Understanding Your Vehicle's A/C

It’s the start of summer and that means turning on the A/C instead of the heat in your car. But what if your car isn’t blowing that refreshing cold air like it used to? It might mean that your A/C needs to be looked at and fixed!

How exactly does your A/C work? It’s a lot of fancy words involving thermodynamics, so here’s the watered down version: When you turn on the A/C, the car’s compressor compresses the system’s refrigerant and raises its temperature. It loses heat while it flows through the condenser, and passes through the receiver/dryer where it gets removed of contaminants and moisture. It moves on to the expansion valve accumulator where it loses pressure and temperature before passing it on to the final step, the evaporator. The evaporator cools down the air even more, removing more moisture, before pushing the air into your car.

It’s complicated but that cold air on a hot day is worth it.

When you notice that your air conditioning isn’t performing as well and keeping you cool as a cucumber, bring your car in for an inspection. For most situations, your car is probably just low on Freon or the refrigerant; but low Freon could be a big sign that something isn’t right. For example, since the A/C is a sealed system, you could have a leak. An inspection will help recharge your car and get down to the root of the air conditioning problem.

However, if the inspection shows that your car has plenty of Freon, it could be a different part of the air conditioning system. The A/C is comprised of five parts: the compressor, condenser, receiver/dryer, evaporator and thermal expansion valve. Here are the signs that these parts show when they need to be replaced:

• Worn compressor: leaks, noise, and erratic or no A/C operation
• Worn condenser: leaks, clogged or damaged tubes, poor A/C performance
• Worn receiver/dryer: poor A/C performance, moisture on glass. Whenever the A/C system is opened for repair, replace the receiver/dryer.
• Worn thermal expansion valve: poor A/C performance, dirty or clogged
• Worn evaporator: poor A/C performance