PHASE CHANGE MATERIAL EVAPORATOR CHARGING CONTROL

A method of controlling an air conditioning compressor in a heating ventilation and air conditioning system having a evaporator including a phase change material is presented. The method includes the steps of measuring an evaporator output air temperature, determining a state of charge value by calculating a difference between an estimated refrigerant temperature based on the evaporator output air temperature and a phase change material freeze temperature and integrating this difference over time and operating the air conditioning compressor to maintain the state of charge value between an upper and lower limit. A method of recovering braking energy in a vehicle containing a heating ventilation and air conditioning system having the evaporator including the phase change material is also presented.