1
0.0
CLIM2000
ESP
0.0
1.0
0.0
0.0
-0.4
-0.1
-0.1
-1.6
0.1
0.0
-1.0
0.1
-0.1
-1.7
0.0
0.0
0.0
-1.4
0.0
0.0
0.0
0.0
-1.5
0.0
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
-0.2
0.1
-0.2
0.8
0.0
0.0
-0.3
0.1
Matthias Achermann
Gerhard Zweifel
Page 4 3
Delta - Mean surface temperature active zone
[°C]
10.0
8.0
6.0
4.0
2.0
0.0
-2.0
-4.0
-6.0
1805- 1810- 1815- 1820- 1830- 1840- 1850- 1860- 1870- 1880- 1890- 2800- 28101800 1805 1810 1815 1820 1830 1840 1850 1850 1850 1850 1850 2800
TRNSYS
1.3
DOE
1.4
IDA
1.0
8.7
8.6
-0.3
-0.1
-0.5
-0.5
-0.3
-0.1
0.8
0.0
-0.1
-4.8
0.1
-0.2
0.2
0.0
0.0
-4.5
0.9
-2.0
0.6
-0.2
-0.1
0.9
0.0
-0.1
-4.8
0.9
-1.2
0.8
0.8
0.0
0.0
-4.4
0.9
-1.9
0.6
0.8
0.0
0.0
-4.7
1.2
CLIM2000
ESP
0.8
8.4
-0.5
0.0
-0.3
0.0
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
-1.7
0.7
Matthias Achermann
Gerhard Zweifel
Page 4 4
2.4.3
Detailed temperature values
This section on the RADTEST was focused on the different temperatures:
- room temperature in the active zone
- floor surface temperature in the active zone
- return water temperature (only cases 2800 and 2810)
The temperatures are plotted for a 4 day summer and winter period. The output values for the different
programs are placed in the same plot.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 4 5
2.4.3.1
Temperatures summer period from July 27 to 30.
Case 1800 – highly
insulated 2 zone model.
Room tem perature active zone case 1800
27
26
[°C]
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
29.07.
12:00
IDA
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
Room tem perature active zone case 1805
Case 1805 - Totally
insulated 2 zone model.
- Infiltration Ach=1.0 1/h
- Internal loads 200 W from
1st may to 30 September
(purely convective)
27
26
[°C]
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
29.07.
12:00
IDA
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
Room tem perature active zone case 1810
Case 1810- The constant
temperature layer between
the concrete layer and the
insulation
- Surface coefficient on
floor only convective.
27
26
[°C]
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
29.07.
12:00
IDA
ESP
30.07.
00:00
30.07.
12:00
31.07.
00:00
Room tem perature active zone case 1815
Case 1815 – Combined
surface coefficient.
Radiation 100% to ceiling.
27
26
[°C]
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
29.07.
12:00
IDA
ESP
30.07.
00:00
RADTEST – Radiant Heating and Cooling Test Cases
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Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
30.07.
12:00
31.07.
00:00
Matthias Achermann
Gerhard Zweifel
Page 4 6
Case 1820 - Ordinary
distribution of the radiation
on all surfaces.
Room tem perature active zone case 1820
27
26
[°C]
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
29.07.
12:00
IDA
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
Case 1830 - Active zone
with normal envelope.
- Without window
- Ach=0.5 1/h
- Internal gains only
convective 365 days.
Room tem perature active zone case 1830
30
25
[°C]
20
15
10
5
0
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
29.07.
12:00
IDA
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
Case 1840 - Active zone
with normal envelope.
Highly conductive wall
included
[°C]
Room tem perature active zone case 1840
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
DOE
IDA
29.07.
00:00
29.07.
12:00
CLIM200
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
Case 1850 – real window
case
[°C]
Room tem perature active zone case 1850
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
TRNSYS
28.07.
00:00
28.07.
12:00
DOE
IDA
29.07.
00:00
29.07.
12:00
CLIM200
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 4 7
Case 1860 - internal gains
purely radiative
[°C]
Room tem perature active zone case 1860
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
TRNSYS
28.07.
00:00
28.07.
12:00
DOE
IDA
29.07.
00:00
29.07.
12:00
CLIM200
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
Case 1870 - internal gains
purely convective
[°C]
Room tem perature active zone case 1870
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
TRNSYS
28.07.
00:00
28.07.
12:00
DOE
IDA
29.07.
00:00
29.07.
12:00
CLIM200
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
Case 1880 - layer
temperatures on a lower level
(summer 18°C winter 30 °C)
[°C]
Room tem perature active zone case 1880
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
TRNSYS
28.07.
00:00
28.07.
12:00
DOE
IDA
29.07.
00:00
29.07.
12:00
CLIM200
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
[°C]
Room tem perature active zone case 1890
28
27
26
25
24
23
22
21
20
27.07.
00:00
Case 1890 – Similar case as
1850, but during summer
time layer is only active from
10 pm to 6 am
TRNSYS did not run this test.
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
DOE
IDA
29.07.
00:00
CLIM200
29.07.
12:00
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 4 8
2.4.3.2
Winter cases from January 2 to 5
Case 1800 – highly
insulated 2 zone model.
Room tem perature active zone case 1800
27
26
[°C]
25
24
23
22
21
20
02.01.
00:00
02.01.
12:00
03.01.
00:00
03.01.
12:00
TRNSYS
04.01.
00:00
DOE
04.01.
12:00
IDA
05.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
Room tem perature active zone case 1805
Case 1805 - Totally
insulated 2 zone model.
- Infiltration Ach=1.0 1/h
- Internal loads 200 W from
1st may to 30 September.
(purely convective)
27
26
[°C]
25
24
23
22
21
20
02.01.
00:00
02.01.
12:00
03.01.
00:00
03.01.
12:00
TRNSYS
04.01.
00:00
DOE
04.01.
12:00
IDA
05.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
Room tem perature active zone case 1810
Case 1810- The constant
temperature layer between
the concrete layer and the
insulation
- Suface coefficient on floor
purely convective.
27
26
[°C]
25
24
23
22
21
20
02.01.
00:00
02.01.
12:00
03.01.
00:00
03.01.
12:00
TRNSYS
04.01.
00:00
04.01.
12:00
IDA
ESP
05.01.
00:00
05.01.
12:00
06.01.
00:00
Room tem perature active zone case 1815
Case 1815 – Combined
surface coefficient.
Radiation 100% to ceiling.
27
26
[°C]
25
24
23
22
21
20
02.01.
00:00
02.01.
12:00
03.01.
00:00
03.01.
12:00
TRNSYS
04.01.
00:00
04.01.
12:00
IDA
ESP
05.01.
00:00
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
05.01.
12:00
06.01.
00:00
Matthias Achermann
Gerhard Zweifel
Page 4 9
Case 1820 - Ordinary
distribution of radiation on
all surfaces.
Room tem perature active zone case 1820
27
26
[°C]
25
24
23
22
21
20
02.01.
00:00
02.01.
12:00
03.01.
00:00
03.01.
12:00
TRNSYS
04.01.
00:00
DOE
04.01.
12:00
IDA
05.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
Case 1830 - Active zone
with normal envelope.
- Without window
- Ach=0.5 1/h
- Internal gains purely
convective 365 days.
Room tem perature active zone case 1830
27
26
[°C]
25
24
23
22
21
20
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
04.01.
00:00
DOE
04.01.
12:00
IDA
05.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
Room tem perature active zone case 1840
Case 1840 - Active zone
with normal envelope.
Highly conductive wall
included
02.01.
12.00
03.01.
00.00
TRNSYS
DOE
IDA
[°C]
28
27
26
25
24
23
22
21
20
02.01.
00.00
03.01.
12.00
04.01.
00.00
CLIM200
04.01.
12.00
05.01.
00.00
05.01.
12.00
06.01.
00.00
ESP
Room tem perature active zone case 1850
02.01.
12.00
03.01.
