Technician Handbook Air Conditioning for Collision Repair System Overview A basic AC system has a high-pressure, discharge side, and a low-pressure, suction side. 1. Beginning with the high side, pressurized, warm liquid refrigerant flows through the Expansion Valve and is turned into very cold, low-pressure droplets. 2. Droplets enter the Evaporator where they vaporize and absorb heat from the vehicle interior, changing into cool, low-pressure gas. The blower fan helps the heat transfer process and circulates the resulting cool air. 3. The Compressor receives the low-pressure, low temperature refrigerant gas and compresses it, changing it to a hot, high-pressure gas. 4.
The hot, high-pressure gas refrigerant enters the Condenser where it condenses back into a liquid and releases heat to the air outside the vehicle. An engine cooling fan helps this heat transfer process. 5. The warm, high-pressure liquid refrigerant passes through the Receiver/ Dryer where some of the liquid refrigerant is stored and a small amount of moisture is removed using a desiccant; then the cycle repeats itself. 22 Collision Repair & Refinish Training