SIST EN ISO 13792:2012
(Main)Thermal performance of buildings - Calculation of internal temperatures of a room in summer without mechanical cooling - Simplified methods (ISO 13792:2012)
Thermal performance of buildings - Calculation of internal temperatures of a room in summer without mechanical cooling - Simplified methods (ISO 13792:2012)
ISO 13792:2011 specifies the required input data for simplified calculation methods for determining the maximum, average and minimum daily values of the operative temperature of a room in warm periods:
a) to define the characteristics of a room at the design stage in order to avoid overheating in summer;
b) to define whether the installation of a cooling system is necessary or not.
Wärmetechnisches Verhalten von Gebäuden - Berechnung von sommerlichen Raumtemperaturen bei Gebäuden ohne Anlagentechnik - Vereinfachtes Berechnungsverfahren (ISO 13792:2012)
Dieses Dokument legt die Eingabedaten fest, die für vereinfachte Berechnungsverfahren zur Bestimmung der täglichen Höchst , Mittel und Mindestwerte der operativen Temperatur eines Raumes in der warmen Jahreszeit für Folgendes erforderlich sind:
a) um festzulegen, welche Kenngrößen eines Raumes im Entwurfsstadium erforderlich sind, um eine Überhitzung im Sommer zu vermeiden;
b) um festzulegen, ob der Einbau einer Kühlanlage erforderlich ist oder nicht.
In Abschnitt 6 sind die Kriterien angegeben, die ein Berechnungsverfahren erfüllen muss, um dem vorliegenden Dokument zu entsprechen.
Performance thermique des bâtiments - Calcul des températures intérieures en été d'un local sans dispositif de refroidissement mécanique - Méthodes simplifiées (ISO 13792:2012)
L'ISO 13792:2012 définit les données d'entrée requises pour les méthodes de calcul simplifiées permettant de déterminer les valeurs journalières maximales, moyennes et minimales de la température opérative d'un local pendant les périodes chaudes, dans le but de:
a) définir les caractéristiques d'un local au stade de projet afin d'éviter un échauffement excessif en été;
b) définir si l'installation d'un système de refroidissement est nécessaire ou non.
Toplotne značilnosti stavb - Izračun notranje temperature prostorov poleti brez mehanskega hlajenja - Poenostavljena metoda (ISO 13792:2012)
Ta mednarodni standard določa potrebne vhodne podatke za poenostavljene metode izračuna za določanje največjih, povprečnih in najmanjših dnevnih vrednosti delovnih temperatur prostorov v toplih obdobjih: a) za določanje značilnosti prostora v času načrtovanja, da se prepreči čezmerno segrevanje poleti; b) za določanje, ali je namestitev sistema hlajenja potrebna ali ne. Točka 6 določa merila, ki jih mora izpolnjevati metoda izračuna, da je skladna s tem mednarodnim standardom.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 13792:2012
01-julij-2012
1DGRPHãþD
SIST EN ISO 13792:2005
7RSORWQH]QDþLOQRVWLVWDYE,]UDþXQQRWUDQMHWHPSHUDWXUHSURVWRURYSROHWLEUH]
PHKDQVNHJDKODMHQMD3RHQRVWDYOMHQDPHWRGD ,62
Thermal performance of buildings - Calculation of internal temperatures of a room in
summer without mechanical cooling - Simplified methods (ISO 13792:2012)
Wärmetechnisches Verhalten von Gebäuden - Berechnung von sommerlichen
Raumtemperaturen bei Gebäuden ohne Anlagentechnik - Vereinfachtes
Berechnungsverfahren (ISO 13792:2012)
Performance thermique des bâtiments - Calcul des températures intérieures en été d'un
local sans dispositif de refroidissement mécanique - Méthodes simplifiées (ISO
13792:2012)
Ta slovenski standard je istoveten z: EN ISO 13792:2012
ICS:
91.120.10 Toplotna izolacija stavb Thermal insulation
SIST EN ISO 13792:2012 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN ISO 13792:2012
---------------------- Page: 2 ----------------------
SIST EN ISO 13792:2012
EUROPEAN STANDARD
EN ISO 13792
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2012
ICS 91.120.10 Supersedes EN ISO 13792:2005
English Version
Thermal performance of buildings - Calculation of internal
temperatures of a room in summer without mechanical cooling -
Simplified methods (ISO 13792:2012)
Performance thermique des bâtiments - Calcul des Wärmetechnisches Verhalten von Gebäuden - Berechnung
températures intérieures en été d'un local sans dispositif de von sommerlichen Raumtemperaturen bei Gebäuden ohne
refroidissement mécanique - Méthodes simplifiées (ISO Anlagentechnik - Vereinfachtes Berechnungsverfahren
13792:2012) (ISO 13792:2012)
This European Standard was approved by CEN on 14 March 2012.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13792:2012: E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 13792:2012
EN ISO 13792:2012 (E)
Contents Page
Foreword .3
2
---------------------- Page: 4 ----------------------
SIST EN ISO 13792:2012
EN ISO 13792:2012 (E)
Foreword
This document (EN ISO 13792:2012) has been prepared by Technical Committee ISO/TC 163 "Thermal
performance and energy use in the built environment" in collaboration with Technical Committee CEN/TC 89
“Thermal performance of buildings and building components” the secretariat of which is held by SIS.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by September 2012, and conflicting national standards shall be
withdrawn at the latest by September 2012.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 13792:2005.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 13792:2012 has been approved by CEN as a EN ISO 13792:2012 without any modification.
