SIST EN ISO 11855-1:2015
(Main)Building environment design - Design, dimensioning, installation and control of embedded radiant heating and cooling systems - Part 1: Definition, symbols, and comfort criteria (ISO 11855-1:2012)
Building environment design - Design, dimensioning, installation and control of embedded radiant heating and cooling systems - Part 1: Definition, symbols, and comfort criteria (ISO 11855-1:2012)
This European Standard shall stipulate the processes and conditions needed to design radiant heating and cooling systems embedded in the structures of the rooms. In addition, this standard includes the determination of heating and cooling capacity, dimensioning, dynamic analysis, installation, operation, and control methods of radiant heating and cooling systems. This international standard is applicable to embedded system that is integrated with the building structure. But this is not applicable to the panel system with open air gap, which is not integrated with the building structure. This standard applies also, as appropriate, to the use of other fluids or electricity instead of water as heating or cooling medium.
Part 1 of this standard specifies the basic definition, symbols, and a comfort criteria regarding the radiant heating and cooling systems.
Umweltgerechte Gebäudeplanung - Planung, Auslegung, Installation und Steuerung flächenintegrierter Strahlheizungs- und -kühlsysteme - Teil 1: Definitionen, Symbole und Komfortkriterien (ISO 11855-1:2012)
Dieser Teil von ISO 11855 legt grundlegende Definitionen, Symbole und Komfortkriterien für Strahlheizungs- und -kühlsysteme fest.
Die Normenreihe ISO 11855 ist für integrierte Flächenheizungs- und -kühlsysteme mit Wasserdurch¬strömung in Wohn-, Gewerbe- und Industriegebäuden anwendbar. Die Verfahren gelten für in Wände, Fußboden- und Deckenkonstruktionen flächenintegrierter Systeme ohne offene Luftspalte. Flächensysteme mit offenen Luftspalten, die nicht in die Gebäudestruktur eingebunden sind, werden nicht von ihr erfasst.
Die Normenreihe ISO 11855 ist zudem gegebenenfalls für die Verwendung von anderen Flüssigkeiten als Wasser als Heiz- und Kühlmittel anwendbar. Die Prüfung von Systemen ist in der Normenreihe ISO 11855 nicht erfasst. Die beschriebenen Verfahren gelten nicht für beheizte oder gekühlte Deckenpaneele oder Träger und Balken.
Conception de l'environnement des bâtiments - Conception, construction et fonctionnement des systèmes de chauffage et de refroidissement par rayonnement - Partie 1: Définition, symboles et critères de confort (ISO 11855-1:2012)
ISO 11855-1:2012 spécifie les définitions de base, les symboles et les critères de confort relatifs aux systèmes de chauffage et de refroidissement par rayonnement.
La série ISO 11855 s'applique aux systèmes de chauffage et de refroidissement de surface intégrés à eau dans les bâtiments résidentiels, commerciaux et industriels. Ces méthodes s'appliquent aux systèmes intégrés dans les murs, sols ou plafonds, sans ouverture à l'air libre. Elles ne s'appliquent pas aux systèmes de panneaux avec ouvertures à l'air libre, qui ne sont pas intégrés dans une structure de bâtiment.
La série ISO 11855 s'applique également, le cas échéant, à l'utilisation d'autres fluides que l'eau en tant que medium de chauffage ou de refroidissement. La série ISO 11855 ne s'applique pas à l'essai des systèmes. Ces méthodes ne s'appliquent pas aux panneaux ou poutres de plafond chauffés ou refroidis.
Načrtovanje gradnje - Načrtovanje, dimenzioniranje, montaža in kontrola vgrajenih hladilnih in ogrevalnih sistemov - 1. del: Definicija, simboli in merila za udobje (ISO 11855-1:2012)
Ta evropski standard določa procese in pogoje, potrebne za načrtovanje ogrevalnih in hladilnih sistemov, vgrajenih v strukture sobe. Poleg tega ta standard zajema določanje grelne in hladilne moči, dimenzioniranje, dinamično analizo, montažo, delovanje in kontrolne metode ogrevalnih in hladilnih sistemov. Ta mednarodni standard se uporablja za vgrajeni sistem, ki je vključen v strukturo stavbe. Vendar se ne uporablja za sistem plošč z odprtim vmesnim zračnim prostorom, ki ni vključen v strukturo stavbe. Ta standard, kadar je to ustrezno, velja tudi za uporabo drugih tekočin ali električne energije namesto vode za ogrevalni ali hladilni medij. V 1. delu tega standarda so določeni osnovna definicija, simboli ter merila za udobje v zvezi z ogrevalnimi in hladilnimi sistemi.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 11855-1:2015
01-oktober-2015
1DGRPHãþD
SIST EN 15377-1:2008
1DþUWRYDQMHJUDGQMH1DþUWRYDQMHGLPHQ]LRQLUDQMHPRQWDåDLQNRQWURODYJUDMHQLK
KODGLOQLKLQRJUHYDOQLKVLVWHPRYGHO 'HILQLFLMDVLPEROLLQPHULOD]DXGREMH ,62
Building environment design - Design, dimensioning, installation and control of
embedded radiant heating and cooling systems - Part 1: Definition, symbols, and comfort
criteria (ISO 11855-1:2012)
Umweltgerechte Gebäudeplanung - Planung, Auslegung, Installation und Steuerung
flächenintegrierter Strahlheizungs- und -kühlsysteme - Teil 1: Definitionen, Symbole und
Komfortkriterien (ISO 11855-1:2012)
Conception de l'environnement des bâtiments - Conception, construction et
fonctionnement des systèmes de chauffage et de refroidissement par rayonnement -
Partie 1: Définition, symboles et critères de confort (ISO 11855-1:2012)
Ta slovenski standard je istoveten z: EN ISO 11855-1:2015
ICS:
91.140.10 Sistemi centralnega Central heating systems
ogrevanja
91.140.30 3UH]UDþHYDOQLLQNOLPDWVNL Ventilation and air-
VLVWHPL conditioning
SIST EN ISO 11855-1:2015 en,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 11855-1:2015
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SIST EN ISO 11855-1:2015
EUROPEAN STANDARD
EN ISO 11855-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2015
ICS 91.140.10; 91.140.30 Supersedes EN 15377-1:2008
English Version
Building environment design - Design, dimensioning, installation
and control of embedded radiant heating and cooling systems -
Part 1: Definition, symbols, and comfort criteria (ISO 11855-
1:2012)
Conception de l'environnement des bâtiments - Conception, Umweltgerechte Gebäudeplanung - Planung, Auslegung,
construction et fonctionnement des systèmes de chauffage Installation und Steuerung flächenintegrierter
et de refroidissement par rayonnement - Partie 1: Définition, Strahlheizungs- und -kühlsysteme - Teil 1: Definitionen,
symboles et critères de confort (ISO 11855-1:2012) Symbole und Komfortkriterien (ISO 11855-1:2012)
This European Standard was approved by CEN on 30 July 2015.
