BS EN 834:2013 Incorporating corrigendum April 2015 BSI Standards Publication Heat cost allocators for the determination of the consumption of room heating radiators — Appliances with electrical energy supply BS EN 834:2013 BRITISH STANDARD National foreword This British Standard is the UK implementation of EN 834:2013, incorporating corrigendum April 2015 It supersedes BS EN 834:1995, which is withdrawn The UK participation in its preparation was entrusted to Technical Committee CPI/30, Measurement of fluid flow in closed conduits A list of organizations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 © The British Standards Institution 2015 Published by BSI Standards Limited 2015 ISBN 978 580 90351 ICS 91.140.10 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 31 August 2013 Amendments/corrigenda issued since publication Date Text affected 30 June 2015 Implementation of CEN corrigendum April 2015: Figure updated BS EN 834:2013 EN 834 EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM August 2013 ICS 91.140.10 Supersedes EN 834:1994 Incorporating corrigendum April 2015 English Version Heat cost allocators for the determination of the consumption of room heating radiators - Appliances with electrical energy supply Répartiteurs de frais de chauffage pour déterminer la consommation des corps de chauffe - Appareils dotés d'une alimentation en énergie électrique Heizkostenverteiler für die Verbrauchserfassung von Raumheizflächen - Geräte mit elektrischer Energieversorgung This European Standard was approved by CEN on 28 December 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 © 2013 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members Ref No EN 834:2013: E BS EN 834:2013 EN 834:2013 (E) Contents Page Foreword Introduction Scope Normative references Terms and definitions Functional principle and measurement methods 11 5.1 5.2 5.3 5.4 General specifications 12 Base condition 12 c-value 13 Rating factors 13 Calendar function 14 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.14 6.16 6.17 6.18 6.19 6.20 Requirements for heat cost allocators 15 Requirements concerning temperature stress 15 Storage temperature 15 Start of counting 15 Idle counting rate 15 Temperature sensors 15 Calculator/central processing unit 16 Auxiliary power supply 16 Overflow of the display 16 Display resolution 16 Functional check 16 Limits of relative display deviation 17 Ageing 17 Electrical, electrostatic and magnetic influences 17 Thermal impact on heat cost allocators operating in accordance with the single-sensor measurement method 17 Thermal impact on heat cost allocators operating in accordance with the two-sensor measurement method 17 Thermal impact on other devices or components 18 Impact on transmission systems 18 Sealing 18 Calendar function 18 Taking into account operating conditions 18 7.1 7.2 7.3 7.4 7.5 Requirements for use and installation 19 Temperature limits 19 Attachment of the sensors 19 Attachment position of the sensors 20 Connecting cable installation 20 Uniformity of heat cost allocators 20 8.1 8.2 8.3 8.4 8.5 Rating requirements 21 Rating factor KQ 21 Rating factor KC 21 Rating factor KT 21 Resulting rating factor K 21 c-value 21 6.15 BS EN 834:2013 EN 834:2013 (E) 9.1 9.2 9.3 Requirements for maintenance and reading 22 Visual reading 22 Close-range reading 22 Remote reading 22 10 10.1 10.2 10.3 10.4 Testing 22 General 22 Test documents 23 Test report 23 Test protocols 23 11 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9 11.10 11.11 11.12 11.13 Test procedures 23 Construction test 23 Sealing test 23 Temperature durability test 23 Test for compliance with the limits of the relative display deviation 24 Ageing resistance test 24 Test of the start of counting at normal operation and also, for heat cost allocators with room temperature sensors, at operation with thermal impact 24 Test of the idle counting rate 25 Test of the counting rate in the case of thermal impact 25 Test for external influences 26 Test of c-values, procedure 26 Test of c-values, scope of testing 26 Test of rating factor KQ 26 Test of rating factor KC 27 12 Marking 27 Annex A (informative) Information and recommendations 28 A.1 General 28 A.2 Heating systems 28 A.3 Recommended field of application 28 A.4 Heat emission not controllable by the consumer 29 A.5 Additional corrections 29 A.6 Documentation of the relationship between the counting rate and the thermal output 30 Bibliography 32 BS EN 834:2013 EN 834:2013 (E) Foreword This document (EN 834:2013) has been prepared by Technical Committee CEN/TC 171 “Heat cost allocation”, the secretariat of which is held by DIN This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by February 2014, and conflicting national standards shall be withdrawn at the latest by February 2014 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights This document supersedes EN 834:1994 Amendments Compared to EN 834:1994, the following changes were made: a) Definitions, requirements and test procedures have been refined and expanded, b) Introduction of new values for the lower temperature limit, c) Uniform definition for the mounting location of heat cost allocators on the radiator According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom BS EN 834:2013 EN 834:2013 (E) Introduction This document deals with heat cost allocators with electrical power supply used for establishing the consumption value of room heating surfaces It specifies the minimum requirements for the construction, materials, production, installation, function and evaluation of the displayed readings established by these measuring devices This document describes test procedures to establish compliance with