ISO 52032-1:2022
(Main)Energy performance of buildings — Energy requirements and efficiencies of heating, cooling and domestic hot water (DHW) distribution systems — Part 1: Calculation procedures
Energy performance of buildings — Energy requirements and efficiencies of heating, cooling and domestic hot water (DHW) distribution systems — Part 1: Calculation procedures
This document specifies the energy performance calculation of water-based distribution systems for space heating, space cooling and domestic hot water (DHW). This document is applicable to the heat flux from the distributed water to the space and the auxiliary energy of the related pumps. The heat flux and the auxiliary energy for pumps can be calculated for any time interval (hour, month and year). The input and output data are mean values of the time interval. Instead of calculating the energy performance of water-based distribution systems, it is also possible to use measurements as long as they follow the time intervals of the whole performance calculation or can be divided into those time intervals.
Performance énergétique des bâtiments — Besoins énergétiques et rendements des systèmes de distribution d'eau chaude sanitaire, chauffage et refroidissement — Partie 1: Modes opératoires de calcul
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INTERNATIONAL ISO
STANDARD 52032-1
First edition
2022-03
Energy performance of buildings —
Energy requirements and efficiencies
of heating, cooling and domestic hot
water (DHW) distribution systems —
Part 1:
Calculation procedures
Performance énergétique des bâtiments — Besoins énergétiques
et rendements des systèmes de distribution d'eau chaude sanitaire,
chauffage et refroidissement —
Partie 1: Modes opératoires de calcul
Reference number
ISO 52032-1:2022(E)
© ISO 2022
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ISO 52032-1:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
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Website: www.iso.org
Published in Switzerland
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ISO 52032-1:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols, subscripts and abbreviated terms . 2
4.1 Symbols . 2
4.2 Subscripts . . 3
4.3 Abbreviated terms . 3
5 General description of the method — Output of the method . 3
6 Calculation of heat losses and auxiliary energy of distribution systems .4
6.1 Output data . 4
6.2 Calculation time intervals . 5
6.3 Input data . 5
6.3.1 Product technical data (quantitative) . 5
6.3.2 Configuration and system design data . 5
6.3.3 Operating or boundary conditions . 6
6.3.4 Constants and physical data . 7
6.3.5 Input data from Annex A (with default choices in Annex B) . 7
6.4 Calculation procedure . . 8
6.4.1 Applicable time interval . 8
6.4.2 Operating conditions calculation . 8
6.4.3 Heat loss calculation . 8
6.4.4 Recoverable energy . 11
6.4.5 Auxiliary energy calculation . 11
6.4.6 Auxiliary energy for ribbon heater . 14
6.4.7 Recoverable and recovered auxiliary energy . 14
6.4.8 Lengths of pipes . 14
7 Quality control .18
8 Conformance check .18
Annex A (normative) Input and method selection data sheet — Template .19
Annex B (informative) Input and method selection data sheet — Default choices .26
Bibliography .34
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ISO 52032-1:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 205, Building environment design.
A list of all parts in the ISO 52032 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO 52032-1:2022(E)
Introduction
This document belongs to the family of International Standards aimed at the international
harmonization of the methodology for assessing the energy performance of buildings. Throughout, this
group of standards is referred to as a “set of EPB standards”.
All EPB standards follow specific rules to ensure overall consistency, unambiguity and transparency.
All EPB standards provide a certain flexibility with regard to the methods, the required input data and
references to other EPB standards. For the correct use of this document a template is given in Annex A
to specify these choices. Default choices are provided in Annex B.
The main target groups of this document are all the users of the set of EPB set of standards (e.g.
architects, engineers, regulators).
Further target groups are parties wanting to motivate their assumptions by classifying the building
energy performance for a dedicated building stock.
[12]1) [4]
More information is provided in ISO/TR 52032-2 and in CEN/TR 15316-6-3 .
Table 1 shows the relative position of this document within the set of EPB standards in the context of
the modular structure as set out in ISO 52000-1.
NOTE 1 In ISO/TR 52000-2 the same table can be found, with, for each module, the numbers of the relevant
EPB standards and accompanying technical reports that are published or in preparation.
NOTE 2 The modules represent EPB standards, although one EPB standard can cover more than one module
and one module can be covered by more than one EPB standard, e.g. a simplified and a detailed method
respectively. See also Clause 2 and Tables A.1 and B.1.
1) Under preparation. Stage at the time of publication: ISO/AWI TR 52032-2.