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, Former Yugoslav Republic of Macedonia, 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
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11855-1:2015 E
worldwide for CEN national Members.
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SIST EN ISO 11855-1:2015
EN ISO 11855-1:2015 (E)
Contents Page
European foreword .3
2
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SIST EN ISO 11855-1:2015
EN ISO 11855-1:2015 (E)
European foreword
The text of ISO 11855-1:2012 has been prepared by Technical Committee ISO/TC 205 “Building environment
design” of the International Organization for Standardization (ISO) and has been taken over as EN ISO
11855-1:2015 by Technical Committee CEN/TC 228 “Heating systems and water based cooling systems in
buildings” the secretariat of which is held by DIN.
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 February 2016, and conflicting national standards shall be withdrawn
at the latest by February 2016.
This standard is applicable for design, construction and operation of radiant heating and cooling systems. The
methods defined in part 2 are intended to determine the design heating or cooling capacity used for the design
and evaluation of the performance of the system.
For identifying product characteristics by testing and proving the thermal output of heating and cooling
surfaces embedded in floors, ceilings and walls the standard series EN 1264 can be used.
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 15377-1:2008.
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, Former Yugoslav Republic of Macedonia, 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 11855-1:2012 has been approved by CEN as EN ISO 11855-1:2015 without any modification.
3
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SIST EN ISO 11855-1:2015
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SIST EN ISO 11855-1:2015
INTERNATIONAL ISO
STANDARD 11855-1
First edition
2012-08-01
Building environment design — Design,
dimensioning, installation and control
of embedded radiant heating and
cooling systems —
Part 1:
Definition, symbols, and comfort criteria
Conception de l’environnement des bâtiments — Conception,
construction et fonctionnement des systèmes de chauffage et de
refroidissement par rayonnement —
Partie 1: Définition, symboles et critères de confort
Reference number
ISO 11855-1:2012(E)
©
ISO 2012
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SIST EN ISO 11855-1:2015
ISO 11855-1:2012(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
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SIST EN ISO 11855-1:2015
ISO 11855-1:2012(E)
Contents Page
Foreword .iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviations .10
5 Comfort criteria .15
5.1 General thermal comfort .15
5.2 Local thermal comfort .17
5.3 Acoustical comfort .20
Annex A (informative) Floor surface temperature for thermal comfort .22
Annex B (informative) Draught .25
Bibliography .26
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SIST EN ISO 11855-1:2015
ISO 11855-1:2012(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 11855-1 was prepared by Technical Committee ISO/TC 205, Building environment design.
ISO 11855 consists of the following parts, under the general title Building environment design — Design,
dimensioning, installation and control of embedded radiant heating and cooling systems:
— Part 1: Definition, symbols, and comfort criteria
— Part 2: Determination of the design and heating and cooling capacity
— Part 3: Design and dimensioning
— Part 4: Dimensioning and calculation of the dynamic heating and cooling capacity of Thermo Active
Building Systems (TABS)
— Part 5: Installation
— Part 6: Control
Part 1 specifies the comfort criteria which should be considered in designing embedded radiant heating and
cooling systems, since the main objective of the radiant heating and cooling system is to satisfy thermal comfort
of the occupants. Part 2 provides steady-state calculation methods for determination of the heating and cooling
capacity. Part 3 specifies design and dimensioning methods of radiant heating and cooling systems to ensure
the heating and cooling capacity. Part 4 provides a dimensioning and calculation method to design Thermo
Active Building Systems (TABS) for energy-saving purposes, since radiant heating and cooling systems can
reduce energy consumption and heat source size by using renewable energy. Part 5 addresses the installation
process for the system to operate as intended. Part 6 shows a proper control method of the radiant heating and
cooling systems to ensure the maximum performance which was intended in the design stage when the system
is actually being operated in a building.
iv © ISO 2012 – All rights reserved
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SIST EN ISO 11855-1:2015
ISO 11855-1:2012(E)
Introduction
The radiant heating and cooling system consists of heat emitting/absorbing, heat supply, distribution, and
control systems. The ISO 11855 series deals with the embedded surface heating and cooling system that
directly controls heat exchange within the space. It does not include the system equipment itself, such as heat
source, distribution system and controller.