the stated requirements and specifies instructions for their nature and scope Scope NOTE See Clause for a definition of the terms used below This European standard applies to heat cost allocators which are used to capture the proportionate thermal output of radiators in consumer units If an account unit comprises consumer units of different types (e.g technically different types of heating systems or differences due to the consumer behaviour, e.g industrial plants as opposed to private apartments), it could be necessary to divide this account unit into groups of users Heat cost allocators enable the determination of the heat consumption only of each radiator in a consumer unit as a share of the total heat consumption of the account unit or user group (see Clause 4); it is therefore necessary to determine this total heat consumption either by measuring the consumed fuel quantity or the amount of heat delivered (the latter by means of a heat meter, for example) For the appropriate use of the heat cost allocators in accordance with this standard, the heating system needs to: correspond to the state of the art at the time of installation of the heat cost allocators; be operated in accordance with the state of the art (see A.2) This standard specifies that heat cost allocators shall not be used for heating systems where the temperature of the heating system falls below or exceeds the temperature limits of the heat cost allocators, where the rating factor for the thermal output, KQ, cannot be clearly specified or where the heating surface is inaccessible This applies usually to the following heating systems: floor heating; radiant ceiling heating; flap-controlled radiators; radiators with ventilators; fan-assisted air heaters; heating systems with steam-operated radiators BS EN 834:2013 EN 834:2013 (E) Normative references Not applicable Terms and definitions For the purposes of this document, the following terms and definitions apply 3.1 heat cost allocator instrument for registration of the proportionate thermal output of radiators in consumer units 3.2 heat cost allocation system overall system, as verified by an inspection authority, consisting of a heat cost allocator, installation equipment, installation instructions, rating system, existing rating factors, maintenance and reading instructions 3.3 measurement method physical principle of measurement in combination with fundamental properties of the appliance type Note to the term: For heat cost allocators in accordance with this standard, the fundamental property of the appliance type characterizing the method is the number of measuring sensors for registering the relevant temperatures The physical principle of measurement which is applied preferably is the temperature dependency of electrical components 3.4 consumer unit dwellings, office, business or industrial premises in which the heat is supplied by a common central heating system or by a common district heating connection 3.5 account unit total of all consumer units 3.6 user group group of consumer units within one account unit, each with a uniform heating system and comparable type of use 3.7 mean heating medium temperature tm mean value of the flow and return temperatures of the heating medium Note to the term: In this standard, tm is determined by adding up the logarithmic heating medium excess temperature, Δtln, (formula (2), see 5.2) and the reference air temperature, tL 3.8 heating medium excess temperature Δt temperature difference between the mean heating medium temperature and the reference air temperature Note to the term: In this standard, the heating medium excess temperature (abbreviated as "excess temperature") is determined as the logarithmic excess temperature Δtln in accordance with formula (2) (see 5.2) BS EN 834:2013 EN 834:2013 (E) 3.9 design flow temperature tV,A value of the flow temperature of the radiators required in order to reach the design indoor temperature in the heated rooms under steady state conditions at a heat load corresponding to a geographically determined design reference outside temperature 3.10 design return temperature tR,A value of the return temperature of the radiators required in order to reach the design indoor temperature in the heated rooms under steady state conditions at a heat load corresponding to a geographically determined design reference outside temperature 3.11 mean design heating medium temperature tm,A mean value of the design flow temperature and the design return temperature Note to the term: In this standard, tm,A is determined by adding up the logarithmic mean value of the design excess temperature and the basic reference air temperature of 20 °C in accordance with formula (2) (see 5.2) 3.12 base condition radiator operating condition which is freely selectable within predefined limits and which is used for specifying the rating factors and for determining the c-values 3.13 basic reference air temperature tL,B value of the air temperature at base condition Note to the term: For tL,B the specified target value is 20 °C, see 5.1 3.14 reference air temperature tL actual value of the air temperature while requirements are specified and measurements are carried out 3.15 heating medium base flow medium flow through the radiator at base condition 3.16 temperature sensors sensors consisting of a sensor element and a sensor casing, which generate a temperature-dependent signal Note to the term: The sensor casing serves both to transfer heat and to protect the sensor element from mechanical influences 3.17 measuring range of temperature sensors temperature range within which temperature sensors can be used Note to the term: For pairs of temperature sensors