Air Conditioner Mold

What is it?

Molds are types of fungi that grow in a natural environment. Tiny particles of molds are found everywhere indoors and outdoors. In nature, molds help break down dead materials. Molds are also very common in buildings and homes. Because mold needs moisture to grow mold growth may be found indoors where there are high humidity levels, like basements and showers. Molds produce microscopic cells called "spores" that are spread easily through the air. You can't fix HVAC mold problems without also fixing all home mold problems.

It's your air conditioning system's job to ventilate your home. The ducts are designed to supply and return airflow to each room. If there is a mold infestation on your home, an increased amount of mold spores develop. As the air conditioning system constantly recycles air throughout your home, it becomes infected by the active mold culture and often is first noticed on the registers. In some cases mold can be caused by the air conditioning system due to lack of maintenance, clogged or leaking drain pans.

What causes it?

Molds produce tiny spores that reproduce. Mold spores float through the indoor and outdoor air repeatedly. When mold spores land on a damp spot indoors, they can begin growing and digesting whatever they are growing on in order to survive. When excessive moisture or water accumulates indoors, mold growth will often occur, particularly if the moisture problem remains undiscovered or un-addressed. There is no practical way to eliminate all molds and mold spores in the indoor environment; the only way to control indoor mold growth is to control moisture.

A properly designed, installed, and maintained air conditioning system shouldn't cause mold. On the other hand, an oversized or improperly designed system may cool your home, but it may not remove enough moisture. Too much moisture in your home's air can increase the potential for mold growth. Improper installation, lack of maintenance, and water drainage issues can also lead to mold growth in an air conditioning system.

How can someone prevent it?

The key to mold control in an air conditioning system is moisture control. It is important to dry water-damaged areas and items within 24-48 hours to prevent mold growth. If mold is a problem in your home, clean up the mold and get rid of the excess water or moisture. Fix leaky plumbing or other sources of water including air conditioning systems. Wash mold off hard surfaces with detergent and water, and dry them completely.

What can be done about it?

If you find patches of mold anywhere in your home, it is important to kill and clean it up quickly to prevent further growth. Remember to stop the source of moisture as well, or the mold could return. Wearing gloves and a face mask, scrub mold off of non-porous surfaces with a stiff brush, a non-ammonia detergent and hot water. A dilute solution of chlorine bleach and water can also be used to kill mold and mold spores, but is not necessary. Surfaces having mold should then be dried completely.

DIY Solutions

In the summer, a closed house with the air-conditioning turned off will have higher humidity levels than an air-conditioned home. A vacant house also receives little or no sunlight through closed shades and no air movement with the fan off and the doors locked.

If you leave the air conditioning running, it will cool the home and remove moisture from the air as well as circulate and filter the air. Molds thrive when the humidity levels exceed 70 percent. Because humidity levels vary from day to day, the thermostat should be left at or below 74 degrees, and the fan should be set to "On."

Moisture-loving mold loves humidity, so measure humidity by using a hygrometer, which can be purchased at hardware stores. If the humidity rises, take measures to reduce it.

Before you begin to use your air conditioner every year, inspect it for mold and have the coils cleaned as needed. Otherwise, your air conditioner may spew mold spores into your home. Remember to empty drip pans regularly so mold doesn't build up there either.

What can a professional do about it?

Usually HVAC-related causes of mold can be corrected by an HVAC contractor. Who should do the cleanup depends on a number of factors. One consideration is the size of the mold problem. If the moldy area is less than about 10 square feet (less than roughly a 3 ft. by 3 ft. patch), you can handle the job yourself.

If there is a lot of water damage or mold growth that covers more than 10 square feet, you should definitely consider hiring a mold cleanup company. You will need professional help if your HVAC system has mold growing inside of it, or if the water and mold damage was caused by sewage or other contaminated water.

 

AirNow, Inc.
190 Atlantic Ave.
Garden City Park, NY 11040
Phone: (516) 355-0032
Fax: (516) 248-4308