I understand how frustrating it can be if the air conditioner of your car doesn't work and leaves you sweating. In summers, it can be a real nightmare. There may be many reasons why a car AC blows hot air. To better understand where the problem lies, it is important to know a little about the components of your car AC.

A refrigerant is a fluid which cools the air by absorbing the heat from the interior of the vehicle, and is responsible for the cooling effect. One of the most important components of the car AC is the compressor, which is a mechanical pump that pumps the refrigerant. The condenser is responsible for the removal of the heat absorbed by the refrigerant. R134a is a new form of refrigerant which is eco-friendly, and less expensive than the R12 coolant which was used in a few older automobiles.

Why is My Car AC Blowing Hot Air?

For your AC to work effectively, it must receive its fuel, which is the refrigerant. The refrigerant is the soul of the AC. The refrigerant passes into a part called compressor, which pumps it. There can be couple of reasons for the air conditioner blowing hot air. It can be because of either a compressor problem, or a problem getting the required amount of refrigerant. Other possible causes can be obstructions in the system, or the blend air door in the HVAC (Heating, Ventilation & Air Conditioning) unit being stuck in the 'HEAT' position, due to which the evaporator receives no air.

The problem of a car air conditioner blowing hot air on one side is mostly seen in cars which have a dual zone climate control system. Such systems allow you to control the temperature in the passenger compartment of the cars as per individual comfort levels. The reason it blows hot air on one side may be because of low refrigerant levels or because of a HVAC door issue. You may require to take it to a mechanic to fix the issue.

Why is My Car Air Conditioner Not Working?

So, there are two possibilities why AC doesn't work. First, either the refrigerant is unable to absorb the heat from the car interiors. Secondly, it must not be getting refrigerant, maybe because of a clogged condenser or refrigerant leak. If you feel that you AC is not throwing enough cool air, then it may also mean that the refrigerant is leaking out.

To get rid of this problem, you've first got to check the condenser of your car. You've got to clean it properly remove the dirt on it, debris, etc. You can clean it with a soft brush, or with forced water. The condenser looks like a mini radiator, and it is situated in front of the radiator of your car. If it doesn't solve your problem, then you would have to take it to a car repair shop and get it checked by them. If it is a leak problem, then your mechanic will track from where it is leaking, and then fix it.

Another main reason why the AC doesn't work in a car is because of a compressor problem. The compressor of your car will not turn on, if there is low refrigerant. And that is because of the low pressure safety switch (it is a part of HVAC system). Well, it is actually good for you and your car because the compressor will wear out, causing further more car problems, if it is not lubricated properly. Hence, it is really very important to check if the compressor engages properly while the AC is turned on.

Now you know what checks needs to be done when your car air conditioner is blowing out hot air. If it can be located and if you think that you can fix it yourself, then go ahead with it. However, the best person for fixing a car air conditioner is a mechanic. Take your car to a car repair shop which are expert at AC repairing.