00.00
TRNSYS
DOE
IDA
[°C]
28
27
26
25
24
23
22
21
20
02.01.
00.00
Case 1850 – real window
case
03.01.
12.00
04.01.
00.00
CLIM200
04.01.
12.00
05.01.
00.00
05.01.
12.00
06.01.
00.00
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 5 0
Case 1860 - internal gains
purely radiative
Room tem perature active zone case 1860
02.01.
12.00
03.01.
00.00
TRNSYS
DOE
IDA
[°C]
28
27
26
25
24
23
22
21
20
02.01.
00.00
03.01.
12.00
04.01.
00.00
CLIM200
04.01.
12.00
05.01.
00.00
05.01.
12.00
06.01.
00.00
ESP
Room tem perature active zone case 1870
02.01.
12.00
03.01.
00.00
TRNSYS
DOE
IDA
[°C]
28
27
26
25
24
23
22
21
20
02.01.
00.00
03.01.
12.00
04.01.
00.00
CLIM200
04.01.
12.00
05.01.
00.00
Case 1870 - internal gains
purely convective
05.01.
12.00
06.01.
00.00
ESP
Room tem perature active zone case 1880
02.01.
12.00
03.01.
00.00
TRNSYS
DOE
IDA
[°C]
28
27
26
25
24
23
22
21
20
02.01.
00.00
03.01.
12.00
04.01.
00.00
CLIM200
04.01.
12.00
05.01.
00.00
Case 1880 - layer
temperatures on a lower level
(summer 18°C winter 30 °C)
05.01.
12.00
06.01.
00.00
ESP
Room tem perature active zone case 1890
02.01.
12.00
03.01.
00.00
TRNSYS
DOE
IDA
[°C]
28
27
26
25
24
23
22
21
20
02.01.
00.00
Case 1890 – Similar case as
1850 but during summer time
layer only active from 10 pm
to 6 am.
TRNSYS did not run this test
03.01.
12.00
04.01.
00.00
CLIM200
04.01.
12.00
05.01.
00.00
05.01.
12.00
06.01.
00.00
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 5 1
2.4.3.3
Floor surface temperatures summer period
Case 1800 – highly
insulated 2 zone model.
Floor surface tem perature active zone case 1800
27
26
[°C]
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
29.07.
12:00
IDA
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
Floor surface tem perature active zone case 1805
Case 1805 - Totally
insulated 2 zone model.
- Infiltration Ach=1.0 1/h
- Internal loads 200 W from
1st may to 30 September.
(purely convective)
27
26
[°C]
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
29.07.
12:00
IDA
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
Floor surface tem perature active zone case 1810
Case 1810- The constant
temperature layer between
the concrete layer and the
insulation
- Surface coefficient on
floor purely convective.
27
26
[°C]
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
29.07.
12:00
IDA
ESP
30.07.
00:00
30.07.
12:00
31.07.
00:00
Floor surface tem perature active zone case 1815
Case 1815 – Combined
surface coefficient.
Radiation 100% to ceiling.
27
26
[°C]
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
29.07.
12:00
IDA
ESP
30.07.
00:00
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
30.07.
12:00
31.07.
00:00
Matthias Achermann
Gerhard Zweifel
Page 5 2
Case 1820 - Ordinary
distribution of radiation on
all surfaces.
Floor surface tem perature active zone case 1820
27
26
[°C]
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
29.07.
12:00
IDA
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
Case 1830 - Active zone
with normal envelope.
- Without window
- Ach=0.5 1/h
- Internal gains only
convective 365 days.
Floor surface tem perature active zone case 1830
27
26
[°C]
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
29.07.
12:00
IDA
30.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
Case 1840 - Active zone
with normal envelope.
Highly conductive wall
included
[°C]
Floor surface tem perature active zone case 1840
30
29
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
TRNSYS
28.07.
12:00
29.07.
00:00
DOE
IDA
29.07.
12:00
30.07.
00:00
CLIM200
30.07.
12:00
31.07.
00:00
ESP
[°C]
Floor surface tem perature active zone case 1850
30
29
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
TRNSYS
28.07.
12:00
29.07.
00:00
DOE
IDA
29.07.
12:00
Case 1850 – real window
case
30.07.
00:00
CLIM200
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
30.07.
12:00
31.07.
00:00
ESP
Matthias Achermann
Gerhard Zweifel
Page 5 3
Case 1860 - internal gains
only radiative
[°C]
Floor surface tem perature active zone case 1860
30
29
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
TRNSYS
28.07.
12:00
DOE
29.07.
00:00
29.07.
12:00
IDA
30.07.
00:00
CLIM200
30.07.
12:00
31.07.
00:00
ESP
[°C]
Floor surface tem perature active zone case 1870
30
29
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
TRNSYS
28.07.
12:00
DOE
29.07.
00:00
29.07.
12:00
IDA
30.07.
00:00
CLIM200
Case 1870 - internal gains
only convective
30.07.
12:00
31.07.
00:00
ESP
[°C]
Floor surface tem perature active zone case 1880
25
24
23
22
21
20
19
18
17
16
15
27.07.
00:00
27.07.
12:00
28.07.
00:00
TRNSYS
28.07.
12:00
DOE
29.07.
00:00
29.07.
12:00
IDA
30.07.
00:00
CLIM200
Case 1880 - layer
temperatures on a lower level
(summer 18°C winter 30 °C)
30.07.
12:00
31.07.
00:00
ESP
[°C]
Floor surface tem perature active zone case 1890
30
29
28
27
26
25
24
23
22
21
20
27.07.
00:00
Case 1890 – Similar case as
1850 but during summer
time layer only active from
10 pm to 6 am.
TRNSYS did not run this test
27.07.
12:00
28.07.
28.07.
29.07.
29.07.
30.07.
00:00
12:00
00:00
12:00
00:00
TRNSYS
DOE
IDA
CLIM200
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
30.07.
12:00
ESP
31.07.
00:00
Matthias Achermann
Gerhard Zweifel
Page 5 4
2.4.3.4
Floor surface temperatures winter period
Case 1800 – highly
insulated 2 zone model.
Floor surface tem perature active zone case 1800
25
24
[°C]
23
22
21
20
19
18
02.01.
00:00
02.01.
12:00
03.01.
00:00
03.01.
12:00
TRNSYS
04.01.
00:00
DOE
04.01.
12:00
IDA
05.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
Case 1805 - Totally
insulated 2 zone model.
- Infiltration Ach=1.0 1/h
- Internal loads 200 W from
1st may to 30 September.
(purely convective)
Floor surface tem perature active zone case 1805
25
24
[°C]
23
22
21
20
19
18
02.01.
00:00
02.01.
12:00
03.01.
00:00
03.01.
12:00
TRNSYS
04.01.
00:00
DOE
04.01.
12:00
IDA
05.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
Case 1810- The constant
temperature layer between
the concrete layer and the
insulation
- Surface coefficient on
floor purely convective.
Floor surface tem perature active zone case 1810
40
39
[°C]
38
37
36
35
34
33
02.01.
00:00
02.01.
12:00
03.01.
00:00
03.01.
12:00
TRNSYS
04.01.
00:00
DOE
04.01.
12:00
IDA
05.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
Case 1815 – Combined
surface coefficient.
Radiation 100% to ceiling.
Floor surface tem perature active zone case 1815
40
39
[°C]
38
37
36
35
34
33
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
04.01.
00:00
DOE
04.01.
12:00
IDA
05.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 5 5
Floor surface tem perature active zone case 1820
Case 1820 - Ordinary
distribution of radiation on
all surfaces.
40
39
[°C]
38
37
36
35
34
33
02.01.
00:00
02.01.
12:00
03.01.
00:00
03.01.
12:00
TRNSYS
04.01.
00:00
DOE
04.01.
12:00
IDA
05.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
Case 1830 - Active zone
with normal envelope.
- Without window
- Ach=0.5 1/h
- Internal gains purely
convective 365 days.
