A dirty or clogged air filter could contribute to the scent, especially if it's clogged with smelly debris. Cleaning or replacing your air filter can help eliminate odors coming through your vents.
If your vents smell like dirty socks or smelly feet, the issue can be mold or mildew. These substances grow where it is dark and moist. So, if some moisture gets into your vents, your vents suddenly become the perfect environment for mold and mildew.
If there's a strange or chemical-like smell coming from your air conditioning, it's a sign there's a problem such as a refrigerant leak, mold, or household chemicals getting drawn into the air handler.
Air Filter Replacement: One of the simplest and most effective ways to get rid of bad smells is to replace the air filter. A dirty air filter can trap and circulate unwanted odor throughout your house or apartment building. Vacuum the Vents: Use a vacuum cleaner to remove dust and debris from vents and registers.
A Strong Musty or Mildew-Like Scent.
Black mold has an infamous, recognizable odor. Detecting this scent could be crucial in identifying a mold problem before it causes too much damage. Experts describe black mold as smelling musty—comparing it to rotting wood or leaves or wet, sweaty socks.
The Negative Effects of Mold in Air Vents
Aside from a musty smell, mold spores can cause people to experience health problems, such as coughing, sneezing, nasal blockage, itchy eyes, skin irritation, breathing difficulties, stuffy nose, runny nose, headaches, and other allergy-like symptoms.
Baking soda, formally known as sodium bicarbonate, is a quick and effective way to mitigate unpleasant odors circulating in your air vents. Baking soda is known for its ability to absorb and neutralize smells from food, pets, bathrooms, and smoke.
What is formaldehyde? Formaldehyde is a colorless chemical with a strong pickle-like odor that is commonly used in many manufacturing processes. It easily becomes a gas at room temperature, which makes it part of a larger group of chemicals known as volatile organic compounds (VOCs).
Gas Source
As the source of the odor is sewer gas, it's a no-brainer that it's coming from your septic tank or sewer system. Sewage gas can get into your home through pipes, especially when a p-trap under a sink, tub or toilet is dry. A p-trap can dry out if there is a long period of non-use.
As mentioned earlier, Freon leaks may produce a faint, sweet odor, similar to acetone or nail polish remover. If you detect this scent near your HVAC system or air vents, it may indicate a refrigerant leak.
If you haven't recently used chemicals or paint, a strong chemical smell could indicate a gas leak, particularly from carbon monoxide. A distinctly chemical odor can result from a crack in the heat exchanger component of your furnace. This component cycles heat out of the combustion chamber.
“Dirty Sock Syndrome” refers to when a foul-smelling, mold- or mildew-like odor comes from your air conditioner when you first turn it on. This happens when moisture, dust, and dirt build up on your AC system's evaporator coil, inviting bacteria and mold to multiply.
Some air conditioners use Freon to cool the AC unit. If there's a leak somewhere, the freon will create a chemically, sometimes sweet smell. Some AC units use different refrigerants, and if there's a leak in the line or elsewhere, it means the coolant is escaping, and that's what you're smelling.
Wipe them down with a mild cleaner
The easiest and quickest way to clean your registers is to wipe them down with a mild cleaner and a rag or sponge. Once you wet the rag with your soap or cleaner, work your way in between each of the slats on the register for the deepest clean.
Since CO has no odor, color or taste, it cannot be detected by our senses. This means that dangerous concentrations of the gas can build up indoors and humans have no way to detect the problem until they become ill.
If you're especially sensitive to scents, a bed with strong off-gassing odors may cause unwanted symptoms, such as headaches, nausea, or dizziness. Individuals with respiratory issues, such as asthma or allergies, could also experience irritation of the airway and difficulty breathing.
Low-dose acute exposure can result in headache, rhinitis, and dyspnea; higher doses may cause severe mucous membrane irritation, burning, and lacrimation, and lower respiratory effects such as bronchitis, pulmonary edema, or pneumonia. Sensitive individuals may experience asthma and dermatitis, even at very low doses.
Answer: NO!
You should, in fact, never put dryer sheets in vents ever. If the air from your air conditioning system smells bad, then it might mean that your AC system needs some work. This can be caused by mold on the evaporator coil, a clog in the drain line or even a leak in your ducts.
If you are sneezing, coughing, or experiencing watery, itchy eyes that seem much worse than normal, your air ducts are probably dirty.
Black mold has a distinct smell. It's often described as musty and earthy and may even smell like rotting vegetables, plants, or paper. Some think it smells like cedar.