AUTO AIR CONDITIONING
Automotive air conditioning has become almost standard, with virtually all new cars coming equipped with AC. When it’s missing, we notice.
There are three main components to the system: the compressor, the condenser, and the evaporator. Let’s take a look at each.
The Compressor
The compressor is a pump driven by a belt attached to the engine’s crank shaft. When the refrigerant is drawn into the compressor, it's in a low-pressure, gaseous state. Once the gas is inside the pump, the compressor lives up to its name. The belt drives the pump, which puts the gas under pressure and forces it out to the condenser. Compressors cannot compress liquids, only gases.
The Condenser
The condenser is much like a radiator and serves the same purpose as the thing that cools your engine, radiating heat out of the system. The refrigerant enters the condenser as a pressurized gas from the compressor. The process of pressurizing the gas and moving it to the condenser creates heat, but air flowing around the twisting tubes of the condenser cool the refrigerant down until it forms a liquid again, like steam cooling down and condensing back into water. The liquid refrigerant is now high pressure liquid and nearly ready to cool the car.
The Evaporator
The evaporator is where the magic happens. While all the other parts of the system are located under the hood, this one is in the cabin under the dash. It also looks like a radiator with tubes and fins, but its job is to absorb heat rather than dissipate it. Refrigerant enters the evaporator as a cold, low-pressure liquid with a very low boiling point, and the heat in the cabin makes the refrigerant boil and become a gas again. In its gaseous form, refrigerant can absorb a lot of heat, so the gas moves out of the evaporator and out of the cabin, taking the heat with it.