The ISO 11855 series addresses an embedded system that is integrated with the building structure. Therefore,
the panel system with open air gap, which is not integrated with the building structure, is not covered by this series.
The ISO 11855 series shall be applied to systems using not only water but also other fluids or electricity as a
heating or cooling medium.
The object of the ISO 11855 series is to provide criteria to effectively design embedded systems. To do this, it
presents comfort criteria for the space served by embedded systems, heat output calculation, dimensioning,
dynamic analysis, installation, operation, and control method of embedded systems.
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SIST EN ISO 11855-1:2015
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SIST EN ISO 11855-1:2015
INTERNATIONAL STANDARD ISO 11855-1:2012(E)
Building environment design — Design, dimensioning,
installation and control of embedded radiant heating and
cooling systems —
Part 1:
Definition, symbols, and comfort criteria
1 Scope
This part of ISO 11855 specifies the basic definitions, symbols, and a comfort criteria for radiant heating and
cooling systems.
The ISO 11855 series is applicable to water based embedded surface heating and cooling systems in
residential, commercial and industrial buildings. The methods apply to systems integrated into the wall, floor or
ceiling construction without any open air gaps. It does not apply to panel systems with open air gaps which are
not integrated into the building structure.
The ISO 11855 series also applies, as appropriate, to the use of fluids other than water as a heating or cooling
medium. The ISO 11855 series is not applicable for testing of systems. The methods do not apply to heated or
chilled ceiling panels or beams.
2 Normative references
ISO 7726:1998, Ergonomics of the thermal environment — Instruments for measuring physical quantities
ISO 7730:2005, Ergonomics of the thermal environment — Analytical determination and interpretation of
thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria
ISO 13731:2003, Ergonomics of the thermal environment — Vocabulary and symbols
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
additional thermal resistance
thermal resistance representing layers added to the building structure and acting mostly as thermal resistances
because of their own low thermal inertia
EXAMPLE Carpets, moquette, and suspended ceilings.
2.2
average specific thermal capacity of the internal walls
thermal capacity related to one square metre of the internal walls
NOTE Since internal walls are shared with other rooms, then just half of the total specific thermal capacity of the wall
must be taken into account, since the second half is influenced by the opposite rooms that are considered to be at the
same thermal conditions as the one under consideration.
2.3
average surface temperature
θ
s,m
average value of all surface temperatures in the occupied or peripheral area
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SIST EN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.4
basic characteristic curve
curve or formula reflecting the relationship between the heat flux and the mean surface temperature difference
NOTE This depends on heating/cooling and surface (floor/wall/ceiling) but not on the type of embedded system.
2.5
calculation time step
length of time considered for the calculation of the temperatures and heat flows in the room and slab
NOTE This is typically assumed to equal 3 600 s.
2.6
circuit
section of system connected to a distributor which can be independently switched and controlled
2.7
circuit total thermal resistance
thermal resistance representing the circuit as a whole, determining a straight connection between the water
inlet temperature and the mean temperature at the pipe level
NOTE It includes the water flow thermal resistance, the convection thermal resistance at the pipe inner side, the pipe
thickness thermal resistance, and the pipe level thermal resistance.
2.8
clothing insulation
basic clothing insulation that is the resistance of a uniform layer of insulation covering the entire body that has
the same effect on sensible heat flow as the actual clothing under standardized (static, wind-still) conditions
NOTE The definition of clothing insulation also includes the uncovered parts of the body, e.g. the head. It is described
as the intrinsic insulation from the skin to the clothing surface, not including the resistance provided by the air layer around
2 2
the clothed body, and is expressed in the clo unit or in m K/W; 1 clo = 0,155 m K/W.
2.9
conductive region of the slab
region of the slab that includes the pipes with thermal conductivities of the layers higher than 0,8 W/(m·K)
NOTE Due to the subdivision of the slab into an upper slab and a lower slab, the conductive region is also subdivided
into an upper conductive region and a lower conductive region.
2.10
convection thermal resistance at the pipe inner side
thermal resistance associated to the convection heat transfer taking place between the water flowing in the
pipe and the pipe inner side, thus connecting the mean water temperature along the circuit with the mean
temperature of the pipe inner side
2.11
convective heating and cooling system
system that directly conditions the air in the room for the purpose of heating and cooling
2.12
convective peak load
maximum cooling load to be extracted by a virtual convective system used to keep comfort conditions in the room
2.13
daily average temperature of the conductive region of the slab
average temperature of the conductive region of the slab during the day
2.14
design cooling capacity
Q
H,c
thermal output by a cooling surface at design conditions
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SIST EN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.15
design cooling load
Q
N,c
required thermal output necessary to achieve the specified design conditions in outside summer design conditions
2.16
design sensible cooling load
required sensible thermal output necessary to achieve the specified design conditions in outside summer
design conditions
2.17
design dew point
θ
Dp,des
dew point determined for the design
2.18
design supply temperature of heating/cooling medium
θ
V,des
value of flow water temperature with the thermal resistance of the chosen floor covering, at maximum value of
heat flux q
max
NOTE The flow and the supply temperature are the same throughout the EN 1264 series.
2.19
design heat flux
q
des
heat flow divided by the heating or cooling surface, taking into account the surface temperature required to
reach the design thermal capacity of a surface heated or cooled space, Q , reduced by the thermal capacity
H
of any supplementary heating or cooling equipment, if applicable
2.20
design heating capacity
Q
H,h
thermal output from a heating surface at design conditions
2.21
design heating load
Q
N,h
required thermal output necessary to achieve the specified design conditions in outside winter design conditions
NOTE When calculating the value of the design heat load, the heat flow from embedded heating systems into
neighbouring rooms is not taken into account.