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ISO 52032-1:2022(E)
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Table 1 — Position of this document within the modular structure of the set of EPB standards
Building (as
Overarching Technical building systems
such)
Domes- Building
Electric-
Descrip- Descrip- Descrip- Ventila- Humidifica- Dehumidifica- tic hot Light- automa-
Heating Cooling ity pro-
tions tions tions tion tion tion water ing tion and
duction
(DHW) control
sub1 M1 sub1 M2 sub1 M3 M4 M5 M6 M7 M8 M9 M10 M11
1 General 1 General 1 General
Common
terms and
Building
definitions;
2 2 energy 2 Needs
symbols,
needs
units and
subscripts
(Free)
Indoor Maximum
Applica-
3 3 conditions 3 load and
tions
without power
systems
Ways to Ways to Ways to
express express express
4 4 4
energy per- energy per- energy per-
formance formance formance
Building
Heat
functions
transfer by Emission
5 and build- 5 5
transmis- and control
ing bounda-
sion
ries
Building
Heat trans- ISO ISO ISO
occupan- Distribu-
fer by infil- 52032-1 52032-1 52032-1
6 cy and 6 6 tion and
tration and (this doc- (this doc- (this doc-
operating control
ventilation ument) ument) ument)
conditions
Aggre-
gation of
energy Internal Storage and
7 7 7
services heat gains control
and energy
carriers
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ISO 52032-1:2022(E)
vii
© ISO 2022 – All rights reserved
Table 1 (continued)
Building (as
Overarching Technical building systems
such)
Domes- Building
Electric-
Descrip- Descrip- Descrip- Ventila- Humidifica- Dehumidifica- tic hot Light- automa-
Heating Cooling ity pro-
tions tions tions tion tion tion water ing tion and
duction
(DHW) control
sub1 M1 sub1 M2 sub1 M3 M4 M5 M6 M7 M8 M9 M10 M11
Building
Solar heat
8 partition- 8 8 Generation
gains
ing
Combus-
8–1
tion boilers
8–2 Heat pumps
Thermal
solar
8–3
photovol-
taics
On-site co-
8–4
generation
District
8–5 heating and
cooling
Direct
8–6 electrical
heater
Wind tur-
8–7
bines
Radiant
8–8 heating,
stoves
Load
Building
Calculated dispatch-
dynamics
9 energy per- 9 9 ing and
(thermal
formance operating
mass)
conditions
Measured Measured Measured
10 energy per- 10 energy per- 10 energy per-
formance formance formance
11 Inspection 11 Inspection 11 Inspection
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ISO 52032-1:2022(E)
viii
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Table 1 (continued)
Building (as
Overarching Technical building systems
such)
Domes- Building
Electric-
Descrip- Descrip- Descrip- Ventila- Humidifica- Dehumidifica- tic hot Light- automa-
Heating Cooling ity pro-
tions tions tions tion tion tion water ing tion and
duction
(DHW) control
sub1 M1 sub1 M2 sub1 M3 M4 M5 M6 M7 M8 M9 M10 M11
Ways to
express
12 12 – 12 BMS
indoor
comfort
External
environ-
13
ment condi-
tions
Economic 15459–
14
calculation 1
NOTE The shaded modules are not applicable
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INTERNATIONAL STANDARD ISO 52032-1:2022(E)
Energy performance of buildings — Energy requirements
and efficiencies of heating, cooling and domestic hot water
(DHW) distribution systems —
Part 1:
Calculation procedures
1 Scope
This document specifies the energy performance calculation of water-based distribution systems for
space heating, space cooling and domestic hot water (DHW).
This document is applicable to the heat flux from the distributed water to the space and the auxiliary
energy of the related pumps.
The heat flux and the auxiliary energy for pumps can be calculated for any time interval (hour, month
and year). The input and output data are mean values of the time interval.
Instead of calculating the energy performance of water-based distribution systems, it is also possible to
use measurements as long as they follow the time intervals of the whole performance calculation or can
be divided into those time intervals.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 7345, Thermal performance of buildings and building components — Physical quantities and definitions
ISO 52000-1:2017, Energy performance of buildings — Overarching EPB assessment — Part 1: General
framework and procedures
ISO 52031, Energy performance of buildings — Method for calculation of system energy requirements and
system efficiencies — Space emission systems (heating and cooling)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7345, ISO 52000-1 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
tapping profile
domestic hot water (DHW) drawn off over time
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ISO 52032-1:2022(E)
3.2
setback mode
operation mode for pumps at the end of scheduled usage time
3.3
boost mode
operation mode for pumps before the beginning of scheduled usage time
3.4
EPB standard
[5]
standard that complies with the requirements given in ISO 52000-1, CEN/TS 16628 and CEN/
[6]
TS 16629
Note 1 to entry: These three basic EPB documents were developed under a mandate given to CEN by the European
Commission and the European Free Trade Association (Mandate M/480), and support essential requirements of
EU Directive 2010/31/EC on the energy performance of buildings (EPBD). Several EPB standards and related
documents are developed or revised under the same mandate.
[SOURCE: ISO 52000-1:2017, 3.5.14.]
4 Symbols, subscripts and abbreviated terms
4.1 Symbols
For the purposes of this document, the symbols given in ISO 52000-1 and the following apply.
Symbol Description Unit
b factor for pump design selection -
B width m
c specific heat Wh/(kg∙K)
C constant -
d diameter m
f resistance ratio -
F force N
h total surface coefficient of heat transfer W/(m∙K)
H height m
L length m
m mass kg
n number -
p differential pressure kPa
P power N
q heat flowrate W/K
Q heat flow kWh
R pressure loss per m kPa/m
t time h
3
v flowrate m /h
3
V volume m
W energy demand kWh
z depth m
β mean part load in a time interval -
ε expenditure energy factor -
θ temperature C°
2
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ISO 52032-1:2022(E)
Symbol Description Unit
λ thermal conductivity W/(m∙K)
3
ρ density kg/m
Ψ linear thermal transmittance W/(m∙K)
V tapping profile 24 [1/h] – per day
Tap
4.2 Subscripts
For the purposes of this document, the subscripts given in ISO 52000-1 and the following apply.
