Guess what it doesn’t just need Freon, you have a Freon leak. How do we know? Because it is a common misconception that your air conditioner uses Freon and that over time that Freon needs to be replaced. Your AC doesn’t use up Freon, meaning it isn’t used up in the cooling of your home. In reality, an air conditioner or heat pump has a sealed refrigerant system that transfers heat from the inside of the home to the outside. The only resource that is used is electricity.
Therefore if you are low on Freon, then it is leaking out and that is the root problem.
If your air conditioner is 4 – 7 years old then problem may be the copper tubing wall and not in the connection points or braze joints. High efficiency equipment uses thinner copper in their evaporator coils because heat transfers faster through the thinner copper. The problem is this thinner tubing also leaks sooner.
Interesting thought – When legislation raised the minimum efficiency of air conditioners and heat pumps to 13 SEER, that resulted in thinner copper tubing walls being used, which resulted in more evaporator coils leaks, and more ozone-damaging Freon released into the atmosphere.
So the next question is what caused the damage to the copper tubing? Formic acid. Formic acid actually corrodes the copper making tiny microscopic pin holes in the tubing. The formic acid penetrates the thinner coil faster. So where is the formic acid coming from?
Formaldehyde in the home can convert into Formic acid on the AC coil. It is extremely mild, but over a period of several years, it will produce pinholes in copper tubing. We call this process formicary corrosion. Formaldehyde is a major pollutant in our homes. Most homes have a measurable amount of formaldehyde in the indoor air, and this will always cause formicary corrosion and Freon leaks.
Trane, of which we are an authorized dealer, has found that aluminum tubing is not susceptible to formicary corrosion and began production of an all-aluminum air conditioning coil in 2005.