which are used for the determination of temperature differences, in addition to the measuring range, there is also a temperature difference range BS EN 834:2013 EN 834:2013 (E) 3.18 upper temperature limit tmax maximum mean design heating medium temperature tm,A of the heating system heating surfaces equipped with heat cost allocators at which the heat cost allocator can be used Note to the term: tmax is a property of the heat cost allocator which is determined by the temperature resistance of the components used 3.19 lower temperature limit tmin minimum mean design heating medium temperature tm,A of the heating system at which the heat cost allocator can be used Note to the term: tmin is a property of the heat cost allocator, which is determined by the measurement method This definition applies to double-pipe systems directly For single-pipe systems, the mean design heating medium temperature tm,A of the heating system is replaced by the mean design heating medium temperature tm,A of the last radiator in the string or, as a substitute, the design return temperature tR,A of the string 3.20 start temperature tZ mean heating medium temperature of the radiator, tZ = tm, at partial load, with the mass flow corresponding to the base condition, at which the heat cost allocators start counting, in accordance with the single-sensor measurement method without a room temperature start sensor 3.21 start excess temperature ΔtZ mean heating medium excess temperature ΔtZ = tm - tL of the radiator at partial load, with the mass flow corresponding to the base condition, at which the heat cost allocators start counting, in accordance with the two-sensor measurement method or single-sensor measurement method with a room temperature start sensor 3.22 c-value measure for the degree of thermal coupling between the temperature sensors and the temperatures to be registered Note to the term: The c-value is defined as a temperature difference ratio, see 5.2, formula 3.23 displayed reading value measuring value produced by the heat cost allocator which can be read off as a numerical value at the display device Note to the term: If this value does not equal zero at the beginning of the measuring period, the displayed reading relevant for the heat cost calculation is determined from the difference between the numerical values at the end and the beginning of the measuring period The reading may be a non-rated value or the consumption value (see 3.24) 3.24 consumption value displayed reading value rated by rating factors BS EN 834:2013 EN 834:2013 (E) 7.3 Attachment position of the sensors The attachment position of the sensors on the heating surface shall be chosen such that, as a result for the measuring period, a suitable relation between the displayed reading value of the heat cost allocator and the heat emission of the radiator is given over a sufficiently large operating range This relation is strongly influenced by the design data and the operating conditions of the radiators [4] The required relation is sufficiently ensured for radiators with a flow from top to bottom (sectional, tubular and panel radiators) for an attachment position between 66 % and 80 % of the overall radiator height (measured from the bottom and relative to the centre of the sensor or the heat conducting back plate) which acts as a heating surface [4] This applies to both the single-sensor measurement method and the two-sensor measurement method With regard to the use of thermostatic radiator valves and the application of lower design temperatures, the recommended attachment position is 75 % of the overall radiator height [4] For this position, it is characteristic for the heating medium to have passed 25 % of the thermally active heating surface For other radiator types, the provision above shall be applied accordingly The attachment position thus shall be specified generally for the authorized bandwidth on the heating surface at the position where the heating medium has passed 20 % to 34 % of the total thermally active heating surface Exceptions are permitted in special cases, e.g for radiators of a small overall height The attachment position specified by the manufacturer shall be adhered to with a tolerance of ±10 mm The horizontal attachment position on radiators with a vertical heating medium flow shall be in or near the centre of the overall radiator length For radiators with central connection and central bottom inflow, the attachment position in the horizontal direction is at 25 % of the overall length For large radiators (large relative to the thermal output or the overall length), it is recommended to install several heat cost allocators Within one account unit, the same rules shall be applied for specifying the attachment position National regulations can require documentation of the relation between the counting rate and the thermal output in accordance with A.6 For multiple-sensor measurement methods, the attachment positions of the sensors shall be specified and documented by the manufacturer Evidence shall be provided for the required relation between the displayed reading value and the heat emission For this purpose, measurements shall be made and evaluated by a test laboratory, see 10.1, in accordance with A.6 7.4 Connecting cable installation The provisions applying for the safety and freedom from disturbance of electricity, signalling and communication installations shall be complied with when installing connecting cables 7.5 Uniformity of heat cost allocators Within one account unit (or within one user group in the case of advance allocation of the heat consumption), only heat cost allocators of the same system (see Clause 4) with a uniform