Bsi bs en 01264 2 2008 + a1 2012 (2013)

BRITISH STANDARD

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

ICS 91.140.10

NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW

BS EN

BS EN
1264-2:2008
1264-2:2008
+A1:2012


BS EN 1264-2:2008+A1:2012
BS EN 1264-2:2008

National foreword
This British Standard is the UK implementation of EN 1264-2:2008+A1:2012.
It supersedes BS EN 1264-2:2008, which is withdrawn.

National foreword

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in the text by tags. Tags indicating changes to CEN text carry the number of
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EN 1264-2:2008.
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.
supersedes
EN 1264-2:1998 which is withdrawn.

The UK participation in its preparation was entrusted to Technical
Committee RHE/6, Air or space heaters or coolers without combustion.
A list of organizations represented on this committee can be obtained on
request to its secretary.
This publication does not purport to include all the necessary provisions
of a contract. Users are responsible for its correct application.
Compliance with a British Standard cannot confer immunity
from legal obligations.

This British Standard was
published under the authority
of the Standards Policy and
Strategy Committee on
31This
MayBritish
2009. Standard
was published under the
authority of the Standards
and Strategy
©Policy
The British
Standards
Committee
on 31 May
Institution
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Published
by BSI Standards
2009.
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© BSI 2009

ISBN 978 0 580 77212 2
ISBN 978 0 580 57997 4

Amendments/corrigenda issued
issued since
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Amendments/corrigenda
Date
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Date
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28 February 2013
Implementation of CEN amendment A1:2012


EUROPEAN STANDARD

EN 1264-2:2008+A1

NORME EUROPÉENNE
EUROPÄISCHE NORM

November 2012

ICS 91.140.10

Supersedes EN 1264-2:2008

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 rafrchissantes
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

Raumflächenintegrierte Heiz- und Kühlsysteme mit
Wasserdurchströmung - Teil 2: Fußbodenheizung:
Prüfverfahren für die Bestimmung der Wärmeleistung unter
Benutzung von Berechnungsmethoden und
experimentellen Methoden

This European Standard was approved by CEN on 13 September 2008 and includes Amendment 1 approved by CEN on 1 October 2012.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, 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

Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2012 CEN

All rights of exploitation in any form and by any means reserved
worldwide for CEN national Members.

Ref. No. EN 1264-2:2008+A1:2012: E


BS EN 1264-2:2008+A1:2012
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)
EN

Contents

Page

Foreword............................................................................................................................................................3
Introduction .......................................................................................................................................................4
1

Scope ....................................................................................................................................................5

2

Normative references ..........................................................................................................................5

3

Definitions and symbols .....................................................................................................................5

4

Thermal boundary conditions ............................................................................................................5

5

Documents for testing .........................................................................................................................6

6
6.1
6.2
6.3
6.4
6.5
6.6
6.7

Calculation of the specific thermal output (characteristic curves and limit curves) ....................7
General approach (see [2], [4]) ...........................................................................................................7
Systems with pipes installed inside the screed (type A and type C) .............................................8
Systems with pipes installed below the screed or timber floor (type B) .......................................9
Systems with surface elements (plane section systems, type D) ............................................... 11
Limits of the specific thermal output .............................................................................................. 11
Influence of pipe material, pipe wall thickness and pipe sheathing on the specific
thermal output ................................................................................................................................... 13
Heat conductivity of screed with inserts ........................................................................................ 14

7

Heat conductivity of the materials .................................................................................................. 14

8

Downward heat loss ......................................................................................................................... 14

9

Test procedure for the determination of the thermal output of systems that cannot be
calculated in accordance with Clause 6 ......................................................................................... 15

10

Test procedure for the determination of the effective thermal resistance of carpets ............... 18 

11

Prove report....................................................................................................................................... 19

12
12.1
12.2
12.3
12.4

Prove system..................................................................................................................................... 20
General ............................................................................................................................................... 20
Master samples ................................................................................................................................. 20
Verification of test equipments ....................................................................................................... 21
Determination of the values sm and φM,s (qN,M,s, qG,M,s(Rλ;B=0,15), Rλ,B,M,s) of primary master
samples.............................................................................................................................................. 21
Verification of software .................................................................................................................... 21

12.5

Annex A (normative) Figures and tables ..................................................................................................... 23
Annex B (informative) Test procedure for the determination of parameters for application in
EN 15377-1:2008 Annex C ................................................................................................................ 40
Annex C (informative) !Influence of the heat exchange coefficient inside the pipe on the
specific thermal output"
" ............................................................................................................... 43
Bibliography ................................................................................................................................................... 44

2


BS EN 1264-2:2008+A1:2012
EN
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

Foreword
This document (EN 1264-2:2008+A1:2012) 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 May 2013, and conflicting national standards shall be withdrawn at
the latest by May 2013.
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 includes Amendment 1 approved by CEN on 1 October 2012.
This document !supersedes EN 1264-2:2008".
The start and finish of text introduced or altered by amendment is indicated in the text by tags ! ".

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: Prove methods for the determination of the thermal output using calculation and
test methods;



Part 3: Dimensioning;



Part 4: Installation;



Part 5: Heating and cooling surfaces embedded in floors, ceilings and walls — Determination of the
thermal output.

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, 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.

