Test winner: Comparison test and efficiency

At the initiative of the German federal foundation for the environment and the DIN-EN-authorised institute for solar energy research, a unique 2-year outdoor comparison test for swimming pool solar absorbers was carried out in 2000-2001 in accordance with the very demanding test criteria of the latest DIN EN 12975, which is still valid today. The advisory board of this rigorous testing process included: The "Stiftung Warentest" testing agency, the University of Stuttgart, the University of Marburg and TÜV Süddeutschland.

All of the (approx. 15 at that time) market participants for swimming pool solar absorbers were invited to participate in this comparison test, insofar as they offered different makes. The aim was a comparative, intensive thermal performance and material test. An elaborate test procedure in which swimming pool solar absorbers mounted on the roof were tested over a period of 2 years - as is usual in practical applications. Eight makes of different designs took part, which at the time represented a combined market share of 87% of the solar absorber systems installed for swimming pools at that time.

The AQSOL solar absorber system (at that time under the name GEBaU) emerged as the TEST WINNER from this strict test procedure with the highest, solar useful heat yields per unit area and the best quality.

The average rankings of the different systems:

  • 1st place  : AQSOL (GEBaU)
  • 2nd place : MZF165
  • 3rd place : Polysol
  • 4th place : Sunline
  • 5th place : Episol
  • 6th place : MS125/8
  • 7th place : Solana
  • 8th place : Solarflex

Note: The comparative test with its meaningful result is still highly significant today. In the comparative test, the so-called finned tubes and the absorber panels achieved the lowest efficiencies. The technology of the different absorber types has not changed since the comparison test and is still the same today. Most of the solar absorber brands mentioned above can no longer be found under the same name today. Today, the solar absorbers are offered under other names, some even as world firsts. However, the technology is exactly the same as at the time of the comparison test at that time, which is why the results still serve as a representative quality comparison today.

Solar heat yields in kWh/m2 absorber area

Swimming pool season from 1 May to 30 September (reference location Würzburg, wind speed 2 m/s).

All test results in a publication from 12/2001 entitled "Solare Freibadbeheizung - Absorberprüfung und Testergebnisse - Planung und Betrieb" [Solar outdoor pool heating - Absorber testing and test results - Planning and operation] can be obtained from: ist-Energieplan GmbH, Werderstr. 34, 79379 Müllheim, www.ist-energieplan.de

Test results: Solar heat yields

Test results: Efficiency curves