If you notice that the bad smells in your home seem to worsen every time you run your air conditioner, the problem may stem from a wide range of factors such as mold and mildew growth, dead critters in the vent, or freon leak, which poses a serious health hazard.
Sharpline Mechanical, one of the leading Northern California’s HVAC experts, explains the reasons why air conditioners emit foul odors and the corresponding way to address them.
Gas leak
Natural gas has no smell, so distributors and utilities add a chemical that gives it a distinct odor–a sulfur or rotten egg smell. This allows people to immediately detect gas leakage and prevent serious health hazards that come with it.
If you notice a sulfur smell, turn off your gas supply and contact your utility company that can detect and repair the source of the gas leak.
Other things you must do when you detect a smell that resembles a rotten egg through your HVAC vents:
- Don’t light up anything.
- Don’t operate anything electrical.
- Open all your windows and doors.
- Evacuate your home.
Rotting carcass
If you smell a rotting carcass, you may want to check if a critter has died in your HVAC or duct system. Additionally, open some windows and doors to improve ventilation.
Dirty AC filters
Dirty filters often give out a stale and dingy smell. To prevent this unpleasant scent, a good rule of thumb is to replace the filters every 2-3 months if you have no allergies and no furry companions.
Mold and mildew growth
Too much moisture in the drain pan or drip lines can lead to mold or mildew growth that emits a musty smell. On its own, the scent is not particularly harmful; however, fungi release spores and gases known as microbial volatile organic compounds that can trigger severe allergic reactions to some people.
Mold symptoms can be serious to some people; they can range from lung infection, headaches, lung or eye irritation, nausea to cancer and fatal allergic reactions.
Cigarette smoking
If you smoke indoors, your air conditioning system will eventually end up smelling like stale cigarette smoke. Also, keep in mind that smoke residue will remain in fabrics, walls, and duct systems for years.
The evaporator coil in your AC system also absorbs some cigarette smoke, which results in an unpleasant smell every time you turn on your air conditioner.
To prevent or address this stale cigarette smell, make sure that you replace your AC filters every 30-60 days and avoid smoking indoors.
Faulty wires or other internal components
If your air conditioner smells like plastic or burning gunpowder, chances are that the internal components (circuit boards, fans, compressors, wires, etc.) are burning. In this case, turn your AC off and call a licensed HVAC company.
Long period of inactivity
If you turn your AC on after a long period of inactivity, you may notice a burnt smell caused by dust that settled within your unit. This problem will go away within a few minutes of running your air conditioner.
Refrigerant leak
If your AC emits a smell similar to a running car exhaust, it might be a sign of a refrigerant leak, which poses a serious health hazard.
A refrigerant is a cooling agent in your AC that when heated emits a smell similar to a car exhaust fume. However, some refrigerants like Freon have a sweet chloroform smell.
If your air conditioner emits a chemical-like smell, open your windows and doors to improve ventilation and immediately call a certified HVAC specialist.