3


BS EN 1264-2:2008+A1:2012
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)
EN

Introduction
This European Standard is based on the realisation 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 prove methods for the determination
of the thermal output of floor heating systems specified in Part 2 of this European Standard. In analogy to the
European Standard EN 442-2 (Radiators and convectors — Part 2: Test methods and rating), these prove
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.

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EN
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

1

Scope

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.

2

Normative references

!The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,

the latest edition of the referenced document (including any amendments) applies.
EN 1264-1:2011, Water based surface embedded heating and cooling systems  Part 1: Definitions and
symbols
EN 1264-3:2009, Water based surface embedded heating and cooling systems  Part 3: Dimensioning"

3

Definitions and symbols

For the purposes of this document, the terms and definitions given in !EN 1264-1:2011" apply.

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 ϑi). It is, 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 contrast, every floor heating system has its own maximum permissible specific thermal output, the limit
specific thermal output, qG. This output is calculated for an ambient (standard) indoor room temperature

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BS EN 1264-2:2008+A1:2012
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

EN

ϑi = 20 °C. The other condition is the maximum surface temperature ϑF, max = 29 °C1) at 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 ϑF, max = 35 °C2) and σ = 0 K.
For the calculation and for the test procedure, the centre of the heating surface is used as the reference point
for ϑF, max, regardless of system type.
The average surface temperature ϑF, m, determining the specific thermal output (see basic characteristic
curve) is linked with the maximum surface temperature. In this context, ϑF, m < ϑF, max always applies.
The achievable value ϑF, m depends on both the floor heating system and the operating conditions
(temperature drop σ = ϑV – ϑR, downward thermal output qu and heat resistance of the floor covering Rλ, B).
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 ∆ϑH [3] (see Equation (1)).



Turbulent pipe flow: mH/di > 4 000 kg/(h ⋅ m).



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

5

The aforementioned last condition does not concern the test procedure of Clause 9.

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.

1)

National regulations may limit this temperature to a lower value.

2)

Some floor covering materials may require lower temperatures.

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BS EN 1264-2:2008+A1:2012
EN
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

6 Calculation of the specific thermal output (characteristic curves and limit
curves)
6.1

General approach (see [2], [4])

The specific thermal output q at the surface of a floor is determined by the following parameters:


Pipe spacing T;



Thickness su and heat conductivity λE of the layer above the pipe;



Heat conduction resistance Rλ, B of the floor covering;



Pipe external diameter D = da, including the sheathing (D = dM) if necessary and the heat conductivity of
the pipe λR or the sheathing λM. In case of pipes having non-circular cross sections, 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 = da shall be used;



Heat diffusion devices having the characteristic value KWL in accordance with 6.3;



Contact between the pipes and the heat diffusion devices or the screed, characterised by the factor aK.

The specific thermal output is proportional to (∆ϑH)n, where the temperature difference between the heating
medium and the room temperature is:
∆ϑH =

ϑV − ϑR
ϑ − ϑi
ln V

ϑ R − ϑi

(1)

and where experimental and theoretical investigations of the exponent n have shown that:
1,0 < n < 1,05

(2)

Within the limits of the achievable accuracy,
n=1

is used.
The specific thermal output is calculated using Equation (3).
m

q = B ⋅ Π( a i i ) ⋅ ∆ϑH
i

(3)

where
is a system-dependent coefficient, in W/(m2 ⋅ K);

B
m

Π( a i i )
i

is a power product linking the parameters of the floor construction with one another (see 6.2,
6.3 and 6.4).

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BS EN 1264-2:2008+A1:2012
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)
EN

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,
Equation (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
Equation (4a).
m

m

q = B ⋅ aB ⋅ a T T ⋅ a umu ⋅ a D D ⋅ ∆ϑH

(4a)

The power product given before the temperature difference ∆ϑH is called the equivalent heat transmission
coefficient KH, which leads to the following abbreviated form of the expression:
q = KH ⋅ ∆ϑH

(4b)

where
B

= B0 = 6,7 W/(m2 ⋅ K) for a pipe heat conductivity λR = λR, 0 = 0,35 W/(m2 ⋅ K) and a pipe wall
thickness sR = sR, 0 = (da – di)/2 = 0,002 m.

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 with reduced moisture addition, λE = 1,2 W/(m2 ⋅ K) shall be used. This value is also
applicable to heating screeds. If a different value is used, its validity shall be checked.
aB is the floor covering factor in accordance with the following equation:

1
aB =

α
1

α

+

+

s u, 0

λ u, 0

s u, 0

λE

+ R λ, B

where

8

α

= 10,8 W/(m2 ⋅ K);

λu, 0

= 1 W/(m ⋅ K);

su, 0

= 0,045 m;

Rλ, B

is the heat conduction resistance of the floor covering, in m2 ⋅ K/W;

λE

is the heat conductivity of the screed, in W/(m ⋅ K);

aT

is a spacing factor in accordance with Table A.1; aT = f (Rλ, B);

au

is a covering factor in accordance with Table A.2; au = f (T, Rλ, B);

(5)


BS EN 1264-2:2008+A1:2012
EN
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

aD

is the pipe external diameter factor in accordance with Table A.3; aD = f (T, Rλ, B).

mT = 1 −

T

0,075

applies where 0,050 m ≤ T ≤ 0,375 m

(6)

mu = 100(0,045 – su)

applies where su ≥ 0,010 m

(7)

mD = 250(D – 0,020)

applies where 0,008 m ≤ D ≤ 0,030 m

(8)

In Equations (6), (7) and (8)
T

is the pipe spacing;

D

is the external diameter of the pipe, including sheathing, where applicable;

su

is the thickness of the screed covering above the pipe.

