23 September 2011
In the building sector the use of thermally driven heat pumps can contribute substantially to energy conservation and the reduction of end-use energy. Within the IEA HPP Annex 34 a medium size absorption heat pump application installed in a storehouse in Graz has been monitored over a period of one year.
The system consists of two directly natural gas-driven ground source ammonia/water absorption heat pumps (each with ca. 40 kW heating capacity). Via a buffer storage space heating of an office building and a storage depot as well as domestic hot water preparation is provided.
During the monitoring period the system showed reliable operation and high energy performance. Based on the lower heating value of the natural gas the seasonal performance of the year 2010 was 1.54 which is approx. 60% higher compared to a condensing gas boiler with a seasonal performance of 96%. However, also room for improvements has been detected, especially at start/stop operation for domestic hot water preparation in summer.