2.22
design heating/cooling medium differential temperature
Δθ
H,des
temperature difference at design heat flux
2.23
design heating medium differential supply temperature
Δθ
V,des
temperature difference between the design supply medium temperature and indoor temperature at design heat flux
2.24
design heating/cooling medium flow rate
m
H
mass flow rate in a circuit which is needed to achieve the design heat flux
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SIST EN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.25
design indoor temperature
θ
i
operative temperature at the centre of the conditioned space used for calculation of the design load and capacity
NOTE The operative temperature is considered relevant for thermal comfort assessment and heat loss calculations.
This value of internal temperature is used for the calculation method.
2.26
distributor
common connection point for several circuits
2.27
draught
unwanted local cooling of a body caused by movement of air and related to temperature
2.28
electric floor (wall, ceiling) heating system
several panel systems that convert electrical energy to heat, raising the temperature of conditioned indoor
surfaces and the indoor air
2.29
embedded surface heating and cooling system
system consisting of circuits of pipes embedded in floor, wall or ceiling construction, distributors and
control equipments
2.30
equivalent heat transmission coefficient
K
H
coefficient describing the relationship between the heat flux from the surface and the heating/cooling medium
differential temperature
2.31
family of characteristic curves
curves denoting the system-specific relationship between the heat flux, q, and the required heating medium
differential temperature Δθ for conduction resistance of various floor coverings
H
2.32
heat flux
q
heat flow between the space and surface divided by the heated/cooled surface
NOTE For heating it is a positive value and for cooling it is a negative value.
2.33
heat transfer coefficient
h
t
combined convective and radiative heat transfer coefficient between the heated or cooled surface and the
space operative temperature (design indoor temperature)
2.34
heating or cooling surface
surface (floor, wall, ceiling) covered by the embedded surface heating/cooling system between the pipes at the
outer edges of the system with the addition of a strip at each edge of width equal to half the pipe spacing, but
not exceeding 0,15 m
2.35
heating or cooling surface area
A
F
area of surface (floor, wall, ceiling) covered by the embedded surface heating/cooling system between the
pipes at the outer edges of the system with the addition of a strip at each edge of width equal to half the pipe
spacing, but not exceeding 0,15 m
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SIST EN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.36
heating/cooling capacity for circuit
Q
HC
heat exchange between a pipe circuit and the conditioned room
2.37
heating/cooling medium differential temperature
Δθ
H
logarithmically determined average difference between the temperature of the heating/cooling medium and the
design indoor temperature
2.38
internal convective heat gains
convective contributions by internal heat gains acting in the room
NOTE Mainly due to people or electrical equipment.
2.39
internal radiant heat gains
radiant contributions by internal heat gains acting in the room
NOTE Mainly due to people or electrical equipment.
2.40
internal thermal resistance of the slab conductive region
total thermal resistance connecting the pipe level with the middle points of the upper conductive region and
lower conductive region of the slab
2.41
limit curves
curves in the field of characteristic curves showing the pattern of the limit heat flux depending on the heating
medium differential temperature and the floor covering
2.42
limit heat flux
q
G
heat flux at which the maximum or minimum permissible surface temperature is achieved
2.43
limit heating medium temperature difference
Δθ
H,G
intersection of the system characteristic curve with the limit curve
2.44
maximum cooling power
maximum thermal power of the cooling equipment, referring only to the room under consideration
2.45
maximum permissible surface temperature
q
max
required design heat flux in the room in order to design supply medium temperature
2.46
maximum operative temperature allowed for comfort conditions
maximum operative temperature allowed in the room according to comfort requirements in cooling conditions
2.47
maximum operative temperature drift allowed for comfort conditions
maximum drift in operative temperature allowed in the room according to comfort requirements
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SIST EN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.48
maximum permissible surface temperature
θ
S,max
maximum temperature permissible for physiological reasons or for the physical building, for calculation of the
limit curves, which may occur at a point on the surface (floor, wall, ceiling) in the occupied or peripheral area
depending on the particular usage at a temperature drop σ of the heating medium equal to 0
2.49
mean radiant temperature
uniform surface temperature of an imaginary black enclosure in which an occupant would exchange the same
amount of radiant heat as in the actual non-uniform enclosure
2.50
mean surface temperature difference
difference between the average surface temperature θ and the design indoor temperature θ
S,m i
NOTE It determines the heat flux.
2.51
metabolic rate
rate of transformation of chemical energy into heat and mechanical work by aerobic and anaerobic metabolic
activities within an organism, usually expressed in terms of unir area of the total body surfaces
2 2
NOTE The metabolic rate varies with each activity. It is expressed in the met unit or in W/m ; 1 met = 58,2 W/m .
1 met is the energy produced per unit surface area of a sedentary person at rest. The surface area of an average person
2 0,725 0,425
can be determined by Dubois Equation, Body Surface Area (m ) = 0,20 247 × Height (m) × Weight (kg) .
2.52
minimum permissible surface temperature
θ
S,min
minimum temperature permissible for physiological reasons or for the physical building, for calculation of the
limit curves, which may occur at a point on the surface (floor, wall, ceiling) in the occupied or peripheral area
depending on the particular usage at a temperature drop σ of the heating medium equal to 0
2.53
nominal heat flux
q
N
limit heat flux achieved without surface covering
2.54
nominal heating/cooling medium differential temperature
Δθ
N
absolute temperature difference at nominal heat flux q
N
2.55
non-active area
area of the surface not covered by a heating/cooling system
2.56
number of active surfaces
number of surfaces in straight thermal connection with the pipe level, so that it distinguishes whether the slab
transfers heat both through the floor side and through the ceiling side or whether the ceiling side is much more
active than the floor side
NOTE Two active surfaces when the conductive region extends from the floor to the ceiling, one active surface otherwise.
