The compressor and condenser are critical for the proper operation of the air conditioning. Without those two parts, your car’s air conditioning system would never function properly. But what is the difference between the AC condenser and compressor?
A car’s condenser and compressor both perform separate but important roles in air conditioning. The compressor changes the refrigerant into a liquid by compressing it and the condenser uses the process called heat exchange to cool the liquid refrigerant.
I’ll take you through how an AC system works and how the compressor and condenser perform their functions. In order to pump out cold, dry air, there are several processes that have to occur which are based on fundamental tenets of physics.
What Is The AC Compressor?
This is one of the most important components of your AC system. It does its job by absorbing heat and cooling the air and gets its power from the engine via a belt drive. The compressor is controlled by a clutch that turns the compressor on and off as the cycle demands.
The compressor in effect does what its name suggests, it squeezes the refrigerant. The refrigerant is in gas form and is compressed or pressed flat in order to prepare for the next stage of cooling.
This process of compressing gas causes physical changes to it. One way to think about air conditioning is that it is an efficient method to carry out a phase change, the gas refrigerant is transformed into cooling liquid vapor.
Air conditioners work on the basis of heat exchange and pressure gradients. Certain substances work very well at changing from liquid to gas and using principles of physics to cool down the air, which are known as refrigerants.
A pressurized gas heats up by absorbing the energy around it. As the refrigerant is inside the air conditioning system, it is then circulated through a series of tubes which results in the gas cooling off. It is at this point it enters the condenser to create cool air.
As this heat dissipates, the refrigerant will then change back to a liquid form, ready for recirculation and the process starts over again.
All of this needs to take place in a sealed system. This is why leaks of refrigerant cause AC units to stop working.
What Is The AC Condenser?
Once the compressor has created the high-pressure refrigerant it flows to the AC condenser. The condenser is like a small radiator located at the front of the car near the main radiator.
As air flows over the condenser, aided by fans, heat is removed from the refrigerant as the heat is transferred to the outside air. This causes the gas to condense back into a liquid. The condenser and compressor have to work together to produce cool air.
The condenser carries out the work of transforming the refrigerant. The condenser is responsible for taking the pressurized gas from the compressor and changing it into a liquid vapor.
The cool air you feel from your automobile’s air conditioning is because of the process that takes place in the condenser, after some filtering and cooling.
What Other Components Does A Car AC Have?
The other important parts of an AC unit are the evaporator, thermal expansion valve, and accumulator.
The evaporator is in effect the final step to cool the air. As the pressurized refrigerant is passed through the evaporator’s tubes, the air is also pumped through, and in the process, it gets chilled, right before it blows into the car’s cabin.
The thermal expansion valve is a way to control the air temperature. It is important to regulate the flow of the super-cool refrigerant into the evaporator. Otherwise, you would just have a blast of freezing air all the time.
The accumulator, also known as the receiver-dryer or dryer, acts as a temporary hold for the refrigerant. It’s important to keep liquid or moisture out of certain sections of the AC system.
The accumulator contains a desiccant, which is a chemical that absorbs this excess moisture as it passes through the air conditioning system. Furthermore, the dryer also has a filter that helps stop debris and dirt from getting into the system.
Why Is My AC Not Working?
If your AC no longer blows cold air consistently there are several things you should check.
One of the most common is to check your refrigerant levels and refill if necessary. Also known as recharging, this can help improve the cooling function. However, given the nature of a vehicle AC’s being a closed system, refrigerant should not be missing. This indicates a leak and you should get it checked.
While you can do a recharge or regas yourself, it is generally best left up to an expert. Refrigerant is not exactly a safe substance and AC maintenance and service can be quite difficult.
Another thing to check is whether your compressor is operating. Turning on the engine and the AC should result in the compressor starting to engage.
Look up pictures of what a compressor looks like and then check to see if yours is running. If not, it’s best to visit a mechanic as there is some fault or you may need a replacement part.
Finally, you can purchase gauges that can test the pressure of your AC system. Generally, an AC system should be charged to 40 psi. By running the car with the AC on and the gauge attached to the low side pressure port, you should get a reading close to 40 psi.
Be aware that doing this improperly can result in refrigerant being released into the air. If you are not confident with auto maintenance it’s worth taking the vehicle to a certified air conditioning technician or your local mechanic.