SIST EN 1264-2:2021
(Main)Water based surface embedded heating and cooling systems - Part 2: Floor heating: Methods for the determination of the thermal output using calculations and experimental tests
Water based surface embedded heating and cooling systems - Part 2: Floor heating: Methods for the determination of the thermal output using calculations and experimental tests
This European Standard specifies the boundary conditions and the prove methods for the determination of the thermal output of hot water floor heating systems as a function of the temperature difference between the heating medium and the room temperature.
This standard shall be applied to commercial trade and practical engineering if proved and certifiable values of the thermal output shall be used.
This European Standard applies to heating and cooling systems embedded into the enclosure surfaces of the room to be heated or to be cooled. This Part of this European Standard applies to hot water floor heating systems. Applying of Part 5 of this European Standard requires the prior use of this Part of this European Standard. Part 5 of this European Standard deals with the conversion of the thermal output of floor heating systems determined in Part 2 into the thermal output of heating surfaces embedded in walls and ceilings as well as into the thermal output of cooling surfaces embedded in floors, walls and ceilings.
The thermal output is proved by a calculation method (Clause 6) and by a test method (Clause 9). The calculation method is applicable to systems corresponding to the definitions in EN 1264 1 (type A, type B, type C, type D). For systems not corresponding to these definitions, the test method shall be used. The calculation method and the test method are consistent with each other and provide correlating and adequate prove results.
The prove results, expressed depending on further parameters, are the standard specific thermal output and the associated standard temperature difference between the heating medium and the room temperature as well as fields of characteristic curves showing the relationship between the specific thermal output and the temperature difference between the heating medium and the room.
Raumflächenintegrierte Heiz- und Kühlsysteme mit Wasserdurchströmung - Teil 2: Fußbodenheizung: Prüfverfahren für die Bestimmung der Wärmeleistung unter Benutzung von Berechnungsmethoden und experimentellen Methoden
EN 1264 gibt Leitlinien für in Wohn- und anderen Gebäuden (z. B. Bürogebäuden, öffentlichen Gebäuden sowie Gewerbe- und Industriegebäuden) installierte raumflächenintegrierte Heiz- und Kühlsysteme und legt einen Schwerpunkt auf Systeme, die für den Zweck der thermischen Behaglichkeit installiert werden.
Die Normenreihe EN 1264 gibt Leitlinien für Heiz- und Kühlsysteme mit Wasserdurchströmung, die in die Raum¬umschließungsflächen des zu heizenden oder des zu kühlenden Raumes eingebettet sind. Sie legt ggf. auch die entsprechende Verwendung anderer Heizmittel als Wasser fest.
Die Normenreihe EN 1264 legt die Identifizierung standardisierter Produktmerkmale durch Berechnung und Prüfung der Wärmeleistung der Heizung für technische Spezifikationen und die Zertifizierung fest. Für das Design, den Bau und den Betrieb dieser Anlagen siehe EN 1264 3 und EN 1264 4 für die Typen A, B, C, D, H, I und J. Für die Typen E, F und G siehe Normenreihe EN ISO 11855.
Die in der Normenreihe EN 1264 festgelegten Systeme grenzen an den tragenden Untergrund der Umschließungsflächen des Gebäudes an und werden direkt oder mit Befestigungshalterungen angebracht. Die Normenreihe EN 1264 trifft keine Festlegungen für in abgehängten Decken montierte Deckensysteme mit einem auslegungsgemäßen offenen Luftspalt zwischen dem System und der Gebäudestruktur, der eine thermisch induzierte Umwälzung der Luft erlaubt. Die Wärmeleistung dieser Systeme kann nach der Normenreihe EN 14037 und EN 14240 bestimmt werden.
EN 1264 2 legt Warmwasser-Fußbodenheizsysteme fest. Die Anwendung von EN 1264 5 erfordert die vorherige Anwendung von EN 1264 2. EN 1264 5 legt die Umrechnung der in EN 1264 2 bestimmten Wärmeleistung der Fußbodenheizsysteme in die Wärmeleistung von Heizflächen in Wänden und Decken sowie in die Kühlleistung von Kühlflächen in Fußböden, Wänden und Decken fest.
EN 1264 2 legt die Randbedingungen und die Prüfverfahren für die Bestimmung der Wärmeleistung von Warmwasser-Fußbodenheizsystemen in Abhängigkeit von der Differenz zwischen der Heizmittel- und der Raumtemperatur fest.
Die Wärmeleistung wird durch ein Berechnungsverfahren und ein Messverfahren geprüft. Das Berechnungsverfahren ist auf Systeme anwendbar, die den Definitionen nach EN 1264 1 (Typ A, B, C, D, H, I und J) entsprechen. Bei Systemen, die diesen Definitionen nicht entsprechen, gibt das Messverfahren Leitlinien. Das Berechnungsverfahren und das Messverfahren entsprechen einander und liefern korrelierende, adäquate Prüfergebnisse.
Als Prüfergebnisse werden die spezifische Norm-Wärmeleistung mit der zugehörigen Norm-Differenz zwischen der Heizmittel- und der Raumtemperatur sowie Kennlinienfelder für die Beziehung zwischen der spezifischen Wärmeleistung und der Differenz zwischen der Heizmittel- und der Raumtemperatur in Abhängigkeit von weiteren Parametern angegeben.
Systèmes de surfaces chauffantes et rafraîchissantes hydrauliques intégrées - Partie 2: Chauffage par le sol: Méthodes de démonstration pour la détermination de l'émission thermique utilisant des méthodes par le calcul et à l'aide de méthodes d'essai
La série EN 1264 fournit des lignes directrices pour les systèmes de surfaces chauffantes et rafraîchissantes intégrées dans les bâtiments résidentiels et non résidentiels (par exemple, des bureaux, des bâtiments publics, commerciaux et industriels), et se concentre sur les systèmes installés à des fins de confort thermique.
La série EN 1264 fournit des lignes directrices pour les systèmes de surfaces chauffantes et rafraîchissantes intégrées dans les parois des pièces à chauffer ou à rafraîchir. Elle spécifie également l'utilisation de fluides caloporteurs autres que l'eau, le cas échéant.
La série EN 1264 spécifie les caractéristiques normalisées des produits en calculant et en mettant à l'essai l'émission thermique du chauffage pour les spécifications techniques et la certification. Pour la conception, la construction et le fonctionnement de ces systèmes, voir l'EN 1264-3 et l'EN 1264-4 pour les types A, B, C, D, H, I et J. Pour les types E, F et G, voir la série EN ISO 11855.
