# SIST EN 1264-2:2009+A1:2013

(Main)## 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

## 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

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

Diese Europäische Norm legt die Randbedingungen und die Prüfverfahren für die Bestimmung der Wärme-leistung von Warmwasser Fußbodenheizsystemen in Abhängigkeit von der Differenz zwischen der Heiz-mittel und der Raumtemperatur fest.

Die vorliegende Norm ist auf den kommerziellen Handel und das praktische Ingenieurwesen anzuwenden, sofern geprüfte und zertifizierbare Werte für die Wärmeleistung erforderlich sind.

Diese Europäische Norm gilt für Heiz und Kühlsysteme, die in die Raumumschließungsflächen des zu heizenden oder zu kühlenden Raumes integriert sind. Der vorliegende Teil dieser Europäischen Norm gilt für Warmwasser-Fußbodenheizsysteme. Die Anwendung von Teil 5 dieser Europäischen Norm erfordert die vorherige Anwendung des vorliegenden Teils dieser Europäischen Norm. Teil 5 dieser Europäischen Norm behandelt die Umrechnung der in Teil 2 bestimmten Wärmeleistung der Fußbodenheizsysteme in die Wärme-leistung von Heizflächen in Wänden und Decken sowie in die Kühlleistung von Kühlflächen in Fußböden, Wänden und Decken.

Die Wärmeleistung wird durch ein Berechnungsverfahren (Abschnitt 6) und ein experimentelles Verfahren (Abschnitt 9) geprüft. Das Berechnungsverfahren ist auf Systeme anwendbar, die den Definitionen nach EN 1264 1 (Typ A, Typ B, Typ C, Typ D) entsprechen. Bei Systemen, die diesen Definitionen nicht entspre-chen, ist das experimentelle Verfahren anzuwenden. Das Berechnungsverfahren und das experimentelle Verfahren entsprechen einander und liefern korrelierende, adäquate Prüfergebnisse.

Als Prüfergebnisse werden die spezifische Normwärmeleistung mit der zugehörigen Normdifferenz 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 présente Norme européenne spécifie les conditions limites et les méthodes de démonstration 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 chauffant et la température ambiante.

La présente norme doit être appliquée aux fins de commercialisation et d’ingénierie pratique, si des valeurs éprouvées et certifiées de l’émission thermique doivent être utilisées.

La présente Norme européenne s'applique aux systèmes de surfaces chauffantes et rafraîchissantes intégrées dans le sol, les plafonds et les murs d'une pièce devant être chauffée ou rafraîchie. Cette partie de la présente norme européenne s’applique aux systèmes de chauffage par le sol à circulation d’eau chaude. L’application de la partie 5 de la présente Norme européenne nécessite l’utilisation préalable de la présente partie. La partie 5 de la présente Norme européenne traite de la conversion de l’émission thermique des systèmes de chauffage par le sol déterminée dans la Partie 2 en émission thermique des surfaces chauffantes intégrées dans les plafonds ou en émission thermique des surfaces rafraîchissantes intégrées dans les sols, les murs et les plafonds.

L’émission thermique est démontrée par une méthode de calcul (Article 6) et par une méthode d’essai (Article 9). La méthode de calcul s’applique aux systèmes correspondant aux définitions données dans l’EN 1264 1 (type A, type B, type C et type D). La méthode d’essai doit quant à elle être appliquée à tous les systèmes ne correspondant pas à ces définitions. Ces deux méthodes sont convergentes et fournissent des résultats de démonstration concordants.

Les résultats de la démonstration, exprimés en fonction d’autres paramètres, constituent l’émission surfacique normalisée et la différence de température associée entre le fluide chauffant et la pièce, ainsi que les familles des courbes caractéristiques qui montrent la relation existant entre l’émission surfacique et la différence de température entre le fluide chauffant et la pièce.

## Ploskovni sistemi za gretje in hlajenje z vodo - 2. del: Talno gretje - Preskusne metode za določevanje oddaje toplote talnega gretja z računsko metodo in preskušanjem