Floor surface tem perature active zone case 1830
40
39
[°C]
38
37
36
35
34
33
02.01.
00:00
02.01.
12:00
03.01.
00:00
03.01.
12:00
TRNSYS
04.01.
00:00
DOE
04.01.
12:00
IDA
05.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
Case 1840 - Active zone
with normal envelope.
Highly conductive wall
included
[°C]
Floor surface tem perature active zone case 1840
40
39
38
37
36
35
34
33
32
31
30
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
DOE
04.01.
00:00
IDA
04.01.
12:00
05.01.
00:00
CLIM200
ESP
05.01.
12:00
06.01.
00:00
[°C]
Floor surface tem perature active zone case 1850
40
39
38
37
36
35
34
33
32
31
30
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
04.01.
00:00
04.01.
12:00
DOE
IDA
CLIM200
05.01.
00:00
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Case 1850 – real window
case
05.01.
12:00
06.01.
00:00
ESP
Matthias Achermann
Gerhard Zweifel
Page 5 6
Case 1860 - internal gains
purely radiative
Floor surface tem perature active zone case 1860
40
[°C]
38
36
34
32
30
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
DOE
04.01.
00:00
IDA
04.01.
12:00
05.01.
00:00
CLIM200
05.01.
12:00
06.01.
00:00
ESP
Floor surface tem perature active zone case 1870
Case 1870 - internal gains
purely convective
40
[°C]
38
36
34
32
30
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
DOE
04.01.
00:00
IDA
04.01.
12:00
05.01.
00:00
CLIM200
05.01.
12:00
06.01.
00:00
ESP
Floor surface tem perature active zone case 1880
Case 1880 - layer
temperatures on a lower level
(Summer 18°C winter 30 °C)
40
[°C]
35
30
25
20
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
DOE
04.01.
00:00
IDA
04.01.
12:00
05.01.
00:00
CLIM200
05.01.
12:00
06.01.
00:00
ESP
Case 1890 – Similar case as
1850 but during summer
time layer only active from
10 pm to 6 am.
Floor surface tem perature active zone case 1890
40
[°C]
38
36
TRNSYS did not run this test
34
32
30
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
DOE
04.01.
00:00
IDA
04.01.
12:00
05.01.
00:00
CLIM200
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
05.01.
12:00
06.01.
00:00
ESP
Matthias Achermann
Gerhard Zweifel
Page 5 7
2.4.4
Detailed water loop
2.4.4.1
Room temperatures
Summer period – different
set point
[°C]
Room tem perature active zone case 2800
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
DOE
IDA
29.07.
00:00
29.07.
12:00
CLIM200
30.07.
00:00
30.07.
12:00
31.07.
00:00
30.07.
12:00
31.07.
00:00
ESP
[°C]
Room tem perature active zone case 2810
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
DOE
IDA
29.07.
00:00
29.07.
12:00
CLIM200
30.07.
00:00
ESP
Room tem perature active zone case 2800
Winter period - both results
similar
02.01.
12.00
03.01.
00.00
TRNSYS
DOE
IDA
[°C]
28
27
26
25
24
23
22
21
20
02.01.
00.00
03.01.
12.00
04.01.
00.00
CLIM200
04.01.
12.00
05.01.
00.00
05.01.
12.00
06.01.
00.00
05.01.
12.00
06.01.
00.00
ESP
Room tem perature active zone case 2810
02.01.
12.00
03.01.
00.00
TRNSYS
DOE
IDA
[°C]
28
27
26
25
24
23
22
21
20
02.01.
00.00
03.01.
12.00
04.01.
00.00
CLIM200
04.01.
12.00
05.01.
00.00
ESP
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 5 8
2.4.4.2
Floor surface temperature detailed water loop
Summer period – different
set point
[°C]
Floor surface tem perature active zone case 2800
30
29
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
IDA
29.07.
12:00
30.07.
00:00
CLIM200
30.07.
12:00
31.07.
00:00
ESP
.
[°C]
Floor surface tem perature active zone case 2810
30
29
28
27
26
25
24
23
22
21
20
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
IDA
29.07.
12:00
30.07.
00:00
CLIM200
30.07.
12:00
31.07.
00:00
ESP
Winter period - both results
similar
[°C]
Floor surface tem perature active zone case 2800
38
36
34
32
30
28
26
24
22
20
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
DOE
04.01.
00:00
IDA
04.01.
12:00
05.01.
00:00
CLIM200
05.01.
12:00
06.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
Floor surface tem perature active zone case 2810
40
[°C]
35
30
25
20
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
DOE
04.01.
00:00
IDA
04.01.
12:00
05.01.
00:00
CLIM200
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
ESP
Matthias Achermann
Gerhard Zweifel
Page 5 9
2.4.4.3
Return water temperature hydronic loop
Summer period – different
set point
Return w ater tem perature floor heating/cooling case 2800
30.0
[°C]
28.0
26.0
24.0
22.0
20.0
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
29.07.
12:00
IDA
30.07.
00:00
CLIM200
30.07.
12:00
31.07.
00:00
ESP
Return w ater tem perature floor heating/cooling case 2810
30.0
[°C]
28.0
26.0
24.0
22.0
20.0
27.07.
00:00
27.07.
12:00
28.07.
00:00
28.07.
12:00
TRNSYS
29.07.
00:00
DOE
29.07.
12:00
IDA
30.07.
00:00
CLIM200
30.07.
12:00
31.07.
00:00
ESP
Winter period - both similar
Return w ater tem perature floor heating/cooling case 2800
40
[°C]
38
No problem during winter
time.
36
34
32
30
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
DOE
04.01.
00:00
IDA
04.01.
12:00
05.01.
00:00
CLIM200
05.01.
12:00
06.01.
00:00
05.01.
12:00
06.01.
00:00
ESP
Return w ater tem perature floor heating/cooling case 2810
40
[°C]
38
36
34
32
30
02.01.
00:00
02.01.
12:00
03.01.
00:00
TRNSYS
03.01.
12:00
DOE
04.01.
00:00
IDA
04.01.
12:00
05.01.
00:00
CLIM200
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
ESP
Matthias Achermann
Gerhard Zweifel
Page 6 0
2.5 Modeller Reports
2.5.1
Preliminary remark
As stated before, the tests were conducted in several steps and modified during the performance.
Based of the experience, in order to clarify the suite, the user’s manual (part I) was redesigned and
restructured. As a consequence, chapters, tables and even cases were renumbered. This has been
considered up to this place in the whole report.
In the following parts of this chapter, the modeller’s reports may refer to cases, chapters and tables
with numbers from earlier versions, differing from the present report. This was intentionally left as it
was, because the editing authors did not want to change the original texts of the different reporting
authors.
For a better navigation, the following table assigning case numbers from earlier versions to the present
ones is given:
Old case number
795
800
1800
1810
1820
1830
3800
3805
3810
3815
3820
3830
1840
1850
1860
1870
1880
1890
2800
2810
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Present case
number
Dropped
800
Dropped
Dropped
Dropped
Dropped
1800
1805
1810
1815
1820
1830
1840
1850
1860
1870
1880
1890
2800
2810
Matthias Achermann
Gerhard Zweifel
Page 6 1
IEA Task 22, Subtask C RADTEST
TRNSYS
Clemens Felsmann
Dresden University of Technology
Germany
[email protected]
June 2002
1. Model and simulation program
All the tests were done with TRNSYS TUD a modificated and rewritten version of TRNSYS 14.2. At
Dresden university the original TRNSYS program source code was subjected to a lot of changes as
well as additions to create a tool characterised by very specific properties in regard to the simulation
and analysis of both operation and control of HVAC-systems in buildings.
The existing model of a underfloor heating system had to be extended to be able to run the radiant
heating and cooling test cases (Radtest). Now it is possible to simulate the behavior of detailed water
loops as well as simplified temperature layers within walls. The so-called active layer devides a wall
into two parts each having the same boundary condition.
