Freon acts as a refrigerant in older car air conditioning units. It has become much less common as scientists discovered the harmful environmental impacts that it was having. That being said, there are still certain air conditioning units that will use freon as a refrigerant.
Freon can be difficult to get hold of in modern times, and many people are unaware of how to replenish freon levels within their air conditioning units.
If you do not replenish the levels of refrigerant in your vehicle, the air conditioning unit will cease to function. In the winter months, this is not much of an issue, but when it begins to get hot you will kick yourself if it is not sorted.
Thankfully, replacing the freon levels in a car’s air conditioning unit is remarkably simple once you know the method to follow. We have detailed this below and answered a few frequently asked questions to help you on your mechanic journey.
What is freon?
Freon is a chlorofluorocarbon (CFC). This is a partly hydrogenated paraffin hydrocarbon that is produced as a volatile by-product of methane, ethane, and propane.
It is a colorless gas also referred to by the name R-22. The trade name Freon was trademarked by a company known as DuPont in the 1930s.
Over the years, as more research has been done into the harmful effects of CFCs, the inclusion of freon in mechanical systems has declined. It is only likely to be found in your car if it was manufactured prior to 2003. Cars produced between 2003 and 2010 are unlikely to use freon, and cars manufactured after 2010 will almost certainly not use freon.
This is due to regulation set out in 2003 which set strict terms on the supply and use of freon as a refrigerant. In 2010 freon ceased to be produced for use in new mechanisms. The legislation allowed for the production of freon to service older equipment until last year, 2020. From now onwards, any freon created must be sourced from recycling.
You must dispose of freon containing products in the appropriate manner. If you are trying to dispose of an old unit that may contain freon at a landfill, you may be asked for proof that the refrigerant has been removed.
Freon containers should only be removed by people who have received adequate training. This prevents health issues and environmental damage from being incurred. You should never cut the lines to a refrigerant unit, or remove the compressor unit yourself.
How does freon work?
Within your car’s air conditioner unit there is an intricate system of compressors and coils. The unit compresses the R-22 gas and makes it incredibly hot. This highly heated gas is then pushed through the coils in the unit. This cools the gas down and changes its state to liquid.
Once the freon is a liquid, it is able to absorb heat from the ambient air. At the same time, cool air is pushed out through the system. The air conditioning unit works in a cycle where the hot air is drawn in and the cool air is expelled.
Without the presence of freon or another refrigerant, the air conditioning unit cannot function correctly. If the refrigerant levels decline too much due to a leak, the air conditioner cannot work at all.
If you are concerned about your refrigerant levels dropping as a result of a leak, it is worth taking your car to a qualified mechanic. They will be able to look over the system for any evidence of a leak and fix it before more refrigerant is added.
It is very unwise to add additional freon to a leaking system as this can cause serious environmental damage.
What do I need to add freon to my car?
To ensure your personal safety while adding refrigerant to your car, you must have a refrigerant dispenser and protective goggles. It is wise to also wear gloves and an N95 mask to fully protect yourself.
The refrigerant dispenser must have a trigger and a pressure gauge. This will allow you to keep an eye on the pressure levels within the system as you refill the refrigerant levels.
How to prepare to add freon to my car?
The first thing that you need to do is gather all of your equipment into one place. Once you have done this, you should attach the refrigerant dispenser to the can containing freon.
To do this, simply insert the can into the base of the dispenser and screw to secure in place. It is vital that this is properly attached as the freon is pressurized. Doing this step incorrectly could result in injury to you or others around you.
Your next step is to check that the refrigerant is the root cause of the problem. To do this, you should run the engine of your car and activate the air conditioning. Set the power to the maximum setting and look for the compressor. This is connected to the engine of your car on the low side fill port with a hose.
Follow the hose until you find a pulley somewhere on the compressor. Look in the center to see if there is a spinning section. If there is, the compressor is working correctly.
If it is not spinning, you need to add about half of the contents of the freon can to the air conditioning unit. If this does not fix the issue, you must take the car to a mechanic as the issue is more complex than you can solve alone.
How to add freon to my car?
Step 1
To add freon to the air conditioning unit, you should open the hood of your car. Look on the left hand side of the engine to find the refrigerant fill port.
This will resemble a small metal pipe with a rubber hose coming from both ends. It will have a plastic lid which must be removed to add in the freon.
It will be located near to the firewall of the engine bay – follow the larger hose to find it. Take great care not to touch the engine bay or hoses as they can reach very high temperatures.