2.57
number of operation hours of the circuit
length of time during which the system runs in the day
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SIST EN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.58
occupied area
A
A
surface area which is heated or cooled, excluding peripheral area
2.59
occupied zone
part of the conditioned zone in which persons normally reside and where requirements as to the internal
environment are satisfied
NOTE Normally, the zone between the floor and 1,8 m above the floor and 1,0 m from outside walls/windows and
heating/cooling appliances, 0,5 m from internal surfaces.
2.60
open air gap
air gap in the floor, wall, or ceiling construction, where air exchange with space or the outside may occur
2.61
operative temperature
OT
θ
o
uniform temperature of an imaginary black enclosure in which an occupant exchanges the same amount of
heat by radiation and convection as in the actual non-uniform environment
2.62
orientation of the room
orientation of the main windowed external wall: East, South or West
NOTE It is used to determine when the peak load from heat gains happens, since internal heat gains are considered
almost constant and the widest variation is expected to happen in solar heat gains.
2.63
outward heat flux
q
U
heat flow which is exchanged through the construction with unconditioned spaces, another building entity, the
ground or outdoor air
2.64
peak load
maximum cooling load to be extracted by the system used to keep comfort conditions in the room
2.65
peripheral area
A
R
surface area which is heated or cooled to a higher or lower temperature
NOTE It is generally an area of 1 m maximum in width along exterior walls. It is not an occupied area.
2.66
pipe level
virtual plane where the pipe circuit lies
2.67
pipe level thermal resistance
thermal resistance associated to the 2-D conduction heat transfer taking place between the pipes and the
embedding layer,
...
SLOVENSKI STANDARD
kSIST FprEN ISO 11855-1:2015
01-maj-2015
1DþUWRYDQMHJUDGQMH1DþUWRYDQMHGLPHQ]LRQLUDQMHPRQWDåDLQNRQWURODYJUDMHQLK
KODGLOQLKLQRJUHYDOQLKVLVWHPRYGHO 'HILQLFLMDVLPEROLLQPHULOD]DXGREMH ,62
Building environment design - Design, dimensioning, installation and control of
embedded radiant heating and cooling systems - Part 1: Definition, symbols, and comfort
criteria (ISO 11855-1:2012)
Umweltgerechte Gebäudeplanung - Planung, Auslegung, Installation und Steuerung
flächenintegrierter Strahlheizungs- und -kühlsysteme - Teil 1: Definitionen, Symbole und
Komfortkriterien (ISO 11855-1:2012)
Conception de l'environnement des bâtiments - Conception, construction et
fonctionnement des systèmes de chauffage et de refroidissement par rayonnement -
Partie 1: Définition, symboles et critères de confort (ISO 11855-1:2012)
Ta slovenski standard je istoveten z: FprEN ISO 11855-1
ICS:
91.140.10 Sistemi centralnega Central heating systems
ogrevanja
91.140.30 3UH]UDþHYDOQLLQNOLPDWVNL Ventilation and air-
VLVWHPL conditioning
kSIST FprEN ISO 11855-1:2015 en,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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kSIST FprEN ISO 11855-1:2015
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kSIST FprEN ISO 11855-1:2015
EUROPEAN STANDARD
FINAL DRAFT
FprEN ISO 11855-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2015
ICS 91.140.10; 91.140.30 Will supersede EN 15377-1:2008
English Version
Building environment design - Design, dimensioning, installation
and control of embedded radiant heating and cooling systems -
Part 1: Definition, symbols, and comfort criteria (ISO 11855-
1:2012)
Conception de l'environnement des bâtiments - Conception, Umweltgerechte Gebäudeplanung - Planung, Auslegung,
construction et fonctionnement des systèmes de chauffage Installation und Steuerung flächenintegrierter
et de refroidissement par rayonnement - Partie 1: Définition, Strahlheizungs- und -kühlsysteme - Teil 1: Definitionen,
symboles et critères de confort (ISO 11855-1:2012) Symbole und Komfortkriterien (ISO 11855-1:2012)
This draft European Standard is submitted to CEN members for unique acceptance procedure. It has been drawn up by the Technical
Committee CEN/TC 228.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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, Former Yugoslav Republic of Macedonia, 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.
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 supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. FprEN ISO 11855-1:2015 E
worldwide for CEN national Members.
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kSIST FprEN ISO 11855-1:2015
FprEN ISO 11855-1:2015 (E)
Contents Page
Foreword .3
2
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kSIST FprEN ISO 11855-1:2015
FprEN ISO 11855-1:2015 (E)
Foreword
The text of ISO 11855-1:2012 has been prepared by Technical Committee ISO/TC 205 “Building environment
design” of the International Organization for Standardization (ISO) and has been taken over as FprEN ISO
11855-1:2015 by Technical Committee CEN/TC 228 “Heating systems and water based cooling systems in
buildings” the secretariat of which is held by DIN.
This document is currently submitted to the Unique Acceptance Procedure.
This document will supersede EN 15377-1:2008.
This standard is applicable for design, construction and operation of radiant heating and cooling systems. The
methods defined in part 2 are intended to determine the design heating or cooling capacity used for the design
and evaluation of the performance of the system.
For identifying product characteristics by testing and proving the thermal output of heating and cooling
surfaces embedded in floors, ceilings and walls the standard series EN 1264 can be used.
