In Central and Northern Europe it has become common to install solar thermal systems that provide heat both for domestic hot water and for space heating.

The collector size of these so called combisystems is typically in the range of
7-20 m² and the tank(s) in the range of 300-2000 litres. Combisystems are often more complex, than solar systems supplying DHW only. As a consequence, system design must be adapted to the specific requirements of the building.

Different practices are used in different countries. In Southern Europe, combisystems are still rarely used, but there is a big potential for systems generating space heating in winter, air-conditioning in summer and DHW throughout the year.

Further information:

• The International Energy Agency (IEA) Solar Heating & Cooling Programme completed its Task 26 on Solar Combisystems in 2003.
• A related project supported by the European Commission's ALTENER Programme,  aimed at converting the findings of the IEA task to information usable for the public. The results are available online.