rating system shall be used which conform in their properties determining the measuring result and intended to operate either in accordance with the single-sensor, two-sensor or multiple-sensor measurement method If, under special operating conditions, e.g in the case of thermal impact, there is no intended relationship between the room sensor and the room temperature to be registered, heat cost allocators operating in accordance with the two-sensor measurement method may use an appropriate substitute value for the room temperature (e.g a constant value of tL = 20 °C) for the duration of the special operating conditions, provided that the counting rate characteristics remain unchanged otherwise 20 BS EN 834:2013 EN 834:2013 (E) It is acceptable to use different heat conducting casing parts (back plates) for adaptation to different types of heating surfaces This also applies to variants of the same type of appliance, e.g compact versions or versions with separately located radiator temperature sensors 8.1 Rating requirements Rating factor KQ Rating using KQ shall be performed based on the radiator actually installed 8.2 Rating factor KC KC shall be applied if this factor gives differences of > % within one account unit KC shall be determined to at least two decimal places 8.3 Rating factor KT KT shall be applied for design room temperatures of < 16 °C KT shall be determined to at least two decimal places 8.4 Resulting rating factor K KQ shall be included in the resulting rating factor in any case KC and KT shall be included depending on the particular case For each heat cost allocator, rating with KQ or the resulting rating factor K is required, which registers the rated radiator output in steps of a maximum of 60 W or % for the output range of up to and including 3000 W, and % for the output range above 000 W Each heat cost allocator shall be visibly marked with the rating factor KQ or the resulting rating factor K or a figure proportional to it, or this information shall be given in any other clearly visible manner Each appliance shall be provided with a serial number or with the figure proportional to KQ or K 8.5 c-value The c-values shall be determined for the base condition in accordance with the specifications given in 5.2 Combinations of radiators and heat cost allocators with c > 0,67 (two-sensor measurement method) or c > 0,3 (single-sensor measurement method and measurement methods with separately located room temperature sensors), measured at base condition, are not permitted As an exception, c-values of up to 0,72 (two-sensor measurement method) or up to 0,4 (single-sensor measurement method and measurement methods with separately located room temperature sensors) are permitted within one account unit, provided that the relevant heated surface does not exceed 25 % of the total heated surface or that the mean design heating medium temperature is higher than 80 °C Installation is permitted only on radiators for which the c-value is known at the time of heat cost billing If the determination of the c-value is to be based on other conditions than the ones specified in 5.2, this shall be specified in full detail; it shall be ensured that heat cost allocators of the same type are treated in the same manner and it shall be possible to relate the result to the c-value in accordance with the specifications given in 5.2 21 BS EN 834:2013 EN 834:2013 (E) 9.1 Requirements for maintenance and reading Visual reading As part of the reading process, the heat cost allocators shall be checked for their general condition, durability of the attachment, integrity of the seal and any damage As part of the annual reading, a functional check shall be carried out in accordance with 6.10 If batteries are used, they shall be marked with the date of manufacture or installation If batteries are used which are permanently connected to the appliance and not intended to be replaced, the marking can also be affixed to the appliance itself or be given as information which can be retrieved from the appliance memory For appliances with replaceable batteries, terminals or other connecting elements shall be checked before each replacement for the occurrence of increased contact resistances due to oxidation, crystallization or soiling After the battery has been replaced, the battery terminals shall be sealed If the batteries are designed to be replaced at intervals of more than one year, the date of the next replacement shall be given at a suitable location For each heat cost allocator, the rating factor KQ or the resulting rating factor K or the figure proportional to these factors shall be given at a suitable location If a serial number is used, it shall be stated in addition for non-rated displayed readings; for rated displayed readings, the serial number can be given instead of the rating factor 9.2 Close-range reading The requirements specified in 9.1 shall be fulfilled This can be done by visual inspection or by self-testing of the appliance in accordance with 6.10 and transmission of the result (error codes) to the reading device 9.3 Remote reading The requirements specified in 9.1 shall be fulfilled to the extent to which this is technically feasible; otherwise, an alternative shall be applied This is achieved by self-monitoring of the appliances as part of the functional check in accordance with 6.10 The result of the functional check shall be transmitted 10 Testing 10.1 General The tests shall be carried out in accordance with Clause 11 and, in addition, cover the requirements given in Clauses 6, 7, and 9, which are not dealt with in Clause 11 The tests are carried out by a test laboratory authorized in accordance with national