Ta evropski standard določa robne pogoje in preskusne metode za določevanje oddaje toplote sistemov talnega gretja s toplo vodo z uporabo funkcije temperaturne razlike med sredstvom ogrevanja in sobno temperaturo. Ta standard se uporablja za komercialno trgovanje in praktični inženiring, če se uporabljajo dokazane in overljive vrednosti oddaje toplote. Ta evropski standard se uporablja za sisteme za gretje in hlajenje, ki so vgrajeni v površine okoli sobe, ki se ogreva in ohlaja. Ta del tega evropskega standarda se uporablja za sisteme talnega gretja s toplo vodo. Uporaba 5. dela tega evropskega standarda zahteva predhodno uporabo tega dela tega evropskega standarda. 5. del tega evropskega standarda obravnava pretvarjanje oddaje toplote sistemov talnega gretja, ki so določeni v 2. delu, v oddajo toplote ploskovnih sistemov za gretje, ki so vgrajeni v zidove in strope, ter v oddajo toplote sistemov za hlajenje, ki so vgrajeni v tla, zidove in strope. Oddajo toplote se dokazuje z računsko metodo (točka 6) in preskušanjem (točka 9). Računska metoda se uporablja za sisteme, ki ustrezajo definicijam v standardu EN 1264-1 (tip A, tip B, tip C, tip D). Za sisteme, ki ne ustrezajo tem definicijam, se uporablja preskusna metoda. Računska in preskusna metoda sta medsebojno skladni ter zagotavljata povezane in ustrezne rezultate preskusa. Rezultati preskusa, izraženi glede na nadaljnje parametre, so standardna specifična oddaja toplote talnega gretja in povezana standardna temperaturna razlika med sredstvom ogrevanja in sobno temperaturo ter tudi polja krivulje delovanja, ki prikazuje razmerje med specifično oddajo toplote talnega gretja in temperaturno razliko med sredstvom ogrevanja in sobo.

### General Information

### RELATIONS

### Standards Content (sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.SUHVNXãDQMHPRaumflächenintegrierte Heiz- und Kühlsysteme mit Wasserdurchströmung - Teil 2: Fußbodenheizung: Prüfverfahren für die Bestimmung der Wärmeleistung unter Benutzung von Berechnungsmethoden und experimentellen MethodenSystèmes 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'essaiWater based surface embedded heating and cooling systems - Part 2: Floor heating: Prove methods for the determination of the thermal output using calculation and test methods91.140.10Sistemi centralnega ogrevanjaCentral heating systemsICS:Ta slovenski standard je istoveten z:EN 1264-2:2008+A1:2012SIST EN 1264-2:2009+A1:2013en,fr,de01-april-2013SIST EN 1264-2:2009+A1:2013SLOVENSKI

STANDARDSIST EN 1264-2:2009+A1:2013

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM

EN 1264-2:2008+A1

November 2012 ICS 91.140.10 Supersedes EN 1264-2:2008English 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 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 STANDARDIZATIONCOMITÉ 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: ESIST EN 1264-2:2009+A1:2013

EN 1264-2:2008+A1:2012 (E) 2 Contents Page Foreword ............................................................................................................................................................3Introduction .......................................................................................................................................................41Scope ....................................................................................................................................................52Normative references ..........................................................................................................................53Definitions and symbols .....................................................................................................................54Thermal boundary conditions ............................................................................................................55Documents for testing .........................................................................................................................66Calculation of the specific thermal output (characteristic curves and limit curves) ....................76.1General approach (see [2], [4]) ...........................................................................................................76.2Systems with pipes installed inside the screed (type A and type C) .............................................86.3Systems with pipes installed below the screed or timber floor (type B) .......................................96.4Systems with surface elements (plane section systems, type D) ............................................... 116.5Limits of the specific thermal output .............................................................................................. 116.6Influence of pipe material, pipe wall thickness and pipe sheathing on the specific thermal output ................................................................................................................................... 136.7Heat conductivity of screed with inserts ........................................................................................ 147Heat conductivity of the materials .................................................................................................. 148Downward heat loss ......................................................................................................................... 149Test procedure for the determination of the thermal output of systems that cannot be calculated in accordance with Clause 6 ......................................................................................... 1510Test procedure for the determination of the effective thermal resistance of carpets ............... 1811Prove report....................................................................................................................................... 1912Prove system..................................................................................................................................... 2012.1General ............................................................................................................................................... 2012.2Master samples ................................................................................................................................. 2012.3Verification of test equipments ....................................................................................................... 2112.4Determination of the values sm and φφφφM,s (qN,M,s, qG,M,s(Rλλλλ;B=0,15), Rλλλλ,B,M,s) of primary master samples .............................................................................................................................................. 2112.5Verification of software .................................................................................................................... 21Annex A (normative)

Figures and tables ..................................................................................................... 23Annex B (informative)

Test procedure for the determination of parameters for application in EN 15377-1:2008 Annex C ................................................................................................................ 40Annex C (informative)

!!!!Influence of the heat exchange coefficient inside the pipe on the specific thermal output"""" ............................................................................................................... 43Bibliography ................................................................................................................................................... 44 SIST EN 1264-2:2009+A1:2013

EN 1264-2:2008+A1:2012 (E) 3 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.