a outer add additional ah ambient heating
amb ambient an regular mode aux auxiliary
avg average atap after tapping boost boost heating
C cooling ci calculation interval
comp components corr correction cs conditioned space
D insulation des design dis distribution
e efficiency el existing em embedded
equi equivalent fl floor H heating
HB hydraulic balance HC heating/cooling HCW heating/cooling/domes-
tic hot water (DHW)
hydr hydraulic i variable
in input ir inner
j zone index ls loss mean mean
nom nominal heat loss non non-insulated op operation
out output p pipe pmp pump
P1 pump control system #1 P2 pump control system #2 rbl recoverable
ref reference rib ribbon rvd recovered
setb setback mode stub open circuited stubs w water
W DHW
4.3 Abbreviated terms
DHW domestic hot water (system)
5 General description of the method — Output of the method
This method covers the calculation of:
— thermal loss of the distribution system for space heating, space cooling and domestic hot water
(DHW) in the zone;
— recoverable thermal loss for space heating, space cooling and DHW in the zone;
— auxiliary energy demand of distribution systems;
— recoverable auxiliary energy in the zone for space heating, space cooling and DHW in the zone;
— recovered auxiliary energy in the fluid in the zone for space heating, space cooling and DHW in the
zone.
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ISO 52032-1:2022(E)
The time interval of the output can be according to the time interval of the input values:
— hourly;
— monthly;
— yearly.
All input and output values are mean values in the corresponding time interval. Because of summarized
time intervals with the same boundary conditions and no dynamic effect being taken into account, the
bin-method is also valid.
6 Calculation of heat losses and auxiliary energy of distribution systems
6.1 Output data
The output data of this method are listed in Table 2.
Table 2 — Output data of this method
Intended
Validity
b
Description Symbol Unit destination Varying
a
interval
module
Thermal loss of the distribution system Yes
Q kWh 0 to ∞ M3–1
H,dis,ls
for heating in the zone
Thermal loss of the distribution system Yes
Q kWh 0 to ∞ M4–1
C,dis,ls
for cooling in the zone
Thermal loss of the distribution system Yes
Q kWh 0 to ∞ M3–1
W,dis,ls
for DHW in the zone
Recoverable thermal loss of the distri- Yes
Q kWh 0 to ∞ M3–1
H,dis,rbl
bution system for heating in the zone
Recoverable thermal loss of the distri- Yes
Q kWh 0 to ∞ M4–1
C,dis,rbl
bution system for cooling in the zone
Recoverable thermal loss of the dis- Yes
Q kWh 0 to ∞ M3–1
W,dis,rbl
tribution system for DHW in the zone
Auxiliary energy for distribution system Yes
W kWh 0 to ∞ M3–1
H,dis
heating in the zone
Auxiliary energy for distribution system Yes
W kWh 0 to ∞ M4–1
C,dis
cooling in the zone
Auxiliary energy for distribution system Yes
W kWh 0 to ∞ M3–1
W,dis
DHW in the zone
Recoverable auxiliary energy for dis- Yes
Q kWh 0 to ∞ M3–1
H,dis,rbl
tribution system heating in the zone
Recoverable auxiliary energy for dis- Yes
Q kWh 0 to ∞ M4–1
C,dis,rbl
tribution system cooling in the zone
Recoverable auxiliary energy for dis- Yes
Q kWh 0 to ∞ M3–1
W,dis,rbl
tribution system DHW in the zone
Recovered auxiliary energy for dis- Yes
Q kWh 0 to ∞ M3–1
H,dis,rvd
tribution system heating in the zone
Recovered auxiliary energy for dis- Yes
Q kWh 0 to ∞ M4–1
C,dis,rvd
tribution system cooling in the zone
a
Practical range, informative.
b
"Varying": value can vary over time; different values per time interval, e.g. hourly values or monthly values (not
constant values over the year).
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ISO 52032-1:2022(E)
Table 2 (continued)
Intended
Validity
b
Description Symbol Unit destination Varying
a
interval
module
Recovered auxiliary energy for distri- Yes
Q kWh 0 to ∞ M3–1
W,dis,rvd
bution system DHW in the zone
a
Practical range, informative.
b
"Varying": value can vary over time; different values per time interval, e.g. hourly values or monthly values (not
constant values over the year).
6.2 Calculation time intervals
The methods described in Clause 6 are suitable for the following calculation time intervals:
— hourly;
— monthly;
— yearly.
For this method, the output time interval is the same as the input time-interval. This method does not
take into account any dynamic effect.
6.3 Input data
6.3.1 Product technical data (quantitative)
Table 3 — Product technical input data list
Catalogue Computed Validity
b
Characteristics Symbol Ref. Varying
a
unit unit interval
Energy efficiency index EEI - 0 to 1 YES
a
Practical range, informative.
b
"Varying": value can vary over time; different values per time interval, e.g. hourly values or monthly values (not
constant values over the year).
6.3.2 Configuration and system design data
6.3.2.1 Process design
The input data of the process design are listed in Table 4.
