A GAS ABSORPTION HEAT PUMP FOR EXISTING RESIDENTIAL BUILDING: HEAT4U PRELIMINARY ACHIEVEMENTS

摘要

The efficiency of energy using products becomes more and more important regarding the environmental issues and the impulsion from regulations requirements. To give a specific answer to the existing houses, the HEAT4U European project has been granted by the European Commission, with the objective of developing a gas absorption heat pump (GAHP) as a high efficient solution for heating and domestic hot water (DHW). This gas technology which is using the outside air and natural gas as energy sources combines different advantages compared to electrical heat pumps. Among them, it can deliver high efficiency at low temperatures, it is energy efficient also with high temperature emission systems (i.e. radiators), it does not impact the grids imposing adoption of smart grid approaches, it uses a natural working fluid without global warming potential, and, finally, provides a 30% to 40% energy saving compared to a condensing boiler. Started since October 2011, the HEAT4U project, led by ROBUR as the main company on the GAHP field, has developed a complete system including a GAHP prototype, system control and all hydraulic means in order to provide energy for both space heating and DHW service. In a first step, the European markets requirements for retrofit applications were analyzed in order to provide an suitable system. This preliminary system has been tested in laboratory conditions in compliance with latest harmonized revisions of test standards (EN12309, EN13203-6). The results of these preliminary prototypes will be detailed in a first part. Some of these tests have allowed to estimate seasonal performance according to Ecodesign and Labeling directives and also to fill in a performance map model to estimate same performance according to different building models, climate conditions and DHW loads. Despite results were measured on preliminary prototypes, they are already very promising for a retrofit application, where electric heat pumps have lower efficiency and boilers have already reached asymptotic limits. Finally, five field tests have been deployed in five different countries to complete the objective of demonstration. The first results will be analyzed in the paper. Now, the successful completion of HEAT4U (ending in October 2014) will offer the opportunity for progressing with the next steps, which consists on gathering conditions for industrialization and commercialization phases, to a successful deployment of GAHP technology in European individual dwellings.