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What’s that Smell? Innocent vs. Hazardous Central Air Conditioner Vent Odors

Just like when your Chicago area furnace kicks on for the first time in the fall, when your central air conditioning goes on for the first time in the spring, you may be welcomed with some unknown vent odors. Why does your central air conditioning smell that way? How long will the odor last and is it something that is hazardous? Here’s a look at some common vent odors you may smell from your central air conditioning unit and what they can mean.

3 Common Air Conditioning Smells and What They Mean

1. The smell of mildew – Your central air conditioning deals with a LOT of moisture. There’s the moisture in the air in the form of humidity, condensation and more. If this moisture doesn’t get drained away, it can lead to the smell of mildew. Mold and mildew could also form because your air conditioning filters are dirty, leading to vent odors. If you smell the odor of mildew, first change your vent filters. If the smell doesn’t rapidly dissipate, contact your local HVAC expert for a thorough cleaning.

2. The odor of old cigarette smoke – Your condenser coil can attract the cigarette smoke of a smoker in your house. This odor is dispersed each time the central air is operated. A coil cleaning will take care of this issue.

3. An unpleasant rotting smell – It is not uncommon in the Midwest for animals to get into an air conditioner unit and die. As the weather warms and the central air is turned on, a very unpleasant rotting odor can be detected. The only way to resolve the issue is to removed the dead animal from the A/C unit and have it cleaned.

The good news is that none of the above odors is necessarily hazardous. Unpleasant? Yes. Will you want to take corrective action to fix the smell? Absolutely. But none of these are an actual danger to the health of you or your family.

4 Potentially Hazardous Odors from your Central Air Conditioner

1. A “rotten egg” smell – While natural gas doesn’t have an odor on its own, suppliers give it a sulphuric, rotten egg smell to make it unpleasant. If you notice this smell, you may have a gas leak near one of your AC vents. You’ll want to leave the house quickly and call your local natural gas provider immediately.

2. A burning smell or that of plastic burning – This could be an indication there has been an electrical short in your system, or are experiencing a problem with an exhaust fan or compressor. Cut power to your unit and call an HVAC technician immediately.

3. A raw sewage smell – A raw sewage odor can be an indication there is a sewer leak at or near AC vents. Methane gas from sewage can be dangerous and a professional AC technician should be contacted quickly to determine the source.

4. A smell of gunpowder – This could be the result of a fan motor or circuit board burn out. Again, power should be cut and a professional HVAC technician contacted immediately.

The above smells, while not necessarily always hazardous, can potential be harmful. In each instance, a professional technician should be contacted.

Contact Althoff Industries when You Smell Strange Odors

If you experience odd odors when first turning on your air conditioner or if your air is not cooling properly when first turned on, we invite you to contact us at Althoff Industries. We proudly serve homeowners in the Northwest Chicago area suburbs with superior HVAC services, including resolving unpleasant odors. Call us and let us know about your situation – we would love to help!

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