Table 4 — Process design input data list
Process design
tapping profile V 24 ∙ [l/h]
tap
temperature difference between hot water tapping temperature to the return
∆ϑW °C
temperature in a circulation loop system (design value)
number of operations of circulation pump n 1/d
nom
average hot water temperature in circulation system without operation ϑ °C
W,avg
resistance ratio of components in the piping system f —
comp
pressure loss per length R kPa/m
HCW,max
pressure losses of additional resistances ∆R kPa
HCW,add
length of pipes L m
5
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ISO 52032-1:2022(E)
Table 4 (continued)
Process design
equivalent length of pipes (e.g. valves, hangers) L m
equi
6.3.2.2 Controls
This identifier (see Table 5) indicates how the pump is controlled.
Table 5 — Identifiers for pump control
Identifier Code Meaning
HEAT_DISTR_CTRL_PMP 0 Uncontrolled
HEAT_DISTR_CTRL_PMP 1 On-off mode
HEAT_DISTR_CTRL_PMP 2 Multi-stage-control
HEAT_DISTR_CTRL_PMP 3 Variable speed control based on ∆p -constant
HEAT_DISTR_CTRL_PMP 4 Variable speed control based on ∆p -variable
In this document a distinction is only made between codes 0, 3 and 4 because codes 1 and 2 relate to the
energy demand and not to the type of operation.
This identifier (see Table 6) indicates how the pump is operating in intermittent control of emission
and/or distribution.
Table 6 — Identifiers for pump control (intermittent)
Identifier Code Meaning
HEAT_DISTR_CTRL 0 No automatic control
HEAT_DISTR_CTRL 1 Fixed time program
HEAT_DISTR_CTRL 2 control with optimum start/stop
HEAT_DISTR_CTRL 3 Control with demand evaluation
In this document a distinction is only made between codes 0, 2 and 3. Code 1 relates to the energy
demand.
The values correspond to those in ISO 52031.
The identifier for pump selection in the design process (see Table 7) takes into account whether the
pump is selected with its working point at the design point or not. Different from design point is also
used for existing pumps.
Table 7 — Identifiers for pump selection
Identifier Code Meaning
PUMP_DISTR_SEL 1 When selection is at design point
PUMP_DISTR_SEL When selection is different from design
2
point
6.3.3 Operating or boundary conditions
Required operating condition data for this calculation procedure are listed in Table 8.
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ISO 52032-1:2022(E)
Table 8 — Operating condition data list
a b
Name Symbol Unit Range Origin module Varying
Operating conditions
Input temperature of the heating circuit ϑ °C 0 to 110 M3–5 Yes
H,in
Output temperature of the heating circuit ϑ °C 0 to 110 M3–5 Yes
H,out
3
Flowrate in the heating circuit v m /h 0 to ∞ Yes
H
Mean part load of heating circuit β — 0 to 1 Yes
H,dis
Input temperature of the cooling circuit ϑ °C 0 to 110 M4–5 Yes
C,in
Output temperature of the cooling circuit ϑ °C 0 to 110 M4–5 Yes
C,out
3
Flowrate in the cooling circuit v m /h 0 to ∞ Yes
C
Mean part load of cooling circuit β — 0 to 1 Yes
C,dis
Temperature of DHW ϑ °C 30 to 70 M8–1 Yes
W
Temperature difference between hot
water tapping temperature to the return Δϑ °C 1 to 20 Yes
W
temperature in a circulation loop system
.
3
Flowrate in the DHW circulation system m /h 0 to ∞ Yes
v
W
Calculation interval t h 1 to 8 760 M1–9 Yes
ci
Total time operation t h 0 to 8 760 M1–6 Yes
op
Surrounding zone temperature in the
ϑ °C −40 to +40 M2–2 Yes
ah,H
calculation interval at heating period
Surrounding zone temperature in the
ϑ °C −40 to +40 M2–2 Yes
ah,C
calculation interval at cooling period
Surrounding zone temperature in the
ϑ °C −40 to +40 M2–2 Yes
amb,W
calculation interval at DHW period
Operation time of the distribution system t h 0 to 8 760 M2–2 Yes
HCW,op
a
Practical range, informative.
b
"Varying": value can vary over time; different values per time interval, e.g. hourly values or monthly values (not
constant values over the year).
6.3.4 Constants and physical data
Table 9 indicates constants and physical data.
Table 9 — Constants and physical data
Name Symbol Unit Value
3
(specific heat ∙ density) of water c ∙ρ kWh/(m ·K) 1,15
w w
−3
Specific heat of water c kWh/(kg∙K) 1,163⋅10
w
3
Density of water ρ kg/m 990
w
6.3.5 Input data from Annex A (with default choices in Annex B)
The user shall follow the templates for choices in references, methods and input given in Annex A.
NOTE Informative default choices are given in Annex B, respecting the template of Annex A.
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ISO 52032-1:2022(E)
6.4 Calculation procedure
6.4.1 Applicable time interval
The procedure can be used with the following time intervals:
— hourly;
— monthly;
— yearly.
The bin-method can also be used because in this method only identical time intervals are summarized.
No dynamic effects are taken into account because there are no significant time constants.
This procedure is not suitable for dynamic simulations.
6.4.2 Operating conditions calculation
6.4.3 Heat loss calculation
6.4.3.1 General
The heat loss calculation of a distribution system is based on the mean water supply temperature, the
surrounding temperature in a space, the thermal transmittance of the pipes, the length of the pipes and
the operation time.
