The Most Common Air Conditioning Smells
Why does my air conditioner smell bad?
What do I do when my central air conditioner smells like chemicals, and what does Freon smell like?
As an HVAC Contractor, these are the questions we hear all the time from homeowners and business owners alike. It’s never a good sign when your Air Conditioner starts to put out terrible odors.
It’s not good for your health. Even worse than that, some smells are toxic and require urgent attention.
So here are the top six and what you can do about it!
Your air conditioning system is one of the most used appliances in your home. So, it’s uncomfortable and super inconvenient when it isn’t working correctly.
Fortunately for us, it’s fairly good at giving us signs when it needs a service. One of the critical things that many home and business owners notice is bad aromas emanating from the air conditioning unit.
However, an odor problem doesn’t necessarily mean that a repair will be expensive but definitely needs to be checked.
It could be as simple as a dirty air filter or mold growth caused by excessive condensation in the HVAC unit or as bad as a freon leak or, even worse, a ruptured sewer vent pipe or a backed-up sewer line near some ductwork.
Here are the six most significant potentially toxic air conditioner smells that you may be smelling:
Table of Contents
1. Burning or Electrical Odors
Electrical smells are a common air conditioning smell and could indicate a mechanical problem with your air conditioner compressor or fan, electrical component failure, or a wiring issue.
These components are made from various chemicals and metals, and prolonged exposure to odors from these is not healthy.
The first few times an air conditioner kicks on, it may emit a burning smell that can smell electrical or dusty.
Usually, after 20 to 30 minutes, the smell can dissipate. If it does, then it was probably burning off the dust in the unit. This is common after the unit has not been used for a while.
However, you should contact a professional HVAC contractor to check out the problem and repair the unit if it continues. If you’re a bit of a DIYer, here’s an article for you on DIY AC repair.
Electrical odors are typically a problem with the compressor, fan motors, or wiring. Attempting to fix these yourself can result in severe injuries.
If you are uncomfortable trying repairs by yourself, contact your local air conditioning specialist to look at it.
2. Gunpowder Smell
The gunpowder smell is the cousin of electrical odors. Distinctive gunpowder-like odors can be due to a fried fan motor or circuit board.
Again with these made from various metals and chemicals, they can pose potential dangers to your respiratory system. Before starting up a system again after a prolonged dormant period, it should be inspected by a professional.
3. Rotten Egg Smell
Provided you didn’t leave any rotten eggs hiding anywhere in your home, if you smell sulfur or it smells like rotten eggs emanating from your air conditioning unit, it’s most likely a natural gas leak somewhere in your home making its way into your ventilation system.
Although gas is odorless, utility providers add the aroma to alert people of a dangerous leak. So if you smell gas, there’s a problem.
Another reason for these AC smells is that you may have a pest problem or a dead animal somewhere in your duct work or attic. So it’s definitely best to get that checked out. Call pest control to remove the dead animal if you find something.
🛑 If it’s a gas smell, do not take it lightly. If you smell sulfur in your home, natural gas is most likely the culprit, and immediate inspection of its source is required.
You should immediately turn off your gas supply, evacuate your home, and call the fire department.
While low-level exposure in itself is hazardous to your health, high levels can reduce oxygen in your blood and lead to a loss of consciousness and even death.
As we all know, gas is highly flammable and explosive and results in dozens of deaths each year.
So, if you notice this type of odor, open all of the windows in your home or business and immediately get out of the building. You should also contact your local natural gas provider.
📗 Related Reading: What Does Sulfur Smell Like? A Homeowners Plumbing Guide
4. Exhaust Fumes
Even if your systems are not powered by gas, exhaust fumes can be present if fluids leak from specific components in your AC or heating systems.
To avoid such dangerous situations, If you smell exhaust-type fumes, you should contact your local HVAC contractor to assess your problem professionally.
Burning oil and other fluids can release large amounts of toxic gas into the environment. This gas can be different in its chemical makeup from its original liquid form.
When inhaled, these particulates can be very hazardous to your health, depleting oxygen in your bloodstream resulting in many serious health issues.
5. Chemical Aromas
Chemical smells can come from many different sources. The following may help you decipher which one is the most likely culprit.
🦨 Open Chemical Containers
Your AC might not even be the source of the smell. Open chemical containers stored near an air conditioning intake or ductwork could be the source. Once picked up in the airflow, these smells will be forced through the rest of the house.