Step 2
Read the instructions on the dispenser for the correct way to attach the dispenser to the fill port. It is recommended to complete this program as fast as possible to stay safe. To do this, grasp the dispenser’s connector and lift the external covering.
Press down on the dispenser’s trigger to push any residual air out of the hose. Press the connector to the refrigerant fill port as you continue to squeeze the trigger, holding the connector sleeve.
This ensures the refrigerant is expelled in a steady stream. This minimizes the risk of moisture and air entering the air conditioning unit of your car.
Release the sleeve, which should force the connector into place. Once this is done, release the trigger.
Check the instructions for the dispenser. There should be a set of maximum and minimum values for pressure readings printed. This will correspond to varying air temperatures.
Step 3
Check the ambient air temperature and cross reference this with the printed table. This will show you the pressure range that you are aiming for.
Once you know the range, read the pressure level of your air conditioning system. If this is lower than the target range, slowly begin to add freon to the unit.
Double check the positioning of the can and then depress the trigger, holding it down for a count of 10. Leave the system to stabilize for around 30 seconds and then check the pressure levels once more.
You should not check the pressure unless the compressor is in action. This is because if it is not engaged, the pressure level reading is likely to be inaccurate.
Continue this process until the pressure reading falls within your target range. It is wise to take a note of the volume of freon added. This is because it cannot be removed without the assistance of a qualified mechanic.
Step 4
When you think you have added a sufficient quantity of freon, allow the system to settle for a few minutes. Once this time has elapsed, check the pressure levels again. If the reading is still within the target range, you can take the connector out of the fill port and replace the plastic cap.
If the can is empty, turn it upside down and depress the trigger for about 60 seconds. YOu can then detach the can from the dispenser. If you need to replace the can while refilling the freon, you can do this without detaching the connector from the fill port.
Step 5
Once everything is back in its original place, you can turn on your car and the air conditioning system.
If you have followed the steps correctly, you should be flooded with cool air. This will not need to be rechecked for around 6 to 12 months.
How do you know if your car AC needs to be recharged?
There are 3 main ways to tell if your car air conditioning unit needs recharging.
These are a loss in cooling ability, the AC clutch failing to engage, and any visible signs that the refrigerant has leaked.
Loss of Cooling Ability
If you notice your air conditioning system functioning at a lesser quality than you are accustomed to, this could be a sign that the system needs to be recharged.
The air conditioning unit works by circulating pressurized refrigerant, such as freon. When the levels of refrigerant are too reduced, the air conditioning system will not function correctly. This may present as the air not blowing out at all, or the system blowing out warm air.
AC Clutch Not Engaging
If you have set your air conditioning unit to the coldest setting, you should hear a clicking noise as the clutch engages. This is due to a signal that is sent from the air conditioning pressure switch.
When the pressure level inside the air conditioning system drops to a level which is too low, the switch will not work and the clutch will not engage. This means that the air conditioning system cannot circulate any cool air and it will not function.
Refrigerant Leaks
If you notice any visible signs of refrigerant leaks then this is a clear indication that the air conditioning system needs a recharge.
This will look like a greasy film on any components of the air conditioning system, or a pool of liquid underneath your car. This will be the refrigerant from your car leaking out until it has all escaped the air conditioning system.
If you suspect a leak in your air conditioning system, we strongly recommend taking your car to a garage or auto shop. Here, a qualified professional can look over your car and find the source of the problem.
This will save you recharging the air conditioning system only to have the same thing happen once more.
How do you detect and repair leaks in the air conditioning unit?
Create a solution of water and dish soap and decant this into a spray bottle. Open the hood of your car and spray this solution over the air conditioning unit. You should ensure that the entire unit is covered in a film of your solution to make sure that you don’t miss any leaks.
Once you have sprayed, watch the surface of the air conditioner. If there are any leaks present, you should begin to see some bubbles forming. This works following the same principle as when you are checking bike tires for a puncture.
If the bubbles that you can see are infrequent and slow to form, this indicates that your leak is small. If the bubbles appear to be foaming then the leak is likely to be large. This will often require professional assistance to repair.
If you have small leaks then you can use a recharge kit that contains a sealant. Try to look out for products that say the sealant is a conditioner. This ensures that it will not clog the pipes of your car’s engine – if the sealant is gooey then it will build up and cause blockages.
How much will it cost to recharge the air conditioning refrigerant in my car?
It is fairly inexpensive to complete, particularly if you can perform the entire process by yourself.
An individual can of refrigerant is likely to set you back somewhere between $30 and $40.