6.4.3.2 Mean water temperature for space heating and space cooling with circulation
The mean water temperature in the distribution systems ϑ for space heating and space cooling
HC;mean
is given by:
ϑϑ+
HC;inHC;out
ϑ = °[]C (1)
HC;mean
2
where
ϑ is the mean water temperature in the distribution system at the time interval, in C°;
HC;mean
ϑ is the input water temperature in the emission system, at the time interval, as determined
HC;in
in the relevant standard under EPB module M3-5, in C°;
ϑ is the output water temperature in the emission system at the time interval, as determined
HC;out
in the relevant standard under EPB module M3-5, in C°.
6.4.3.3 Mean water temperature for DHW with circulation
The mean water temperature in the distribution system θ for DHW with circulation is given by:
W,mean
Δϑ
W
ϑϑ=− (2)
W;mean W
2
...
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 52032-1
ISO/TC 205
Energy performance of buildings —
Secretariat: ANSI
Energy requirements and efficiencies
Voting begins on:
2021-12-23 of heating, cooling and domestic hot
water (DHW) distribution systems —
Voting terminates on:
2022-02-17
Part 1:
Calculation procedures
Performance énergétique des bâtiments — Besoins énergétiques
et rendements des systèmes de distribution d'eau chaude sanitaire,
chauffage et refroidissement —
Partie 1: Modes opératoires de calcul
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 52032-1:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2021
---------------------- Page: 1 ----------------------
ISO/FDIS 52032-1:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
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ISO/FDIS 52032-1:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols, subscripts and abbreviated terms . 2
4.1 Symbols . 2
4.2 Subscripts . . 3
4.3 Abbreviated terms . 3
5 General description of the method — Output of the method . 3
6 Calculation of heat losses and auxiliary energy of distribution systems .4
6.1 Output data . 4
6.2 Calculation time intervals . 5
6.3 Input data . 5
6.3.1 Product technical data (quantitative) . 5
6.3.2 Configuration and system design data . 5
6.3.3 Operating or boundary conditions . 6
6.3.4 Constants and physical data . 7
6.3.5 Input data from Annex A (with default choices in Annex B) . 7
6.4 Calculation procedure . . 8
6.4.1 Applicable time interval . 8
6.4.2 Operating conditions calculation . 8
6.4.3 Heat loss calculation . 8
6.4.4 Recoverable energy . 11
6.4.5 Auxiliary energy calculation . 11
6.4.6 Auxiliary energy for ribbon heater . 14
6.4.7 Recoverable and recovered auxiliary energy . 14
6.4.8 Lengths of pipes . 14
7 Quality control .18
8 Conformance check .18
Annex A (normative) Input and method selection data sheet — Template .19
Annex B (informative) Input and method selection data sheet — Default choices .26
Bibliography .34
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ISO/FDIS 52032-1:2021(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 205, Building environment design.
A list of all parts in the ISO 52032 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO/FDIS 52032-1:2021(E)
Introduction
This document belongs to the family of International Standards aimed at the international
harmonization of the methodology for assessing the energy performance of buildings. Throughout, this
group of standards is referred to as a “set of EPB standards”.
All EPB standards follow specific rules to ensure overall consistency, unambiguity and transparency.
All EPB standards provide a certain flexibility with regard to the methods, the required input data and
references to other EPB standards. For the correct use of this document a template is given in Annex A
to specify these choices. Default choices are provided in Annex B.
The main target groups of this document are all the users of the set of EPB set of standards (e.g.
architects, engineers, regulators).
Further target groups are parties wanting to motivate their assumptions by classifying the building
energy performance for a dedicated building stock.
[12]1) [4]
More information is provided in ISO/TR 52032-2 and in CEN/TR 15316-6-3 .
Table 1 shows the relative position of this document within the set of EPB standards in the context of
the modular structure as set out in ISO 52000-1.
NOTE 1 In ISO/TR 52000-2 the same table can be found, with, for each module, the numbers of the relevant
EPB standards and accompanying technical reports that are published or in preparation.
NOTE 2 The modules represent EPB standards, although one EPB standard can cover more than one module
and one module can be covered by more than one EPB standard, e.g. a simplified and a detailed method
respectively. See also Clause 2 and Tables A.1 and B.1.
1) Under preparation. Stage at the time of publication: ISO/AWI TR 52032-2.
