In a basic automotive HVAC system, which component absorbs heat from the cabin air to produce cooling?

• A. Condenser
• B. Expansion device
• C. Compressor
• D. Evaporator

Answer: (D)

The evaporator is the component that absorbs heat from the cabin air to produce cooling. In a basic automotive HVAC system, refrigerant passes through the evaporator at low pressure and low temperature. As cabin air is blown across the cold surface of the evaporator coil, the refrigerant evaporates, taking in heat from the air (the latent heat of vaporization) and cooling the air that then circulates back into the cabin. The moisture in the air also condenses on the evaporator, helping dehumidify the cabin. The refrigerant then returns as a low-pressure gas to the compressor to continue the cycle. The other parts—condenser, expansion device, and compressor—play different roles (reject heat outside, reduce pressure, and increase pressure), but they don’t remove heat from the cabin air in the same way the evaporator does.