For a pipe spacing T > 0,375 m, the specific thermal output is approximately calculated using
q = q 0,375

0,375
T

(9)

where
q0,375

is the specific thermal output, calculated for a spacing T = 0,375 m.

For coverings above the pipe su ≤ 0,065 m as well as for coverings above the pipe 0,065 m < su ≤ s u* (for s u*
see below), Equation (4a) applies directly. The value of s u* depends on the pipe spacing as follows:
For a spacing T ≤ 0,200 m, s u* = 0,100 m applies.
For a spacing T > 0,200, s u* = 0,5 T applies. In this relation, always the actual spacing T shall be used, even
if the calculation is done in accordance with Equation (9).
For coverings above the pipe su > s u* , Equation (4b) shall be used. In this case, the equivalent heat
transmission coefficient shall be determined in accordance with the following equation:
1

KH =

1
K

H, su = su*

In Equation (10), K
pipe.

s − s u*
+ u

(10)

λE

H, su = su*

is the power product from Equation (4a), calculated for a covering s u* above the

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 su of the weight bearing layer and its variable heat
conductivity λE are covered by the factor au. The pipe diameter has no effect. However, the contact between

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EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

EN

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 as follows:
m

q = B ⋅ aB ⋅ a T T ⋅ au ⋅ aWL ⋅ aK ⋅ ∆ϑH

(11)

where
B

= B0 = 6,5 W/(m2 ⋅ K) under the conditions given for Equations (4a) and (4b);

aT

is the pipe spacing factor in accordance with Table A.6; aT = f (su/λE);

mT see Equation (6);
au

is the covering factor, which is calculated in accordance with the following equation:

1
au =

+

α

1

α

s u, 0

λ u, 0

+

su

(12)

λE

where

α

= 10,8 W/(m2 ⋅ K);

λu, 0

= 1 W/(m ⋅ K);

su, 0

= 0,045 m;

aWL

is the heat conduction factor (see Tables A.8); aWL = f (KWL, T, D).

The following applies to the characteristic value KWL:
K WL =

s WL ⋅ λ WL + bu ⋅ s u ⋅ λ E
0,125

(13)

where
bu

= f (T) shall be taken from Table A.7;

sWL ⋅ λWL

is the product of the thickness and the heat conductivity of the heat diffusion device;

su ⋅ λE

is the product of the thickness and the heat conductivity of the screed or timber covering.

If the width L of the heat diffusion device is smaller than the pipe spacing T, the value aWL, L = T determined in
accordance with Tables A.8, shall be corrected as follows:
aWL = aWL, L = T – (aWL, L = T – aWL, L = 0)[1 – 3,2(L/T) + 3,4 (L/T)2 – 1,2(L/T)3]

(14)

The heat conduction factors aWL, L = T and aWL, L = 0 shall be taken from Tables A.8a to A.8f. For L = T, the
tables with KWL in accordance with Equation (13) apply directly, for L = 0, the tables apply with KWL
determined in accordance with Equation (13) with sWL = 0.

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BS EN 1264-2:2008+A1:2012
EN
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

aK is the correction factor for the contact in accordance with Table A.9; aK = f (T).
The correction factor for the contact aK covers additional heat transmission resistances due to cases 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 aK.
aB is the floor covering factor:
aB =

1
1+ B ⋅ au ⋅ a

mT
T

with f (T) = 1 + 0,44

⋅ a WL ⋅ a K ⋅ R λ, B ⋅ f (T )

(15)

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), the following equation applies:
m

q = B ⋅ aB ⋅ a T T ⋅ au ⋅ ∆ϑH

(16)

where
= B0 = 6,5 W/(m2 ⋅ K) and

B
m

aT T

= 1,06;

au

is the covering factor in accordance with Equation (12);

aB

is the floor covering factor:

aB =

6.5

1
m

1 + B ⋅ a u ⋅ a T T ⋅ Rλ, B

(17)

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 the following expression in form of a product:
 ∆θ 

q G = ϕ ⋅ BG ⋅  H 
 ϕ 

nG

(18)

where

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EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)
EN

BG is a coefficient in accordance with Table A.4a (applicable to su/λE ≤ 0,079 2) and Table A.4b
(applicable to su/λE > 0,079 2) for type A and type C systems or in accordance with Table A.10 for
type B systems; or BG = 100 W/(m2 ⋅ K) for systems with surface elements;

nG is an exponent in accordance with Table A.5a (applicable to su/λE ≤ 0,079 2) and Table A.5b
(applicable to su/λE > 0,079 2) for type A and type C systems or in accordance with Table A.11 for
type B systems; or nG = 0 for systems with surface elements;

ϕ

is a factor for the conversion to any values of the temperatures ϑF, max and ϑi.
1,1

 ϑ F, max − ϑ i 
ϕ= 
 with ∆ϑ0 = 9 K
 ∆ϑ o


(19)

The limit temperature difference between the heating medium and the room ∆ϑH, G is calculated as follows
from the intersection of the characteristic curve with the limit curve (see Figure A.5):

∆ϑ H, G


 BG
=ϕ⋅
mi
 B ⋅ Π ai
i


1

 1− nG





(20)

For type A and type C systems, the above mentioned Equations (18) and (20) apply directly to pipe
spacing T ≤ 0,375 m. In case of spacing T > 0,375 m, for these systems the following conversion shall be
made:
q G = q G; 0,375

0,375
⋅ fG
T

(21)

∆ϑ H, G = ∆ϑ H, G; 0,375 ⋅ f G

(22)

where
qG; 0,375

is the limit specific thermal output, calculated for a spacing T = 0,375 m;

ϑH, G; 0,375

is the limit temperature difference between the heating medium and the room,
calculated for a spacing T = 0,375 m.