regulations or by a European accredited test laboratory The tests are system tests The results only apply to the tested heat cost allocator system as a whole Testing of individual parts or components (e.g in the case of technical alterations) is only permitted when taking into account a complete system test which has already been performed previously This system test will then be modified or supplemented for the relevant aspects which have been retested The integration of the retested items in the system test shall be authorized by the person or organization having ordered the system test An attestation of the compliance with the requirements of this standard for individual parts or components of the system is not permitted An attestation can only be issued for the system as a whole, the tested parts or components forming part of this system An authorized complete test of this system, the test being modified or supplemented as required, forms the basis for an attestation 22 BS EN 834:2013 EN 834:2013 (E) 10.2 Test documents The documents required for the test, the test certificates, documentation, calculations, construction drawings, instructions for installation, etc., shall be provided by the applicant The test laboratory shall treat the documents provided to it confidentially The documents are the property of the applicant and shall not be made available to third parties without the approval of the applicant 10.3 Test report A report of the test shall be prepared which shall contain the following information with reference to Clause 11: a) test laboratory; b) applicant; c) manufacturer; d) description of the appliance, specification of the versions of the tested type; e) field of application; f) test results; g) date; h) signature of the person responsible for the test 10.4 Test protocols The test protocols explain the various tests and present the results They shall be attached to the test report The test laboratory shall treat the test results and protocols confidentially They are the property of the applicant and shall not be made available to third parties without the approval of the applicant 11 Test procedures 11.1 Construction test The conformity of the appliance to the construction drawings is verified by visual inspection; if necessary, the physical dimensions are checked 11.2 Sealing test The function and construction of the sealing or of an alternative type of protection provided for this purpose are verified by visual inspection 11.3 Temperature durability test A batch of complete appliances for each appliance type is tested for 24 hours in a heating chamber at a temperature of K above the upper temperature limit tmax (see 3.18) Compliance with the requirements of 6.1 is verified by checking whether the display deviations for one of the measuring points in accordance with 11.4 are within the limits prior to and after the test 23 BS EN 834:2013 EN 834:2013 (E) 11.4 Test for compliance with the limits of the relative display deviation A batch of appliances is used to verify the measurement method given by the manufacturer and the scheduled counting rate characteristic for compliance with the requirement given in 6.11 for a radiator with c ≤ 0,1, at a heating medium flow corresponding to the base condition (see 5.1) and heating medium excess temperatures Δt of 60 K, 30 K, 12 K and K, but at least K above the start temperature tZ or the start excess temperature tZ - tL, with limit deviations of ± 1,5 K, based on a room temperature of 20 °C A reproducible installation of the appliance shall be ensured This can be verified by measuring the surface temperature on the outside of the heat cost allocator casing at points that provide the thermal contact between the temperature sensor and the radiator or the room The manufacturer is to indicate the temperatures to be expected at these locations For a heating medium excess temperature of 30 K, the above test shall be carried out with three different resulting rating factors with the ratio of 1:2:4 Five appliances are tested for each rating factor As a check of the intended resulting rating factors, the test for compliance with the display deviation limits is done on the basis of the displayed reading values after their normalization to the lowest value of the resulting rating factors used The limits of the relative display deviation given in 6.11 shall not be exceeded by any of the test specimens 11.5 Ageing resistance test Five operative appliances with known counting rate characteristic are subjected to ageing by exposing them to 300 temperature cycles of a maximum duration of 100 each Ageing can be performed: a) in a heat chamber A temperature cycle is generated by slowly heating the heat cost allocators, over a maximum of 45 min., up to a temperature of [0,8 × (tmax – 20 °C) + 20 °C] ± K and then by cooling to (25 ± 2) °C b) on an electrically heated, oil-filled radiator In this case, the heat cost allocators are fitted at the installation height specified by the applicant A temperature cycle is generated by slowly heating the radiator, over a maximum period of 45 min., to a surface temperature at the installation position of the heat cost allocators corresponding to the temperature tmax (see 3.18) ± K and then by cooling to (25 ± 2) °C For appliances with radiator sensors which are located separately from the calculator, the temperature sensors are heated up to the temperature of tmax ± K during the temperature cycles Appliance components (central processing units, calculators, etc.) which are not mounted on the radiator are heated in the heating chamber to an appliance temperature of (50 ± 2) °C and then cooled to (25 ± 2) °C In the subsequent test carried out