EN 12977-2:2012

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Thermische Solaranlagen und ihre Bauteile - Kundenspezifisch gefertigte Anlagen - Teil 2: Prüfverfahren für solar betriebene Warmwasserbereiter und KombinationssystemeInstallations solaires thermiques et leurs composants - Installations assemblées à façon -
Partie 2: Méthodes d'essai pour chauffe-eau solaires et installations solaires combinéesThermal solar systems and components - Custom built systems - Part 2: Test methods for solar water heaters and combisystems91.140.65Oprema za ogrevanje vodeWater heating equipment91.140.10Sistemi centralnega ogrevanjaCentral heating systems27.160Solar energy engineeringICS:Ta slovenski standard je istoveten z:EN 12977-2:2012SIST EN 12977-2:2012en,fr,de01-julij-2012SIST EN 12977-2:2012SLOVENSKI
STANDARDSIST-TS CEN/TS 12977-2:20101DGRPHãþD

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 12977-2
April 2012 ICS 27.160 Supersedes CEN/TS 12977-2:2010English Version
Thermal solar systems and components - Custom built systems - Part 2: Test methods for solar water heaters and combisystems
Installations solaires thermiques et leurs composants - Installations assemblées à façon - Partie 2: Méthodes d'essai pour chauffe-eau solaires et installations solaires combinées
Thermische Solaranlagen und ihre Bauteile - Kundenspezifisch gefertigte Anlagen - Teil 2: Prüfverfahren für solar betriebene Warmwasserbereiter und Kombinationssysteme This European Standard was approved by CEN on 19 February 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.
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Reference conditions for performance prediction . 28A.1General . 28A.2Pipe diameter and insulation thickness . 30A.3Calculation of mains water temperature at reference location . 30A.4Space heating load . 31Annex B (normative)
Additional information regarding the calculation of the fractional energy savings . 37B.1Definition of a conventional reference water heating system . 37B.2Calculation of fractional energy savings for other conditions . 37Annex C (informative)
Short-term system testing . 39C.1General . 39C.2Instrumentation, data acquisition and processing . 39C.3Check of short-term system performance . 41C.4Short-term test for long-term system performance prediction . 44Annex D (informative)
Long-term monitoring . 51D.1General . 51D.2Evaluation chart . 52SIST EN 12977-2:2012

Determination of water wastage . 53Bibliography . 54 Figures Figure 1 — Energy balance for one-store and two-store solar-plus-supplementary systems . 21Figure 2 — Comparison of the gross auxiliary energy demand of the solar heating system, Qaux, to the gross energy demand of the conventional heating system, Qconv . 22Figure 3 — Energy balance for solar only systems . 24Figure 4 — Energy balance for solar preheat systems . 25Figure C.1 — Principle of the short term system performance check: Check and intercomparison of useful energy gain . 41Figure C.2 — Principle of the short-term test and of the subsequent long term system performance prediction . 45Figure C.3 — Example of the predicted performance dependence on load level and irradiation for a solar domestic hot water heating system (see [8]) . 50 Tables Table 1 — Division for factory made and custom built solar heating systems . 6Table 2 — Symbols, definition and unit (1 of 2) . 10Table 2 — Symbols, definition and unit (2 of 2) . 11Table 3 — Presentation of system performance indicators for solar-plus-supplementary systems . 26Table 4 — Presentation of system performance indicators for solar-only and solar preheat systems . 26Table A.1 — Reference conditions for performance presentation (1 of 2) . 28Table A.1 — Reference conditions for performance presentation (2 of 2) . 29Table A.2 — External pipe diameter and insulation thickness for forced-circulation systems . 30Table A.3 — Data for calculation of the mains water temperature at the reference locations . 31Table A.4 — Space heating load file for Stockholm. 32Table A.5 — Space heating load file for Davos . 33Table A.6 — Space heating load file for Würzburg (1 of 2) . 34Table A.6 — Space heating load file for Würzburg (2 of 2) . 35Table A.7 — Space heating load file for Athens – Example to be updated . 36Table C.1 — Variables to be measured and corresponding maximum sampling intervals . 43Table C.2 — Variables to be measured during system test, and corresponding maximum sampling intervals . 46Table C.3 — Range of variations of the driving variables to be scanned during a test outdoors . 47Table C.4 — Permissible standard deviation for secondary collector parameters . 49 SIST EN 12977-2:2012