SIST EN 1264-2:2009+A1:2013EN 1264-2:2008+A1:2012 (E) 4 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.

SIST EN 1264-2:2009+A1:2013EN 1264-2:2008+A1:2012 (E) 5 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 SIST EN 1264-2:2009+A1:2013

EN 1264-2:2008+A1:2012 (E) 6 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 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.

1) National regulations may limit this temperature to a lower value. 2) Some floor covering materials may require lower temperatures. SIST EN 1264-2:2009+A1:2013

EN 1264-2:2008+A1:2012 (E) 7 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 = iRiVRVϑϑϑϑϑϑ−−−ln (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). q = B ⋅ )(iimia ⋅ ∆ϑH (3) where B is a system-dependent coefficient, in W/(m2 ⋅ K); )(iimia is a power product linking the parameters of the floor construction with one another (see 6.2, 6.3 and 6.4). SIST EN 1264-2:2009+A1:2013

EN 1264-2:2008+A1:2012 (E) 8 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). q = B ⋅ aB ⋅ TTma ⋅ uuma ⋅ DDma ⋅ ∆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: B,EuuuBRssa+++=λαλα0,0,0,11 (5) where 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); SIST EN 1264-2:2009+A1:2013

EN 1264-2:2008+A1:2012 (E) 9 aD is the pipe external diameter factor in accordance with Table A.3; aD = f (T, Rλ, B). 075,01Tm−=T 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 Tqq375,0375,0= (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 ≤ *us (for *us see below), Equation (4a) applies directly. The value of *us depends on the pipe spacing as follows: For a spacing T ≤ 0,200 m, *us = 0,100 m applies. For a spacing T > 0,200, *us = 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 > *us, Equation (4b) shall be used. In this case, the equivalent heat transmission coefficient shall be determined in accordance with the following equation: EuuHuuλ**11ssKKssH,−+== (10) In Equation (10), *uussH,K=is the power product from Equation (4a), calculated for a covering *us above 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 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 SIST EN 1264-2:2009+A1:2013

EN 1264-2:2008+A1:2012 (E) 10 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: q = B ⋅ aB ⋅ TTma ⋅ 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: Euuuuλαλαssa++=110,0 , (12) 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: 0,125EuuWLWLWLλλ⋅⋅+⋅=sbsK (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. SIST EN 1264-2:2009+A1:2013

EN 1264-2:2008+A1:2012 (E) 11 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: )T(fRaaaaB11am⋅⋅⋅⋅⋅⋅+=B,KWLTuBT (15) 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), the following equation applies: q = B ⋅ aB ⋅ TTma ⋅ au ⋅ ∆ϑH (16) where B = B0 = 6,5 W/(m2 ⋅ K) and TTma

= 1,06; au is the covering factor in accordance with Equation (12); aB is the floor covering factor: B,TuBTRaaBam⋅⋅⋅+=11 (17) 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 the following expression in form of a product: GHGGnBq⋅⋅=ϕθ∆ϕ (18) where SIST EN 1264-2:2009+A1:2013

EN 1264-2:2008+A1:2012 (E) 12 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. ϕ1,1oiϑ∆ϑ−ϑ=maxF,with ∆ϑ0 = 9 K (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):

11GiiGGH,nmiaBB−⋅⋅=ϕϑ∆ (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: GGGfTqq⋅=375,0375,0; (21) GGH,GH,f⋅=375,0;ûûϑϑ (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: TqeTqqqfTs375,0)375,0(375,0)173,0/(20375,02⋅⋅⋅−−=−⋅−G;G;maxG,maxG,Gu (23) where SIST EN 1264-2:2009+A1:2013

EN 1264-2:2008+A1:2012 (E) 13 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: TLG,TLWL,WLG==⋅=qaaq (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: ()⋅⋅Π⋅π+=Ta1,1B1B1mi0ii (25) −λ−−λ00,s2ddln21s2ddln21R,aaRRaaR 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: SIST EN 1264-2:2009+A1:2013

EN 1264-2:2008+A1:2012 (E) 14 ()⋅⋅⋅π+=Ta1,1B1B1m0iii (26) −λ−−λ+λ00s2ddln21s2ddln21ddln21R,MMR,RaaRaMM Any oxyge

**...**

## Questions, Comments and Discussion

## Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.