in accordance with 11.4 at one of the specified temperature points, the display deviation limits given in 6.11 shall not exceed twice their value after ageing has been completed If the display deviations caused by the ageing process are not systematic (e.g drift not in the same direction), the test specimens are subjected to a further 300 temperature cycles, after which the test is repeated 11.6 Test of the start of counting at normal operation and also, for heat cost allocators with room temperature sensors, at operation with thermal impact The test of the start of counting is carried out at the mass flow rate of the base condition Five heat cost allocators of each type shall be tested simultaneously on one radiator The attachment point and the installation instructions supplied by the applicant shall be adhered to The test shall be carried out on a radiator with good thermal contact (vertical profile panel radiator) and on a radiator with poor thermal contact (single-sensor c-value ≥ 0,25) For heat cost allocators without room temperature sensors, the test is carried out on both radiators in a series of tests exclusively at normal operation For heat cost allocators with room 24 BS EN 834:2013 EN 834:2013 (E) temperature sensor, the test is carried out on both radiators in two series of tests each In the first series, compliance with the requirement of 6.3 is checked with the heat cost allocators at normal operation In the second series, compliance with the requirement of 6.3 is checked under thermal impact in combination with the increased excess start temperature in accordance with 6.15 for a radiator with good thermal contact Thermal impact is induced by covering each heat cost allocator with a hood consisting of foamed PUR [thermal conductivity approximately 0,025 W/(m · K)] with a wall thickness of (25 – 30) mm Each test series starts at a radiator operating state below the start temperature or excess start temperature to be tested (start-up criterion) at which none of the installed heat cost allocators is counting Then the heating medium temperature is increased in increments of (0,5 to 1) K and the start-up of the heat cost allocator is monitored The test is considered to be passed if all installed heat cost allocators of one test series count when the start-up criterion ± K is reached For appliances which, at normal operation, can be used for both the single-sensor and the two-sensor measurement method, the complete test programme shall be run for both measurement methods 11.7 Test of the idle counting rate For each type of heat cost allocator, five specimens shall be tested at identical test conditions The heat cost allocators are placed in a heat chamber and subjected to a room temperature of 27 °C The idle counting rate is determined from the progression of the displayed reading and the test duration The scheduled counting rate is determined, with c = 0, from the scheduled counting rate characteristic for the heating medium temperature tm = 80 °C (single-sensor measurement method) or for the heating medium excess temperature Δt = 60 K (two-sensor measurement method) The test for compliance with the requirement of 6.4 is considered to be passed if, for all heat cost allocators of one test series, the measured idle counting rate is within % of the calculated scheduled counting rate 11.8 Test of the counting rate in the case of thermal impact The test for compliance with the requirements of 6.14 and 6.15 is performed under the test conditions defined in 6.14 Four specimens shall be tested for each type of heat cost allocator The scheduled counting rate characteristic of the types to be tested shall be known The temperatures of the front surfaces of the heat cost allocators or of the casings of separately located room sensors shall be measured Of the tested appliances, two appliances each are subjected to thermal impact For appliances with room sensors inside the casing (compact version), the thermal impact is induced by covering each heat cost allocator with a hood consisting of foamed PUR [thermal conductivity approximately 0,025 W/(m · K)] with a wall thickness of 25 mm to 30 mm For sensors which are located separately from the appliance, the thermal impact is created by external heat supply The covering or heat supply shall bring about a temperature increase of the front surface of at least 15 K The counting rate Rthb of the thermally impacted and Ru of the non-impacted heat cost allocators is determined from the progression of the displayed reading and the test duration In addition, the heating medium excess temperature shall be measured The requirement of 6.14 is considered to be met if the measured counting rate Rthb is greater than the thermally non-impacted counting rate Ru or no more than % less For the test for compliance with the requirement of 6.15, the values Rthb and Ru and the heating medium excess temperature shall be determined as described above From the scheduled counting rate characteristic of the relevant heat cost allocator type, the counting rate Rsoll is determined in accordance with the measured heating medium excess temperature The reduced counting rate Rred which is obtained for an air temperature increased by K and thus a heating medium excess temperature reduced by K is also determined from the scheduled counting rate characteristic The test is considered to be passed if the condition Rthb/Ru ≥ Rred/Rsoll is fulfilled 25 BS EN 834:2013 EN 834:2013 (E) 11.9 Test for external influences The heat cost allocators shall be tested for compliance with the requirements of 6.13, 6.16 and 6.17 The test in accordance with 6.16 is carried out at ambient temperatures of °C and 50 °C 11.10 