2. Test cases
Radtest bases on ENVELOPE BESTEST from IEA Task12 that in its high mass basic test has to be
fulfilled. All test cases - simple tests as well as detailed models - are setted out in the RADTEST
specifications and it is in general not very difficult to create appropriate simulation models.
Nevertheless it was not possible to construct a model for test case 1890 without making a lot of
changes in the TRNSYS source code. In this test case the temperature layer is shutted down partly
during the summer period. Meanwhile the temperature of the active layer which is an input value of
the program is undefined and a result of the simulation respectively.
The detailed model cases base on a detailed water loop model instead of a simple temperature layer.
The heat transfer between the pipe system and the floor depends on the geometric layout and the
thermal properties of the building element. Therefore an (equivalent) exterior heat transfer coefficient
for the pipes was calculated.
3. Results
All output data required to fill out the pre-formated EXCEL-sheet are available.
4. Summary
The RADTEST is useful to validate radiant heating and cooling systems in buildings. It is hardly to
find similar validation procedures.
For a more practical point of view test cases with detailed water loops are more interesting than cases
with a temperature layer. It also would be really interesting to have a look at the thermal behavior of a
mass flow controlled radiant heating system instead of a temperature controlled one.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 6 2
IEA Task 22, Subtask C RADTEST
DOE 2.1E
HANS DÜRIG AG - Simulation für Gebäudeenergie
Markus Dürig
CH-3132 Riggisberg
SWITZERLAND
June 2002
1 Introduction
This report is the result of the experiences made with DOE2.1e carrying out the IEA RADTEST
procedure. Its aim is to outline modelling particularities when performing radiant heating and cooling
calculations with DOE2. Furthermore, results in comparison to other building energy programs are
commented and an overall conclusion for the use of DOE2 in the field of radiant heating and cooling
calculations is made.
2 Important program capabilities of DOE2.1e concerning radiant heating and cooling
Due to its program algorithms DOE2 has certain limitations in modelling of radiant heating and
cooling cases. Nevertheless, various calculations have been carried out with good results not only in
this test procedure, but also for energy consultant jobs, using simulation models that take this fact into
account. The major points that need special attention are described below.
surface coefficients
• combined surface coefficients (convection and radiation): e.g. two walls are coupled together
with their combined surface coefficient having only a connection over the zone air
temperature.
• constant surface coefficients: there is only one interior-surface coefficient (for every wall) to
be defined over the whole simulation period. Thus, an average value for heating and cooling,
depending on the simulation period, has to be defined.
• one surface coefficient per wall: only one coefficient, which is valid for both wallsides, can
be defined for interior walls. Only exterior walls have an outside (which is calculated hourly
by the program) and an inside surface coefficent.
Inserting a heating / cooling layer into a construction
DOE2 does not give the possibility to insert a layer for heating and cooling into a construction.
Therefore, an artificial zone (in the following called DUMMY-ZONE) which represents this layer, has
to be used (see also section 0).
Output variables
Because loads are calculated in the LOADS program and then passed as a whole to the SYSTEMS
program which allows to simulate a floating room temperature, information of heat fluxes through
individual walls of a zone are lost in the SYSTEMS program. This also affects how the model in
DOE2 has to be built in order to get the desired output variables (see also section 0).
3 Model description
Floor heat model
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 6 3
Layer definition
The model used for the heated and cooled floor in the RADTEST cases is shown in Figure 2.5-1. Two
DUMMY-ZONES are required in order to calculate both, the heat flux to the active zone (Qup) and the
heat flux to the basement (Qdown).
Each of the DUMMY-ZONES is served by an own system to hold the desired layer temperature
according to the test specification. Qup and Qdown respectively, is equal the energy consumption of the
system that serves the corresponding DUMMY-ZONE.
Q& up
active zone
1
DOE2 - model
hcr,us, DOE
INTERIOR-WALL
concrete slab
upper DUMMY-ZONE
hcr,us, DOE
2
ZONE
hcr,ls, DOE
lower DUMMY-ZONE
insulation
INTERIOR-WALL
steel concrete slab
hcr,ls, DOE
Q& down
basement
variables
h
Q
indices
surface coefficient
heat flux
c
r
us
ls
DOE
convection
radiation
upper side
lower side
input in DOE2
Fi
gure 2.5-1: schematic representation of the floor heat model
Determination of floor surface coefficients
As mentioned in section 0 only one surface coefficient per interior wall can be defined. The
calculation of the floor surface coefficient for the upper and lower side is done according to the test
specification [3], section 3.4.6. The mean floor surface temperature and the room air temperature
which are needed for this calculation are obtained from a first run of simulations. This floor surface
coefficient calculated in that way represents an average coefficient over the whole simulation period.
Correction of floor surface coefficients for the use in DOE2
According to [1] the following approach in the weighting factor calculation is used in DOE2 to
determine the radiative heat exchange between two surfaces (m and i):
QRim = K Rim* (Tm − Ti )
Equation 2.5-1
where QRim is the heat flow from surface i to surface m, Ti and Tm are the surface temperatures and
KRim is calculated as:
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 6 4
3
K Rim = 4 * ε i * σ * (TR ) * Fim * Ai
Equation 2.5-2
where εi is the emissivity of surface i, σ is the Stefan-Boltzmann constant, TR is a reference
temperature in absolute units, Fim is the view factor between surfaces i and m and Ai the surface.
TR is set to 21.1 °C (70 °F), which is too low for heating purposes. With higher surface temperatures
more energy than calculated by DOE2 would be stored with radiation in ambient walls and less energy
transmitted directly to the room air. To compensate for this effect, the surface coefficient determined
as described in section 0 is reduced with respect to the reference temperature TR used in DOE2:
3
 T 
f corr =  R 
 TR,eff 
Equation 2.5-3
where TR,eff is the effective floor surface temperature and TR is the reference temperature used by
DOE2 (21.1 °C). Both temperatures in Equation 2.5-3 are in absolute units.
It has to be emphasized that this correction is only an approximation which is made because the
default surface temperatures in DOE2 for the weighting-factor calculation can not be changed.
Input of floor surface coefficient in DOE2
The film-resistance at position 2 in Figure 2.5-1 should be as small as possible, so that the surface
temperature of the concrete slab on the layer side is equal the DUMMY-ZONE temperature.
Therefore, the floor surface coefficient as described in section 0 must not be input directly in DOE2
because it is used on both wallsides. Following models are possible1:
Model 1
hcr,DOE = 0.5 * hcr
Model 2
hcr,DOE = 999 W/m2*K (small film-resistance). To compensate the too low film-resistance at position 1
an additional thermal resistance without thermal capacity has to be input.
Model 3
hcr,DOE = hcr
To compensate the too high film-resistance on the DUMMY-ZONE side, the layer temperature has to
be set higher (ϑLayer, corrected) so that the desired layer temperature is equal ϑsurface (see following figure).
1
The models are a compromise to find a good model that incorporates the correct surface coefficient on the
active zone side and the correct temperature on the layer side. The model must not change the total resistance of
the construction.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 6 5
ϑLayer, corrected
ϑsurface
temperature drop
due to film-
1
ϑactive zone
2
ϑroom
dconcrete slab
Figure 2.5-2: correction of the layer temperature
ϑLayer, corrected is chosen in order that ϑsurface = ϑLayer from test description
For the RADTEST cases model 3 has been chosen as this is the best approximation to reality in this
certain case.
The disadvantage of model 3, that ϑsurface depends relatively strong on the temperature difference
ϑLayer, corrected - ϑactive zone, is not really significant in the RADTEST calculation as the temperatures are
almost constant over a wide range of the simulation period.
Real case with detailed water loop
The model described in section 0 is used as well for the detailed water loop test (cases 2800 and 2810).
Prior to the simulation the layer temperature has to be determined in function of the mean medium
temperature and the geometrical and physical properties of the floorheating. The room temperature
which is required for this calculation as well, is obtained from a first simulation.
