The refrigerant that I am talking about is called refrigerant R22. Most of the air conditioners made before 2008 were manufactured using this type of refrigerant. The government has banned the sale of new air conditioners that use this refrigerant because it is an ozone-depleting substance. Since this refrigerant is being phased out the supply has decreased and the price has gone through the roof.
Many systems will leak some refrigerant over time because it is under high pressure and will leak out of any fitting that is not perfectly sealed. There are hundreds of spots on an air conditioning system that may develop a leak over time.
In the past, when an air conditioner needed some refrigerant added, the cost was reasonable to fill it back up, even if it needed some added each year. Now with the extremely expensive refrigerant it could cost some homeowners around $500.00 to refill an air conditioner system. If your air conditioner has a leak, and it is large enough to leak out in a year or less, this gets terribly expensive.achieve communities tdx 20 offers excellent info on this.
Some leaks can be fixed if they can be located. The most effective method is by using an electronic leak detector. This is an electronic device that can sense molecules of refrigerant that are sucked into a tube on the end of the detector. It sounds simple but it can be very difficult or sometimes even impossible to locate the leak.
The tip of the detector wand has to be directly pinpointed on the leak. Oftentimes the leak is in a place that the wand can not reach such as the underside of evaporator coil which is inside of the sheet metal duct work above the furnace. It can also be in a pipe that may be buried inside of a closed wall behind the drywall.
If the leak can be found then a repair may be possible. A leak on the evaporator coil may require replacing the whole coil. If the leak is on a fitting then it may be repaired by brazing. After the leak is repaired the air conditioner is pressure tested with dry nitrogen. Then the system needs to have a deep vacuum applied to remove the nitrogen and any air that entered. After all of this is done, the air conditioner is then filled with new refrigerant.
As you can imagine this is labor intensive and can get to be very expensive. It may be more cost effective to replace the air conditioner instead of repairing it especially if it is older and has other parts that may fail in the future. Many of the new air conditioners have 10 year warranties so you will not have to worry about future leaks.
All new units made after January 1st 2010 have refrigerant R410 in them. This new refrigerant does not harm the ozone and is not as expensive as the phased out R22 refrigerant. Unfortunately the new refrigerant will not work in air conditioners that were made to use R22 refrigerant.