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ISO/FDIS 52032-1:2021(E)
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© ISO 2021 – All rights reserved
Table 1 — Position of this document within the modular structure of the set of EPB standards
Building (as
Overarching Technical building systems
such)
Domes- Building
Electric-
Descrip- Descrip- Descrip- Ventila- Humidifica- Dehumidifica- tic hot Light- automa-
Heating Cooling ity pro-
tions tions tions tion tion tion water ing tion and
duction
(DHW) control
sub1 M1 sub1 M2 sub1 M3 M4 M5 M6 M7 M8 M9 M10 M11
1 General 1 General 1 General
Common
terms and
Building
definitions;
2 2 energy 2 Needs
symbols,
needs
units and
subscripts
(Free)
Indoor Maximum
Applica-
3 3 conditions 3 load and
tions
without power
systems
Ways to Ways to Ways to
express express express
4 4 4
energy per- energy per- energy per-
formance formance formance
Building
Heat
functions
transfer by Emission
5 and build- 5 5
transmis- and control
ing bounda-
sion
ries
Building
Heat trans- ISO ISO ISO
occupan- Distribu-
fer by infil- 52032-1 52032-1 52032-1
6 cy and 6 6 tion and
tration and (this doc- (this doc- (this doc-
operating control
ventilation ument) ument) ument)
conditions
Aggre-
gation of
energy Internal Storage and
7 7 7
services heat gains control
and energy
carriers
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ISO/FDIS 52032-1:2021(E)
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Table 1 (continued)
Building (as
Overarching Technical building systems
such)
Domes- Building
Electric-
Descrip- Descrip- Descrip- Ventila- Humidifica- Dehumidifica- tic hot Light- automa-
Heating Cooling ity pro-
tions tions tions tion tion tion water ing tion and
duction
(DHW) control
sub1 M1 sub1 M2 sub1 M3 M4 M5 M6 M7 M8 M9 M10 M11
Building
Solar heat
8 partition- 8 8 Generation
gains
ing
Combus-
8–1
tion boilers
8–2 Heat pumps
Thermal
solar
8–3
photovol-
taics
On-site co-
8–4
generation
District
8–5 heating and
cooling
Direct
8–6 electrical
heater
Wind tur-
8–7
bines
Radiant
8–8 heating,
stoves
Load
Building
Calculated dispatch-
dynamics
9 energy per- 9 9 ing and
(thermal
formance operating
mass)
conditions
Measured Measured Measured
10 energy per- 10 energy per- 10 energy per-
formance formance formance
11 Inspection 11 Inspection 11 Inspection
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ISO/FDIS 52032-1:2021(E)
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Table 1 (continued)
Building (as
Overarching Technical building systems
such)
Domes- Building
Electric-
Descrip- Descrip- Descrip- Ventila- Humidifica- Dehumidifica- tic hot Light- automa-
Heating Cooling ity pro-
tions tions tions tion tion tion water ing tion and
duction
(DHW) control
sub1 M1 sub1 M2 sub1 M3 M4 M5 M6 M7 M8 M9 M10 M11
Ways to
express
12 12 – 12 BMS
indoor
comfort
External
environ-
13
ment condi-
tions
Economic 15459–
14
calculation 1
NOTE The shaded modules are not applicable
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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 52032-1:2021(E)
Energy performance of buildings — Energy requirements
and efficiencies of heating, cooling and domestic hot water
(DHW) distribution systems —
Part 1:
Calculation procedures
1 Scope
This document specifies the energy performance calculation of water-based distribution systems for
space heating, space cooling and domestic hot water (DHW).
This document is applicable to the heat flux from the distributed water to the space and the auxiliary
energy of the related pumps.
The heat flux and the auxiliary energy for pumps can be calculated for any time interval (hour, month
and year). The input and output data are mean values of the time interval.
Instead of calculating the energy performance of water-based distribution systems, it is also possible to
use measurements as long as they follow the time intervals of the whole performance calculation or can
be divided into those time intervals.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 7345, Thermal performance of buildings and building components — Physical quantities and definitions
ISO 52000-1:2017, Energy performance of buildings — Overarching EPB assessment — Part 1: General
framework and procedures
ISO 52031, Energy performance of buildings — Method for calculation of system energy requirements and
system efficiencies — Space emission systems (heating and cooling)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7345, ISO 52000-1 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
tapping profile
domestic hot water (DHW) drawn off over time
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ISO/FDIS 52032-1:2021(E)
3.2
setback mode
operation mode for pumps at the end of scheduled usage time
3.3
boost mode
operation mode for pumps before the beginning of scheduled usage time
3.4
EPB standard
[5]
standard that complies with the requirements given in ISO 52000-1, CEN/TS 16628 and CEN/
[6]
TS 16629
Note 1 to entry: These three basic EPB documents were developed under a mandate given to CEN by the European
Commission and the European Free Trade Association (Mandate M/480), and support essential requirements of
EU Directive 2010/31/EC on the energy performance of buildings (EPBD). Several EPB standards and related
documents are developed or revised under the same mandate.
[SOURCE: ISO 52000-1:2017, 3.5.14.]
4 Symbols, subscripts and abbreviated terms
4.1 Symbols
For the purposes of this document, the symbols given in ISO 52000-1 and the following apply.
Symbol Description Unit
b factor for pump design selection -
B width m
c specific heat Wh/(kg∙K)
C constant -
d diameter m
f resistance ratio -
F force N
h total surface coefficient of heat transfer W/(m∙K)
H height m
L length m
m mass kg
n number -
p differential pressure kPa
P power N
q heat flowrate W/K
Q heat flow kWh
R pressure loss per m kPa/m
t time h
3
v flowrate m /h
3
V volume m
W energy demand kWh
z depth m
β mean part load in a time interval -
ε expenditure energy factor -
θ temperature C°
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ISO/FDIS 52032-1:2021(E)
Symbol Description Unit
λ thermal conductivity W/(m∙K)
3
ρ density kg/m
Ψ linear thermal transmittance W/(m∙K)
V tapping profile 24 [1/h] – per day
Tap
4.2 Subscripts
For the purposes of this document, the subscripts given in ISO 52000-1 and the following apply.