Les systèmes spécifiés dans la série EN 1264 sont fixés directement ou à l'aide de supports de fixation au plancher porteur des parois du bâtiment. La série EN 1264 ne spécifie pas les systèmes de plafond montés dans un plafond suspendu, dont l'entrefer ouvert conçu entre le système et la structure du bâtiment permet la circulation de l'air induite par la chaleur. L'émission thermique de ces systèmes peut être déterminée selon la série EN 14037 et l'EN 14240.
L'EN 1264-2 spécifie les systèmes de chauffage hydrauliques par le sol. L'application de l'EN 1264-5 nécessite l'utilisation préalable de l'EN 1264-2. L'EN 1264-5 spécifie la conversion de l'émission thermique des systèmes de chauffage par le sol déterminée dans l'EN 1264-2 en émission thermique des surfaces chauffantes intégrées dans les murs et les plafonds ou en émission thermique des surfaces rafraîchissantes intégrées dans les sols, les murs et les plafonds.
L'EN 1264-2 spécifie les conditions limites et les méthodes d'essai pour la détermination de l'émission thermique des systèmes de chauffage par le sol à circulation d'eau chaude sous la forme d'une fonction de la différence de température entre le fluide caloporteur et la température ambiante.
L'émission thermique est mise à l'essai par une méthode de calcul et par une méthode de mesure. La méthode de calcul s'applique aux systèmes correspondant aux définitions données dans l'EN 1264-1 (types A, B, C, D, H, I et J). La méthode de mesure fournit des recommandations pour les systèmes ne correspondant pas à ces définitions. Ces deux méthodes sont convergentes et fournissent des résultats d'essai concordants.
Les résultats de l'essai, exprimés en fonction d'autres paramètres, constituent l'émission thermique surfacique normalisée et la différence de température normalisée associée entre le fluide caloporteur et la pièce, ainsi que les familles des courbes caractéristiques qui montrent la relation existant entre l'émission thermique surfacique et la différence de température entre le fluide caloporteur et la pièce.
Ploskovni sistemi za ogrevanje in hlajenje z vodo - 2. del: Talno ogrevanje - Metode za določevanje oddaje toplote z izračuni in preskušanjem
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 1264-2:2021
01-julij-2021
Nadomešča:
SIST EN 1264-2:2009+A1:2013
Ploskovni sistemi za ogrevanje in hlajenje z vodo - 2. del: Talno ogrevanje -
Metode za določevanje oddaje toplote z izračuni in preskušanjem
Water based surface embedded heating and cooling systems - Part 2: Floor heating:
Methods for the determination of the thermal output using calculations and experimental
tests
Raumflächenintegrierte Heiz- und Kühlsysteme mit Wasserdurchströmung - Teil 2:
Fußbodenheizung: Prüfverfahren für die Bestimmung der Wärmeleistung unter
Benutzung von Berechnungsmethoden und experimentellen Methoden
Systèmes de surfaces chauffantes et rafraîchissantes hydrauliques intégrées - Partie 2:
Chauffage par le sol: Méthodes de démonstration pour la détermination de l'émission
thermique utilisant des méthodes par le calcul et à l'aide de méthodes d'essai
Ta slovenski standard je istoveten z: EN 1264-2:2021
ICS:
91.140.10 Sistemi centralnega Central heating systems
ogrevanja
SIST EN 1264-2:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 1264-2:2021
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SIST EN 1264-2:2021
EN 1264-2
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2021
EUROPÄISCHE NORM
ICS 91.140.10 Supersedes EN 1264-2:2008+A1:2012
English Version
Water based surface embedded heating and cooling
systems - Part 2: Floor heating: Methods for the
determination of the thermal output using calculations and
experimental tests
Systèmes de surfaces chauffantes et rafraîchissantes Raumflächenintegrierte Heiz- und Kühlsysteme mit
hydrauliques intégrées - Partie 2: Chauffage par le sol: Wasserdurchströmung - Teil 2: Fußbodenheizung:
Méthodes de démonstration pour la détermination de Prüfverfahren für die Bestimmung der Wärmeleistung
l'émission thermique utilisant des méthodes par le unter Benutzung von Berechnungsmethoden und
calcul et à l'aide de méthodes d'essai experimentellen Methoden
This European Standard was approved by CEN on 12 April 2021.
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, Republic of North Macedonia, Romania, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1264-2:2021 E
worldwide for CEN national Members.
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SIST EN 1264-2:2021
EN 1264-2:2021 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Thermal boundary conditions . 6
5 Documents for testing . 7
6 Calculation of the specific thermal output (characteristic curves and limit curves) . 7
6.1 General approach . 7
6.2 Systems with pipes installed inside the screed (types A, C, H, I, J) . 9
6.3 Systems with pipes installed below the screed or timber floor (type B) . 11
6.4 Systems with surface elements (plane section systems, type D) . 12
6.5 Limits of the specific thermal output . 13
6.6 Influence of pipe material, pipe wall thickness and pipe sheathing on the specific
thermal output . 15
6.7 Thermal conductivity of screed with inserts . 15
7 Thermal conductivity of the materials . 16
8 Downward heat loss . 16
9 Test procedure for the determination of the thermal output of systems that cannot
be calculated in accordance with Clause 6 . 17
10 Test report . 20
11 Test system . 20
11.1 General . 20
11.2 Master samples . 20
11.3 Verification of test equipment . 21
11.4 Determination of the values s and ϕ (q , q (R = 0,15)) of primary
m M,s N,M,s G,M,s λ;B
master samples . 21
11.5 Verification of software . 21
12 Calculation of the specific heat capacity of the system (C-Value) . 22
Annex A (normative) Figures and tables . 23
Annex B (normative) Influence of the heat exchange coefficient inside the pipe on the
specific thermal output . 38
Annex C (normative) Material data . 39
Bibliography . 41
2
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SIST EN 1264-2:2021
EN 1264-2:2021 (E)
European foreword
This document (EN 1264-2:2021) has been prepared by Technical Committee CEN/TC 130 “Space
heating appliances without integral heat sources”, the secretariat of which is held by UNI.
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 November 2021 and conflicting national standards
shall be withdrawn at the latest by November 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 1264-2:2008+A1:2012.