Test of c-values, procedure The c-values shall be tested at base condition on the completely painted radiator A batch of three heat cost allocators of each type shall be examined under identical test conditions The attachment positions and installation instructions provided by the applicant shall be observed In this test, the temperatures or measuring signals corresponding to the specification given in 5.2 shall be measured and the c-values shall be calculated on this basis The measurements are to be conducted as follows: Laboratory measuring instruments are used to measure the sensor temperatures, or, if the characteristic curves of the sensors are known, the sensor signals are taken directly from the heat cost allocator The difference between the individual c-values of the installed heat cost allocators shall not exceed 0,02 11.11 Test of c-values, scope of testing The c-values for the following seven basic radiator types shall be determined by measurement: a) cast-iron column radiator; b) steel plate radiator; c) vertical profile panel radiator; d) non-profile panel radiator; e) steel pipe radiator; f) aluminium radiator; g) panel radiator with horizontal water flow If the applicant submits c-values for these radiators, the test laboratory compares these values with the results of its own measurements For installation on other radiators whose c-values have not been established through the measurements carried out on the seven basic radiators, the applicant shall submit the values to the test laboratory for confirmation The test laboratory will ascertain the accuracy of the submitted values by remeasurement of a sample of % of the c-values submitted The c-values submitted by the applicant may deviate unsystematically by up to ± 0,02 from the values obtained by the test laboratory In addition, systematic deviations are acceptable, provided that they not alter the rating factor KC by more than ± % 11.12 Test of rating factor KQ The test shall be carried out based on a table to be provided by the applicant with the existing rating factors The graduations in the table are used to calculate whether each radiator output is registered with the accuracy required in 8.4 26 BS EN 834:2013 EN 834:2013 (E) Compliance with the accuracy and the application of the rating factors KQ is verified based on appropriate documentation to be provided by the applicant 11.13 Test of rating factor KC Evidence of the knowledge and application of the rating factors KC shall be produced by the applicant 12 Marking The heat cost allocator shall be visibly marked with the following data: appliance type; serial number of the appliance or resulting rating factor K or rating factor KQ or the figure proportional to these rating factors (see 8.4); lower temperature limit, tmin; upper temperature limit, tmax 27 BS EN 834:2013 EN 834:2013 (E) Annex A (informative) Information and recommendations A.1 General This annex includes information and recommendations for the condition of heating systems (A.2), for the field of application of various measurement methods of heat cost allocation (A.3), recommendations for dealing with heat emission of heating surfaces not controllable by the consumer (A.4), information on additional corrections (A.5) and possible documentation of the relationship between the counting rate and the thermal output (A.6) A.2 Heating systems It is recommended that heating systems equipped with heat cost allocators have the following properties: a) radiators are equipped with a room temperature controlling device to be operated by the user (e.g thermostatic radiator valves); b) a correctly adjusted central controller with outdoor temperature sensor is applied to control the flow temperature; c) for replaceable or additional radiators the reference system (see 5.3.1) shall be applied which had been applied when the building was first equipped with radiators; d) the heating system is adjusted hydraulically, i.e the heating medium flow rates are adjusted in accordance with the design condition; e) the temporarily reduced heating of adjoining rooms or consumer units should be taken into account when designing the heating surfaces Recommendation a) should be observed in any case, as it is regarded as a necessary supplementary requirement when registering the heat consumption Recommendations b) and c) are intended to reduce the level of allocation errors and recommendations d) and e) are intended to ensure sufficient heating A.3 Recommended field of application Table A.1 contains information on the recommended field of application for the various measurement methods 28 BS EN 834:2013 EN 834:2013 (E) Table A.1 — Recommended fields of application for heat cost allocators on electrical power supply (HKVE) a Heating system Users on the string Design temperatureb Pipe installation °C tm,A < 55 design range low temperature 55 ≤ tm,A < 60 60 ≤ tm,A < 85 design range above low temperature 85 ≤ tm,A horizontal single-pipe >1 vertical tV,A ≤ 95 and ΔtA ≤ 20 tV,A > 95 or ΔtA > 20 double-pipe HKVE single-sensor Komp FF multi-sensor FF c Komp - - + + + + + + + + + + +d + +d + + + + + + + + + + + + + + + + + + + + + + = suitable– = unsuitable a Requirements and shall be fulfilled b tm,A mean design heating medium temperature on the radiator; ΔtA design temperature drop of the single-pipe string; tV,A design flow temperature of the heating system c Komp = compact appliances, FF = appliances with locally separately located radiator sensors (remote sensors) d Appliance-specific upper temperature limit shall be observed A.4 Heat emission not controllable by the consumer Heat emission from pipes leading through the consumer unit not controllable by the