Homeowners and business owners often store chemicals in garages and attics to keep them out of harm’s way. However, these can eventually leak if not sealed properly and make their way into the airflow.
Please find all the chemical containers around your home and business and safely store them away from your AC system for safety’s sake.
🦨 The AC unit itself
If your AC system smells like paint thinner, formaldehyde, or any other chemicals, it must be assessed before use.
Many fluids are used within your AC system. They can be the culprit for an assortment of chemical-type smells when the unit malfunctions. Contact your local HVAC contractor for a proper diagnosis.
🦨 Ozone Smells
Electrostatic-type air filters can produce ozone and emanate an odor that smells like chlorine.
Also, certain types of UV lights installed to irradiate filter surfaces to kill bacteria can produce ozone. Ozone is very unhealthy for people if inhaled in large enough quantities.
Some can experience chest pains, while others may have trouble breathing. If you are unsure about what type of system you have. It’s best to call your local HVAC contractor to check on your system.
🦨 Glue Odors
If you have recently had any ductwork done, this may answer your home’s chemical smells. The glue used for duct installation can give off a heavy chemical odor while drying.
In this case, the smell won’t disappear immediately; you must wait for the smell to fade. Run your AC fan, open the windows to your home or business, and wait for it to dissipate. If the problem persists, then discuss this with your local HVAC contractor.
🦨 Freon Leaks
Freon is a chlorofluorocarbon or CFC, also known as a refrigerant. Freon removes heat from the atmosphere and transfers it to somewhere else, usually outside your home or business.
This is what keeps you cool inside. But unfortunately, it is also harmful when it’s not contained appropriately. Freon travels within a closed system in condenser and evaporator coils and lines.
These coils and lines, which are mostly made of copper, can sometimes crack and result in a refrigerant leak.
What does Freon smell like?
A freon leak smells like coolant in your car and has a slightly sweet aroma.
🛑 Freon leaks can be toxic.
If you suspect a refrigerant leak, talk to your local HVAC contractor, who can use a freon leak detector to find and repair the issue.
6. Mold or Musty Smells
Does your AC smell like dirty socks? An air conditioning system that smells like mold and mildew is one of the most common AC smells coming from an HVAC system.
When the AC is running, a lot of condensation builds up within the unit. If this moisture doesn’t drain properly, it can escape into the air flow, end up in the air ducts, and cause mold to buildup in your ductwork.
A clogged condensate drain line can cause this. So, it’s worth checking out. Call your local HVAC contractor to check out your HVAC system and air ducts for mold and mildew.They will also check your condensate line for blockages if you don’t know where to find it.
Duct cleaning is an easy way to improve your indoor air quality. Mold is not a serious problem with the air conditioner itself.
However, the poor indoor air quality resulting from mold in your system is dangerous to you and your family’s health. Mold can increase the risk of respiratory infections in both children and adults.
It is best to keep your air conditioner off until this problem can be remedied. So, if your AC smells musty, it’s best to engage a professional to check it out.
Related Reading: The Importance of a Clean Evaporator Coil
Related Reading: Everything You Need To Know About Your Furnace Room
What Air Conditioners Should Smell Like…
Now that you are fully informed about the types of AC smells, you can better discuss a solution with your local HVAC Contractor.
When troubleshooting a problem, use your other senses as well. Listen for abnormal sounds like knocking within the HVAC system when running.
Look for excess water around the unit or other liquids that don’t belong there. Often, the smells indicate that the system just needs a service.
However, more serious odors like sulfur or gas indicate a more significant problem.
If you are experiencing an electrical or burning odor, immediately shut down the unit and contact your local HVAC technician.
Your local HVAC contractor can quickly diagnose any issue you have and recommend various solutions to get your AC back up and running safely.
Dealing with other common AC problems? Check out: Top 18 Common AC Problems and Solutions.
Call an HVAC Contractor!
So we have you covered whether you are looking for an Air Conditioning or a Furnace Repair technician and need emergency service for your HVAC equipment. Don’t let air conditioner smells ruin your day; give us a call at Phyxter Home Services.
We have the best local and independent home service contractors who are experts in all types of HVAC systems. And if you’re looking for a replacement filter, we can help you, too.
Check out our article on choosing the right filter for your home: Air Filter Guide. MERV Filter Ratings and What They Mean For Homeowners
Related Reading: Suspect a Furnace Gas Leak? Here’s What To Do!