The main changes compared to the previous edition are listed below:
a) Modification of the Title;
b) Clarification of the Scope;
c) Improved wording, especially the term “prove method”;
d) Modification of Clause 9;
e) Deletion of Clause 10, Test procedure for the determination of the effective thermal resistance of
carpets and all references to this Clause;
f) Deletion of Figures A.9, A.10 and A.11;
g) Table A.13, Heat conductivities for materials was moved to the new Annex C and was modified;
h) Deletion of Annex B, Test procedure for the determination of parameters for application in the
EN 15377 series;
i) Addition of new Clause 12, Calculation of the specific heat capacity of the system (C-Value).
EN 1264, Water based surface embedded heating and cooling systems, consists of the following parts:
— Part 1: Definitions and symbols;
— Part 2: Floor heating: Methods for the determination of the thermal output using calculations and
experimental tests;
— Part 3: Dimensioning;
— Part 4: Installation;
— Part 5: Determination of the thermal output for wall and ceiling heating and for floor, wall and ceiling
cooling.
According to the CEN-CENELEC Internal Regulations, the national standards organisations 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, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
3
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SIST EN 1264-2:2021
EN 1264-2:2021 (E)
Introduction
The EN 1264 series is based on the realization that in the field of commercial trade, the thermal output
of heating and cooling systems represents the basis of rating. In order to be able to evaluate and
compare different heating and/or cooling systems, it is therefore necessary to refer to values
determined using one single, unambiguously defined method. The basis for doing so is the test methods
for the determination of the thermal output of floor heating systems specified in EN 1264-2. In analogy
to EN 442-2, Radiators and convectors — Part 2: Test methods and rating, these test methods provide
characteristic partial load curves under defined boundary conditions as well as the characteristic
output of the system represented by the standard thermal output together with the associated standard
temperature difference between the heating medium and the room temperature.
4
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SIST EN 1264-2:2021
EN 1264-2:2021 (E)
1 Scope
The EN 1264 series gives guidelines for surface embedded heating and cooling systems installed in
buildings, residential and non-residential (e.g. office, public, commercial and industrial buildings) and
focuses on systems installed for the purpose of thermal comfort.
The EN 1264 series gives guidelines for water based heating and cooling systems embedded into the
enclosure surfaces of the room to be heated or to be cooled. It also specifies the use of other heating
media instead of water, as appropriate.
The EN 1264 series specifies standardized product characteristics by calculation and testing the
thermal output of heating for technical specifications and certification. For the design, construction and
operation of these systems, see EN 1264-3 and EN 1264-4 for the types A, B, C, D, H, I and J. For the
types E, F and G, see the EN ISO 11855 series.
The systems specified in the EN 1264 series are adjoined to the structural base of the enclosure
surfaces of the building, mounted directly or with fixing supports. The EN 1264 series does not specify
ceiling systems mounted in a suspended ceiling with a designed open air gap between the system and
the building structure which allows the thermally induced circulation of the air. The thermal output of
these systems can be determined according to the EN 14037 series and EN 14240.
EN 1264-2 specifies hot water floor heating systems. The application of EN 1264-5 requires the prior
use of EN 1264-2. EN 1264-5 specifies the conversion of the thermal output of floor heating systems
determined in EN 1264-2 into the thermal output of heating surfaces embedded in walls and ceilings as
well as into the thermal output of cooling surfaces embedded in floors, walls and ceilings.
EN 1264-2 specifies the boundary conditions and the test methods for the determination of the thermal
output of hot water floor heating systems as a function of the temperature difference between the
heating medium and the room temperature.
The thermal output is tested by a calculation method and by a measurement method. The calculation
method is applicable to systems corresponding to the definitions in EN 1264-1 (type A, B, C, D, H, I
and J). The measurement method gives guidance for systems not corresponding to these definitions.
The calculation method and the measurement method are consistent with each other and provide
correlating and adequate test results.
The test results, expressed depending on further parameters, are the standard specific thermal output
and the associated standard temperature difference between the heating medium and the room
temperature as well as fields of characteristic curves showing the relationship between the specific
thermal output and the temperature difference between the heating medium and the room.
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.
EN 1264-1, Water based surface embedded heating and cooling systems — Part 1: Definitions and symbols
EN 1264-3:2021, Water based surface embedded heating and cooling systems — Part 3: Dimensioning
5
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SIST EN 1264-2:2021
EN 1264-2:2021 (E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1264-1 apply.
ISO and IEC maintain terminological 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/
4 Thermal boundary conditions
A floor heating surface with a given average surface temperature exchanges the same thermal output in
any room with the same indoor room temperature (standard indoor room temperature ϑ). It is
i
therefore possible to give a basic characteristic curve of the relationship between specific thermal
output and average surface temperature that is independent of the heating system and applicable to all
floor heating surfaces (including those having peripheral areas with greater heat emissions) (see
Figure A.1 in normative Annex A).
In contrast, every floor heating system has its own maximum permissible specific thermal output, the
limit specific thermal output, q . This output is calculated for an ambient (standard) indoor room
G
1
temperature ϑ = 20 °C. The other condition is the maximum surface temperature ϑ = 29 °C at
i F,max
temperature drop between supply and return of the heating medium σ = 0 K. The maximum specific
thermal output for the peripheral area will be achieved at a maximum surface temperature
2
ϑ = 35 °C and σ = 0 K.
F,max
For the calculation and for the test procedure, the centre of the heating surface is used as the reference
point for ϑ , regardless of system type.
F, max
The average surface temperature ϑ , determining the specific thermal output (see basic characteristic
F, m
curve) is linked with the maximum surface temperature. In this context, ϑ < ϑ always applies.
F,m F, max
The achievable value ϑ depends on both the floor heating system and the operating conditions
F,m
(temperature drop σ = ϑ − ϑ , downward thermal output q and thermal resistance of the floor
V R u
covering R ).
λ,B
1
National regulations can limit this temperature to a lower value.
2
Some floor covering materials can require lower temperatures.
6
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SIST EN 1264-2:2021
EN 1264-2:2021 (E)
The calculation of the specific thermal output is based on the following conditions:
— the heat transfer at the floor surface occurs in accordance with the basic characteristic curve;
— the temperature drop of the heating medium σ = 0; the extent to which the characteristic curve
depends on the temperature drop, is covered by using the logarithmically determined temperature
difference between the heating medium and the room Δϑ (see Formula (1));
H
— turbulent pipe flow: m /d > 4 000 kg/(h ∙ m);
H i
— there is no lateral heat flow;
— the heat-conducting layer of the floor heating system is thermally decoupled by thermal insulation
from the structural base of the building. The thermal insulation need not be directly below the
system.
The aforementioned last condition does not concern the test procedure of Clause 9.
5 Documents for testing
The system supplier’s documents are taken as the basis for the determination of the thermal output.