Zone Model
The active zone is input using the SUNSPACE2 feature of DOE2. This model incorporates a more
detailed radiation calculation.
Glazing
The glazing properties from the test specification have been input in the window-4 database format for
the use with DOE2. The angle dependent values from the ENVELOPE-BESTEST specification [2]
have been used for this purpose.
Weather file
The binary weather file for DOE2 was made using its weather processor. The source is a TMY-file
from the ENVELOPE-BESTEST [2].
2
The SUNSPACE feature is originally intended to use for rooms with exterior glazing that have another window
adjacent to an interior room. Solar energy transmitted from the SUNSPACE-Windows though interior windows
is then calculated.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 6 6
4 Comments on results
Temperatures in active zone
Following observations on the room-temperatures in floating mode (temperatures between heating and
cooling setpoint, i.e. 20 and 27 °C) can be made:
Whereas in the summer period (27th to 30th July) there is a good agreement with the other simulation
programs, in the winter period (2nd to 5th January) the room temperature generally descends too fast.
The reason for this behaviour could be that the DOE2 model underestimates the storage of radiation
energy from the floor to the inner side of the ambient walls, because weighting factors are calculated
at a reference temperature of 21.1 °C for the radiation calculation. This explains why better results can
be observed in the summer period: at this time the floor surface temperature is closer to the reference
temperature than in heating mode.
Surface temperatures
There is a good agreement in the mean surface temperatures compared to other programs. On the other
hand, the plots show that there is not enough dynamical behaviour. Although, temperatures are
reasonable for many of the cases in the summer period, the winter period shows a rather flat surface
temperature curve. An improvement can be observed from case 1850 to case 1880 where the
temperature level of the floor heating is lower (30° instead of 40 °C).
Different reasons can be considered:
•
•
•
constant surface coefficient: dynamical processes such as solar radiation falling on the floor
and causing a change in the floor surface temperature and therefore in the surface coefficient
are neglected. Instead a constant surface coefficient for the floor has to be input.
Radiation and convection from the floor to ambient walls are calculated with a combined
surface coefficient.
Distribution of solar radiation in the zone: the amount of solar energy falling on a surface has
to be input as a constant fraction.
5 Conclusion
Although there are different limitations in modelling a radiant heating and cooling model with DOE2,
the test shows good results and a good conformity to the other simulation programs.
Special attention has to be paid to the determination of the surface coefficient, which has to be input
by the user. Furthermore, different models (or variations of the model described in this paper) are
possible and it has to be decided by the user which one has to be chosen according to the given task.
Floor surface temperatures show a poorer dynamic behaviour in winter than in summer. Better results
are obtained with lower floor-heating temperatures (compare case 1850 with case 1880).
6 References
[1]
DOE2, Engineers Manual
[2]
IEA Task 12, Envelope BESTEST
[3]
IEA Task 22, RADTEST, Radiant heating and cooling test cases
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 6 7
IEA Task 22, Subtask C RADTEST
IDA-ICE
Matthias Achermann
University of Applied Science, Luzern
Switzerland
[email protected]
June 2002
Introduction
The modeller report documents the RADTEST results calculated by IDA-ICE version 3.0. IDA-ICE is
a Swedish simulation software developed and distributed by EQUA Stockholm [1].
Model approach
The building is modelled as described in the test specifications. For the cases with the active floor
layer the standard floor heating model was used to provide heating and cooling power into the floor. In
some cases modifications in the system parameters and/or the linkable variables were made.
The floor heating model used in IDA-ICE is macro using a floor heat component (hydronic driven
layer) with two wall parts on each side (cover layer and floor construction below). The heat extraction
from the water to the surface of the wall part is described by a constant surface coefficient. It is the
mean heat extraction from the hydronic tubes into the floor. In that way, the heat flows into the wall
parts above and below. The wall parts are developed as an infinite difference model of a multi-layer
component. Each wall part is divided in several layers depending on the construction. Each layer has
to be subdivided in a certain number of sub layers to get accurate storage capacity if the modeller uses
heavy weight constructions. For the RADTEST the default values from IDA-ICE were used.
Floor Heat Component
Pic. 1. IDA-ICE
floor heat macro
Input specification
To run the RADTEST cases with the standard ICE model, the hydronic connections were
disconnected. The supply mass flow was set as constant. Depending on the test case a schedule is
controlling the mass flow. To get a constant floor temperature, the mass flow was set to an infinite big
value. In that way, the heat extraction to the room finally depends only on the resistance of the floor
construction and the surface coefficients. Surface coefficients were determined by IDA-ICE, if the
modeller uses the detailed zone model.
For the cases with the detailed water loop the floor heat component was modified in same manner as
the simple ones. The difference between two cases are the modified input parameters such as the mass
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 6 8
flow which is a real designed mass flow determined by the design temperature spread. The mass flow
and the temperature level of the floor heat/cool system are controlled by schedules.
Results
With the model assumptions above, IDA-ICE provides accurate results which show a good agreement
with the reference programs.
At one point, the results varies from the references programs. This are the heat fluxes from the active
layer to active zone and basement. The peak heat and cooling power are much higher than the other
programs. A detailed analyse of this behaviour shows that, if the temperature level of the active layer
changes (May 1st and October 1st) a huge heat flux is determined for a few hours. See picture 2. This
behaviour only occurs in the heat flux variable – the heating and cooling energy consumption and the
local zone temperatures (controlled in active zone, free floating in basement) do not react in that way.
It seams, that the massive heat flux is damped by the floor construction. In fact that the big heat fluxes
occurs only a few hours the influence on the annually heat fluxes is not remarkable and can be
neglected.
Week: from 2002-04-29 to 2002-05-05
60000.0
50000.0
40000.0
30000.0
20000.0
10000.0
0.0
Pic. 2. upward
heatflux if
setpoint changes
-10000.0
-20000.0
-30000.0
-40000.0
-50000.0
-60000.0
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Flux[1], W
Flux[2], W
Conclusions
To run this test series with IDA-ICA no certain complication has occurred . The first runs (blind test)
showed once more that the modeller itself can have a big influence on the accuracy of the results.
Some modeller errors could be found on that way. It is important to have simple test cases to compare
simple model approaches to make quick energy estimations with a good accuracy.
To compare detailed models, the variation of detailed test cases should be increased. It would be nice
to have a comparison of different order of tube installation and different control strategies.
Matthias Achermann, Horw 26. June 2002
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 6 9
IEA Task 22, Subtask C RADTEST
CLIM 2000
Joseph Ojalvo
EDF - Electricite de France
June 2002
Introduction
RADTEST
Radiant heating and cooling systems are known all over the globe. Radiant heating systems are in use
in residential buildings as floor heating systems. The majority of radiant cooling systems are in use in
commercial buildings, primarily as ceiling-based systems. In many instances, radiant system use for
heating and cooling purposes based on time of the year.
To take into account the behaviour of radiant heating and cooling in dynamic simulation programs,
specific models or modelling methods should be available. Some of these methods are well known,
but there is a need to validate these models and methods to improve confidence in them.
The goal of this work is be sure that the tested programs are able to accurately model radiant heating
and cooling systems. Additionally, the relation between the simplified approaches and the detailed
floor heating and cooling models should be quantified.
The RADTEST is a uniform set of unambiguous test cases for a software to software diagnostic
comparison. It has been developed in the frame work of IEA Task22.
The RADTEST cases contain 14 runs. The procedure is subdivided in two parts. In the first part, a
simplified method with a constant temperature layer is used. In the second part, a detailed hydronic
system model is used.
CLIM2000
The studies were carried out with the version 2.6 of the CLIM2000 software program.
CLIM2000 allows the behaviour of a whole building to be simulated. The simulation is divided into
three stages.