The factor fG shall be determined as follows, depending on the ratio su/T:
For su/T ≤ 0,173, fG = 1 applies.
For su/T > 0,173, the following equation applies:

fG =

where

12

2
0,375
) ⋅ e −20 ⋅ ( su / T −0,173 )
T
0,375
⋅
T

q G, max − ( q G, max − q G; 0,375 ⋅
q G; 0,375

(23)


BS EN 1264-2:2008+A1:2012
EN
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

qG, max

is the maximum permissible specific thermal output in accordance with Table A.12,

calculated for an isothermal surface temperature distribution using the basic characteristic
curve (Figure A.1), with (ϑF, m – ϑi) = (ϑF, max – ϑi).

For type B systems, Equations (18) and (20) apply directly, when the pipe spacing T and the width of the
heat diffusion device L are the same. For L < T, the value of the specific thermal output qG, L = T, calculated in
accordance with Equation (18), shall be corrected using the following equation:
qG =

a WL

a WL, L = T

⋅ q G, L = T

(24)

where
aWL, L = T

is the heat conduction factor in accordance with Table A.8;

aWL

is the heat conduction factor, calculated in accordance with Equation (14).

The limit temperature difference between the heating medium and the room ∆ϑH, G remains unchanged as
with L = T.
For ∆ϑF, max – ∆ϑi = 9 K, ϕ = 1 and Rλ, B = 0, the limit specific thermal output qG is designated as standard
specific thermal output qN, and the associated limit temperature difference between the heating medium and
the room ∆ϑH, G is designated as standard temperature difference between the heating medium and the

room ∆ϑN (see Figure A.5). These values serve as characteristic values in the system comparison.
The maximum possible value of the specific thermal output qG, max for an isothermal surface temperature
distribution is represented by the ordinate value for ϑF, m = ϑF, max on the basic characteristic curve (see
Figure A.1).
Table A.12 gives values for qG, max, depending on the maximum floor surface temperature ϑF, max and the
standard indoor room temperature ϑi.
If (due to calculation and interpolation inaccuracies as well as linearization) higher values for qG than qG, max
are calculated using Equations (18), (21), (24), qG, max has to be used.

6.6 Influence of pipe material, pipe wall thickness and pipe sheathing on the specific
thermal output
The factors B0 are specified in Equations (4a) and (11) for a pipe heat conductivity λR, 0 = 0,35 W/(m ⋅ K), a
wall thickness sR, 0 = 0,002 m. For other materials (see Table A.13) with a heat conductivity of the pipe
material λR or other wall thicknesses sR, the factor B shall be calculated using:

( )

1
1 1,1
i
=
+ ⋅ Π am
⋅T⋅
i
B B0
π i

(25)

 1


da
da
1
−
ln
ln


 2λ R d a − 2s R 2λ R , 0 d a − 2s R, 0 
If the pipe has an additional sheathing with an external diameter dM, an internal diameter da and a heat
conductivity of the sheathing λM, the following equation applies:

13


BS EN 1264-2:2008+A1:2012
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)
EN

( )

1
1 1,1
=
+ ⋅ Π a mi i ⋅ T ⋅
B B0
π i

(26)

 1

da
d
dM
1
1
−
ln M +
ln
ln


da
2λ R d a − 2s R 2λ R, 0 d M − 2s R, 0 
 2λ M
Any oxygen diffusion barrier layers with thicknesses ≤ 0,3 mm need not be considered. In this case,
Equation (25) shall be used.
In cases with air gaps within the sheathing, Equation (26) only applies if a valid average value λM including
the air gaps is available.

6.7

Heat conductivity of screed with inserts

Where system plates for type A systems are used, the heat conduction in the screed is changed by inserts
(such as attachment studs or similar components). If their volume fraction in the screed amounts to

15 % ≥ ψ ≥ 5 %, an effective heat conductivity λ E′ of the component is to be expected.

λ E′ = (1 – ψ) ⋅ λE + ψ ⋅ λW

(27)

where

λE is the heat conductivity of the screed;
λW is the heat conductivity of the attachment studs;
ψ

7

is the volume fraction of the attachment studs in the screed.

Heat conductivity of the materials

For carrying out the calculation, the heat conductivities specified in Table A.13 are used. If the materials
listed in Table A.13 are used, the values of this table shall be taken. For other materials, the heat
conductivities shall be taken from effectual European Standards if available or shall be verified by a
certificate prepared by an approved testing body.