3
---------------------- Page: 5 ----------------------
SIST EN ISO 13792:2012
---------------------- Page: 6 ----------------------
SIST EN ISO 13792:2012
INTERNATIONAL ISO
STANDARD 13792
Second edition
2012-03-15
Thermal performance of buildings —
Calculation of internal temperatures of
a room in summer without mechanical
cooling — Simplified methods
Performance thermique des bâtiments — Calcul des températures
intérieures en été d'un local sans dispositif de refroidissement
mécanique — Méthodes simplifiées
Reference number
ISO 13792:2012(E)
©
ISO 2012
---------------------- Page: 7 ----------------------
SIST EN ISO 13792:2012
ISO 13792:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 13792:2012
ISO 13792:2012(E)
Contents Page
Foreword . iv
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and units . 2
3.1 Terms and definitions . 2
3.2 Symbols and units . 2
3.3 Subscripts . 5
4 Input data and results . 6
4.1 Assumptions . 6
4.2 Boundary conditions and input data . 6
4.2.1 Boundary conditions . 6
4.2.2 Heat transfer coefficients . 7
4.2.3 Geometrical and thermophysical parameters of the room envelope . 7
4.2.4 Air change rate . 10
4.2.5 Internal gain . 11
4.3 Output data . 11
5 Calculation procedure . 11
6 Validation procedures . 12
6.1 Introduction . 12
6.2 Validation procedure for the calculation method . 12
6.2.1 General . 12
6.2.2 Geometry . 12
6.2.3 Description of elements . 13
6.2.4 Combination of elements . 14
6.2.5 Climatic data . 15
6.2.6 Internal energy sources . 16
6.2.7 Ventilation pattern . 17
6.2.8 Test results . 17
6.3 Validation procedure for the sunlit factor due to external obstructions . 18
Annex A (informative) Examples of solution model . 21
Annex B (informative) Air changes for natural ventilation . 37
Annex C (informative) Evaluation of shaded area of a plane surface due to external obstructions . 39
Annex D (informative) Internal gains . 42
Annex E (informative) Examples of calculation . 44
Annex F (informative) Normative references to international publications with their corresponding
European publications . 53
© ISO 2012 – All rights reserved iii
---------------------- Page: 9 ----------------------
SIST EN ISO 13792:2012
ISO 13792:2012(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 13792 was prepared by Technical Committee ISO/TC 163, Thermal performance and energy use in the
built environment, Subcommittee SC 2, Calculation methods.
This second edition cancels and replaces the first edition (ISO 13792:2005), which has been technically
revised. The main changes compared to the previous edition are given in the following table.
