Heat pumps are seen as a highly efficient promising technology for space heating and cooling. Their efficiency has been widely studied for different types of heat pumps operating with various energy sources including air, ground, and water. However, different components of the heat pump need to be closely investigated to improve the performance of the system. This study surveys the effects of compressor cooling fan, to evaluate how a heat pump system behaves at different fan speeds. Refrigerant R134a has been used as a circulating fluid in the system. The results obtained from detailed experiments are analyzed to optimize the performance of the entire system using a compressor cooling fan, considering COP, P-h diagrams, efficiency, and thermodynamic properties. It is concluded that cooling the compressor has a remarkable effect on the thermodynamic state of refrigerant which leads to a positive influence not only on the compressor efficiency but also on the entire heat pump unit.