8

Downward heat loss

The downward specific heat loss of floor heating systems towards rooms under the system is calculated in
accordance with the following equation !(see Figure A.5 of EN 1264-3:2009)":
qU =

1
⋅ (R O ⋅ q + ϑ i − ϑ U )
RU

where

14

qU

downward specific heat loss

q

specific thermal output of the floor heating system

RU

downwards partial heat transmission resistance of the floor structure

RO

upwards partial heat transmission resistance of the floor structure

ϑi

standard indoor room temperature of the floor heated room

ϑU

indoor room temperature of a room under the floor heated room

(28)


BS EN 1264-2:2008+A1:2012
EN
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

With respect to !Figure A.5 of EN 1264-3:2009" the following applies:
RO =

s
1
+ R λ,B + U
α
λU

(29)

where
2

1/α = 0,092 6 m ·K/W
RU = Rλ,ins + Rλ,ceiling + Rλ,plaster + Rα,ceiling

(30)

where
2

Rα,ceiling = 0,17 m ·K/W
In the special case of ϑi = ϑU the simple equation
qU = q ⋅

RO
RU

(31)

applies.
For a more detailed calculation of the downward heat loss, see Part 3 of this European Standard.

9 Test procedure for the determination of the thermal output of systems that
cannot be calculated in accordance with Clause 6
For constructions which do not correspond to the basic construction of the types A, B, C or D, or in case of
dimensions or material data outside the scope of the calculation method, the specific thermal output shall be
determined by testing (experimentally) as follows.
A test sample consisting of at least three heating pipes, with the pipe spacing to be tested, in accordance
with the system design of the floor heating to be investigated is positioned in the testing equipment according
to Figure A.6 [4]. The size of the test sample shall be approximate 1 m × 1 m on appointment with the test
laboratory and shall cover preferably three-pipe spacing. In Figure A.6 the cooling plates simulate the room
above the floor heating system (see key 1), i.e. the temperature of the heated room ϑi, and the room below
(see key 4). For the cooling plates the construction according to Figure A.7 is recommended consisting of
panel radiators with flat tubes in which disconnecting points realize the appropriate cooling water flow. The
heat transfer resistance 1/α at the floor surface is simulated by the heat transfer layer (see key 2).The two
lateral heating pipes serve as a protection field to enable the optimum undisturbed temperature field around

the central pipe. The heat transfer resistance 1/α at the floor surface, given by the basic characteristic curve,
is replaced by the heat conduction resistance s/λ of the heat transfer layer (see key 2) of equal magnitude
(mean value):
1/α = s/λ = 0,092 6 m2 ⋅ K/W

(32)

The tolerance on the value s/λ is ± 0,01 m2 ⋅ K/W.
The temperature drop of the sample ϑV –ϑR (see Figure A.8) shall not exceed 0,5 K. The temperature rise of
the water flow in the cooling plates ϑC,out – ϑC,in (see Figure A.7) shall not exceed 0,3 K.

ϑV is the heat water supply temperature of the sample
ϑR

is the heat water return temperature of the sample

15


BS EN 1264-2:2008+A1:2012
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)
EN

ϑC,out is the outlet cooling water temperature of the cooling plates
ϑC,in is the inlet cooling water temperature of the cooling plates
Temperatures shall be measured with a permissible uncertainty of ± 0,1 K.
The temperature field of the floor surface is measured in order to determine the values ϑF, m andϑF, max. The
measurement shall be carried out in the undisturbed area around the central pipe or central pipes and, at

least, over the width of one pipe spacing. If possible, it is recommended using two pipe spacing. The
configuration of the measuring points using two pipe spacing should be done in principle as shown in Figure
A.8. For an example, with the measuring values ϑF, i (see Figure A.8) the calculation procedure is as follows:
ϑF,m = (

8

∑

ϑF,i +

2

ϑF,max =

17

∑ϑ
11

F,i

+

ϑF,1 + ϑF,9 + ϑF,10 + ϑF,18
2

) / 16

ϑF,5 + ϑF,14

2

where
ϑ F,i are the local floor surface temperatures (measuring points)
ϑ F,m is the average floor surface temperature
ϑ F,max is the maximum floor surface temperature
In the case of not feasible values of the measured temperature field caused by inhomogeneity of the screed,
another part of the surface shall be taken.
Because of the fact that the temperature drop of the sample ϑV –ϑR is very little and the fact that the
temperature measurements shall be carried out in the undisturbed area around the central pipe no variation is necessary
depending on the laying system (spirally or meandering).

NOTE 1

NOTE 2
The explanations above refer to the most usual case that the floor heating system is characterized by the
repetition of the pipe spacing. The test sample in Figure A.6 which is symmetrical with respect to the central pipe is
based on this fact. If another dimension characterizes the system the procedure has to be adjusted.

In a first working step the test is realized for Rλ,B = 0.
The average floor surface temperature ϑF, m is determining the specific thermal output, and the maximum
floor surface temperature ϑF, max is limiting the thermal output. The measurement is carried out when steady
state conditions are reached and a temperature of both cooling plates of ϑi = 20 °C ± 0,5 K is maintained.
Under these conditions the average temperature of the heating medium ϑH is set to achieve a maximum
floor surface temperature of ϑF, max = 29 °C (i.e. ϑF, max – ϑi = 9 K), and in this case the difference between
the average temperature of the heating medium and the temperature of the cooling plates ϑH - ϑi = ∆ϑH =
∆ϑN (standard value) applies.
If it is not possible to set the value of the temperature difference (ϑF, max – ϑi) exactly to 9 K, a value slightly
below and a value slightly above 9 K shall be set and the results used to formulate a mean value.