Endorsement notice
The text of ISO 11855-1:2012 has been approved by CEN as FprEN ISO 11855-1:2015 without any
modification.
3
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kSIST FprEN ISO 11855-1:2015
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kSIST FprEN ISO 11855-1:2015
INTERNATIONAL ISO
STANDARD 11855-1
First edition
2012-08-01
Building environment design — Design,
dimensioning, installation and control
of embedded radiant heating and
cooling systems —
Part 1:
Definition, symbols, and comfort criteria
Conception de l’environnement des bâtiments — Conception,
construction et fonctionnement des systèmes de chauffage et de
refroidissement par rayonnement —
Partie 1: Définition, symboles et critères de confort
Reference number
ISO 11855-1:2012(E)
©
ISO 2012
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kSIST FprEN ISO 11855-1:2015
ISO 11855-1:2012(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
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kSIST FprEN ISO 11855-1:2015
ISO 11855-1:2012(E)
Contents Page
Foreword .iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviations .10
5 Comfort criteria .15
5.1 General thermal comfort .15
5.2 Local thermal comfort .17
5.3 Acoustical comfort .20
Annex A (informative) Floor surface temperature for thermal comfort .22
Annex B (informative) Draught .25
Bibliography .26
© ISO 2012 – All rights reserved iii
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kSIST FprEN ISO 11855-1:2015
ISO 11855-1:2012(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 11855-1 was prepared by Technical Committee ISO/TC 205, Building environment design.
ISO 11855 consists of the following parts, under the general title Building environment design — Design,
dimensioning, installation and control of embedded radiant heating and cooling systems:
— Part 1: Definition, symbols, and comfort criteria
— Part 2: Determination of the design and heating and cooling capacity
— Part 3: Design and dimensioning
— Part 4: Dimensioning and calculation of the dynamic heating and cooling capacity of Thermo Active
Building Systems (TABS)
— Part 5: Installation
— Part 6: Control
Part 1 specifies the comfort criteria which should be considered in designing embedded radiant heating and
cooling systems, since the main objective of the radiant heating and cooling system is to satisfy thermal comfort
of the occupants. Part 2 provides steady-state calculation methods for determination of the heating and cooling
capacity. Part 3 specifies design and dimensioning methods of radiant heating and cooling systems to ensure
the heating and cooling capacity. Part 4 provides a dimensioning and calculation method to design Thermo
Active Building Systems (TABS) for energy-saving purposes, since radiant heating and cooling systems can
reduce energy consumption and heat source size by using renewable energy. Part 5 addresses the installation
process for the system to operate as intended. Part 6 shows a proper control method of the radiant heating and
cooling systems to ensure the maximum performance which was intended in the design stage when the system
is actually being operated in a building.
iv © ISO 2012 – All rights reserved
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kSIST FprEN ISO 11855-1:2015
ISO 11855-1:2012(E)
Introduction
The radiant heating and cooling system consists of heat emitting/absorbing, heat supply, distribution, and
control systems. The ISO 11855 series deals with the embedded surface heating and cooling system that
directly controls heat exchange within the space. It does not include the system equipment itself, such as heat
source, distribution system and controller.
The ISO 11855 series addresses an embedded system that is integrated with the building structure. Therefore,
the panel system with open air gap, which is not integrated with the building structure, is not covered by this series.
The ISO 11855 series shall be applied to systems using not only water but also other fluids or electricity as a
heating or cooling medium.
The object of the ISO 11855 series is to provide criteria to effectively design embedded systems. To do this, it
presents comfort criteria for the space served by embedded systems, heat output calculation, dimensioning,
dynamic analysis, installation, operation, and control method of embedded systems.
© ISO 2012 – All rights reserved v
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kSIST FprEN ISO 11855-1:2015
INTERNATIONAL STANDARD ISO 11855-1:2012(E)
Building environment design — Design, dimensioning,
installation and control of embedded radiant heating and
cooling systems —
Part 1:
Definition, symbols, and comfort criteria
1 Scope
This part of ISO 11855 specifies the basic definitions, symbols, and a comfort criteria for radiant heating and
cooling systems.
The ISO 11855 series is applicable to water based embedded surface heating and cooling systems in
residential, commercial and industrial buildings. The methods apply to systems integrated into the wall, floor or
ceiling construction without any open air gaps. It does not apply to panel systems with open air gaps which are
not integrated into the building structure.
The ISO 11855 series also applies, as appropriate, to the use of fluids other than water as a heating or cooling
medium. The ISO 11855 series is not applicable for testing of systems. The methods do not apply to heated or
chilled ceiling panels or beams.
2 Normative references
ISO 7726:1998, Ergonomics of the thermal environment — Instruments for measuring physical quantities
ISO 7730:2005, Ergonomics of the thermal environment — Analytical determination and interpretation of
thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria
ISO 13731:2003, Ergonomics of the thermal environment — Vocabulary and symbols
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
additional thermal resistance
thermal resistance representing layers added to the building structure and acting mostly as thermal resistances
because of their own low thermal inertia
EXAMPLE Carpets, moquette, and suspended ceilings.
2.2
average specific thermal capacity of the internal walls
thermal capacity related to one square metre of the internal walls
NOTE Since internal walls are shared with other rooms, then just half of the total specific thermal capacity of the wall
must be taken into account, since the second half is influenced by the opposite rooms that are considered to be at the
same thermal conditions as the one under consideration.
