Can Mold Grow In A Duct System?

Can mold grow in a duct system, and what problems can it cause?

Mold spores require a stable temperature, a food source and moisture to live and reproduce. HVAC systems provide all of these things. Any dust or dirt that passes through your air filter provide a good food source.

The furnace or air conditioner is designed to maintain a comfortable temperature, and moisture is available from several of the components in an HVAC system. Ductwork provides humid conditions, the humidifier in the furnace is wet and often holds standing water, and cooling coils are ideal areas for mold growth.

Live molds can release spores that can trigger allergic or asthmatic reactions, sometimes severe, in about 10 percent of the population.

Mold, both living and dead, can produce toxins that may cause short-term allergic reactions.

We have dealt with mold conditions inside ductwork and HVAC systems numerous times. We give the ductwork and HVAC system a very thorough cleaning, and then use encapsulation as well as a biocide application. We also recommend that the system be inspected and re-treated again after 6-8 months.

In those rare cases where mold has been detected in an HVAC system, it is also recommended that you install an Ultra Violet Light (UV) system.

A UV system is placed directly inside the ductwork, and there are typically two ways to do it. Some people go with both of them but having either one is more than what most people have.

The first, and most common, is to install a UV system inside the return air duct. It is similar to a metal box, and it contains a small fan and a UV bulb. It shines a bright light into all of the air that must pass it on its way back towards your furnace fan. The process will kill of molds, bacteria and fungae that may be inside your duct system.

The second type is a longer UV buld, sometimes referred to as a sword, and it is mounted inside the supply air plenum of your furnace or air handler. The light from the bulb covers the evaporator coil inside your furnace, killing any bacteria at its source, since evaporator coils are generally the biggest producer of germs due to standing water inside the coil’s tray.

Either type of UV lighting system can be extremely benefical to your family’s health.

The downsides to these systems is that in some cases it is necessary to replace the UV bulb yearly. And if the light goes out, then the system cannot do its intended job. With the return air duct mounted system, it is necessary for the installer to determine that the light itself does not shine on the existing air filter, as the light from the unit will affect the air filter.

We carry UV systems from two manufacturers, and the Sanuvox one is very good. For more information about a UV lighting system for your own home or office, take a look at this video.

Also Read : Cost Benefits of Commercial Duct Cleaning