IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration Subtask A Report, Date: November 2010
2 System Design
In Figure 2 the hydraulic scheme of the installed system in Gröbming is shown. There are
two solar collector fields, one on the ground with 30.2 m 2 and the second is integrated in the
façade with 15.8 m 2 . From the solar collectors the heat flows through a heat exchanger to the
hot water storage. Three 1500 liter water storages connected in series are used to store the
solar energy. Depending on the return temperature from the heat exchanger the medium is
stratified to the hot medium or cold storage. In winter the return flow from the distribution
systems is delivered into storage 1 and in summer, when the cooling mode is running, into
storage 3. Out of storage 3 the hot water can be distributed to different recipients, the
domestic hot water station, the absorption chiller, the swimming pool as well as the space
heating for the building. This can also be done alternatively from storage 1 or 2 if the
temperature is sufficient.
Figure 2: Hydraulic scheme of the solar cooling system in Gröbming
From the central distribution station the hot water is spread to the different recipients. In
summer time, when the cooling mode is enabled, the chilled water is also distributed through
the same central distributor station.
The recooling water loop connects the absorption chiller directly to the wet cooling tower.
The absorption chiller PSC-12 is located outside the building. As a consequence of this
location, twice a year a maintenance worker has to discharge and charge the hydraulic
cycles of the absorption chiller as well as of the cooling tower before and after the winter
period to avoid freezing damages.
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