Air conditioners will grow less mold if operated in a specific way. In this article I will explain why this is and how to operate them correctly to reduce mold growth.
Air conditioners are notorious mold producers. In this article I will explain why this is and how to reduce this problem.
Air Conditioners Grow Mold – the Reason
Here is what mold requires to grow well:
Those are pretty low requirements. Mold grows so much better if it is dark, warm, and the air doesn’t move.
Now let’s look at the inside of an air conditioner.
It is moist, because cool temperatures cause moisture in the air to condense. Removing moisture from the air is almost as important to comfort as reducing temperature.
It has food, because the air conditioner is constantly taking in dust-laden air from the room. This sticks to the wet cooling fins, where it sticks. Central air conditioners don’t have this problem as long as the air filter is properly installed.
Temperatures are cooler than ideal for mold, but not cold enough to destroy the mold. When the air conditioner turns off, the temperature rises and becomes perfect.
It is pretty dark inside an air conditioner.
When the air conditioner is off, the air does not move.
Preventing Mold Growth in Air Conditioners
A dry air conditioner will not grow any mold. This is the key to cracking the problem.
The solution is simple: run the air conditioner on fan only (cool off) for sufficiently long to dry out the interior. I have seen it suggested that the air conditioner should run for 2 hours. Even 15 – 20 minutes should help substantially. This will work for split air conditioners, window-mounted (“window shaker”) models, and car air conditioners. In the case of a car air conditioner, even turning off the air conditioner and running the fan on high while recirculating the air (which will be much dryer than taking outside air) for a couple of minutes makes a huge difference in my experience.
For central air, this should be unnecessary, as long as the dust filter is properly fitted.
Have you tried this method? How does it work for you? Leave a comment and share your experiences.
This comment from John might be interesting to some:
These modern air conditioners sling the condensate on the condenser. The dust,and anything else in the air plugs the condenser. The dust along with the wet conditions cause mold to grow. Solution, forget the warranty, my health is more important.I am going to drill a drain hole in mine