iv © ISO 2012 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 13792:2012
ISO 13792:2012(E)
Clause/subclause Changes
2 Added ISO 9050, ISO 10292, and ISO 15927-2
3.2 and 3.3 Deleted g and m
Added subscript sl
4.2.1.2 Added first and second list items, descriptions of the reference
4.2.3 Replaced U* by U
Replaced g by S as the solar heat gain factor
f
Deleted Equation (1) and replaced old Equations (2) to (6) by Equations (1)
to (5)
Amended Equations (2) to (4)
4.2.3.2 Third list item, replaced g by S
f1
6.2.5 Added the descriptions of the latitudes in Tables 7, 8 and 9
A.2.1 Amended the descriptions of symbols S and n
f
A.2.2 Amended Equation (A.1)
A.2.3 Added the equation to define A
t
Amended Equation (A.24)
A.3.1 Amended Equations (A.28), (A.31), (A.32), (A.33) and (A.34)
A.3.2.1 Amended Equation (A.35)
Amended the unit for c
A.3.2.2.1 Amended Equations (A.38), (A.39), (A.40), (A.45) and (A.47)
Changed the description of H
T
A.3.2.2.2 Amended Equation (A.49)
A.3.2.3 Amended Equation (A.52)
A.3.3 Amended Equation (A.53)
C.2 Added a title to Table C.1
E.1 Amended the description of S in Table E.5
f
E.3 Replaced U* by U
m m
© ISO 2012 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 13792:2012
ISO 13792:2012(E)
Introduction
Knowledge of the internal temperature of a room in warm periods is needed for several purposes, such as:
a) defining the characteristics of a room at the design stage, in order to prevent or limit overheating in
summer;
b) assessing the need for a cooling installation.
The internal temperature is influenced by many parameters such as climatic data, envelope characteristics,
ventilation and internal gains. The internal temperature of a room in warm periods can be determined using
detailed calculation methods. ISO 13791 lays down the assumptions and the criteria to be satisfied for
assessment of internal conditions in the summer with no mechanical cooling. However, for a number of
applications, the calculation methods based on ISO 13791 are too detailed. Simplified methods are derived
from more or less the same description of the heat transfer processes in a building. Each calculation method
has its own simplification, assumptions, fixed values, special boundary conditions and validity area.
A simplified method can be implemented in many ways. In general, the maximum allowed simplification of the
calculation method and the input data is determined by the required amount and accuracy of the output data.
This International Standard defines the level, the amount and the accuracy of the output data and the allowed
simplification of the input data.
No particular calculation methods are included in the normative part of this International Standard. As
examples, two calculation methods are given in Annex A. They are based on the simplification of the heat
transfer processes that guarantees the amount and the accuracy of the output data and the simplification of
the input data required by this International Standard.
The use of these simplified calculation methods does not imply that other calculation methods are excluded
from standardization, nor does it hamper future developments. Clause 6 gives the criteria to be satisfied in
order for a method to comply with this International Standard.
vi © ISO 2012 – All rights reserved
---------------------- Page: 12 ----------------------
SIST EN ISO 13792:2012
INTERNATIONAL STANDARD ISO 13792:2012(E)
Thermal performance of buildings — Calculation of internal
temperatures of a room in summer without mechanical
cooling — Simplified methods
1 Scope
This International Standard specifies the required input data for simplified calculation methods for determining
the maximum, average and minimum daily values of the operative temperature of a room in warm periods:
a) to define the characteristics of a room at the design stage in order to avoid overheating in summer;
b) to define whether the installation of a cooling system is necessary or not.
Clause 6 gives the criteria to be met by a calculation method in order to satisfy this International Standard.
2 Normative references
The following referenced documents are indispensable for the application 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 6946, Building components and building elements — Thermal resistance and thermal transmittance —
Calculation method
ISO 7345, Thermal insulation — Physical quantities and definitions
ISO 9050, Glass in building — Determination of light transmittance, solar direct transmittance, total solar
energy transmittance, ultraviolet transmittance and related glazing factors
ISO 10077-1, Thermal performance of windows, doors and shutters — Calculation of thermal transmittance —
Part 1: General
ISO 10292, Glass in building — Calculation of steady-state U values (thermal transmittance) of multiple
glazing
ISO 13370, Thermal performance of buildings — Heat transfer via the ground — Calculation methods
ISO 13791, Thermal performance of buildings — Calculation of internal temperatures of a room in summer
without mechanical cooling — General criteria and validation procedures
ISO 15927-2, Hygrothermal performance of buildings — Calculation and presentation of climatic data —
Part 2: Hourly data for design cooling load
EN 410, Glass in building — Determination of luminous and solar characteristics of glazing
EN 673, Glass in building — Determination of thermal transmittance (U value) — Calculation method
EN 13363-1, Solar protection devices combined with glazing — Calculation of solar and light transmittance —
Part 1: Simplified method
© ISO 2012 – All rights reserved 1
---------------------- Page: 13 ----------------------
SIST EN ISO 13792:2012
ISO 13792:2012(E)
3 Terms, definitions, symbols and units
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7345 and the following apply.