The following documents shall be provided:
— installation drawing (section) of the floor heating system, covering two pipe spacing, including the
peripheral area and giving information on the materials used (if necessary, the test results
regarding the thermal conductivity values of the materials shall be provided);
— technical documentation of the system.
This information shall contain any details necessary for the calculation of the construction customary
on site. It shall be submitted to the installer in the same form.
With a member of the testing body present, a demonstration surface of approximately 2 m × 2 m is
constructed to represent the actual construction used on site.
6 Calculation of the specific thermal output (characteristic curves and limit
curves)
6.1 General approach
The specific thermal output q at the surface of a floor is determined by the following parameters:
— Pipe spacing T;
— Thickness s and thermal conductivity λ of the layer above the pipe;
u E
— Thermal conduction resistance R of the floor covering;
λ,B
— Pipe external diameter D = d , including the sheathing (D = d ) if necessary and the thermal
a M
conductivity of the pipe λ or the sheathing λ . In case of pipes having non-circular cross sections,
R M
the equivalent diameter of a circular pipe having the same circumference shall be used in the
calculation (the screed covering shall not be changed). Thickness and thermal conductivity of
permanently mounted diffusion barrier layers with a thickness up to 0,3 mm need not be
considered in the calculation. In this case, D = d shall be used;
a
7
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SIST EN 1264-2:2021
EN 1264-2:2021 (E)
— Heat diffusion devices having the characteristic value K in accordance with 6.3;
WL
— Contact between the pipes and the heat diffusion devices or the screed, characterized by the factor
a .
K
The calculation method is limited to the boundary conditions listed in Table 1.
Table 1 — Criteria for selection of the simplified calculation method
Type of Figure Boundary conditions Reference to
system method
A, C, H, I, J Figure A.2 T ≥ 0,050 m 6.2
s ≥ 0,01 m
u
0,008 m ≤ D ≤ 0,03 m
s /λ ≥ 0,01
u e
B Figure A.3 0,05 m ≤ T ≤ 0,45 m 6.3
0,014 m ≤ D ≤ 0,022 m
0,01 m ≤ s /λ ≤ 0,18
u e
D Figure A.4 6.4
n
The specific thermal output is proportional to (Δϑ ) , where the temperature difference between the
H
heating medium and the room temperature is:
ϑ −ϑ
V R
∆ϑ =
H
ϑ −ϑ
V i
ln
ϑϑ−
Ri
(1)
and where experimental and theoretical investigations of the exponent n have shown that:
10,,<
(2)
Within the limits of the achievable accuracy,
n = 1
is used.
8
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SIST EN 1264-2:2021
EN 1264-2:2021 (E)
The specific thermal output is calculated using Formula (3).
m
i
q B⋅ a ⋅∆ϑ
i H
∏
i
(3)
where
2
B
is a system-dependent coefficient, in W/(m ∙ K);
m is a power product linking the parameters of the floor construction with one another
i
a
i
∏
(see 6.2, 6.3 and 6.4).
i
A distinction shall be made between systems, where the pipes are installed inside or below the screed
or wood floors, and systems with surface elements (plane section systems). For usual constructions,
Formula (3) applies directly. For systems with additional devices for heat distribution, for air filled
hollow sections or for other components influencing the heat distribution, the thermal output is
determined experimentally in accordance with Clause 9.
6.2 Systems with pipes installed inside the screed (types A, C, H, I, J)
For these systems (see Figure A.2), the characteristic curves are calculated in accordance with
Formula (4).
mm
m
TD
u
q= Ba⋅ ⋅ a ⋅⋅a a ∆⋅ϑ
BT u D H
(4)
mm
m
TD
u
The product Ba⋅ ⋅⋅a a ⋅ a is called the equivalent heat transmission coefficient K , which leads
H
BT u D
to the abbreviated form of the expression, Formula (5):
qK= ⋅∆ϑ
H H
(5)
where
2 2
B = B = 6,7 W/(m ∙ K) for a pipe thermal conductivity λ = λ = 0,35 W/(m ∙ K) and a pipe wall
0 R R,0
thickness s = s = (d − d )/2 = 0,002 m;
R R,0 a i
a is a spacing factor in accordance with Table A.1; a = f (R );
T T λ,B
a is a covering factor in accordance with Table A.2; a = f (T, R );
u u λ,B
a is the pipe external diameter factor in accordance with Table A.3; a = f (T,
D D
R ).
λ,B
applies where 0,,050 m≤≤T 0 375 m (6)
T
m 1−
T
0,075
(7)
applies where s ≥ 0,010 m
ms=100⋅ 0,045−
( )
u
uu
applies where 0,,008 m≤≤D 0 030 m
(8)
mD250⋅− 0,020
( )
D
9
=
=
=
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SIST EN 1264-2:2021
EN 1264-2:2021 (E)
For other materials with different heat conductivities or for different pipe wall thicknesses, or for
sheathed pipes, B shall be calculated in accordance with 6.6.
For a heating screed, a value for λ of Table C.1 shall be used. If a different value is used, its validity shall
E
be checked.
a is the floor covering factor in accordance with Formula (9):
B
s
1 u,0
+
α λ
u,0
(9)
a =
B
s
1
u,0
++ R
λ,B
αλ
E
where
2
α
= 10,8 W/(m ∙ K);
λ = 1 W/(m ∙ K);
u,0
s = 0,045 m;
u,0
2
R
is the thermal conduction resistance of the floor covering, in m ∙ K/W;
λ,B
λ is the thermal conductivity of the screed, in W/(m ∙ K);
E
In Formulae (6), (7) and (8)
T is the pipe spacing;
D is the external diameter of the pipe, including sheathing, where applicable;
s is the thickness of the screed covering above the pipe.
u
For a pipe spacing T > 0,375 m, the specific thermal output is approximately calculated using
0,375
qq=
0,375
T
(10)
where
q is the specific thermal output, calculated for a spacing T = 0,375 m.
0,375
*
For systems with s ≤ 0,065 m as well as 0,065 m < s ≤ s , Formula (4) applies directly. The value of
u u
u
*
s depends on the pipe spacing as follows:
u
*
For a spacing T ≤ 0,200 m, s = 0,100 m applies.
u
*
For a spacing T > 0,200 m, s = 0,5 T applies. In this relation, always the actual spacing T shall be used,
u
even if the calculation is done in accordance with Formula (10).
