Surviving the Summer Heat: Knowing Your Car’s A/C System

Posted June 10, 2014

Summer in White Bear Lake is around the corner, and with it comes summer heat. The days are hot, and getting hotter – make sure you stay cool in the heat by checking the A/C in your car! Understanding the components in your vehicle’s air conditioning and some common issues can help you keep cool all summer long.

Components

This guide from About.com reviews the main components of automotive air conditioning:

“Your air conditioning system is made up of a compressor, a condenser, an evaporator (or drier), refrigeration lines and a couple of sensors here and there.

• Compressor: This is the heart of your a/c system. The compressor is what takes the refrigerant (the gas) and pressurizes it so it will cool the air. It’s run by an engine belt. The compressor also has an electrically operated clutch that turns the compressor on and off as you demand more cool air.
• Condenser: The condenser is like a miniature radiator, usually mounted at the front of the car right next to your big radiator. Sometimes the condenser will have its own electric cooling fan, too. The hot, compressed air passes through the condenser and gets lots cooler. As it cools, it becomes a liquid.
• Evaporator: The evaporator is another little radiator that does just the opposite task as the condenser. As the super-cool liquid is passed through its tubes, air is forced through and gets really cold, right before it hits your face. As it warms up again, the refrigerant starts turning back into a gas.
• Thermal Expansion Valve: You don’t always want to freeze your toes off, so the a/c system has a valve that controls the flow of super-cool refrigerant to the evaporator. This way you can regulate how cold the air blowing on you gets. There are a few types of valves in use these days, but they all do the same thing.
• Drier or Accumulator: The drier, also known as the receiver-drier, is sort of the safety catch for your system. The compressor is only supposed to compress the gas form of your refrigerant. However, there’s always a chance that some liquid could make it back that far. The drier catches this liquid before it can damage your compressor. Since even the tiniest leak or careless installation can introduce water moisture to the system, the drier absorbs this chemically, using what’s called a dessicant (similar to that packet of “DO NOT EAT” that comes with electronics). The drier also has a filter that catches any gunk that might be in there.

Different systems also have sensors here and there to tell it pressure and temperatures, but they are specific to a make and model of vehicle.”

Common Problems

As the heat rises and you use your car’s A/C more and more, you may notice small issues, like taking too long to cool your vehicle or blowing air that is only mildly cool when it’s turned on high.

If your air conditioning is cool but not cold, there could be a few culprits. Check your cabin air filter – if it is dirty or clogged, your A/C may be less effective. You can also check for leaves, bugs, or dirt preventing the air from going through the condenser. If there are no blocks or clogs, this problem may be caused by low pressures or stuck cooling fans.

The compressor also can cause issues keeping your car cold. The clutch engaging and disengaging rapidly could indicate you are low on refrigerant. If it is not engaging at all, there may be an issue with voltage or the clutch. Lack of voltage may be caused by a bad fuse, cycling switch, or low refrigerant pressure.

The most common problem associated with A/C systems is leaks. A leak in the air conditioning system causes refrigerant to escape slowly out of the system into the atmosphere. Low levels of refrigerant could indicate a leak, and as the level gets too low it can trigger a low pressure cutoff switch that will prevent the air conditioning from working. Bring your vehicle into our shop – our technicians will look for leaks and recharge your refrigerant!

If you are experiencing any problems with your car’s air conditioning in the summer heat, stop by our shop for an inspection. Keep you’re A/C working so you can keep cool this summer!