This paper establishes a set of gas-engine heat pump (GEHP) experimental systems with R134a as the refrigerant and natural gas as the primary energy source to drive the open compressor. The performance of a GEHP with cooling and hot water supply were tested with evaporator water inlet temperatures ranging from 12-22 °C

ambient air temperature ranging from 24.2-35.6 °C

and gas engine speeds ranging from 1400-2000 r/min. The results show that the effects of evaporator water inlet temperature and gas engine speed on the system performance were more significant than those of ambient air temperatures. As gas engine speed varies from 1400 r/min to 2000 r/min

the COP1

COP2

PER1

and PER2 of the system increases by 15.5%

9.9%

18.8%

and 13.5%

respectively. Within the range of working conditions

the average cooling water outlet temperature can reach 6.7-19.3 °C

the average hot water outlet temperatures can reach 40.7-61.7 °C

and the primary energy ratio (PER2) of GEHP system can reach 1.14-1.45 considering heat recovery.