First off—no, there is probably not an angry cat, or a snake, somewhere in your air conditioner. The latter could technically happen, but it’s extremely rare—and if it does happen it’s likely to be a small, harmless critter.
Anyway now that’s out of the way—what is causing that hissing noise coming from the direction of your air conditioner? Also described as a bubbling sound by some homeowners, it seems to resemble the sound a tire makes when air is escaping it.
This, dear homeowner, is likely refrigerant escaping your air conditioner. But what does that mean?
First, What Does Refrigerant Do?
To adequately fill you in on what leaking refrigerant means for your air conditioner, we first need to explain what exactly refrigerant does within your air conditioning system. Your AC doesn’t “generate” coolness in the way that your heater generates heat (by combusting fuel or using electrical resistance).
When you feel the cool air coming from your AC vents, what you’re actually feeling is the absence of heat. The refrigerant cycle in your AC enables heat to be removed from your inside air.
The indoor air conditioning unit houses what’s called the evaporator coil. This is where refrigerant, fittingly enough, evaporates in your system. As it does this, it draws heat out of the air. The cooled air is then redistributed throughout your home, while the warmed refrigerant is sent to the outdoor unit.
In the condenser (again, fittingly), the refrigerant is condensed. As this occurs, the refrigerant releases its heat, which is expelled outdoors with the assistance of the fins on the outdoor unit.
So let’s get back to what happens when refrigerant escapes from—leaks, from—your air conditioning system.
As you can imagine from what you’ve just learned, a low refrigerant level (called a refrigerant charge) negatively impacts the overall cooling capacity of your air conditioner. AC systems are designed to work with a specific refrigerant charge. A low charge always suggests a problem. Refrigerant, as we alluded to at the beginning of this post, is not consumed like a fuel would be, but is instead recycled throughout the system over and over, in a closed loop, ideally throughout the air conditioner’s lifespan.
So, if your refrigerant charge is down, it means either that your air conditioner was inadequately charged to start with or that you have a leak. Whatever the case may be, you’ll need a pro to address the problem. We’ll find the leak, fix the leak, and recharge the refrigerant as needed.
Too little refrigerant means too much strain on your AC system, and this seriously reduced energy efficiency can lead to a whole host of other problems, such as a frozen coil, and eventual serious damage to the compressor. If you notice anything “off” with your air conditioner, the best thing you can do is to call a trained and experienced pro in to take a look.