How To Add Freon To Air Conditioning Units

If you have noticed that your window air conditioning unit is not blowing cold air anymore, you are likely low on Freon.  Freon is the refrigerant that provides the cooling for most air conditioners, and while it doesn't wear out or go bad, Freon leaks can occur.  Once you've found and patched the leak, you'll need to add new Freon to the system so it can operate properly again.  This is a fairly simple job that you can do with just a few common tools and a Freon kit, which is available at most hardware stores.

Access the Unit

Start by unplugging the air conditioning unit and placing it on a smooth surface where you can work on it.  Once in place, find the screws that hold the shell of the air conditioner in place.  There are usually at least six screws along the edges, so make sure you find them all.  Once removed, you can slide the cover off so you can see into the air conditioner. 

Prepare to Add Freon

Look into the air conditioner and attempt to find a copper line, which goes into the compressor.  This is the refrigerant line, and it should have an access valve built right into it.  The valve could either be a skinny one that is soldered onto the refrigerant line, or it may have a saddle valve, which will be block shaped and wrapped all the way around the copper line.  In either case, you'll need to remove the cap that is placed over the valve, which can be done with a small adjustable wrench. 

Adding Freon

Once the valve is opened, connect the proper refrigerant charging hose, which comes with the Freon kit, to both the bottle of refrigerant and the access valve in the air conditioner.  Open the valve on the bottle of Freon so it can flow into the hose.  The hose should have a pressure gauge on it, so check the pressure levels now.  Compare those levels against the chart that will come included with the Freon kit to see how much pressure your unit should take (it is based on how large the air conditioner is). 

To add more Freon, simple plug in the air conditioner and set it to the coldest settings.  This will circulate the Freon so more can enter the system.  Run the system for about thirty seconds, and then turn it off so you can check the pressure gauge again.  Repeat this process until you have reached the recommended pressure levels.   Once there, close the refrigerant valve, and remove the hose.  Place the valve cap in the air conditioner and close the whole unit back up.  You can then place it back in the window and run it like normal. If it still has problems afterwards, contact professionals like those at Home Smart Colorado.

It should be noted that Freon is technically a single brand of refrigerant, which was trademarked by DuPont.  Over time, this has become the common name by which all refrigerants used in air conditioners has become known.  You can choose any brand of refrigerant kit that is approved for your window air conditioner without any problem.