3 Reasons Why Your Air Conditioner is the Perfect Breeding Ground for Mold

August 21, 2013

But it’s not just creepy, it’s harmful to the health of asthma sufferers in your home. 

According to the EPA, “Molds can trigger asthma episodes in sensitive individuals with asthma. People with asthma should avoid contact with or exposure to molds.”
 
But did you know that your air conditioner (more accurately, the inside unit) is a perfect breeding ground for mold?
 
 We’ll give you 3 reasons why that is and what you can do about it.

It creates moisture

Mold needs a considerable amount of moisture to grow. The EPA lists moisture control as the #1 way to control mold in your home. 

However, your air conditioner’s evaporator (indoor) unit produces plenty of moisture.
 
How?
 
The evaporator unit’s cold coil absorbs heat from your warm return air. This creates condensation on the coils. It’s the same thing that happens when you have a glass of water with ice in it. The moisture in the air around the cold glass cools down and causes the glass to “sweat” little beads of water.
 
It’s that condensation gives the mold a way to grow on the evaporator coil. But remember, the air that blows on that evaporator coil to be cooled is blown back into your home.
 
So if the evaporator coil has mold all over it, you’re spreading mold spores all over your home. 
 
Yikes.

It’s dark in there

Unlike normal plants, mold can grow in complete darkness. It grow better in the dark because there’s more moisture in the air and there’s no ultraviolet (UV) rays to destroy the mold.

Your air conditioner’s evaporator (indoor) unit is a closed unit, so the amount of moisture we mentioned before won’t evaporate as quickly due to the lack of light. Like we just mentioned before, more moisture=mold’s paradise.

It’s warm in there

According to the North Carolina Department Health and Human services, “Many fungi grow well at temperatures between 60 and 80 degrees Fahrenheit, which are also ideal temperatures for human comfort.”

Your evaporator unit reaches the temperatures perfect for mold growth because it contains a blower that blows your warm indoor air over the cool evaporator coils.

The solution

So, is there a way to keep mold and other bacteria off your evaporator coil? 

Indeed there is! Remember when we said that mold does not play well with UV rays? Well, you can recreate that with special UV lights that can be installed on your indoor unit. That way, mold can’t settle and grow on the coils. 
 
If you’re interested, check out Santa Fe’s line of UV lights that can combat molds and bacteria to keep them out of your HVAC system.