30 May 2005


Heat pump for residential heating constitutes a key technology to lower CO2 emissions
associated with building heating. The heat pump system capable to replace the current fuel or gas
burner heating system needs to provide heat at a high condensing temperature (around 55°C) in order
not to change the hydronic network. The heat pump system needs also to provide 100% of heating
capacity even for low outside temperature, for Europe typically –15°C.
The paper presents a new design of a variable capacity heat pump capable to provide heat at such
a high level of temperature by using variable composition blends, and a two-stage system.
The seasonal energy efficiency is calculated and a comparison is performed with the current heating
system using fuel or gas in order to forecast the gains in terms of CO2 emissions for European
climatic conditions and different generation mixes.