Firstly the building is described by means of a graphics editor providing multi-windowed dialogue in
the form of a set of icons. This is called Formal Type (TF), and represents the models chosen by the
user. These elementary models, about one hundred in CLIM2000, describe physical laws (conduction,
convection, etc.) with a set of continuous equations.
Secondly, these sets of equations are transformed into an electrical circuit representation and solved by
the ESACAP solver. In order to simulate these equations, ESACAP uses a Gear's method with a
variable sample time.
Finally, a post-treatment of the simulation data is possible via a graphic tool, as well as via a transfer
to EXCEL.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 7 0
Main modelling assumptions
Building envelope
2m
2.7 m
Each wall is discretized by using several layers of material, in accordance with the material
specifications.
6m
N
6m
2.7 m
2.7 m
8m
Primary zone
Thermal active
fl
Secondary zone
Insulatio
Soil
Materials properties
(W/m.K)
(kg/m3)
Concrete block
0,510
1400
1000
Foam insulation
0,04
10
1400
Wood siding
0,14
530
900
Concrete slab
1,13
1400
1000
Fiberglas quilt
0,04
12
840
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Cp (J/kg.K)
Matthias Achermann
Gerhard Zweifel
Page 7 1
Roof deck
0,14
530
900
Plasterboard
0,16
950
840
Steel concrete
1,8
2400
1100
Soil
1,3
1500
800
Transparent Window
Double-glazed window, whose properties are :
ƒ Uair-air = 3.0 W/m²K
ƒ Absorptance ( direct radiation)
angle (deg)
dir
0
10
20
dir
30
40
diff
ƒ Transmittance ( direct radiation) :
dir
dir
60
70
80
0.116 0.116 0.119 0.123 0.127 0.133 0.138 0.141 0.136
ƒ Absorptance ( diffuse radiation) :
angle (deg)
50
0
10
20
30
0
= 0.128
40
50
60
70
80
0.748 0.747 0.745 0.739 0.725 0.693 0.622 0.475 0.229
ƒ Transmittance ( diffuse radiation) :
90
diff
90
0
= 0.644
No solar protection
The model used (TF114) doesn't take into account any thermal inertia.
‰
High conductance wall
We use the same model as for the transparent window. The transmittance coefficients are set to 0. The
absorptance coefficients are set to 0.6.
Exterior surface coefficient
The exterior radiative exchanges are automatically calculated by CLIM2000.
Hence, the exterior surface coefficient only takes into account the convective part. It is determined by
removing the radiative part (estimated to 4.63 W/m²K) from the combined coefficient.
ε
(emissivity)
Walls and roof
Window and High
conductive wall
0.9
α (abs.)
hconv
0.6
24.67 W/m²K
16.37 W/m²K
Interior surface coefficient
Single value of the combined radiative and convective surface coefficient.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 7 2
ε (emissivity)
walls, floor, ceiling,
window
0.9
hglob
8.29 W/m²K
Heated and cooled floor
We use here a combined radiative and convective surface coefficient. The value depends on the
direction of the heat flow and the difference between the mean surface temperature and the
room-temperature.
Tpz : room-temperature in primary zone
Tfloor : mean floor temperature
Tceiling : mean ceiling temperature
Upward heat flow
Tpz < Tfloor or Tsz > Tceiling
hglob = 8.92 * T − T
air
surf
Downward heat flow
Tsz : room-temperature in secondary zone
Tpz > Tfloor or Tsz < Tceiling
Detailed water loop model D
hglob = 6.22 * T − T
air
surf
hglob = 7.00 * T − T
air
surf
Weather data
We used the weather file DRYCOLD.TMY provided with the RADTEST.
‰
Used data
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
‰
day / month / year / hour
dry bulb temperature (°C)
Text [TMY]
dew point (°C)
total horizontal solar radiation (kJ/m²) Φgl-hz [TMY]
direct normal solar radiation (kJ/m²)
Φdir-n [TMY]
station pressure (kPa)
Patm [TMY]
wind speed (m/s)
wind direction (deg.)
Adaptations to meet CLIM2000 requirements
ƒ CLIM2000 uses the universal time (Greenwich), while the TMY file uses the
solar time.
► time [UT] = time [TMY] + 7h
ƒ total horizontal solar radiation converted in W/m²
► Φgl-hz = Φgl-hz [TMY] / 3.6
ƒ direct normal solar radiation converted in W/m²
► Φdir-n = Φdir-n [TMY] / 3.6
ƒ calculation of the diffuse horizontal solar radiation (W/m²)
► Φdiff-hz = Φgl-hz – Φdir-hz
Φdiff-hz = Φgl-hz – Φdir-n * sin h avec h = solar height (rad.)
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 7 3
0.1
0.1
0.1
ƒ sky temperature (°C)
► Tsky = Text – 20
ƒ atmospheric pressure converted in Pa
► Patm = Patm [TMY] *1000
Infiltration
The air change in the primary zone due to infiltration is modelled with a double ventilation system
(mechanical exhaust and supply).
Standard conditions at sea level
ƒ T0 = 15°C = 288.16 K
ƒ P0 = 101 321 kPa
ƒ ρ0 = 1.201385 kg/m3
Site specific conditions
ƒ
ƒ
ƒ
ƒ
ƒ
altitude = 1609 m
Troom (room-temperature in primary zone) = 20°C = 293.16 K
Text (mean annual outside dry-bulb temperature) = 9.7°C = 282.86 K
ACH (exhaust) : τ out = 0,5 vol/h
Interior air volume : Vroom = 129.6 m3
Palt = P0 * e −1,219755.10
−4
*alt
⇒
P1609m = 83 265.56 kPa
P0
P1609 m
=
ρ0 * T0 ρroom * Troom
⇒
ρroom =
P0
P1609 m
=
ρ0 * T0 ρext * Text
⇒
ρext =
P1609 m T0
*
*ρ
P0
Troom 0
P1609 m T0
*
*ρ
P0
Text 0
⇒
ρroom = 0.97045 kg/m3
⇒
ρext = 1.0058 kg/m3
Calculation of the mass flow.
m& = τ out *Vroom * ρroom
⇒
m& = 62,886 kg/h
The inlet mass flow is equal to the outlet mass flow, so the inlet infiltration rate can be
determined as follows.
m& = τ out *Vroom * ρroom = τ adm *Vroom * ρext
⇒
τ adm = 0.4824 vol/h
The heat loss due to infiltration is specified in the RADTEST at 18.440 W/K. We decided to
calibrate the air Cp value on this heat loss value.
Φ heat _ loss =
m&
* Cp
3600
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
⇒
Cp = 1056 J/kg.K
Matthias Achermann
Gerhard Zweifel
Page 7 4
Solar loads
The solar loads transmitted through the window are distributed over the internal surfaces (α = 0.6),
according to the solar distribution fractions (S.D.F) shown in the table below. In practice, the window
is divided in as many portions as internal surfaces, each portion being connected to its corresponding
surface. The surface of each portion is proportional to the corresponding solar fraction, as shown in the
table below. The solar radiation transmitted by each portion is assumed to be totally absorbed by its
corresponding surface.
Surface
S.D.F
Floor
Ceiling
North wall
East wall
South wall
West wall
Solar lost through
window
TOTAL
0.642
0.168
0.053
0.038
0.026
0.038
0.035
Window
portion
7.704 m²
2.016 m²
0.636 m²
0.456 m²
0.312 m²
0.456 m²
0.42 m²
1
12 m²
Internal loads
The convective part (80 W) of the internal gains are totally applied to the air node.
The radiative part (120 W) of the internal gains is evenly distributed over the internal surfaces, as
shown in the table below.
Floor
Ceiling
North wall
East wall
South wall
South
window
West wall
TOTAL
33.6 W
33.6 W
15.1 W
11.3 W
6.7 W
8.4 W
11.3 W
120 W
This distribution is suitable for every cases except the 1860 and 1870 ones.
Case 1870 : the internal loads (200 W) are exclusively convective, and totally applied to the air node.
