Why does my home AC unit smell bad?
1. Dirty Sock Smell Comming From Your Air Ducts?
The most common foul odor is called “Dirty Sock” smell, caused by mold and bacteria growing on the evaporative coil due to a clogged condensation drain line. This happens when too much dirt and debris build-up on the evaporative coil restricting airflow and compromising your energy efficiency and indoor air quality. With the excess moisture dirt and debris build up enough and become stuck on the evaporative coil-like sludge. The sludge that becomes too water-heavy due to the condensation will fall off the coil into the condensation drain pan and eventually clogging the 3/4″ drain line. The remaining sludge just sticks to the evaporative coil choking it for air and affecting your air quality, the longevity, and your energy dollars.
Issues with the Evaporator Coil
Your evaporative coil is working extremely hard to allow the most air through and remove as much condensation as possible. Dirty ducts that are returning the air to the evaporative coil only to be supplied back through the system.. is the air your breathing. If your filter stopped all dust particles then no air would flow through it, even with the best filters dirt and debris is still building upon the air return’s duct walls and flowing right to the evaporative coil.
Summer is a Distructuve Time for AC Units
It’s common to have an odor issue permeating from your air handler and air ducts if you don’t routinely service them. It’s important to understand that the most destructive time of the year for your A/C unit is during our long summers. It’s critical that you maintain your A/C unit and indoor air quality by checking or changing your air filter frequently, cleaning the evaporative coil every spring, cleaning of the air ducts and connection boxes every 2 to 3 years. Some people will have the evaporative coils cleaned twice a year, once during the spring and once during the fall. Most will never realize that the build-up starts right at the filter infiltrating the air duct before the coil. To avoid this you should have an air duct cleaning before you clean your evaporative coils. Have you ever had your evaporative coils cleaned without checking the air ducts that are attached to it first?
2. Rotten Egg Smell Comming From Your Air Ducts?
The second most common foul smell is the “Rotten Egg” smell, caused by a dead decomposing animal such as a bird or most commonly a rodent. This could also be caused by a furnace or gas pack heater that runs off of natural gas that has a gas leak in the system emitting a rotten egg smell. For easy detection and safety reasons natural gas has a chemical additive called Mercaptansince, it’s odorless and colorless. A bird or a rodent can find there a way to your attic or crawl space and into an air duct that had a hole or loose connection. The air ducts are sometimes referred to as “The Rodent Highway” when they take refuge in your air ducts after infiltrating your home. This makes your air ducts highly unsanitary and presents an odor issue immediately. Having an animal die in one your air ducts one of the worst experiences you can deal with especially in the heat of summer.
If this ever happens to you, you should call a pest control company to inspect and remove the dead animal, have your home and air ducts sealed, clean and sanitize your air ducts and A/C unit as soon as possible.
3. Toxic or Burning Smell Coming From Your Air Ducts?
The third most common foul odor is the “Toxic Burnt” smell, this happens when an electrical component starts to fail or completely fails. Most commonly when this occurs it will be the blower motor that’s grinding away creating friction on moving parts or a motherboard that is shorting out. Wear and tear of mechanical parts and eventually complete failure is unavoidable but you can prevent your air ducts and A/C system from absorbing the toxic smell by acting quick and making necessary repairs with a complete cleaning of your air ducts and A/C unit.