Causes of Bad Smells in Vents

Before you can get into how to get odor out of air vents and ducts, you first need to understand what might be causing the problem.

The following are common causes of bad smells in vents:

• Mold and mildew

Mold and mildew are fungi that like to grow in cool, dark and damp places. Having an air conditioner that is too large for your home, setting your thermostat too low and leaks in the ventilation system can cause water to condense, creating moisture that encourages mold and mildew growth. Moisture left behind after flood damage is another potential cause of mildew and mold problems. 

If you have an air vent that smells musty, vinegary or like decaying leaves, you may have a mold or mildew problem. Not only can the fungus cause bad smells, but it could also pose a risk for breathing problems and allergies. In most cases, the solution to mold and mildew problems is thorough cleaning. You may also need to take steps to reduce the risk of moisture buildup in the future by setting the thermostat higher or having your HVAC system repaired or replaced. 

• Clogged Air Filters

HVAC systems use filters to remove fine particulates from the air. Over time, the impurities taken out of the air accumulate on an air filter, reducing airflow. When this happens, the material caught in the vent may start to decay and give off odors. In some cases, the debris stuck in the filter naturally has a bad scent that you can smell when air moves through the vent. 

The most common cause of clogged air filters is not changing the parts frequently enough. Changing your air filters according to the recommended schedule is the best way to prevent clogged air filters and the odors they cause. 

• Dead Animals

A rotten, pungent odor could mean that a dead animal is present in your air ducts. Mice and rats are the most common causes of this problem, but other animals like pigeons and opossums can also get trapped inside ventilation systems. If you suspect that a dead animal is the cause of the issue, call a professional pest control company or HVAC repair service promptly. Animals can carry viruses and bacteria that could make your family sick, so removing them as soon as possible is important for protecting your health. 

Can Smells Travel Through Vents? 

Smells can absolutely travel from one room through the air vents into another. Bad smells can happen due to airborne particles that travel in the air when you turn on your heating and cooling systems.