Auto A/C Terms - Glossary
Cold

We all think about air conditioning as being cold or that it makes cold air. That really is not what happens. Air conditioning is really all about heat. That is because everything in our environment has some amount of heat in it. It is only when a substance reaches a temperature known as absolute zero that it no longer contains any heat. Therefore, you should understand that cold is not a positive state. Cold is just the absence of heat.

When A/C systems cool the vehicle, they are just removing the heat from the air that is passing over the evaporator. If that hot air is humid, you will see a constant drip of water running from behind the passenger side front tire. That condensation is occurring because the humidity condenses when the hot air meets the cold evaporator.

None the less, the air conditioning system still only removes the heat and humidity from the air entering the vehicle. In removing that heat, it allows the passengers better temperature control and overall comfort.