A 1.3-RT gas-engine heatpump (GEHP), the smallest in the world, has been developed. The engine and auxiliary parts for this system were specially designed for the GEHR The main hurdles before the system could be commercialized were noise, vibration, durabili~ reliability, and cost.

The specifications of the 1.3-RT heat pump are as follows: cooling capacity and COP:* 10,000-15,900 Btu/h and 0.93-0. 73; heating capacity and COP: 15,500-25,800 Btu/h and 1.54-1.34; noise level: 50 dB(A)/1m; engine thermal efficiency: 30%H; lifetime: more than 20,000 hours; and maintenance: ignition plug exchange every 2000 hours and an engine oil exchange every 4000 hours.