16


BS EN 1264-2:2008+A1:2012
EN
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

Given that (ϑF, max – ϑi) = 9 K is maintained and the average temperature difference of the floor surface and
the room (ϑF, m – ϑi) is determined, this temperature difference is used within the basic characteristic curve
(Figure A.1) and gives the standard specific thermal output:

qN = 8,92 ⋅ (ϑF, m – ϑ i) 1N,1

(33)

The standard specific thermal output qN, together with the above determined corresponding value of the
standard temperature difference ∆ϑ N, gives the equation for the characteristic curve for Rλ, B = 0:
qN = KH, N ⋅ ∆ϑ N

with the following gradient of the characteristic curve (the equivalent heat transmission coefficient):

K H, N =

qN

∆ϑ

(34)

N

′ applies
If for a given resistance of the covering R λ′ , B , the gradient of the characteristic curve K H
′ see below Equation (36)), for any resistance of the floor covering Rλ, B > 0, the
(determination of K H
associated gradient of the characteristic curve KH(Rλ, B) can be determined in accordance with the following
equation:

K H = K H ( R λ, B ) =

K H, N
R λ, B K H, N
1+
(
− 1)
′ B KH
′
R λ,

(35)

Using Equation (35), the gradients of the characteristic curves KH(Rλ, B) can be calculated for thermal
resistances Rλ, B = 0,05 m2 ⋅ K/W, 0,10 m2 ⋅ K/W and 0,15 m2 ⋅ K/W.
′ to be used in Equation (35), another
In order to establish the gradient of the characteristic curve K H
measurement like the one described above for Rλ, B = 0, has to be carried out, but with a resistance of the
floor covering Rλ′ , B = 0,15 m2 ⋅ K/W ± 0,01 m2 ⋅ K/W. By doing this measurement, the limit specific thermal
′ G are determined, which give the needed value K H

′ and the limit temperature difference ∆ ϑ H,
′ :
output q G
′ = KH
′ ( R λ,
′ B) =
KH

′
qG
′ G
∆ϑ H,

(36)

In accordance with the following Equation (37), the limit temperature differences ∆ϑH, G for the heat
conduction resistances Rλ, B > 0 are given by the interfaces of the characteristic curves and the limit curve
resulting from the measurement data and the gradient KH of the characteristic curve calculated from
Equation (35):

∆ϑH, G = ϕ ⋅

′ ⋅ ∆ϑ N − q N ∆ϑ H
′ ,G
qG
′ ,G ) − q N + q G
′
K H ⋅ ( ∆ϑ N − ∆ϑ H

(37)

For systems having several spacing, the maximum and the minimum spacing as well as sufficient
intermediate spacing to achieve a spacing ratio not exceeding 1:2, shall be tested in accordance with the
method described. Values for spacing not tested this way, shall be determined by interpolation using suitable
polynomials. The results shall be presented in a prove report as specified in Clause 11.

17


BS EN 1264-2:2008+A1:2012
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)
EN

10 Test procedure for the determination of the effective thermal resistance of
carpets
If carpets are used for floor covering a special problem occurs. Because of the surface structure of carpets
their thermal resistance Rλ,B cannot be determined by the two plate method as generally used for other
materials. This circumstance is primary due to the pressure which takes effect on a carpet sample if using
this method. Further a possible change of the heat exchange coefficient due to the surface structure has to
be considered. For these reasons the effective (see below) thermal resistance Rλ,B of carpets shall be
determined by a one plate method as described in this chapter.
The equipment for testing is shown in Figures A.9, A.10 and A.11. The dimensions should be at least
1m x 1m. The equipment is situated in the centre of the floor of a test booth in accordance with EN 14037-2
(Figure A.9), i.e. in a room with constant controlled ambient room temperatures. Between the test equipment
and the floor of the booth insulation is recommended (key 3). The essential parts of the equipment are a
heating plate (key 2) in accordance with the cooling plate in Figure A.7, a heat flow meter plate (key 1) with a
well-known thermal conduction resistance RHFM, temperature measuring sensors on the surfaces and a
globe thermometer Gl according to EN 14037-2.

NOTE
Between the heat flow meter plate (key 1) and the heating plate (key 2) an elastic layer shall be interposed,
for instance consisting of PE lather of about 2 mm thickness.

The meaning of the used symbols is as follows:
q

specific thermal output

ϑGl

ambient reference temperature measured with globe thermometer

ϑH

average heating medium temperature

ϑHFM,a

temperature of the surface on top of the heat flow meter plate

ϑHFM,b

temperature of the surface at the bottom of the heat flow meter plate

Rα

heat exchange resistance on the heating surface

RHFM

thermal conduction resistance of the heat flow meter plate

Rλ,B

effective thermal resistance of carpet covering

subscripts

1: means test 1 (example: ϑGl,1 is the valid value of ϑGl of test 1)
2: means test 2 (example: ϑGl,2 is the valid value of ϑGl of test 2)

For the thermal conduction resistance of the heat flow meter plate the following specification is valid:
The material of the plate is plexiglass with the thickness of 10 mm. Its thermal conduction resistance
depends on the temperature t as follows:
2

RHFM = - 0,000188 ⋅ t + 0,0578 m ·K/W

with t = (ϑHFM,a + ϑHFM,b)/2

Temperatures shall be measured with a permissible uncertainty of ± 0,1 K. Temperature differences shall be
measured with a permissible uncertainty of ± 0,05 K.
The temperature drop of the heating medium shall not exceed 0,5 K if possible.
Two test procedures are necessary. The globe thermometer in both cases is situated 0,75 m above the
centre of the heating surface, i.e. in test 2 higher above the floor of the test booth by the thickness of the
carpet.
Test 1

Test 1 aims to the determination of the heat exchange resistance Rα. In this test the heating surface is the

upper surface of the heat flow meter plate and no carpet exists, see Figure A.10.