Case 1860 : the internal loads (200 W) are exclusively radiative, and evenly distributed over the
internal surfaces, as shown in the table below.
Floor
Ceiling
55.9 W
55.9 W
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 7 5
North wall
East wall
South wall
South
window
West wall
TOTAL
25.2 W
18.9 W
11.2 W
14.0 W
18.9 W
200 W
Thermal active floor
Simplified model with a constant temperature layer
The constant temperature layer is inserted in the electrical circuit representation as a source of tension.
material layer
constant
temperature
layer
material layer
Detailed water loop model
The reference model comprises 5 layers : upper-covering, concrete slab including the pipes, insulation,
concrete floor and under-covering. The 2D conductive heat transfer is dealt with in a section
perpendicular to the pipe direction, accounting for simplifications due to symmetry. The mesh is not
variable ; it has been previously determined with a specific tool. The elementary section is divided in 4
major regions, as shown on the drawing below.
upper-covering
concrete slab
upper-covering
concrete slabinsulation
pipe location
insulation
concrete floor
concrete floor
under-covering
under-covering
The water loop simplified model is then based on the thermal-electrical analogy.
The solar radiation hitting the floor is supposed to be totally absorbed.
Our modelling assumes that the pipe is in contact with the insulation layer. The nonexistent under &
upper-covering layers have been modelled by setting to a very low value (10-5) the corresponding
thickness, density and specific heat , while setting to a high value (105) the corresponding
conductivity.
The water flow in the pipe is set to 0.6012 m3/h when working, or else 0 m3/h. The supply water
temperature is set to 20°C or 40°C in accordance with the test specification.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 7 6
Temperature control strategies for the primary zone
The air temperature in the primary zone is controlled by a convective heating and cooling system.
‰
Pure sensible heating and cooling, without capacity limitations
‰
Equipment characteristics
ƒ heating capacity : 1000 kW
ƒ cooling capacity : 1000 kW
ƒ Effective efficiency : 100 %
‰
Thermostat control of room-air temperature
Heating
Tcons = 20°C
Free Floating
Cooling
Tcons = 27°C
20°C
The thermostat used is a proportional one. The proportional band was set to a very
low value to approximate a non-proportional thermostat as required in the test
specification.
Preconditioning period
A preconditioning period of 3 months has been added before the 1 year simulation period.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 7 7
ESP-r/HOT3000
Kamel Haddad
CANMET Energy Technology Centre
Ottawa, Canada
[email protected]
July 2002
Introduction
This report describes the modelling strategy and assumptions used for the proposed Radiant Heating
and Cooling Test Cases (RADTEST) carried out by CETC at Natural Resources Canada using a
modified version of the ESP-r software (ESRU 1996) called ESP-r/HOT3000. ESP-r/HOT3000 retains
ESP-r’s modelling approach but includes new models for ground coupling, air infiltration, furnace, air
and ground source heat pumps, DHW, and fuel cells. The simulator used was bpsh3k version 1.7 of
March 2002 (based on bps version 9.21b of Jan 2002).
The RADTEST test cases description and the basis of the modeling approach are both described in the
report by Achermann (2001). At this point, only the Simple Test Cases (795-1890) and the Additional
Test Cases (3800-3830) are modeled using ESP-r/HOT3000. All the required characteristics of the
Simple and Additional Test Cases, specified in the RADTEST report, are included in the ESPr/HOT3000 simulation models created. Details about various aspects of these simulation models, as
they are implemented in the ESP-r/HOT3000 environment, are presented in the following sections of
this report.
Modeling of the Constant-Temperature Active Layer
The constant temperature layer for test cases 1820-1890 and 3800-3830 is modeled as an air zone. The
temperature in this zone is controlled using an ideal controller that maintains the temperature at the
desired level specified in the RADTEST Manual. The ideal controller works by injecting convectively
at the air point the required amount of heat.
For Test Case 1820, the constant-temperature zone is placed on top of the floor as shown in Figure 1.
For Test Case 1830, the constant-temperature zone is placed on the under side of the floor as shown in
Figure 2. Figure 3 shows the placement of the constant-temperature zone between the concrete and the
insulation for Test Case 1840.
It is found that the temperature of the constant-temperature zone can be maintained at the desired set
point specified in the RADTEST Manual through a control law associated with the ideal controller.
Whenever there is a sudden jump or drop in the temperature of the constant-temperature zone, it is
found that the temperature of the basement starts to gradually approach the temperature of the active
layer. After a certain period of time, the temperature of the basement becomes almost equal to the
temperature of the active layer.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 7 8
Primary Zone
Adiabatic
hconv = 2000 W/m2-K
thickness = 1 mm
k = 200 W/m-K
longwave emissivity = 0.9
Constant T Air Zone
Adiabatic
Concrete
Insulation
Concrete
Basement
Figure 1: Placement of the constant-temperature zone for Test Case 1820
Primary Zone
Concrete
Insulation
Concrete
Adiabatic
hconv = 2000 W/m2-K
Constant T Air Zone
Adiabatic
thickness = 1 mm
k = 200 W/m-K
longwave emissivity = 0.9
Basement
Figure 2: Placement of the constant-temperature zone for Test Case 1830
Primary Zone
Adiabatic
hconv = 2000 W/m2-K
Concrete
Constant T Air Zone
Adiabatic
Insulation
Concrete
Basement
Figure 3: Placement of the constant-temperature zone for Test Case 1840
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 7 9
Weather File
The TMY weather data provided with the RADTEST report was used to construct the required ESPr/HOT3000 weather file.
Infiltration
ESP-r/HOT3000 does not account for the variation of outdoor density with altitude. Therefore, the
infiltration rate adjustment factor of 0.822 specified in the RADTEST Manual was used.
Heat Transfer Coefficients
Exterior Heat Transfer Coefficients:
ESP-r/HOT3000 calculates automatically the outside radiation and convection heat transfer
coefficients. Therefore, the total heat transfer coefficient data given in Table 1-4 of the RADTEST
Manual is not used.
Interior Heat Transfer Coefficients:
By default, the interior convection and radiation heat transfer coefficients are estimated internally in
ESP-r/HOT3000. This default approach is used for all surfaces except for estimating the convection
heat transfer coefficients of the heated/cooled floor and of the ceiling and floor of the constanttemperature zone used to represent the constant-temperature layer.
Interior Heat Transfer Coefficient on Top of Heated/Cooled Floor (Applies for all Test Cases Except
Case 3810):
For the top surface of the heated floor of the primary zone, it is assumed that the convection heat
transfer coefficient is 45% of 8.92x(Tfloor-Tra)0.1. This correlation is implemented in the ESPr/HOT3000 source code and is used every time step when the floor surface temperature is greater than
that of the air inside the primary zone. The 45% value is the fraction of the total heat transfer
coefficient attributed to convection for “Upward heat transfer on horizontal surfaces” based on the
data in Table 1-5 of the RADTEST Manual. The longwave emissivity of the top surface of the heated
floor facing the primary zone is set to 0.9, and the radiative heat transfer between this surface and the
primary zone is predicted internally by ESP-r/HOT3000. The only exception to this is for Case 3810
where the longwave emissivity is set to 0.01 to suppress radiation heat transfer.
Table 1-5 of the RADTEST Manual also indicates that the fraction of the total heat transfer coefficient
attributed to convection is 16% for “Downward heat transfer on horizontal surface”. It is assumed then
that the convection heat transfer on top of the cooled floor of the primary zone is equal to 16% of
8.6x(Tra-Tfloor)0.1. This correlation is also implemented in the ESP-r/HOT3000 source code and is used
every time step when the floor surface temperature is less than the primary zone air temperature.
Again in this case, the longwave emissivity of the top surface of the cooled floor facing the primary
zone is set to 0.9 (except for Case 3810 where it is set to 0.01), and the radiative heat transfer between
this surface and the primary zone is predicted internally by ESP-r/HOT3000.
