Development of Energy Efficient R-134a Automotive Air Conditioning System Using Internal Heat Exchanger

Automotive Air conditioning (A/C) System is constantly undergoing improvements over the past decades to achieve higher efficiency. Internal heat exchanger (IHX) so far, has not been given much importance to use in automotive A/C systems. The IHX transfers heat from the hot liquid refrigerant from condenser outlet to the suction gas. Although previous researchers have investigated performance of IHX, this study is distinguished from the previous studies with respect to the type, size and material used for IHX construction. This paper describes the way to improve both capacity and energy efficiency of R-134a automotive A/C System. Three different experiments are conducted under steady state condition in a system test bench calorimeter: one without heat exchanger (baseline) and with two different heat exchangers. The experimental results show that cooling capacity of evaporator increases by 4.84% and 3.17%, Coefficient of performance (COP) increases by 11% and 7.18% and compressor input power reduces by 6.05% and 4.18% with the use of Cu and Al IHX respectively.