consumer (forced heat consumption) should be taken into account in the consumption-based billing if the share of the heat emission from the pipes substantially influences the accuracy of the allocation ([7] ,[8], [9]) A.5 Additional corrections Within the context of heat cost billing, additional correction factors are permissible which are in accordance with national specifications, particularly if they are not of a metrological nature 29 BS EN 834:2013 EN 834:2013 (E) A.6 Documentation of the relationship between the counting rate and the thermal output The relationship between the counting rate of the heat cost allocator and the thermal output of the radiator is documented during the installation of the heat cost allocator at the attachment position specified by the manufacturer The documentation is done for two radiator types with two models each, the models having a different overall height, i.e.: 1) steel pipe radiator three columns, overall height: 750 mm, overall length of section: 45 mm/46 mm and four columns, minimum overall height, overall length of section 45 mm/46 mm each with a standard thermal output of 200 W ± 200 W in accordance with EN 442-2; 2) vertical profile panel radiator with convection plates Type PKKP, overall height: 600 mm and Type PKKPKP, minimum overall height each with a standard thermal output of 200 W ± 200 W in accordance with EN 442-2 NOTE "Minimum overall height" refers to the minimum overall height at which the attachment position as specified in the installation instructions of the manufacturer can be achieved (recommendation: 75 % of the overall radiator height in accordance with 7.3) The tests shall be carried out in a closed test space in accordance with EN 442-2 or in an open test booth in accordance with DIN 4704-2 For heat cost allocators operating in accordance with the two-sensor measurement method, the preferred use of the open test booth is recommended, since the thermal boundary conditions there are a good representation of the real operating conditions in heated spaces The thermal output and the counting rate are determined at the same stationary thermal equilibrium For each test, three heat cost allocators are used which, under laboratory conditions, may operate at an increased counting rate The temperatures detected by the measuring sensors should be registered, if possible The test series are performed on the basis of the mean heating medium flow rates A, B, C, D of the system, which arise from the temperature combinations tV, (tV – tR), tL in accordance with Table A.2 Table A.2 — Temperature combinations for the specification of the heating medium flow rates of the system Flow temperature tV °C (90 ± 2) (75 ± 2) (70 ± 2) (70 ± 2) Temperature drop (tV – tR) °K (20 ± 5) (10 ± 5) (30 ± 5) (40 ± 5) Reference air temperature tL °C (20 ± 2) (20 ± 2) (20 ± 2) (20 ± 2) Designation of the resulting heating medium flow rate of the system A B C D The values for the permissible deviation from the scheduled value, ± K, for tV and tL given in Table A.2 shall be applied for both parameters in the same manner only, either as a positive or as a negative deviation 30 BS EN 834:2013 EN 834:2013 (E) While maintaining the corresponding heating medium flow rate of the system (acceptable deviation: ± %), the thermal partial-load equilibria are set at reduced flow temperatures tV in accordance with Table A.3 Table A.3 — Partial-load equilibria at reduced flow temperatures Heating medium flow rate of the system A B A C D Reduced flow temperature tV °C 70 53 38 38 38 Reduced return temperature tR ≈ 57 °C ≈ 48 ≈ 34 ≈ 29 ≈ 25 Reference air temperature tL °C (20 ± 2) (20 ± 2) (20 ± 2) (20 ± 2) (20 ± 2) NOTE The reduced return temperatures are the result of the test parameters, the values of tR in Table A.3 are approximate values The test results for the operating states of Table A.2 and Table A.3 can be documented in a suitable manner to show the relationship between the counting rate and the thermal output, also stating the corresponding values of the flow temperature and the heating medium flow rate Provided that the requirements of 10.2 are met, they can be used by the manufacturer for analyses of the quality of registering the consumption using heat cost allocators, cf [4] and [5] 31 BS EN 834:2013 EN 834:2013 (E) Bibliography [1] EN 442-2, Radiators and convectors — Teil 2: Test methods and rating [2] DIN 4704-2, Thermal testing of heating appliances — Part 2: Open test booth [3] Zöllner, G und W.-D Geisenheimer: Untersuchung zur unteren Temperatur-Einsatzgrenze und zur StartTemperaturdifferenz für Heizkostenverteiler nach dem Zweifühler-Kompakt-Messverfahren GesundheitsIngenieur 125 (2004) Heft 1, S – 13 [4] Zöllner, G und W.-D Geisenheimer: Optimale Montagehöhe für Heizkostenverteiler nach dem Zweifühler-Kompakt-Messverfahren an Radiatoren HLH 54 (2003) Nr 3, S 42 – 49 und Nr 4, S 36 – 39 [5] Otto Paulsen: Heat cost allocators Additional documentation for measuring accuracy Version 4.3 December 2002, adjusted February 2003, adjusted August 2004, revised English version March 2005, Danish Technological Institude 2004 [6] Bindler, J.-E., Zöllner, G.: Über die Problematik der Wärmeabgabe ungedämmter Strangleitungen für die verbrauchsabhängige Heizkostenabrechnung, Stadt Gebäudetechnik 12/93, S 30-38 [7] Zöllner, G., Geisenheimer, W.-D.: Bedeutung der Rohrwärmeabgabe für die verbrauchsabhängige Heizkostenabrechnung., HLH Bd 53 (2002) Nr 6, S 24-34 [8] Mügge, Günter; Schmid, Jörg; Tritschler, Markus: Anwendungskriterien für die Berücksichtigung unerfasster Rohrwärmeabgabe bei der Heizkostenvabrechnung HLH (2008) Nr 11 und 12 [9] VDI 2077 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