When you run your air conditioning system, are you immediately transported to the school locker room? Our sense of smell is distinctly associated with our memory, and revisiting your school days is likely to have been triggered by a less than fresh scent coming from your AC. This phenomenon is known as Dirty Sock Syndrome and only occurs when your HVAC system is being used to cool your home.
The Causes of Dirty Sock Syndrome:
This smell of a dirty locker room which is emitted from your HVAC system when you are trying to cool your home is not actually a fault with the system itself. It is caused by an accumulation of bacteria inside the evaporator coil. The evaporator coil is a very porous aluminum component which provides the ideal damp and cool conditions for attracting and allowing bacteria to accumulate. This bacteria build up could be the result of paint high VOC counts or mold, dust, pet dander or other debris already existing inside the home.
The Dirty Sock Syndrome phenomenon can be triggered when you frequently switch between heating and cooling your home. When the bacteria which has accumulated on the coil is warmed then cooled, its growth can be jump started, spreading that unpleasant odor.
The causes of Dirty Sock Syndrome may not be a reflection of poor housekeeping habits. It can even be caused by some home improvements. For example, if you have installed new laminate flooring recently in your home, the glue could contain VOCs which trigger the unpleasant odors. It can also be affected by weather conditions. For example, some winters we can experience some very odd weather conditions where we need the heating on one day and need to cool down with the AC the next. This switching between heating and cooling allows the bacteria to build up, so next time we switch on the AC, we notice that unpleasant smell. Fortunately, while this is not a common problem, it is not a serious issue and can be easily remedied.
Possible Solutions:
There are a number of ways to deal with Dirty Sock Syndrome and prevent future occurrences. One preventative measure is to install a UV light filter during HVAC installation. It may also be possible to have this fitted retroactively in your existing system. A UV light filter will kill any bacteria in the system and prevent Dirty Sock Syndrome. As a happy side effect, the air in your home will also be purer and cleaner.
If you are already experiencing the unpleasant odors from Dirty Sock Syndrome, your evaporator coil will need to be cleaned. This should be done with a non acid cleaner to prevent coil damage. Once the coil is cleaned, it could be coated with epoxy to prevent bacteria buildup. At this point, you could also consider installing a UV light.
Dirty Sock Syndrome is not due to a fault or deficient HVAC system, but by pre-existing bacteria inside the home. Fortunately, it is preventable and easy to fix, so you won’t be stuck with a smelly AC system for very long.