How does the Heating & Air Conditioning System work?
It’s easy to forget how important the climate control features are in a car. If they ever stop working, you’ll be shivering or sweating, and remembering exactly why your car has them.
The heating and air conditioning systems are fairly simple. The heater utilizes heat from your car’s engine. Engine heat is absorbed by coolant, to keep the engine from overheating. Some of that coolant runs through the heater core, where it is met by outside air that is blown through the system. That air absorbs some of the heat from the coolant. The coolant then returns to the engine to absorb more heat, while the now-warm air is circulated into the vehicle to increase the cabin temperature.
The air conditioning system is a little more complex, but still straightforward. Refrigerant is compressed in the air conditioning compressor, and turns into a hot gas. It is then cooled into a liquid state by the air conditioning condenser, at which points it heads to the expansion valve. While traveling through the expansion valve, it returns to a low-pressure gas, and quickly cools to a chill in the evaporator. From there, a fan blows air that is cooled by the evaporator, and sent into the car’s cabin.