10
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SIST EN 1264-2:2021
EN 1264-2:2021 (E)
*
For coverings above the pipe s > s , Formula (5) shall be used. In this case, the equivalent heat
u
u
transmission coefficient shall be determined in accordance with the Formula (11):
1
K =
H
*
ss−
1
uu
+
K λ
*
E
H, ss=
uu
(11)
*
In Formula (11), K is the power product from Formula (4), calculated for a covering s above
*
u
H, ss=
uu
the pipe.
The limit curves are calculated in accordance with 6.5.
6.3 Systems with pipes installed below the screed or timber floor (type B)
For these systems (see Figure A.3), the variable thickness s of the weight bearing layer and its variable
u
thermal conductivity λ are covered by the factor a . The pipe diameter has no effect. However, the
E u
contact between the heating pipe and the heat diffusion device or any other heat distribution device is
an important parameter. In this case, the characteristic curve is calculated using Formula (12):
m
T
q Ba⋅ ⋅ a ⋅⋅a a ⋅ a ⋅∆ϑ
B T u WL K H
(12)
where
2
B
= B = 6,5 W/(m ∙ K) under the conditions given for Formulae (4) and (5);
0
a is the pipe spacing factor in accordance with Table A.8; a = f (s /λ );
T T u E
m see Formula (6);
T
a is the covering factor, which is calculated in accordance with Formula (13):
u
s
1 u,0
+
α λ
u,0
a =
u
s
1
u
+
α λ
E
(13)
where
2
α = 10,8 W/(m ∙ K);
λ = 1 W/(m ∙ K);
u,0
= 0,045 m;
s
u,0
a is the heat conduction factor (see Tables A.10 onwards); a = f (K , T, D).
WL WL WL
11
=
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SIST EN 1264-2:2021
EN 1264-2:2021 (E)
Formula (14) applies to the characteristic value K :
WL
s ⋅λλ+ bs⋅⋅
WL WL u u E
K =
WL
0,125
(14)
where
b = f (T) shall be taken from Table A.9;
u
s ∙ λ is the product of the thickness and the thermal conductivity of the heat diffusion device;
WL WL
s ∙ λ is the product of the thickness and the thermal conductivity of the screed or timber
u E
covering.
If the width L of the heat diffusion device is smaller than the pipe spacing T, the value a
WL,L = T
determined in accordance with Tables A.10 onwards, shall be corrected using Formula (15):
23
LL L
aa= − a − a 1−+3,,2 3 4 − 1,2
( )
WL WL,L T WL,L T WL,L 0
T T T
(15)
The heat conduction factors a and a shall be taken from Tables A.10 to A.15. For L = T, the
WL,L = T WL,L = 0
tables with K in accordance with Formula (14) apply directly, for L = 0, the tables apply with K
WL WL
determined in accordance with Formula (14) with s = 0.
WL
a is the correction factor for the contact in accordance with Table A.9; a = f (T).
K K
The correction factor for the contact a covers additional thermal transmission resistances due to cases
K
where there is only spot or line contact between the heating pipe and the heat diffusion device. These
resistances depend on the manufacturing tolerances of the pipes and heat conduction devices as well as
on the care taken in installing them, and are, therefore, subject to fluctuations in individual cases. For
this reason, Table A.16 gives a calculated average value for a .
K
is the floor covering factor:
a
B
1
a = (16)
B
m
T
1+⋅Ba ⋅ a ⋅ a ⋅⋅a R ⋅ f T
( )
u T WL K λ,B
with f (T) = 1 + 0,44 T
The limit curves are calculated in accordance with 6.5.
6.4 Systems with surface elements (plane section systems, type D)
For floors covered with surface elements (see Figure A.4), Formula (17) applies:
m
T
q Ba⋅ ⋅ a ⋅ a ⋅∆ϑ
BT u H
(17)
12
=
===
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EN 1264-2:2021 (E)
where
2
B = B = 6,5 W/(m ∙ K) and
0
m
= 1,06;
T
a
T
a is the covering factor in accordance with Formula (13);
u
a is the floor covering factor:
B
1
a = (18)
B
m
T
1+⋅Ba ⋅⋅a R
uT λ,B
6.5 Limits of the specific thermal output
The procedure for the determination of the limits of the specific thermal output is shown in principle
within Figure A.5.
The limit curve (see Figure A.5) gives the relationship between the specific thermal output and the
temperature difference between the heating medium and the room for cases where the maximum
permissible difference between surface temperature and indoor room temperature (9 K or 15 K
respectively) is achieved.
The limit curve is calculated using Formula (19):
n
G
∆θ
H
q ϕ⋅ B ⋅
GG
ϕ
(19)
where
B is a coefficient in accordance with Table A.4 (applicable to s /λ ≤ 0,079 2) and Table A.5
G u E
(applicable to s /λ > 0,079 2) for type A, C, H, I and J systems or in accordance with Table A.17 for
u E
2
type B systems; or B = 100 W/(m ∙ K) for systems with surface elements of type D;
G
n is an exponent in accordance with Table A.6 (applicable to s /λ ≤ 0,079 2) and Table
...
SLOVENSKI STANDARD
oSIST prEN 1264-2:2020
01-januar-2020
Ploskovni sistemi za ogrevanje in hlajenje z vodo - 2. del: Talno ogrevanje -
Preskusne metode za določevanje oddaje toplote z metodo izračuna in
preskušanjem
Water based surface embedded heating and cooling systems - Part 2: Floor heating:
Prove methods for the determination of the thermal output using calculation and test
methods
Raumflächenintegrierte Heiz- und Kühlsysteme mit Wasserdurchströmung - Teil 2:
Fußbodenheizung: Prüfverfahren für die Bestimmung der Wärmeleistung unter
Benutzung von Berechnungsmethoden und experimentellen Methoden
Systèmes de surfaces chauffantes et rafraîchissantes hydrauliques intégrées - Partie 2 :
Chauffage par le sol: Méthodes de démonstration pour la détermination de l'émission
thermique utilisant des méthodes par le calcul et à l'aide de méthodes d'essai
Ta slovenski standard je istoveten z: prEN 1264-2
ICS:
91.140.10 Sistemi centralnega Central heating systems
ogrevanja
oSIST prEN 1264-2:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 1264-2:2020
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oSIST prEN 1264-2:2020
DRAFT
EUROPEAN STANDARD
prEN 1264-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2020
ICS 91.140.10 Will supersede EN 1264-2:2008+A1:2012
English Version
Water based surface embedded heating and cooling
systems - Part 2: Floor heating: Prove methods for the
determination of the thermal output using calculation and
test methods
Systèmes de surfaces chauffantes et rafraîchissantes Raumflächenintegrierte Heiz- und Kühlsysteme mit
hydrauliques intégrées - Partie 2 : Chauffage par le sol: Wasserdurchströmung - Teil 2: Fußbodenheizung:
Méthodes de démonstration pour la détermination de Prüfverfahren für die Bestimmung der Wärmeleistung
l'émission thermique utilisant des méthodes par le unter Benutzung von Berechnungsmethoden und
calcul et à l'aide de méthodes d'essai experimentellen Methoden
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 130.
