Factory made systems — EN 12976 Part 1 and 2
The standard series EN 12976 for factory made systems was changed e. g. with regard to the requirements concerning the suitability for drinking water according to EN 1717 (protection against pollution of portable water in drinking water installations and general requirements of devices to prevent pollution by backflow).
2. Custom built systems - CEN/TS 12977 Part 1, 2, 4 and 5 and EN 12977 Part 3
The most changes made during the revision were related to the standard series ENV 12977 for custom built systems since this standard series was fundamentally revised and extended by two additional parts. The new standard series CEN/TS[3] 12977 consisting of in total five parts (see Table 2) is expected to be published for formal vote during the second half of 2008.
The fundamental revision and the amendment of two additional parts were necessary due to the extension of the scope from solar domestic hot water systems to solar combisystems. Solar combisystems are systems that provide heat for domestic hot water preparation and for space heating.
Since the most significant differences between solar thermal domestic hot water systems and solar combisystems are related to the heat store and to the controller specific parts related to these components were added.
The performance testing of stores for solar domestic water heating systems is described in EN 12977-3. Since the core procedures in this standard were already included in the previous version ENV 12977-3 /3/ it was decided to establish this standard as a real EN standard. The formal vote by the CEN member countries related to this part was carried out during the summer of 2008 with a positive outcome. Therefore the official publication of this standard can be expected by the end of 2008.
The first new part of the standard series CEN/TS 12977 is part 4 dedicated to performance testing of combistores. The amendment of the standard series for custom built systems by this part is a logical consequence of the extension of the whole standard series to combisystems.
Since the controllers used in solar combisystems are typically much more complex and advanced than the ones used in solar domestic hot water systems it was also necessary to account for this aspect by additional procedures. Therefore CEN/TS 12977-5 named “Performance test methods for control equipment” was added as the second new part. Beside quality assurance and improvement of the reliability of all control equipment, the parameters of the controllers determined by the test procedures of part 5 are required in order to determine the performance of thermal solar systems by means of computer simulation /4/.
At present (summer 2008) the formal vote within the CEN member countries for CEN/TS 12977 Part 1, 2, 4 and 5 is under preparation. In case of a positive voting result the publication of the final version of these standards can be expected for early 2009.
The revised version of the standard series EN 12975, EN 12976 and CEN/TS 12977 will form an excellent basis for the further development of the European solar thermal market and for Solar Keymark certification. However, in order to consider future technological developments such as tracking concentrating solar collectors or solar cooling systems periodical revisions of the standards will be required
