R-134a Heat Pump Application for the Buses by Using Engine Coolant as a Heat Source

This work is based on a premise that a heat pump (HP) can replace a plurality of passenger heaters and an auxiliary heater (fuel fired heater) of the buses. It means that we can take advantages of the design cost, weight, and package efficiency. In addition, the optimized climate control units from integrating cooling and heating into the HP can improve the heating efficiency.

This paper shows a real application of R-134a HP, using engine coolant as a heat source, remodeling a roof mounted air-conditioner (AC). Furthermore, the bench test and the on-vehicle experimental results served to compare the heating performance of HP with conventional heating systems.