A detailed study of prominent factors affecting evaporator frosting in a mobile air conditioning (MAC) system

In an automotive air conditioning system, evaporator is well designed for effective heat transfer between refrigerant and air flowing over the evaporator. Hence, the better cooling and dehumidifying the incoming air. Sometimes, at the low ambient temperature and higher relative humidity conditions a frost is observed. It is accumulated over the evaporator and often become thicker enough to block the flow of air completely passing through the evaporator resulting in a rise in vehicle cabin temperature. Current work presents the probable causes of frost formation and their effects on the performance of evaporator and hence, the performance of the automotive air conditioning system. There are four major factors, thermistor poor response, undercharged and overcharged system, clogged air-filter, and also the type of compressor causing frost formation over the evaporator are considered for analysis. Current work presents the experimental analysis of the evaporator performance in the low ambient conditions with the above factors in different iterations. With the above analysis new methods and guidelines can be generated in order to avoid frost formation over the evaporator.