Skip to Content

An Important Reminder About Refrigerant in Your AC


Ever heard these phrases before? “You need to top off the refrigerant in your AC,” or “It’s time to get a refrigerant refill on your AC.” These are based on very common misunderstandings about how air conditioners work, and sometimes unscrupulous people who claim they are HVAC “technicians” try to use them on homeowners.

Here are the facts, straight from your favorite HVAC blogger dog: the only time you’ll need to have more refrigerant put into your air conditioning system is if there is a refrigerant leak. Otherwise, you can expect the amount of refrigerant in the AC will stay the same and keep circulating through it for the lifetime of the system. 

Refrigerant Doesn’t Get “Used Up” in the AC

I understand why people can get confused about refrigerant. It comes from thinking about the AC as a device that “creates” cooling. If it creates cooling, it must be using up some energy source to create it, and therefore that must be the refrigerant. 

But this isn’t how an AC works! An air conditioner doesn’t “create” cooling. What it does is remove heat from one place and releases it in another, and removing heat lowers the temperature of the air. I know something about this as a dog because this is why dogs pant. We’re releasing heat from our bodies to cool down. The way your AC removes heat from your house is with refrigerant, which absorbs heat from inside by evaporating, then releases it outside by condensing. The refrigerant isn’t used up by condensing and evaporating over and over again—it just changes from gas to liquid to gas again. 

Refrigerant Leaks Are a Serious Problem

Here’s something extremely important to remember: an air conditioner is designed to run on a specific amount of refrigerant, which is known as its charge. It can’t be more—which is why you should never allow anyone to “top-off” the refrigerant—and it can’t be less. Either situation will lead to the air conditioner breaking down. You can avoid too much refrigerant easily: just make sure you only work with our experts whenever you need an AC repair. We’ll never put more refrigerant into an air conditioner if it doesn’t need it.

Low refrigerant, on the other hand, can happen without you doing anything. The refrigerant line can develop leaks and allow the chemical refrigerant to start to escape. You’ll need air conditioning repair in Knoxville, TN if your AC has refrigerant leaks. Our experts will locate the leaks, seal them, and restore the correct charge of refrigerant to the system.

How can you tell your AC is losing refrigerant? There are several warnings signs:

  • The air conditioner isn’t cooling as well as it should.
  • Indoor humidity is rising. 
  • You can hear a hissing sound from the AC.
  • Your cooling costs are getting abnormally high. 
  • The evaporator coil has ice on it.
  • The AC is going through short cycles (less than 10 minutes).

These might be signs of other problems in the AC, but trust me, you’ll want the issue fixed, whatever it is! 

Stay cool,