Most people don’t really bother to think how their air conditioner works in their car. Until it stops working, that is. You climb into your car on a sweltering day, crank the A/C, and get blasted by nothing but hot air on the entire ride home.
This is where understanding your A/C system and how it works might have helped you prevent this problem in the first place. Fortunately, the A/C system in your car is simple enough to understand and easy to have maintained.
The entire process of cooling your car on a hot day requires several different pieces of machinery which eventually lead to cold air.
Compressor – The sole job of the compressor is evident in the name; it compresses a refrigerant gas. It does this via a belt driven by your engine. Occasionally, a compressor belt can slip off or break. This will lead to A/C failure, but it is an easy fix.
Condenser – The condenser uses radiant heating to separate the gas from the heat generated by compressing it in the previous step. The result is a cool liquid refrigerant.
Receiver-Dryer – This part of the unit is primarily responsible for filtering out moisture and particulates that can hard your A/C system. Because of its nature, this part of the system can wear out over time and is a usual culprit with air conditioning under-performance.
Also called the accumulator, this part is commonly replaced when problems with A/C systems are experienced. It should be replaced regularly due to the fact that it helps protect the rest of your A/C system.
Expansion Valve – The expansion valve is the part of the A/C system you can control from your dash board. It regulates how much of the fluid refrigerant is being sent to the final phase of the process, the evaporator.
The expansion valve can sometimes become blocked by debris from the rest of the system. Over time, this can restrict lubricant flow to the compressor and lead to a larger failure. An important part of a healthy A/C system is making sure the expansion valve is clear.
Evaporator – The evaporator is designed to take warm or hot air from your car and replace it with cold air. When the liquid refrigerant is exposed to heat it boils and returns to a gaseous state. This heated refrigerant is then removed and sent back to the compressor to start the process over. In its place, you get a blast of cold dry air.
The evaporator is an important part of the system that is very susceptible to failure. A small leak in the unit can lead to refrigerant loss and an under-performing A/C system. The unit can also corrode over time and require replacement.
Problems can occur at multiple points across your system and lead to addition problems at other points in the system. Aside from the major components, you can also get leaks in tubing or joints that can lead to failures. Because of the widespread effects of even small issues, it is important that you get your A/C system checked regularly just like you would do for your engine.