18


BS EN 1264-2:2008+A1:2012
EN
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)
2

Remark: The value Rα coming from the basic characteristic curve (0,0926 (m K/W)) is not used because the
measured temperature ϑGl in this test doesn't exactly apply to the respective procedure used for the basic
characteristic curve [1].
With the measured temperatures ϑHFM,a,1, ϑHFM,b,1 the specific thermal output comes from the heat flow meter
plate using the following equation:

q=

(ϑHFM,b,1 − ϑHFM,a,1 )

(38)

R HFM

During the test the ambient reference temperature is maintained on ϑGl,1 = 20 °C ± 0,5 K by appropriate
cooling of the test booth and the average heating medium temperature ϑH,1 is set to achieve with Equation
2
(38) a value q = 80 ± 2,0 W/m .

With this result and the measured corresponding temperatures ϑHFM,a,1, ϑGl,1 the heat exchange resistance Rα
can be calculated according to:
Rα =

(ϑHFM,a,1 − ϑ Gl,1 )

(39)

q

Test 2

Test 2 aims to the determination of the effective thermal resistance of carpet covering Rλ,B using the result Rα
of test 1. In this test the respective carpet lies on the upper surface of the heat flow meter plate, see
Figure A. 11.
Corresponding to test 1 ϑGl,2 is maintained on 20 °C ± 0,5 K. With the measured temperatures ϑHFM,a,2,
ϑHFM,b,2 the specific thermal output is given by the following equation:
q=

(ϑHFM,b,2 − ϑHFM,a,2 )

(40)

R HFM

The average heating medium temperature ϑH,2 is set to achieve with Equation (40) again a value
2
q = 80 ± 2,0 W/m With this value, the measured temperatures ϑHFM,a,2, ϑGl,2 and the value Rα of test 1 the
effective thermal resistance of the carpet covering can be calculated as follows:
R λ,B =

(ϑHFM,a,2 − ϑ Gl,2 )
q

− Rα

(41)

Following from the described procedure, i.e. the determination of Rα without carpet, the gained value Rλ,B of
Equation (41) includes not only the thermal conduction resistance but also (should the occasion arise) the
above mentioned effect of a changed heat exchange coefficient. This attribute is necessary for using this
value for the determination of the thermal output according to the calculation method (Clause 6) and to the
test procedure (Clause 9). For that reason the supplement "effective" is used.
For carpets used in practice as floor covering for floor heating systems only values Rλ,B determined by the
test method described above are valid to determinate the thermal output in accordance with this standard.
This means that the effective thermal resistance Rλ,B of the respective carpet must be available.

11 Prove report
For a given construction the results shall be documented for each scheduled pipe spacing T and each
scheduled thickness sU above the pipe. The testing body presents this valid results in a prove report. The

19


BS EN 1264-2:2008+A1:2012
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)
EN

results are documented in a field of characteristic curves with linear coordinates, using the following
equation:

q = f (∆ϑH, Rλ, B)
The characteristic curves are drawn for values of the thermal resistance Rλ, B = 0, Rλ, B = 0,05,
2
2
Rλ, B = 0,10 and Rλ, B = 0,15 ·m K/W. Values of Rλ, B > 0,15 m ·K/W are not in accordance with this
standard.
Into this field of characteristic curves, also the limit curves in accordance with Equation (18) are entered.
These characteristic curves give for Rλ, B = 0 the standard specific thermal output qN and the associated

standard temperature difference ∆ϑN in accordance with 6.5. Further shall be documented the values of the
limit specific output qG and the associated limit temperature difference ∆ϑH,G depending on the remaining
above mentioned values Rλ, B in accordance with 6.5.

The proved system shall be identified by a technical description in accordance with Clause 5. These
documents shall contain all dimensions and materials which influence the thermal properties. The results are
valid for that system defined in such a way. If any change is made by the supplier of the system which affects
the principles of the thermal proving, a new proving shall be carried out.

12 Prove system
12.1 General
The prove system consists of the following components:
•

Approved test laboratory which is accredited according to EN ISO/IEC 17025. The laboratory takes part
at all inter-comparison tests among the approved laboratories. The laboratory shall fulfil the requirements
of this standard.

•

Computer system including the software to calculate the specific thermal output (field of characteristic
curves and limit curves) according to Clause 6 of this standard.

•

Test equipment for the test procedure according to Clause 9 of this standard.

•

Test equipment for the test procedure according to Clause 10 of this standard.

•

Master sample, primary and secondary one.

•

Constructional conformity: The participating laboratory shall state the conformity of its test equipments to
this European Standard.

•

Software conformity: The participating laboratory shall state the conformity of its software to this
European Standard.

