Now that May long weekend has passed, it is finally time to start thinking about cooled seats, moonroofs and air conditioners. While it may be true that not every car has any one of these features, more often than not, vehicles have air conditioning units. With the weather getting hotter, we don’t want you to be caught without cold air. Read on to learn both about how the air conditioning unit in your vehicle works, and when to get your A/C unit recharged.
How Does My Vehicle’s A/C Unit Work?
The process starts with refrigerant passing through the A/C system’s compressor. The compression process doesn’t cause any state changes but rather puts the gas under pressure.
Next, the high-pressure gas is put into the condenser. The gas starts out very hot but the air moving around all of the coils in the condenser helps to cool it down. In fact, the air cools the refrigerant down so much, it becomes a liquid.
Before moving over to the evaporator and expansion valve, the liquid refrigerant is put through a receiver dryer where desiccants (small granules that attract water, like those little “do not eat” packages found in shoe boxes) remove all the water from the refrigerant. Even though refrigerant is designed to keep your vehicle cool, ice crystals forming in the system would cause some serious problems.
Now that the water has left the system, the high-pressure liquid is put through the thermal expansion valve. This process allows the liquid to depressurize. The valve’s ability to sense pressure regulates the flow of refrigerant to maintain a steady flow of liquid. This same valve can wear out over time.
Finally, this lower pressure liquid moves into the evaporator. At this point, the refrigerant is quite cold (0 degrees Celsius). Unlike water, the refrigerant won’t freeze at this temperature, in fact when it comes in contact with the cabin’s temperature, the refrigerant will actually turn back into a gas. One of the properties of refrigerant gas is the ability to absorb heat.
Both humidity and warm air are removed from the cabin through this process. Cool air is blown into the cabin and the process begins again. This process also allows the evaporator to attract the dirt and pollen in the air along with condensing the water in the air. Hence, if you see a drip in the passenger footwell where the evaporator is located, it is most likely just water.
What Are Freon Fluid and Refrigerant?
Freon is the brand name for one of the original refrigerants: R-12 or CFC-12. The first air conditioners, or at least those prior to 1996, used this. The problem is, being a chlorofluorocarbon, it was determined that it was causing too much damage to the ozone layer. From 1996 onwards, vehicles have been using R-134a and R-1234yf. In fact, if you find your vehicle has the old system, it needs to be transitioned to R-134a.
R-134a has been used in vehicles since 1996 and is not nearly the ozone depleter or contaminant that R-12 was. However, in the mid 2010’s a new refrigerant was added to the mix: R-1234yf. With a lower global warming potential, this new refrigerant has been slowly migrated into vehicle lineups since about 2013/2014 depending on the brand.
As with most things that are better for the environment, they come at a cost. R-1234yf is both more expensive and takes significantly longer to do an A/C recharge.
Not sure where to find this label? Sheri-Ann shows us over on our Tik Tok Channel
What Does Recharging My A/C System Mean?
Have you noticed that your vehicle either isn’t blowing cold air, or it isn’t as cool as it used to be? That’s when you know it is time to recharge your air conditioning system.
Recharging your A/C unit is the technical term for draining your A/C unit of refrigerant, and replacing it. Because your Air Conditioning unit is supposed to be a closed system, if you don’t have a “full tank” of refrigerant it means there is a leak in the system. Some fluorescent dye is added when the recharge is done to locate the leak so it can then be repaired.
What Should I Know Before an A/C Service?
Remember how we mentioned that the different types of fluid had different costs and recharge times?
Under the hood and at the front of your engine, you will see a label with air conditioning information. On GM vehicles, it shows a snowflake. This is the information about your air conditioner unit. Here is how things will change depending on the refrigerant your vehicle uses:
R-134a: This can be done in a relatively short amount of time, you could probably wait out the service in the lounge.
R-1234yf: This will be a longer and more expensive service. In fact, it costs roughly 4 times as much to get the R-1234yf refrigerant and it takes 4 times as long to conduct the recharge service.
While you may think to save yourself some money and just do it yourself. We will advise that maybe the R-134a systems can handle the do-it-yourself kit, however, R-1234yf systems need to be as pure as possible to operate. This means the dyes and sealants that are notorious in the do-it-yourself kit can cause serious problems to your air conditioning system. We would be more than happy to get your air conditioner working as planned and help you with any potential leaks. You can book your service appointment in-store, over the phone at 780-486-3333, or online here.