22 February 2002
With their background of energy-saving and environmental attributes, gas engine-driven heat pumps (GHPs) are growing in popularity. They have created a firm position in the medium-to-small-scale commercial space cooling and heating market in particular, but products developed for residential applications have recently been attracting attention. On the other hand, even greater efficiency is being demanded in order to cope with global environmental problems and energy issues. As for GHPs, in addition to more highly efficient devices such as engines and compressors, waste heat recovery is an effective method to improve efficiency. This paper describes systems for utilizing the waste heat from residential GHPs to provide comfortable air conditioning and efficient supplies of hot water.