3.1.1
internal environment
closed space delimited from the external environment or adjacent spaces by the building fabric
3.1.2
room element
wall, ceiling, roof, floor, door or window that separates the internal environment from the external environment
or an adjacent space
3.1.3
room air
air in the room
3.1.4
internal air temperature
temperature of the room air
3.1.5
internal surface temperature
temperature of the internal surface of a building element
3.1.6
mean radiant temperature
uniform surface temperature of an enclosure in which an occupant would exchange the same amount of
radiant heat as in the actual non-uniform enclosure
3.1.7
operative temperature
uniform temperature of an enclosure in which an occupant would exchange the same amount of heat by
radiation plus convection as in the actual non-uniform environment
NOTE For simplification, the mean value of the air temperature and the mean radiant temperature of the room can be
used.
3.2 Symbols and units
For the purposes of this document, the following symbols and units apply.
Symbol Definition Unit
2
A area m
2
A cavity area m
c
2
A thermal mass area m
m
2
A sunlit area m
s
2
A exposed area m
t
2
A wall area m
w
C heat capacity J/K
C internal heat capacity J/K
i
2 © ISO 2012 – All rights reserved
---------------------- Page: 14 ----------------------
SIST EN ISO 13792:2012
ISO 13792:2012(E)
C heat capacity of the enclosure elements J/K
m
c specific heat capacity J/(kg·K)
c specific heat capacity of air at constant pressure J/(kg·K)
a
d thickness m
F decrement factor —
a
F surface factor —
s
F surface factor of the envelope —
sm
f correction factor for transmission thermal load —
c
f exposure factor —
ex
f correction factor for solar thermal load —
r
f sunlit factor —
s
f solar-to-air factor —
sa
f solar loss factor —
sl
f frame factor —
t
f ventilation factor —
v
H heat transfer coefficient due to the air ventilation W/K
ei
H conventional heat transfer coefficient between the external W/K
em
environment and the internal surface of the heavy components
H global heat transfer coefficient between the internal and external W/K
es
environment
H heat transfer coefficient due to internal exchanges by convection W/K
is
and radiation
H conventional internal heat transfer coefficient W/K
ms
H heat transfer coefficient of the envelope W/K
T
2
h surface coefficient of heat transfer W/(m ·K)
2
h convective heat transfer coefficient W/(m ·K)
c
2
h radiative heat transfer coefficient W/(m ·K)
r
2
I intensity of solar radiation W/m
2
I reflected component of the solar radiation reaching the surface W/m
r
l length m
N number of components facing the indoor environment —
c
N number of external components —
e
N number of heavy opaque components —
h
N number of light opaque components —
l
number of opaque components —
Np
N number of internal sources —
s
N number of glazing components —
w
n air changes per hour l/h
2
q density of heat flow rate W/m
2
R thermal resistance m ·K/W
© ISO 2012 – All rights reserved 3
---------------------- Page: 15 ----------------------
SIST EN ISO 13792:2012
ISO 13792:2012(E)
2
R thermal resistance due to air ventilation m ·K/W
ei
S solar heat gain factor —
f
S solar heat gain factor for the closed cavity —
fc
S solar direct transmittance —
f1
S secondary heat transfer factor —
f2
S tertiary heat transfer factor —
f3
S solar heat gain factor for the ventilated cavity —
fv
T thermodynamic temperature K
t time s
2
U thermal transmittance W/(m ·K)
2
U thermal transmittance between the external environment and the air W/(m ·K)
e
cavity
2
U thermal transmittance between the internal environment and the air W/(m ·K)
i
cavity
2
U thermal transmittance of the glazing component W/(m ·K)
w
3
V volume m
v velocity m/s
x vertical shaded distance —
v
2
Yadmittance W/(m ·K)
2
Y total admittance W/(m ·K)
T
solar absorptance —
sr
solar altitude angle degrees
long-wave emissivity of the surface —
Celsius temperature °C
external air temperature °C
ae
outdoor air temperature °C
ei
outdoor air temperature of the heavy external components °C
em
outdoor air temperature of the light external components °C
es
mass temperature °C
m
daily average value of the operative temperature °C
op,av
daily minimum value of the operative temperature °C
op,min
daily maximum value of the operative temperature °C
op,max
star temperature °C
s
thermal conductivity W/(m·K)
3
density kg/m
3
density of air kg/m
a
solar reflectance —
sr
solar direct transmittance —
sr
heat flow rate W
4 © ISO 2012 – All rights reserved
---------------------- Page: 16 ----------------------
SIST EN ISO 13792:2012
ISO 13792:2012(E)
transmission thermal load contribution W
co
heat flow rate due to the solar radiation through the glazing W
er
components
mean daily value of the heat flux due to the solar radiation through W
erm
