Skip to Content

It’s Not Normal to “Top Off” Refrigerant in Your AC System

manometer pressure

Something that keeps me busy all the time in my job as an HVAC Blogger Dog is tracking down myths and misconceptions about home heating and air conditioning systems. There are plenty out there, and I’ve dealt with quite a few before on my blog. Some of these myths are basic misunderstandings that spread around until too many people think they’re the truth. Others, unfortunately, are outright deceptions used by dishonest—and unlicensed—so- called “technicians” who want to trick people out of money by fixing a problem that doesn’t exist.

The myth of needing to “top off refrigerant” in an air conditioning system is usually a misunderstanding. We often receive calls during the summer from customers who think they have to have a bit more refrigerant to get through the summer. In most cases, they don’t. I’ll explain.

Under Normal Circumstances, Refrigerant Shouldn’t Be Added to an AC

“An AC’s refrigerant needs to be topped off regularly.” How wrong is this? As wrong as inviting a cat as a guest speaker at the National Convention of Mouse Safety. As wrong as giving your dog chocolate to eat. As wrong as … well, you get the point.

The simple fact: refrigerant doesn’t get “used up” while an air conditioner is operating. An AC is designed to use the same amount of refrigerant, called its charge, for its full service life. The refrigerant is not a fuel source like gasoline or electricity that the AC consumes. It circulates in a closed loop evaporating and then condensing, never dissipating.

The idea that you just naturally will need to put more refrigerant in the AC, like a gas fill-up? That’s like thinking you need to fill up your car tires with air each time you go for a drive. If someone were to add more refrigerant to an air conditioner that has its proper charge, it will change the refrigerant pressure in the system, leading to numerous problems—such as a broken compressor. Overinflating your tires is bad, and so is overcharging your air conditioner.

But … There Are Situations Where You’ll Need a Refrigerant Recharge

As the last header said, under normal circumstances, you don’t need to put more refrigerant into an AC. So what are the abnormal circumstance?

To go back to the tire analogy: LEAKS!

The copper lines that move refrigerant around the AC system can suffer from and start losing refrigerant. This is bad news because it will not only affect the air conditioner’s cooling power, it may cause the compressor to break down because of the change in pressure. There’s another problem with leaks, which is that spilled refrigerant is terrible for the environment.

Here are some warning signs you have refrigerant leaks:

  • Ice is starting to develop along the evaporator coil
  • You can hear a hissing sound coming from either the indoor or outdoor cabinet
  • There are hot spots in rooms that used to be cool

You’re not qualified to put more refrigerant in your system! Get our team for the air conditioning repair in Knoxville, TN you need. We’ll find out if your AC has lost refrigerant, and then take care of sealing the leaks and then recharging the refrigerant to its proper levels—not a bit over or under.

Have your AC repaired with our expert assistance. Russell & Abbott provides air conditioning, heating, indoor air quality and commercial HVAC services.