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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1264-2:2020 E
worldwide for CEN national Members.
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prEN 1264-2:2020 (E)
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Thermal boundary conditions . 7
5 Documents for testing . 8
6 Calculation of the specific thermal output (characteristic curves and limit curves) . 8
6.1 General approach . 8
6.2 Systems with pipes installed inside the screed (type A and type C) . 9
6.3 Systems with pipes installed below the screed or timber floor (type B) . 11
6.4 Systems with surface elements (plane section systems, type D) . 13
6.5 Limits of the specific thermal output . 13
6.6 Influence of pipe material, pipe wall thickness and pipe sheathing on the specific
thermal output . 15
6.7 Heat conductivity of screed with inserts . 15
7 Heat conductivity of the materials . 16
8 Downward heat loss . 16
9 Test procedure for the determination of the thermal output of systems that cannot
be calculated in accordance with Clause 6 . 17
10 Test report . 19
11 Test system . 20
11.1 General . 20
11.2 Master samples . 20
11.3 Verification of test equipment . 20
11.4 Determination of the values s and ϕ (q , q (R = 0,15)) of primary
m M,s N,M,s G,M,s λ;B
master samples . 21
11.5 Verification of software . 21
Floor heating system with pipes inside the screed (type A), tacker system . 21
Floor heating system with pipes inside the screed (type A) . 21
Floor heating system with pipes below the screed (type B) . 21
Floor heating system with pipes inside the screed (type A) . 22
Annex A (normative) Figures and tables . 23
2
Specific thermal output q (W/m ) . 23
Average temperature difference between surface and indoor room temperature (ϑ − ϑ )
F,m i
in K . 23
Cooling plate below (see Figure A.7) . 27
2
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Annex B (informative) Influence of the heat exchange coefficient inside the pipe on the
specific thermal output . 38
Annex C (normative) Calculation of the specific heat capacity (C-Value) . 39
Annex D (normative) Material data . 40
Bibliography . 42
3
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prEN 1264-2:2020 (E)
European foreword
This document (prEN 1264-2:2020) has been prepared by Technical Committee CEN/TC 130 “Space
heating appliances without integral heat sources”, the secretariat of which is held by UNI.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 1264-2:2008+A1:2012.
This European Standard, Water based surface embedded heating and cooling systems, consists of the
following parts:
— Part 1: Definitions and symbols;
— Part 2: Floor heating: Methods for the determination of the thermal output using calculations and
experimental tests;
— Part 3: Dimensioning;
— Part 4: Installation;
— Part 5: Determination of the thermal output for wall and ceiling heating and for floor, wall and ceiling
cooling.
The main changes with respect to the previous edition are listed below:
a) Modified the title;
b) Clarified the scope;
c) Improved wording, especially the term “prove method”;
d) Modified Clause 9;
e) Deleted Clause 10 Test procedure for the determination of the effective thermal resistance of carpets
and all references to this Clause;
f) Removed Figures A.9, A.10 and A.11;
g) Table A.13 Heat conductivities for materials was moved to the new Annex D and was expanded;
h) Deleted Annex B Test procedure for the determination of parameters for application in EN 15377;
i) Added new Annex C Calculation of the specific heat capacity (C-Value).
4
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prEN 1264-2:2020 (E)
Introduction
EN 1264 is based on the realization that in the field of commercial trade, the thermal output of heating
and cooling systems represents the basis of rating. In order to be able to evaluate and compare different
heating and/or cooling systems, it is, therefore, necessary to refer to values determined using one single,
unambiguously defined method. The basis for doing so are the test methods for the determination of the
thermal output of floor heating systems specified in EN 1264-2. In analogy to EN 442-2, Radiators and
convectors — Part 2: Test methods and rating, these test methods provide characteristic partial load
curves under defined boundary conditions as well as the characteristic output of the system represented
by the standard thermal output together with the associated standard temperature difference between
the heating medium and the room temperature.
5
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prEN 1264-2:2020 (E)
1 Scope
EN 1264 covers surface embedded heating and cooling systems installed in buildings, residential and
non-residential (e.g. office, public, commercial and industrial buildings) and focuses on systems installed
for the purpose of thermal comfort.
EN 1264 applies to water based heating and cooling systems embedded into the enclosure surfaces of the
room to be heated or to be cooled. It also applies as appropriate to the use of other heating media instead
of water.
EN 1264 applies to identify standardized product characteristics by calculation and testing the thermal
output of heating for technical specifications and certification. For the design, construction and operation
of these systems, EN ISO 11855 applies.
The systems covered in EN 1264 are adjoined to the structural base of the enclosure surfaces of the
building, mounted directly or with fixing supports. It does not cover ceiling systems mounted in a
suspended ceiling with a designed open air gap between the system and the building structure which
allows the thermally induced circulation of the air. The thermal output of these systems can be
determined according to ISO 18566, EN 14037 and EN 14240.
EN 1264-2 applies to hot water floor heating systems. Applying of EN 1264-5 requires the prior use of
EN 1264-2. EN 1264-5 deals with the conversion of the thermal output of floor heating systems
determined in EN 1264-2 into the thermal output of heating surfaces embedded in walls and ceilings as
well as into the thermal output of cooling surfaces embedded in floors, walls and ceilings.
EN 1264-2 specifies the boundary conditions and the test methods for the determination of the thermal
output of hot water floor heating systems as a function of the temperature difference between the heating
medium and the room temperature.
The thermal output is tested by a calculation method and by a measurement method. The calculation
method is applicable to systems corresponding to the definitions in EN 1264-1 (type A, type B, type C,
type D). For systems not corresponding to these definitions, the measurement method shall be used. The
calculation method and the measurement method are consistent with each other and provide correlating
and adequate test results.
The test results, expressed depending on further parameters, are the standard specific thermal output
and the associated standard temperature difference between the heating medium and the room
temperature as well as fields of characteristic curves showing the relationship between the specific
thermal output and the temperature difference between the heating medium and the room.
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.
