As a heating, cooling and plumbing company, we get many folks that call in for service that have already begun the process of trying to figure out what might be wrong with their air conditioners. One of the more common thoughts is that the thermostat must be defective, which actually makes sense to me since it is the one component that is regularly seen and used by a homeowner, even if it is not usually the problem.
The most common we hear, however, is that “my system needs Freon”. What is “Freon” anyway? The accurate term is refrigerant, which is the chemical or chemical blend that moves through the system, changing states and creating a cooling effect when its pressure is dropped. The name “Freon” was just a trade name that DuPont placed on their containers to differentiate their product from everyone else’s. It’s not unlike referring to a soft drink as a “Coke”.
I think generally a homeowner thinks they need refrigerant because either 1) they have had to have it added in the past, or 2) they have heard of other people needing a refrigerant recharge. Here is where the problem lies; because the refrigerant circuit, by design, is a 100% sealed system, if you have to add more to it, the stuff has leaked out somewhere. It can leak out in the vapor or liquid form, depending on which part of the system the leak exists. It is not like topping off the oil in your car, in which case you would just assume it burned off during the combustion process. In fact, if it were not for the failure of moving mechanical parts, a refrigerant cycle would continue endlessly without ever needing human involvement. But it must be the accurate amount. An overcharge is just as bad as an undercharge and in some cases even worse. It’s not one of those “if some is good, more is better” scenarios.
So in the event you need a refrigerant charge, the first question you should ask is, “where is the leak?”.
It is critical that any leak(s) are found for the following reasons:
1) An undercharge will result in an increase in energy consumption.
2) An undercharge will reduce your cooling capacity
3) Some refrigerant types are being phased out due to environmental reasons and are getting VERY expensive
4) An undercharge will reduce the life expectancy of your compressor, which is a very expensive repair