the glazing components
heat flow to air node W
i
convective heat flow of each internal source W
intc
radiative heat flow of each internal source W
intr
internal source thermal load W
is
heat flow to mass node W
m
heat flow to star node W
s
solar thermal load W
sr
thermal load due to the ventilation solar factor W
sv
thermal load W
T
ventilation thermal load W
v
time lag of the density of heat flow rate h
solar wall azimuth angle degrees
3.3 Subscripts
a air va ventilation through air cavity
b building cd conduction
c convection ec external ceiling
D direct solar radiation ef external floor
d diffuse solar radiation eq equivalent
e external ic internal ceiling
g ground if internal floor
i internal il inlet section
l leaving the section lr long-wave radiation
m average mr mean radiant
n normal to surface op operative
r radiation sa solar to air
s surface sk sky
sl solar loss t time
sr short wave radiation v ventilation
© ISO 2012 – All rights reserved 5
---------------------- Page: 17 ----------------------
SIST EN ISO 13792:2012
ISO 13792:2012(E)
4 Input data and results
4.1 Assumptions
For the scope of this International Standard the following basic assumptions are made:
the room is considered a closed space delimited by enclosure elements;
the air temperature is uniform throughout the room;
the various surfaces of the enclosure elements are isothermal;
the thermophysical properties of the material composing the enclosure elements are constant;
the heat conduction through each enclosure element is one dimensional;
air spaces within the envelope elements are considered as air layers bounded by two isothermal
surfaces;
the mean radiant temperature is calculated as an area-weighted average of the radiant temperature at
each internal surface;
the operative temperature is calculated as the arithmetic mean value of the internal air temperature and
the mean radiant temperature;
the distribution of the solar radiation on the internal surfaces of the room is time-independent;
the spatial distribution of the radiative part of the heat flow due to internal sources is uniform;
the long-wave radiative and the convective heat transfers at each internal surface are treated separately;
the dimensions of each component are measured at the internal side of the enclosure element;
the effects of the thermal bridges on heat transfers are neglected.
4.2 Boundary conditions and input data
4.2.1 Boundary conditions
4.2.1.1 General
The elements of the envelope are divided into:
external elements: these include the elements separating the internal environment from the outside and
from other zones (i.e. attic, ground, crawl space);
internal elements: these include the elements (vertical and horizontal) separating the internal environment
from other rooms which can be considered to have the same thermal conditions.
4.2.1.2 External elements
External elements are those separating the room from the external environment and from zones at different
thermal conditions (e.g. attic, ground, crawl space).
6 © ISO 2012 – All rights reserved
---------------------- Page: 18 ----------------------
SIST EN ISO 13792:2012
ISO 13792:2012(E)
Boundary conditions consist of defined hourly values of:
external air temperature;
intensity of the solar radiation on each orientation;
sky radiant temperature;
air temperature for the adjacent zones which cannot be considered at the same thermal conditions as the
examined room.
For elements in contact with the ground the external temperature is assumed to be the mean monthly value of
the external air temperature.
4.2.1.3 Internal elements
Internal elements are those separating the room from other rooms which can be considered to have the same
thermal conditions.
Internal elements are assumed to be adiabatic, which means that the values of the following quantities are
considered to be the same on either side of the element:
the air temperature;
the mean radiant temperature;
the solar radiation absorbed by the surface.
4.2.2 Heat transfer coefficients
For the purposes of this International Standard the following values shall be used:
2
internal convective heat transfer coefficient h = 2,5 W/(m ·K);
ci
2
internal long-wave radiative heat transfer coefficient h = 5,5 W/(m ·K);
ri
2
external convective heat transfer coefficient h = 8,0 W/(m ·K);
ce
2
external long-wave radiative heat transfer coefficient h = 5,5 W/(m ·K);
re
2
internal surface coefficient of heat transfer h = 8,0 W/(m ·K);
i
2
external surface coefficient of heat transfer h = 13,5 W/(m ·K).
e
4.2.3 Geometrical and thermophysical parameters of the room envelope
4.2.3.1 Opaque elements
For each element the following data are required:
area calculated using the internal dimensions;
thermal inertia characteristics (see
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.