a outer add additional ah ambient heating
amb ambient an regular mode aux auxiliary
avg average atap after tapping boost boost heating
C cooling ci calculation interval
comp components corr correction cs conditioned space
D insulation des design dis distribution
e efficiency el existing em embedded
equi equivalent fl floor H heating
HB hydraulic balance HC heating/cooling HCW heating/cooling/domes-
tic hot water (DHW)
hydr hydraulic i variable
in input ir inner
j zone index ls loss mean mean
nom nominal heat loss non non-insulated op operation
out output p pipe pmp pump
P1 pump control system #1 P2 pump control system #2 rbl recoverable
ref reference rib ribbon rvd recovered
setb setback mode stub open circuited stubs w water
W DHW
4.3 Abbreviated terms
DHW domestic hot water (system)
5 General description of the method — Output of the method
This method covers the calculation of:
— thermal loss of the distribution system for space heating, space cooling and domestic hot water
(DHW) in the zone;
— recoverable thermal loss for space heating, space cooling and DHW in the zone;
— auxiliary energy demand of distribution systems;
— recoverable auxiliary energy in the zone for space heating, space cooling and DHW in the zone;
— recovered auxiliary energy in the fluid in the zone for space heating, space cooling and DHW in the
zone.
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ISO/FDIS 52032-1:2021(E)
The time interval of the output can be according to the time interval of the input values:
— hourly;
— monthly;
— yearly.
All input and output values are mean values in the corresponding time interval. Because of summarized
time intervals with the same boundary conditions and no dynamic effect being taken into account, the
bin-method is also valid.
6 Calculation of heat losses and auxiliary energy of distribution systems
6.1 Output data
The output data of this method are listed in Table 2.
Table 2 — Output data of this method
Intended
Validity
b
Description Symbol Unit destination Varying
a
interval
module
Thermal loss of the distribution system Yes
Q kWh 0 to ∞ M3–1
H,dis,ls
for heating in the zone
Thermal loss of the distribution system Yes
Q kWh 0 to ∞ M4–1
C,dis,ls
for cooling in the zone
Thermal loss of the distribution system Yes
Q kWh 0 to ∞ M3–1
W,dis,ls
for DHW in the zone
Recoverable thermal loss of the distri- Yes
Q kWh 0 to ∞ M3–1
H,dis,rbl
bution system for heating in the zone
Recoverable thermal loss of the distri- Yes
Q kWh 0 to ∞ M4–1
C,dis,rbl
bution system for cooling in the zone
Recoverable thermal loss of the dis- Yes
Q kWh 0 to ∞ M3–1
W,dis,rbl
tribution system for DHW in the zone
Auxiliary energy for distribution system Yes
W kWh 0 to ∞ M3–1
H,dis
heating in the zone
Auxiliary energy for distribution system Yes
W kWh 0 to ∞ M4–1
C,dis
cooling in the zone
Auxiliary energy for distribution system Yes
W kWh 0 to ∞ M3–1
W,dis
DHW in the zone
Recoverable auxiliary energy for dis- Yes
Q kWh 0 to ∞ M3–1
H,dis,rbl
tribution system heating in the zone
Recoverable auxiliary energy for dis- Yes
Q kWh 0 to ∞ M4–1
C,dis,rbl
tribution system cooling in the zone
Recoverable auxiliary energy for dis- Yes
Q kWh 0 to ∞ M3–1
W,dis,rbl
tribution system DHW in the zone
Recovered auxiliary energy for dis- Yes
Q kWh 0 to ∞ M3–1
H,dis,rvd
tribution system heating in the zone
Recovered auxiliary energy for dis- Yes
Q kWh 0 to ∞ M4–1
C,dis,rvd
tribution system cooling in the zone
a
Practical range, informative.
b
"Varying": value can vary over time; different values per time interval, e.g. hourly values or monthly values (not
constant values over the year).
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ISO/FDIS 52032-1:2021(E)
Table 2 (continued)
Intended
Validity
b
Description Symbol Unit destination Varying
a
interval
module
Recovered auxiliary energy for distri- Yes
Q kWh 0 to ∞ M3–1
W,dis,rvd
bution system DHW in the zone
a
Practical range, informative.
b
"Varying": value can vary over time; different values per time interval, e.g. hourly values or monthly values (not
constant values over the year).
6.2 Calculation time intervals
The methods described in Clause 6 are suitable for the following calculation time intervals:
— hourly;
— monthly;
— yearly.
For this method, the output time interval is the same as the input time-interval. This method does not
take into account any dynamic effect.
6.3 Input data
6.3.1 Product technical data (quantitative)
Table 3 — Product technical input data list
Catalogue Computed Validity
b
Characteristics Symbol Ref. Varying
a
unit unit interval
Energy efficiency index EEI - 0 to 1 YES
a
Practical range, informative.
b
"Varying": value can vary over time; different values per time interval, e.g. hourly values or monthly values (not
constant values over the year).
6.3.2 Configuration and system design data
6.3.2.1 Process design
The input data of the process design are listed in Table 4.
