The Ultimate Guide to Your Car’s Air Conditioning

As the summer months start, you’ll turn on your car’s air conditioning without thinking. If you have an older model of a car or if you’ve gone from a model with air conditioning back to one that doesn’t have it, you’ll feel the difference straight away. Without air conditioning, you’ll get little but slightly cooled air at best, and warm air blowing on you at worst. What is it that changes from a traditional air fan to proper air conditioning that actually cools you down?

How Air Conditioning in Your Car Works

The best way to make sure that your air conditioning doesn’t end up breaking one day, leaving you with a hot and sweaty trip to a local mechanic, is to understand basic maintenance and how your air conditioning works. Knowing how your air conditioning works means you’ll know how to make sure that it lasts for as long as possible and will minimize how often you need to think about getting it fixed. Without this knowledge, you may find that your air conditioning is malfunctioning regularly. This will lead to more trips to the garage, ultimately leaving you with a larger hole in your wallet.

The process your air conditioner uses to cool your car starts with the refrigerant. This is the liquid that’s used by the system to draw heat out from the air. The refrigerant is transported around the air conditioning unit by the compressor. Refrigerant is also known as cooling fluid and starts off in a liquid form. Refrigerant works through heat absorption. As warm air goes past the cooling liquid, it draws out the heat as energy. Through this process, it boils and becomes a gas, which is pushed through the system into ambient air that cools the refrigerant back down into a liquid, ready to go back into the system to cool more air. This cooling process can be understood if we think about how boiling water happens. To boil water, you need to apply heat, which is absorbed by the water as energy, and in turn, heats up. You have to continually transfer heat energy into the water, removing it from the heat source. Eventually, enough energy is absorbed so that the water turns into a gas. This same process happens with an air conditioning unit to cool the heat in the air – the refrigerant just turns to gas at a much lower temperature.

Air Conditioning Recharge

As we’ve seen, the refrigerant is the key to making an air conditioning system work correctly. If you don’t have enough of it, the system won’t be able to efficiently cool the warm air in your car, and you’ll simply feel warm air being blown out of your fans. This amount of refrigerant in your system will slowly decrease over time as it’s lost through small gaps in the rubber hoses that fix the air ducts that move air around the car. Also, periods of inactivity can negatively affect the quantities of refrigerant in your car. One way to help this is to have your air conditioning running through the winter months, as well as the summer.

Will Your Air Conditioning Be Checked in an MOT?

After the first three years of a car being made, it will need to undergo a yearly MOT to ensure that it’s still road-worthy. As a part of this, the car’s tires and mechanics will be tested. Your air conditioning isn’t a part of this check, though. In addition, it’s essential to know that even if you take your car for a service, the air conditioning will generally not be checked as standard. Because of this, it’s crucial to check if your air conditioning is being maintained, and it’s a good idea to find a mechanic that will do this for a reasonable price at least once per year. This check will make sure that the system is running correctly, and that you can get any issues fixed before they become more significant.

Why the Air Conditioning Stopped Working

The main thing that will cause your air conditioning to stop working is an issue with the refrigerant. The first thing you’ll notice is that your car doesn’t cool down as effectively, especially when temperatures get over a certain amount. This will then continue to get worse until you can feel any cold air at all. There are several reasons why you may not have enough refrigerant in your system. The main one is that you have a leak. This is common but not difficult to fix, especially if caught early.

The process of finding a leak, fixing it, and adding new refrigerant into the system starts with a full performance test. This gives the mechanic a clear idea of how significant the leak is. Also, the amount of refrigerant is weighed to see how far off the expected amount it is. A pressure check is then done to find the leak, as well as a vacuum leak. Once the leak is identified, the refrigerant in the system is removed with a special pump, and then the leak is fixed. Refrigerant is added back into the system, and a final test is done to check if the system is working again. It’s likely that something will need to be replaced, such as the primary seals found here:

To prevent your air conditioning from needing all of this work, we recommend regular services. In a service, all parts of the system, including the fan, drive belt, filters, and seals will be checked thoroughly. The pollen filter will also be checked, as well as a full treatment for bacteria that can build up in the system and cause inefficiencies. Your air conditioning is a vital system to have working, especially in the summer. Without it, driving can become miserable. Make sure to use the information above to ensure you never need to drive without it.


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