Thanks to the combined use both of renewable and free available ambient-energy on the one hand and electrical energy to drive machine's compressor on the other hand, this technology can save up to 50 % of primary energy for space heating in new one family houses (stated by the IEA Heat Pump Centre (HPC),whereby a traditionally oil driven heating system is compared to a heat pump driven).

Figure 1: Plants connection draft for winter use

Using this kind of heat pumps, most of the primary energy is consumed to drive machine's compressor with electricity. Contrary to this, in thermally driven heat pumps this electricity driven compressor is replaced by a thermally driven one. Since its driving heat can be provided by solar thermal energy, biomass or waste heat for example, further primary energy savings are expected using this technology. Moreover, thermally driven heat pumps can serve for heating as well as for cooling purposes with the same advantages in primary energy savings.

Figure 2: Plants connection draft for summer use

Figure 1 and Figure 2 show an example how a plant connection with a thermally driven heat pump (ABS) and biomass as driving heat could look like. While in winter (Figure 1) the environment serves as heat source for the building, in summer (Figure 2) it is used to reject the heat of the building and to cool it through this.

Annex 34 is a 3 year initiative under the patronage of the IEA Heat Pump Program (Project period: October 2007 until September 2010) and follows the goal to reduce the environmental impact of heating and cooling due to the use of Thermally Driven Heat Pumps. Thereby, one of the main objectives is to quantify the economic, environmental and energy performance of integrated thermally driven heat pumps in cooling and heating systems in a range of climates, countries and applications. From this, those areas and applications with the greatest environmental benefit, the best economics and the greatest market potential will be identified. Its work is based on the results from Annex 24, "Absorption Machines for Heating and Cooling in Future Energy Systems", cooperates with the IEA-SHC Task 38, "Solar Air-Conditioning and Refrigeration" and is subdivided into the following tasks:
 

• Task A Market overview and state of the art
• Task B Performance evaluation
• Task C Apparatus technology
• Task D System technology
• Task E Implementation

Through the participation at Annex 34 and the leadership of task D, EURAC's Institute for Renewable Energy pursues the goal of collecting and elaborating specific know-how on the one hand and actively enhance a fast know-how transfer to the affected industry on the other hand.

The target of the activity is to allow a faster market penetration of this technology, to enhance the realization of high quality systems and to support local and international companies.

A first workshop, "Anwendungsmöglichkeiten von thermisch betriebenen Wärmepumpen" has been carried out on 11th of April 2008 in the premises of EURAC in cooperation with TIS Innovation Park.

http://www.heatpumpcentre.org/

For further information about the partners, please refer to the homepage of the project