Table 4 — Process design input data list
Process design
tapping profile V 24 ∙ [l/h]
tap
temperature difference between hot water tapping temperature to the return
∆ϑW °C
temperature in a circulation loop system (design value)
number of operations of circulation pump n 1/d
nom
average hot water temperature in circulation system without operation ϑ °C
W,avg
resistance ratio of components in the piping system f —
comp
pressure loss per length R kPa/m
HCW,max
pressure losses of additional resistances ∆R kPa
HCW,add
length of pipes L m
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ISO/FDIS 52032-1:2021(E)
Table 4 (continued)
Process design
equivalent length of pipes (e.g. valves, hangers) L m
equi
6.3.2.2 Controls
This identifier (see Table 5) indicates how the pump is controlled.
Table 5 — Identifiers for pump control
Identifier Code Meaning
HEAT_DISTR_CTRL_PMP 0 Uncontrolled
HEAT_DISTR_CTRL_PMP 1 On-off mode
HEAT_DISTR_CTRL_PMP 2 Multi-stage-control
HEAT_DISTR_CTRL_PMP 3 Variable speed control based on ∆p -constant
HEAT_DISTR_CTRL_PMP 4 Variable speed control based on ∆p -variable
In this document a distinction is only made between codes 0, 3 and 4 because codes 1 and 2 relate to the
energy demand and not to the type of operation.
This identifier (see Table 6) indicates how the pump is operating in intermittent control of emission
and/or distribution.
Table 6 — Identifiers for pump control (intermittent)
Identifier Code Meaning
HEAT_DISTR_CTRL 0 No automatic control
HEAT_DISTR_CTRL 1 Fixed time program
HEAT_DISTR_CTRL 2 control with optimum start/stop
HEAT_DISTR_CTRL 3 Control with demand evaluation
In this document a distinction is only made between codes 0, 2 and 3. Code 1 relates to the energy
demand.
The values correspond to those in ISO 52031.
The identifier for pump selection in the design process (see Table 7) takes into account whether the
pump is selected with its working point at the design point or not. Different from design point is also
used for existing pumps.
Table 7 — Identifiers for pump selection
Identifier Code Meaning
PUMP_DISTR_SEL 1 When selection is at design point
PUMP_DISTR_SEL When selection is different from design
2
point
6.3.3 Operating or boundary conditions
Required operating condition data for this calculation procedure are listed in Table 8.
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ISO/FDIS 52032-1:2021(E)
Table 8 — Operating condition data list
a b
Name Symbol Unit Range Origin module Varying
Operating conditions
Input temperature of the heating circuit ϑ °C 0 to 110 M3–5 Yes
H,in
Output temperature of the heating circuit ϑ °C 0 to 110 M3–5 Yes
H,out
3
Flowrate in the heating circuit v m /h 0 to ∞ Yes
H
Mean part load of heating circuit β — 0 to 1 Yes
H,dis
Input temperature of the cooling circuit ϑ °C 0 to 110 M4–5 Yes
C,in
Output temperature of the cooling circuit ϑ °C 0 to 110 M4–5 Yes
C,out
3
Flowrate in the cooling circuit v m /h 0 to ∞ Yes
C
Mean part load of cooling circuit β — 0 to 1 Yes
C,dis
Temperature of DHW ϑ °C 30 to 70 M8–1 Yes
W
Temperature difference between hot
water tapping temperature to the return Δϑ °C 1 to 20 Yes
W
temperature in a circulation loop system
.
3
Flowrate in the DHW circulation system m /h 0 to ∞ Yes
v
W
Calculation interval t h 1 to 8 760 M1–9 Yes
ci
Total time operation t h 0 to 8 760 M1–6 Yes
op
Surrounding zone temperature in the
ϑ °C −40 to +40 M2–2 Yes
ah,H
calculation interval at heating period
Surrounding zone temperature in the
ϑ °C −40 to +40 M2–2 Yes
ah,C
calculation interval at cooling period
Surrounding zone temperature in the
ϑ °C −40 to +40 M2–2 Yes
amb,W
calculation interval at DHW period
Operation time of the distribution system t h 0 to 8 760 M2–2 Yes
HCW,op
a.
Practical range, informative.
b.
"Varying": value can vary over time; different values per time interval, e.g. hourly values or monthly values (not
constant values over the year).
6.3.4 Constants and physical data
Table 9 indicates constants and physical data.
Table 9 — Constants and physical data
Name Symbol Unit Value
3
(specific heat ∙ density) of water c ∙ρ kWh/(m ·K) 1,15
w w
−3
Specific heat of water c kWh/(kg∙K) 1,163⋅10
w
3
Density of water ρ kg/m 990
w
6.3.5 Input data from Annex A (with default choices in Annex B)
The user shall follow the templates for choices in references, methods and input given in Annex A.
NOTE Informative default choices are given in Annex B, respecting the template of Annex A.
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ISO/FDIS 52032-1:2021(E)
6.4 Calculation procedure
6.4.1 Applicable time interval
The procedure can be used with the following time intervals:
— hourly;
— monthly;
— yearly.
The bin-method can also be used because in this method only identical time intervals are summarized.
No dynamic effects are taken into account because there are no significant time constants.
This procedure is not suitable for dynamic simulations.
6.4.2 Operating conditions calculation
6.4.3 Heat loss calculation
6.4.3.1 General
The heat loss calculation of a distribution system is based on the mean water supply temperature, the
surrounding temperature in a space, the thermal transmittance of the pipes, the length of the pipes and
the operation time.
6.4.3.2 Mean water temperature for space heating and space cooling with circulation
The mean water temperature in the distribution systems ϑ for space heating and space co
...
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