EN 1264-1, Water based surface embedded heating and cooling systems - Part 1: Definitions and symbols
prEN 1264-3:2019, Water based surface embedded heating and cooling systems — Part 3: Dimensioning
EN 1264-5, Water based surface embedded heating and cooling systems - Part 5: Heating and cooling
surfaces embedded in floors, ceilings and walls - Determination of the thermal output
EN ISO 11855, Building environment design — Design, dimensioning, installation and control of embedded
radiant heating and cooling systems
EN 14037, Free hanging heating and cooling surfaces for water with a temperature below 120 °C
6
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prEN 1264-2:2020 (E)
EN 14240, Ventilation for buildings - Chilled ceilings - Testing and rating
EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
(ISO/IEC 17025:2017)
ISO 18566, Building environment design — Design, test methods and control of hydronic radiant heating
and cooling panel systems
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1264-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
4 Thermal boundary conditions
A floor heating surface with a given average surface temperature exchanges the same thermal output in
any room with the same indoor room temperature (standard indoor room temperature ϑ ). It is therefore
i
possible to give a basic characteristic curve of the relationship between specific thermal output and
average surface temperature that is independent of the heating system and applicable to all floor heating
surfaces (including those having peripheral areas with greater heat emissions) (see Figure A.1).
In contrast, every floor heating system has its own maximum permissible specific thermal output, the
limit specific thermal output, q . This output is calculated for an ambient (standard) indoor room
G
1)
temperature ϑ = 20 °C. The other condition is the maximum surface temperature ϑ = 29 °C at
i F,max
temperature drop between supply and return of the heating medium σ = 0 K. The maximum specific
thermal output for the peripheral area will be achieved at a maximum surface temperature
2)
ϑ = 35 °C and σ = 0 K.
F,max
For the calculation and for the test procedure, the centre of the heating surface is used as the reference
point for ϑ , regardless of system type.
F, max
The average surface temperature ϑ , determining the specific thermal output (see basic characteristic
F, m
curve) is linked with the maximum surface temperature. In this context, ϑ < ϑ always applies.
F,m F, max
The achievable value ϑ depends on both the floor heating system and the operating conditions
F,m
(temperature drop σ = ϑ − ϑ , downward thermal output q and heat resistance of the floor covering
V R u
R ).
λ,B
1
National regulations may limit this temperature to a lower value.
2
Some floor covering materials may require lower temperatures.
7
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prEN 1264-2:2020 (E)
The calculation of the specific thermal output is based on the following conditions:
— The heat transfer at the floor surface occurs in accordance with the basic characteristic curve.
— The temperature drop of the heating medium σ = 0; the extent to which the characteristic curve
depends on the temperature drop, is covered by using the logarithmically determined temperature
difference between the heating medium and the room Δϑ (see Formula (1)).
H
— Turbulent pipe flow: m /d > 4 000 kg/(h ∙ m).
H i
— There is no lateral heat flow.
— The heat-conducting layer of the floor heating system is thermally decoupled by thermal insulation
from the structural base of the building.
NOTE The aforementioned last condition does not concern the test procedure of Clause 9.
5 Documents for testing
The system supplier’s documents are taken as the basis for the determination of the thermal output. The
following documents shall be provided:
— Installation drawing (section) of the floor heating system, covering two pipe spacing, including the
peripheral area and giving information on the materials used (if necessary, the test results regarding
the heat conductivity values of the materials shall be provided).
— Technical documentation of the system.
This information shall contain any details necessary for the calculation of the construction customary on
site. It shall be submitted to the installer in the same form.
With a member of the testing body present, a demonstration surface of approximately 2 m × 2 m is
constructed to represent the actual construction used on site.
6 Calculation of the specific thermal output (characteristic curves and limit
curves)
6.1 General approach
The specific thermal output q at the surface of a floor is determined by the following parameters:
— Pipe spacing T;
— Thickness s and heat conductivity λ of the layer above the pipe;
u E
— Heat conduction resistance R of the floor covering;
λ,B
— Pipe external diameter D = d , including the sheathing (D = d ) if necessary and the heat
a M
conductivity of the pipe λ or the sheathing λ . In case of pipes having non-circular cross sections,
R M
the equivalent diameter of a circular pipe having the same circumference shall be used in the
calculation (the screed covering shall not be changed). Thickness and heat conductivity of
permanently mounted diffusion barrier layers with a thickness up to 0,3 mm need not be considered
in the calculation. In this case, D = d shall be used;
a
8
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— Heat diffusion devices having the characteristic value K in accordance with 6.3;
WL
— Contact between the pipes and the heat diffusion devices or the screed, characterized by the factor
a .
K
n
The specific thermal output is proportional to (Δϑ ) , where the temperature difference between the
H
heating medium and the room temperature is:
ϑ −ϑ
V R
∆ϑ = (1)
H
ϑ −ϑ
V i
ln
ϑϑ−
Ri
and where experimental and theoretical investigations of the exponent n have shown that:
10,,<
Within the limits of the achievable accuracy,
n = 1
is used.
The specific thermal output is calculated using Formula (3).
m
i
q B⋅ a ⋅∆ϑ (3)
i H
∏
i
where
B 2
is a system-dependent coefficient, in W/(m ∙ K);
is a power product linking the parameters of the floor construction with one another
m
i
a
∏ i
(see 6.2, 6.3 and 6.4).
i
A distinction shall be made between systems, where the pipes are installed inside or below the screed or
wood floors, and systems with surface elements (plane section systems). For usual constructions,
Formula (3) applies directly. For systems with additional devices for heat distribution, for air filled
hollow sections or for other components influencing the heat distribution, the thermal output is
determined experimentally in accordance with Clause 9.
6.2 Systems with pipes installed inside the screed (type A and type C)
For these systems (see Figure A.2), the characteristic curves are calculated in accordance with
Formula (4a).
mm
m
TDu
q= Ba⋅ ⋅ a ⋅⋅a a ∆⋅ϑ (4a)
BT u D H
mm
m
TD
u
The product Ba⋅ ⋅⋅a a ⋅ a is called the equivalent heat transmission coefficient K , which leads
H
BT u D
to the abbreviated form of the expression, Formula (4b):
9
=
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prEN 1264-2:2020 (E)
qK= ⋅∆ϑ (4b)
H H
where
2 2
B = B = 6,7 W/(m ∙ K) for a pipe heat conductivity λ = λ = 0,35 W/(m ∙ K) and a pipe wall
0 R R,0
thickness s = s = (d − d )/2 = 0,002 m.