2.3
average surface temperature
θ
s,m
average value of all surface temperatures in the occupied or peripheral area
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kSIST FprEN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.4
basic characteristic curve
curve or formula reflecting the relationship between the heat flux and the mean surface temperature difference
NOTE This depends on heating/cooling and surface (floor/wall/ceiling) but not on the type of embedded system.
2.5
calculation time step
length of time considered for the calculation of the temperatures and heat flows in the room and slab
NOTE This is typically assumed to equal 3 600 s.
2.6
circuit
section of system connected to a distributor which can be independently switched and controlled
2.7
circuit total thermal resistance
thermal resistance representing the circuit as a whole, determining a straight connection between the water
inlet temperature and the mean temperature at the pipe level
NOTE It includes the water flow thermal resistance, the convection thermal resistance at the pipe inner side, the pipe
thickness thermal resistance, and the pipe level thermal resistance.
2.8
clothing insulation
basic clothing insulation that is the resistance of a uniform layer of insulation covering the entire body that has
the same effect on sensible heat flow as the actual clothing under standardized (static, wind-still) conditions
NOTE The definition of clothing insulation also includes the uncovered parts of the body, e.g. the head. It is described
as the intrinsic insulation from the skin to the clothing surface, not including the resistance provided by the air layer around
2 2
the clothed body, and is expressed in the clo unit or in m K/W; 1 clo = 0,155 m K/W.
2.9
conductive region of the slab
region of the slab that includes the pipes with thermal conductivities of the layers higher than 0,8 W/(m·K)
NOTE Due to the subdivision of the slab into an upper slab and a lower slab, the conductive region is also subdivided
into an upper conductive region and a lower conductive region.
2.10
convection thermal resistance at the pipe inner side
thermal resistance associated to the convection heat transfer taking place between the water flowing in the
pipe and the pipe inner side, thus connecting the mean water temperature along the circuit with the mean
temperature of the pipe inner side
2.11
convective heating and cooling system
system that directly conditions the air in the room for the purpose of heating and cooling
2.12
convective peak load
maximum cooling load to be extracted by a virtual convective system used to keep comfort conditions in the room
2.13
daily average temperature of the conductive region of the slab
average temperature of the conductive region of the slab during the day
2.14
design cooling capacity
Q
H,c
thermal output by a cooling surface at design conditions
2 © ISO 2012 – All rights reserved
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kSIST FprEN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.15
design cooling load
Q
N,c
required thermal output necessary to achieve the specified design conditions in outside summer design conditions
2.16
design sensible cooling load
required sensible thermal output necessary to achieve the specified design conditions in outside summer
design conditions
2.17
design dew point
θ
Dp,des
dew point determined for the design
2.18
design supply temperature of heating/cooling medium
θ
V,des
value of flow water temperature with the thermal resistance of the chosen floor covering, at maximum value of
heat flux q
max
NOTE The flow and the supply temperature are the same throughout the EN 1264 series.
2.19
design heat flux
q
des
heat flow divided by the heating or cooling surface, taking into account the surface temperature required to
reach the design thermal capacity of a surface heated or cooled space, Q , reduced by the thermal capacity
H
of any supplementary heating or cooling equipment, if applicable
2.20
design heating capacity
Q
H,h
thermal output from a heating surface at design conditions
2.21
design heating load
Q
N,h
required thermal output necessary to achieve the specified design conditions in outside winter design conditions
NOTE When calculating the value of the design heat load, the heat flow from embedded heating systems into
neighbouring rooms is not taken into account.
2.22
design heating/cooling medium differential temperature
Δθ
H,des
temperature difference at design heat flux
2.23
design heating medium differential supply temperature
Δθ
V,des
temperature difference between the design supply medium temperature and indoor temperature at design heat ufl x
2.24
design heating/cooling medium flow rate
m
H
mass flow rate in a circuit which is needed to achieve the design heat flux
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kSIST FprEN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.25
design indoor temperature
θ
i
operative temperature at the centre of the conditioned space used for calculation of the design load and capacity
NOTE The operative temperature is considered relevant for thermal comfort assessment and heat loss calculations.
This value of internal temperature is used for the calculation method.
2.26
distributor
common connection point for several circuits
2.27
draught
unwanted local cooling of a body caused by movement of air and related to temperature
2.28
electric floor (wall, ceiling) heating system
several panel systems that convert electrical energy to heat, raising the temperature of conditioned indoor
surfaces and the indoor air
2.29
embedded surface heating and cooling system
system consisting of circuits of pipes embedded in floor, wall or ceiling construction, distributors and
control equipments
2.30
equivalent heat transmission coefficient
K
H
coefficient describing the relationship between the heat flux from the surface and the heating/cooling medium
differential temperature
2.31
family of characteristic curves
curves denoting the system-specific relationship between the heat flux, q, and the required heating medium
differential temperature Δθ for conduction resistance of various floor coverings
H
2.32
heat flux
q
heat flow between the space and surface divided by the heated/cooled surface
NOTE For heating it is a positive value and for cooling it is a negative value.
2.33
heat transfer coefficient
h
t
combined convective and radiative heat transfer coefficient between the heated or cooled surface and the
space operative temperature (design indoor temperature)
2.34
heating or cooling surface
surface (floor, wall, ceiling) covered by the embedded surface heating/cooling system between the pipes at the
outer edges of the system with the addition of a strip at each edge of width equal to half the pipe spacing, but
not exceeding 0,15 m
2.35
heating or cooling surface area
A
F
area of surface (floor, wall, ceiling) covered by the embedded surface heating/cooling system between the
pipes at the outer edges of the system with the addition of a strip at each edge of width equal to half the pipe
spacing, but not exceeding 0,15 m
4 © ISO 2012 – All rights reserved
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kSIST FprEN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.36
heating/cooling capacity for circuit
Q
HC
heat exchange between a pipe circuit and the conditioned room
2.37
heating/cooling medium differential temperature
Δθ
H
logarithmically determined average difference between the temperature of the heating/cooling medium and the
design indoor temperature
2.38
internal convective heat gains
convective contributions by internal heat gains acting in the room
NOTE Mainly due to people or electrical equipment.