12.2 Master samples
The construction and the materials of the master samples used for the test equipment of Clause 9 are shown
in Figure A.12. The primary and the secondary master sample are of the same construction and materials.

The laboratory shall equip itself with master sample 2. Master sample 1 will be circulated among the
laboratories participating at the prove system. The manufacturing process has to ensure that for all samples
the materials are from the same charge and the dimensions correspond correctly. About this a verification is
requested in a complete report and kept available for any further check.

20


BS EN 1264-2:2008+A1:2012
EN
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

For the purposes of the test equipment of Clause 10 a mat with smooth surfaces containing of foamed
rubber ("Moosgummi") shall be chosen in coordination of the participating test laboratories and used as
master sample 1 as described above. The thermal resistance shall be set in the range of Rλ, B = 0,1 to 0,15
2
m ·K/W. About this a verification is requested in a complete report and kept available for any further check.
For the test equipment of Clause 10 a master sample 2 is not necessary, see below.
The purpose of the master samples is as follows:
a)

to verify if the reproducibility of test values among test laboratories is within the limits set by this
European Standard,

b)

to establish a common basis for all test equipments to verify that the repeatability of test values in each
test equipment is within the limits set by this European Standard.

12.3 Verification of test equipments
All test equipments shall be verified for:
Reproducibility precision of the test methods:
The reproducibility shall be proved by the prove laboratory using the primary master sample. The results of
the tests carried out with the test equipment in accordance with close 9 shall be within the tolerance
sm = ± a1 % (determination of a1 see 12.4) of the values qN,M,s and qG,M,s(Rλ;B=0,15). The results of the tests

carried out with the test equipment in accordance with Clause 10 shall be within the tolerance sm = ± a2 %
(determination of a2 see 12.4) of the value Rλ,B,M,s The prove laboratories have to prove the reproducibility in
periodical tests.
Repeatability precision of the test methods:

The repeatability shall be proved by the prove laboratory using its own secondary master sample. The tests
shall be carried out periodically in a distance of 12 months. The results of the tests carried out with the test
equipment in accordance with Clause 9 and with those in accordance with Clause 10 shall be within a
tolerance range s0 = 2 %. For the equipment of Clause 10 only Test 1 of Clause 10 is necessary (this means
a master sample 2 is not needed). At the starting of the test equipments three consecutive measurements
shall be carried out to prove the fulfilment of the above requirements.

12.4 Determination of the values sm and φM,s (qN,M,s, qG,M,s(Rλ;B=0,15), Rλ,B,M,s) of primary
master samples
The φM,s –values of the primary master samples will be determined by a round robin measurement of all
laboratories participating at the prove system. The procedure shall be carried out by a workgroup composed
of members of the participating laboratories with the collaboration of the responsible working group
CEN/TC 130. Each laboratory determines φO,s –values as an average of three consecutive measurements.
All test results shall be within the tolerance range s0 = 2 %. The workgroup of the participating laboratories
determinates in accordance with the working group CEN/TC 130 the values ± a1 % and a2 % for sm. The
values φM,s will be formed by the workgroup as an average from the φO,s –values of the laboratories, whereby
no φO,s –values shall be used, which differ more than ± a1 % or a2 % respectively from the respective average

value of all laboratories.

12.5 Verification of software
For each calculation result shall be documented the valid boundary conditions.
The software shall be verified for reproducibility and repeatability. For this purpose the following systems
shall be calculated and the results documented according to this European Standard:

21


BS EN 1264-2:2008+A1:2012
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)
EN

1

Floor heating system with pipes inside the screed (type A), tacker system

Pipe
Spacing T
Cement screed sU
2

Floor heating system with pipes inside the screed (type A)

Pipe
Spacing T
Cement screed sU

3

PE-X 16 x 2 mm
50/100/300/450 mm
50 mm

Cu 12 x 0,7 mm with PVC sheathing 2 mm with air included
100/200/300 mm
45 mm

Floor heating system with pipes below the screed (type B)

Pipe
PE-X 14 x 2 mm
Spacing T
100/200/300 mm
Ω-Aluminium plate heat diffusion devices 0,6 mm, L = 98 mm
Anhydrite screed sU 30 mm
4

Floor heating system with pipes inside the screed (type A)

Pipe
Spacing T
Concrete sU

PE-X 25x2,5 mm
150/300/450 mm
100 mm

The reproducibility of the calculation results (carried out in accordance to Clause 6) shall be within the
tolerance sm = ± 0,5 % of the values qN,M,s and qG,M,s(Rλ;B=0,15).
The values qN,M,s and qG,M,s(Rλ;B=0,15) are determined in a procedure according to 12.4.
The repeatability shall be proved periodically. No deviations are allowed.

22


BS EN 1264-2:2008+A1:2012
EN
EN1264-2:2008+A1:2012
1264-2:2008+A1:2012(E)
(E)

Annex A
(normative)
Figures and tables

Text in Figure

1

Specific thermal output q (W/m2)

2

Average temperature difference between surface and indoor room temperature (ϑF, m – ϑi) in K

Key

ϑi

Standard indoor room temperature in °C

ϑF, m

Average surface temperature in °C

q

Specific thermal output in W/m2, q = 8,92 (ϑF, m – ϑi)1,1
Figure A.1 — Basic characteristic curve

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