R R,0 a i
a is a spacing factor in accordance with Table A.1; a = f (R );
T T λ,B
a is a covering factor in accordance with Table A.2; a = f (T, R );
u u λ,B
a is the pipe external diameter factor in accordance with Table A.3; a = f (T,
D D
R ).
λ,B
T
m 1− applies where 0,,050 m≤≤T 0 375 m (5)
T
0,075
ms=100⋅ 0,045− applies where s ≥ 0,010 m (6)
( )
uu u
mD250⋅− 0,020 applies where 0,,008 m≤≤D 0 030 m (7)
( )
D
For other materials with different heat conductivities or for different pipe wall thicknesses, or for
sheathed pipes, B shall be calculated in accordance with 6.6.
2
For a heating screed with reduced moisture addition, λ = 1,2 W/(m ∙ K) shall be used. This value is also
E
applicable to other heating screeds. If a different value is used, its validity shall be checked.
a is the floor covering factor in accordance with Formula (8):
B
s
1 u,0
+
α λ
u,0
(8)
a =
B
s
1
u,0
++ R
λB,
αλ
E
where
α 2
= 10,8 W/(m ∙ K);
λ = 1 W/(m ∙ K);
u,0
s = 0,045 m;
u,0
R 2
λ,B is the heat conduction resistance of the floor covering, in m ∙ K/W;
λ is the heat conductivity of the screed, in W/(m ∙ K);
E
In Formulae (5), (6) and (7)
T is the pipe spacing;
D is the external diameter of the pipe, including sheathing, where applicable;
s is the thickness of the screed covering above the pipe.
u
For a pipe spacing T > 0,375 m, the specific thermal output is approximately calculated using
0,375
qq= (9)
0,375
T
10
=
=
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where
q is the specific thermal output, calculated for a spacing T = 0,375 m.
0,375
* *
(for see below), Formula (4a) applies
For systems with s ≤ 0,065 m as well as 0,065 m < s ≤ s s
u u u u
*
directly. The value of s depends on the pipe spacing as follows:
u
*
For a spacing T ≤ 0,200 m, = 0,100 m applies.
s
u
*
= 0,5 T applies. In this relation, always the actual spacing T shall be used, even
For a spacing T > 0,200, s
u
if the calculation is done in accordance with Formula (9).
*
For coverings above the pipe s > s , Formula (4b) shall be used. In this case, the equivalent heat
u
u
transmission coefficient shall be determined in accordance with the Formula (10):
1
K = (10)
H
*
ss−
1
uu
+
K λ
*
E
H, ss=
uu
*
In Formula (10), K is the power product from Formula (4a), calculated for a covering s above
*
u
H, ss=
uu
the pipe.
The limit curves are calculated in accordance with 6.5.
6.3 Systems with pipes installed below the screed or timber floor (type B)
For these systems (see Figure A.3), the variable thickness s of the weight bearing layer and its variable
u
heat conductivity λ are covered by the factor a . The pipe diameter has no effect. However, the contact
E u
between the heating pipe and the heat diffusion device or any other heat distribution device is an
important parameter. In this case, the characteristic curve is calculated using Formula (11):
m
T
q Ba⋅ ⋅ a ⋅⋅a a ⋅ a ⋅∆ϑ (11)
B T u WL K H
where
B 2
= B = 6,5 W/(m ∙ K) under the conditions given for Formulae (4a) and (4b);
0
a is the pipe spacing factor in accordance with Table A.6; a = f (s /λ );
T T u E
m see Formula (5);
T
a is the covering factor, which is calculated in accordance with Formula (12):
u
11
=
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prEN 1264-2:2020 (E)
s
1
u,0
+
α λ
u,0
a = (12)
u
s
1
u
+
α λ
E
where
2
α = 10,8 W/(m ∙ K);
λ = 1 W/(m ∙ K);
u,0
s = 0,045 m;
u,0
a is the heat conduction factor (see Tables A.10 onwards); a = f (K , T, D).
WL WL WL
Formula (13) applies to the characteristic value K :
WL
s ⋅λλ+ bs⋅⋅
WL WL u u E
K = (13)
WL
0,125
where
b = f (T) shall be taken from Table A.7;
u
s ∙ λ is the product of the thickness and the heat conductivity of the heat diffusion device;
WL WL
s ∙ λ is the product of the thickness and the heat conductivity of the screed or timber covering.
u E
If the width L of the heat diffusion device is smaller than the pipe spacing T, the value a
WL,L = T
determined in accordance with Tables A.10 onwards, shall be corrected using Formula (14):
23
LL L
(14)
aa= − a − a 1−+3,,2 3 4 − 1,2
( )
WL WL,L T WL,L T WL,L 0
T T T
The heat conduction factors a and a shall be taken from Tables A.10 to A.15. For L = T,
WL,L = T WL,L = 0
the tables with K in accordance with Formula (13) apply directly, for L = 0, the tables apply with K
WL WL
determined in accordance with Formula (13) with s = 0.
WL
a is the correction factor for the contact in accordance with Table A.9; a = f (T).
K K
The correction factor for the contact a covers additional heat transmission resistances due to cases
K
where there is only spot or line contact between the heating pipe and the heat diffusion device. These
resistances depend on the manufacturing tolerances of the pipes and heat conduction devices as well as
on the care taken in installing them, and are, therefore, subject to fluctuations in individual cases. For this
reason, Table A.9 gives a calculated average value for a .
K
a is the floor covering factor:
B
1
a = (15)
B
m
T
1+⋅Ba ⋅ a ⋅ a ⋅⋅a R ⋅ f T
( )
u T WL K λB,
with f (T) = 1 + 0,44 T
The limit curves are calculated in accordance with 6.5.
12
===
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6.4 Systems with surface elements (plane section systems, type D)
For floors covered with surface elements (see Figure A.4), Formula (16) applies:
m
T
q Ba⋅ ⋅ a ⋅ a ⋅∆ϑ (16)
BT u H
where
2
B = B = 6,5 W/(m ∙ K) and
0
m = 1,06;
T
a
T
a is the covering factor in accordance with Formula (12);
u
a is the floor covering factor:
B
1
a = (17)
B
m
T
1+⋅Ba ⋅ a ⋅ R
uT λB,
6.5 Limits of the specific thermal output
The procedure for the determination of the limits of the specific thermal output is shown in principle
within Figure A.5.
The limit curve (see Figure A.5) gives the relationship between the specific thermal output and the
temperature difference between the heating medium and the room for cases where the maximum
permissible difference between surface temperature and indoor room temperature (9
...
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