2.39
internal radiant heat gains
radiant contributions by internal heat gains acting in the room
NOTE Mainly due to people or electrical equipment.
2.40
internal thermal resistance of the slab conductive region
total thermal resistance connecting the pipe level with the middle points of the upper conductive region and
lower conductive region of the slab
2.41
limit curves
curves in the field of characteristic curves showing the pattern of the limit heat flux depending on the heating
medium differential temperature and the floor covering
2.42
limit heat flux
q
G
heat flux at which the maximum or minimum permissible surface temperature is achieved
2.43
limit heating medium temperature difference
Δθ
H,G
intersection of the system characteristic curve with the limit curve
2.44
maximum cooling power
maximum thermal power of the cooling equipment, referring only to the room under consideration
2.45
maximum permissible surface temperature
q
max
required design heat flux in the room in order to design supply medium temperature
2.46
maximum operative temperature allowed for comfort conditions
maximum operative temperature allowed in the room according to comfort requirements in cooling conditions
2.47
maximum operative temperature drift allowed for comfort conditions
maximum drift in operative temperature allowed in the room according to comfort requirements
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kSIST FprEN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.48
maximum permissible surface temperature
θ
S,max
maximum temperature permissible for physiological reasons or for the physical building, for calculation of the
limit curves, which may occur at a point on the surface (floor, wall, ceiling) in the occupied or peripheral area
depending on the particular usage at a temperature drop σ of the heating medium equal to 0
2.49
mean radiant temperature
uniform surface temperature of an imaginary black enclosure in which an occupant would exchange the same
amount of radiant heat as in the actual non-uniform enclosure
2.50
mean surface temperature difference
difference between the average surface temperature θ and the design indoor temperature θ
S,m i
NOTE It determines the heat flux.
2.51
metabolic rate
rate of transformation of chemical energy into heat and mechanical work by aerobic and anaerobic metabolic
activities within an organism, usually expressed in terms of unir area of the total body surfaces
2 2
NOTE The metabolic rate varies with each activity. It is expressed in the met unit or in W/m ; 1 met = 58,2 W/m .
1 met is the energy produced per unit surface area of a sedentary person at rest. The surface area of an average person
2 0,725 0,425
can be determined by Dubois Equation, Body Surface Area (m ) = 0,20 247 × Height (m) × Weight (kg) .
2.52
minimum permissible surface temperature
θ
S,min
minimum temperature permissible for physiological reasons or for the physical building, for calculation of the
limit curves, which may occur at a point on the surface (floor, wall, ceiling) in the occupied or peripheral area
depending on the particular usage at a temperature drop σ of the heating medium equal to 0
2.53
nominal heat flux
q
N
limit heat flux achieved without surface covering
2.54
nominal heating/cooling medium differential temperature
Δθ
N
absolute temperature difference at nominal heat flux q
N
2.55
non-active area
area of the surface not covered by a heating/cooling system
2.56
number of active surfaces
number of surfaces in straight thermal connection with the pipe level, so that it distinguishes whether the slab
transfers heat both through the floor side and through the ceiling side or whether the ceiling side is much more
active than the floor side
NOTE Two active surfaces when the conductive region extends from the floor to the ceiling, one active surface otherwise.
2.57
number of operation hours of the circuit
length of time during which the system runs in the day
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kSIST FprEN ISO 11855-1:2015
ISO 11855-1:2012(E)
2.58
occupied area
A
A
surface area which is heated or cooled, excluding peripheral area
2.59
occupied zone
part of the conditioned zone in which persons normally reside and where requirements as to the internal
environment are satisfied
NOTE Normally, the zone between the floor and 1,8 m above the floor and 1,0 m from outside walls/windows and
heating/cooling appliances, 0,5 m from internal surfaces.
2.60
open air gap
air gap in the floor, wall, or ceiling construction, where air exchange with space or the outside may occur
2.61
operative temperature
OT
θ
o
uniform temperature of an imaginary black enclosure in which an occupant exchanges the same amount of
heat by radiation and convection as in the actual non-uniform environment
2.62
orientation of the room
orientation of the main windowed external wall: East, South or West
NOTE It is used to determine when the peak load from heat gains happens, since internal heat gains are considered
almost constant and the widest variation is expected to happen in solar heat gains.
2.63
outward heat flux
q
U
heat flow which is exchanged through the construction with unconditioned spaces, another building entity, the
ground or outdoor air
2.64
peak load
maximum cooling load to be extracted by the system used to keep comfort conditions in the room
2.65
peripheral area
A
R
surface area which is heated or cooled to a higher or lower temperature
NOTE It is generally an area of 1 m maximum in width along exterior walls. It is not an occupied area.
2.66
pipe level
virtual plane where the pipe circuit lies
2.67
pipe level thermal resistance
thermal resistance associated to the 2-D conduction heat transfer taking place between the pipes and the
embedding layer, virtually referred to the pipe level, thus connecting the mean temperature of the pipe outer
side with the mean temperature at the pipe level
2.68
pipe spacing
spacing or distance between pipes embedded in the surface
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ISO 11855-1:2012(E)
2.69
pipe thickness thermal resistance
thermal resistance associated to the conduction heat transfer taking place thr
...
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