Sensitivity of Simulation Results to Radiative/Convective Split of the Interior Heat Transfer
Coefficient on Top of the Heated/Cooled Floor:
It is to be noted that the RADTEST document does not address how to split the total heat transfer
coefficient, between the heated floor and the primary zone, into convective and radiative components.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 8 0
It is found that the assumed split of this total heat transfer coefficient can have a large impact on the
predicted loads of the conditioned zone. For example, when the total heat transfer coefficient is treated
as described in the previous two paragraphs of this report, the annual heating and cooling loads are
found to be 0.255 and 17.13 MWh, respectively, for case 1820. When the total heat transfer coefficient
between the heated floor and the primary zone is assumed to be 100% convective, these heating and
cooling loads for case 1820 become 0.284 and 28.82 MWh, respectively. The longwave emissivity of
the top surface of the heated floor is set to a very small value (0.01) in this case to suppress radiation
heat transfer.
It seems then that the assumed radiative and convective split of the total heat transfer coefficient,
between the heated floor and the primary zone, has a large impact on the predicted loads. This is
especially true for the cooling load. It is then suggested that the RADTEST Manual be modified to
give guidance as to how to treat this radiative and convective split. It is expected that this will reduce
the spread in the simulation results from the various simulation programs.
Interior Heat Transfer Coefficient on Top of the Heated/Cooled Floor for Test Case 3810:
For this Test Case the RADTEST Manual indicates that “Surface Coefficient on Floor only
Convective”. On the one hand this can mean that the total heat transfer coefficient, plotted in Diagram
1-1 and 1-2 of the RADTEST Manual, on top of the floor needs to be set in the simulation model
equal to the convective heat transfer coefficient with radiation set to zero. But it can also mean that
only the convective portion of the total heat transfer coefficient in Diagram 1-1 and 1-2 needs to be
accounted for in the simulation. This issue then needs to be clarified in the Manual.
Table 1 then lists two sets of results for Test Case 3810. The first one (3810) is for when the total heat
transfer coefficient from the Manual is set to the convective heat transfer coefficient in the simulation
with radiation set to zero. The second (3810-2) is for when only the convective portion of the total
heat transfer coefficient given in the Manual is accounted for in the simulation with radiation still set
to zero. Again the fraction of the total heat transfer coefficient that is convective is assumed to be 45%
for a heated floor and 16% for a cooled floor.
Interior Heat Transfer Coefficients for the Constant-Temperature Zone:
The convection heat transfer coefficient on the inside of the floor and ceiling of the constanttemperature zone, used to represent the constant-temperature layer, is set to a high value (2000 W/m2K). This is to minimize the temperature difference between the air and the interior surfaces of this
zone so that the condition of a constant-temperature layer is satisfied.
Glazing Optical Properties
Values for direct-beam transmittance in Table 1-7 of the RADTEST Manual are used. Solar
absorptance values for the inner and outer layers of the window are obtained from Appendix E of IEA
BESTEST and Diagnostic Method Manual (Judkoff and Neymark 1995).
Annual Cooling Energy for Test Case 800
According to IEA BESTEST and Diagnostic Method Manual (Judkoff and Neymark 1995), the total
annual heating and cooling energies, obtained using ESP-r, for Test Case 800 are 4.868 and 0.113
MWh respectively. Based on the simulations carried for RADTEST using ESP-r/HOT3000, it is found
that total annual heating and cooling energies for Test Case 800 are 4.878 and 0.209 MWh
respectively. The heating energy is almost exactly the same as that reported in the IEA BESTEST
Manual. However, there is a large difference between the annual cooling energy reported in IEA
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 8 1
BESTEST Manual and that obtained in the course of this task. The ESP-r/HOT3000 input files used
for the present task were checked again and no errors with the input were discovered. Given that the
total annual heating energy obtained in this task and that reported in IEA BESTEST Manual are
almost exactly the same, it is possible that there was a problem with the entry of the cooling energy
data for Case 800 in IEA BESTEST.
Results
Table 1 lists values for annual heating load, annual cooling load, peak heating load, peak cooling load,
maximum and minimum primary zone temperature, maximum and minimum basement temperature,
and maximum and minimum temperature for the top surface of the heated/cooled floor.
Table 1: Simulation Results for Simple Test Cases (795-1890) and Additional Test Cases
(3800-3830)
Qh,tot
Qc,tot
Qh,max
Qc,max
(MWh)
(MWh)
(kW)
(kW)
795
3.925
0.153
2.50
800
4.878
0.209
1800
4.88
1810
Case
Tmax
Tmin
Tb,max
Tb,min
Tfl,max
Tfl,min
0.56
27
20
---
---
28.32
15.28
3.38
0.81
27
20
---
---
28.72
13.67
0.203
3.36
0.80
27
20
28.57
13.97
28.64
13.79
4.849
0.190
3.33
0.77
27
20
26.98
16.28
28.50
14.07
1820
0.255
17.128
0.89
4.85
27
20
40.0
20.01
39.96
19.99
1830
2.568
0.091
2.80
0.56
27
20
40.06
19.99
28.20
18.32
1840
0.254
7.909
0.95
3.28
27
20
40.0
20.01
35.89
19.48
1850
0.121
10.980
0.78
5.39
27
20
40.0
20.01
39.00
19.58
1860
0.152
10.748
0.83
5.36
27
20
40.0
20.01
39.04
19.63
1870
0.085
11.338
0.71
5.45
27
20
40.0
20.01
38.93
19.50
1880
0.356
1.856
1.12
3.0
27
20
30.0
18.01
32.70
18.04
1890
0.045
11.414
0.69
5.39
27
20
40.0
22.41
39.0
19.61
3800
0.329
0.
0.19
0.
23.3
20
23.11
18.35
23.26
19.04
3805
3.422
0.075
1.72
0.41
27
20
26.26
18.33
26.66
19.04
3810
0.113
14.742
0.5
3.78
27
20
40.0
19.37
34.36
20
3810-2
0.090
7.083
0.48
2.27
27
20
40.0
19.37
36.54
20
3815
0.116
9.985
0.49
2.83
27
20
40.0
19.37
35.7
19.97
3820
0.118
10.212
0.49
2.87
27
20
40.0
19.37
35.63
19.96
3830
0.089
9.651
0.54
3.01
27
20
40.0
20.01
35.65
19.59
Conclusions
ESP-r/HOT3000 is successfully used to create simulation models for Test Cases 795-1890 and 38003830 of the IEA Radiant Heating and Cooling Test Cases. The only change to the ESP-r source code
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 8 2
required is to implement the proper correlations, given in the RADTEST Manual, for the convection
heat transfer coefficient on the heated or cooled constant-temperature floor. All the other aspects of the
test cases are easily modeled using existing ESP-r/HOT3000 capabilities. The results show that it is
possible to properly model the active layer using a constant-temperature air zone. Results obtained in
this work also indicate that the simulation results are strongly dependent on the assumed
convective/radiative split of the total heat transfer coefficient on top of the heated/cooled floor.
References
Achermann, M. 2001. RADTEST: Radiant Heating and Cooling Test Cases. International Energy
Agency, Task 22: Building Energy Analysis Tools: Subtask C.
Clarke J. A. 1977. Environmental Systems Performance. Ph.D. Thesis, University of Strathclyde,
Glasgow, Scotland.
Energy Systems Research Unit (ESRU). 1996. The ESP-r System for Building Energy Simulation.
User Guide, Version 9 Series. University of Strathclyde, Scotland.
Judkoff, R. and J. Neymark. 1995a. Building Energy Simulation Test (BESTEST) and Diagnostic
Method. NREL/TP-472-6231. Golden, Colo.: National Renewable Energy Laboratory.
RADTEST – Radiant Heating and Cooling Test Cases
International Energy Agency (IEA)
Solar Heating & Cooling Programme
Task 22: Building Energy Analysis Tools, Subtask C
Matthias Achermann
Gerhard Zweifel
Page 8 3
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