NOTE 1 Forced circulation systems can be classified either as factory made or as custom built, depending on the market approach chosen by the final supplier. NOTE 2 Both factory made and custom built systems are performance tested under the same set of basic reference conditions as specified in EN 12976-2:2006, Annex B and in EN 12977-2:2012, Annex A. In practice, the installation conditions may differ from these reference conditions. c) Test methods and procedures for the analysis of large custom built solar heating systems Quality assurance is of primary importance for large custom built systems. The total investment cost for such systems is higher than for smaller ones, although the specific investment cost (i.e., per m² collector area) is lower. In several European countries, the potential of large custom built systems from the point of view of conventional energy savings is much larger than for smaller ones. Moreover, the return on investment is in many cases more favourable for large systems than for small ones. Hence, both the purchasers of large custom built systems and the governments are interested in efficient, reliable and durable systems, the thermal performance of which may be accurately predicted, checked and supervised. The test methods in this document provide a means of verifying the compliance of large custom built systems with the requirements in EN 12977-1. NOTE 3 Within the framework of the EU ALTENER Programme the project "Guaranteed Solar Results" (GSR) was addressing similar objectives in respect of quality assurance (see [7], [8]). Similar procedures and monitoring equipment were used as described in Annexes C and D. It might be necessary to update Annexes C and D at a later stage during a revision of this document when more expertise is available. As large custom built systems are by definition unique systems, only general procedures on how to check and supervise them may be given. An additional difficulty in the formulation of procedures is the fact that they have to be adapted to the dimension of the large custom built system considered, which may vary from typically 30 m² to 30 000 m² of collector area. Therefore, several possible levels of analysis are included (Annexes C and D). The objective of the two short-term system tests presented in Annex C is the characterization of system performance and/or the estimation of the ability of the system to deliver the energy claimed by the designer. In principle, two approaches for short-term system testing are referred to in this European Standard: 1) a simplified check of short-term system performance, carried out by intercomparison of the measured thermal solar system heat gain with the one predicted by simulation, using the actual weather and operating conditions as measured during the short-term test; SIST EN 12977-2:2012

Ds shift term for the calculation of mains water temperature at reference location
fsav fractional energy savings % fsol solar fraction % Gd diffuse solar irradiance on tilted plane W/m² Gg global solar irradiance (on horizontal plane) W/m² Gh hemispherical solar irradiance on tilted plane W/m² Hc hemispherical solar irradiation on collector plane MJ/m² Kατ incidence angle modifier
Qaux gross auxiliary energy demand of the solar heating system MJ Qaux,net net auxiliary energy demand of the solar heating system delivered by the auxiliary heater to the store or directly to the heat distribution system MJ Qconv gross energy demand of the conventional heating system MJ Qconv,net net energy demand of the conventional heating system MJ Qd heat demand MJ QL energy delivered at the outlet of the solar heating system MJ Ql store heat losses of the solar heating system MJ Ql,a store heat losses of the store heated by auxiliary energy (in case of a two-store-solar-plus-supplementary system) MJ Ql,s store heat losses of the store heated by solar energy (in case of a two-store-solar-plus-supplementary system) MJ Ql,conv store heat losses of the conventional heating system MJ Qohp heat diverted from the store as active overheating protection, if any
MJ Qpar parasitic energy (electricity) for the collector loop pump(s) and control unit MJ Qsav energy savings due to the solar heating system MJ Qsol energy delivered by the collector loop to the store MJ T* reduced temperature difference; T* = (ϑm – ϑa)/Gh m² × K/W (UA)hx heat transfer capacity rate of a heat exchanger W/K (UA)S heat loss capacity rate of the store of the solar heating system
W/K SIST EN 12977-2:2012
ηaux overall generation efficiency of the auxiliary heater of the solar heating system
ηconv overall generation efficiency of the heater of the conventional heating system
θreq required temperature for sensor high-temperature resistance °C θsens sensor temperature °C
For large custom built systems verify the compliance with the requirements given in EN 12977-1:2012, 6.6.2 by checking the documentation included in EN 12977-1:2012, 6.8.4. 6.6.3 Snow and wind loads See EN 1991-1-3 and EN 1991-1-4 where applicable. Moreover, check whether the documents for the installer comply with EN 12977-1:2012, 6.6.3. 6.7 Initial operation, inspection and commissioning This subclause applies to large systems only. Before initial operation:  check whether the system layout and components are as described in the documentation;  check the record of the adjustments for the corresponding fittings. For each fitting a recorded adjustment shall exist;  if there is a supervisor of the system, ensure that he has been sufficiently instructed. The procedure for short-term system testing referred to in EN 12977-1:2012, 6.7 (only if needed or required) is given in Annex C. The procedure for long-term system monitoring referred to in EN 12977-1:2012, 6.7 (only if needed or required) is given in Annex D. SIST EN 12977-2:2012
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