Solar Cooling


Cold from solar power

Since June 2002, Fraunhofer UMSICHT operates a solar-assisted air conditioning and heating system.

For this, a solar thermal 108 m² collector field of evacuated tubes was installed. In summer, the system supplies chilled water for air conditioning of offices, laboratories and conference rooms. A thermally driven absorption chiller (working fluids are H2O and LiBr solution) generates the cold, the needed driving heat is provided by the sun. In spring and autumn, when low ambient air temperature and cold demand occur at the same time, the heat rejection system of the absorption chiller is used to supply chilled water directly – such operation without the absorption chiller is called “free cooling”. Furthermore, the heating system of the institute can be used to drive the absorption chiller, presenting times of low solar yield. In winter time, the solar collector field is used to assisting the heating system.

The solar assisted cooling and heating system was erected with the objectives to gain experiences in operation and conception of such a system for the energy supply of buildings. This kind of energy supply is sustainable and a very promising technology for sunbelt regions.

View on the collector surface of building C