What odors from an AC mean
Every type of odor that comes from an AC unit indicates a particular type of issue with the system. Some cabe solved with home servicing or cleaning, but others may signal serious problems that require professional intervention.
The foul odor
Like the smell of rotten eggs or something rancid, this odor may indicate that there is a dead critter in the back of the AC. It can come from birds or rodents, since either may become stuck in AC units.
Foul odor also probably indicates a blockage in the duct, which can lead to water leaking or dripping, aside from a bad smell. Even ductless AC units may have this issue as it’s not uncommon for insects or small reptiles to get trapped inside the devices.
The gas odor
This is the most concerning type of odor that can come from an AC unit. It often indicates that there’s a gas leakage in the system. The fact that natural gas has methyl mercaptan added to it in order to have a distinctive scent, makes this an unmistakable issue.
It’s recommended to turn off the gas supply and contact professionals to come and locate the source of the leak and fix the issue.
The gunpowder or burning plastic odor
There are two reasons for this type of odor to come out of an AC unit. The first is that one or more components are burning. Burning components can sometimes be due to an electrical surge, faulty wiring, and various other factors. Turning off the AC is a must, as is opening the unit to check for any visible fires or damage.
Another reason for smelling this odor is burning or heated dust particles. Inactive AC units can get very dusty. Once the unit is turned back on after a period of inactivity, it heats up all the dust settled inside, but the dust can give off an odor similar to burning gunpowder or burning plastic.
The car exhaust odor
Car exhaust odor is another common AC smell that indicates a problem—specifically, a problem with the refrigerant line. If there’s a leak of refrigerant fluid, when heated, it can emanate carburetor-type exhaust fumes, which have a potent odor as well as many harmful chemicals.
Smelling this odor may also be an indicator of why the AC unit is underperforming. Hence it’s best to call a professional fast after turning the AC unit off and venting the room.
The stale odor
Easily the most common type of odor, smelling something stale coming out of the AC usually indicates the presence of mold. Mold is a significant occurrence in high-humidity tropical climates where water accumulation is more common.
Interior leaks that go unseen for too long facilitate the growth of mold and fungi. In some situations, it can indicate that the filters are dirty.
Smelling any of these odors, no matter how mild they may be, is cause for concern. Immediate troubleshooting is vital to ensure safety and the continued efficient operation of the AC unit.
Modern Air Conditioning & Heating is a Boulder City-based HVAC company offering 15 years of experience in residential and commercial HVAC services for all makes and models. You can also call us directly at (702) 919-4365.
