A properly functioning HVAC may be one of the best ways to prevent mold growth in your home or office. But because of the air distribution system of an HVAC, a malfunctioning system may be the perfect vehicle to spread mold spores throughout the building. Often, the difference between the two comes down to a small detail – which is why HVAC requires proper design, assessment, and maintenance to keep it preventing – not exacerbating – mold growth.

While there are many parts to the HVAC to be aware of, one particular component is both the chief problem as well as the easiest to fix. Properly designing and maintaining the drain pan is easy to do and can prevent mold in the future.

In an HVAC system, the drain pan is usually located under and downstream from the coils. By electrical means, or by circulating liquid or steam within, the coils heat or cool the air flowing through the ventilation. The drain pan collects condensate water and moisture that has been dehumidified by the cooling coils and allows it to exit the system via a drain line.

This drain pan is a simple concept, yet it is a critical component of your HVAC. If the drain pan is not working properly, the condensate water it collects will not exit the system and may spill, be carried into the interior of the ductwork, or pool. This standing water accumulates creating a microbial habitat for mold, bacteria, and other microorganisms – as well as dirt in which they can feed.

There are several ways in which the drain pan can malfunction:

1) The drain line becomes plugged with dirt and debris, preventing water from exiting and causing the drain pan to overflow and flood the interior of the air handler and ductwork. If mold begins to grow, it creates a snowball effect – the mold clogs the drain line causing more mold to grow.

2) The drain pan corrodes and starts to leak, allowing water to flood the interior of the air handler and ductwork.

3) The drain pan is flat or the incline is not steep enough. The water does not easily run off the drain pan and instead is allowed to stagnate on the pan, providing a habitat for mold.

Fortunately, all of these problems are easily fixed:

1) To prevent the drain line from clogging, simply use a wider drain line. Often, these drain lines are chosen to be as small as possible. But a wider drain line will help prevent clogging and also be able to handle excess water.

2) Drain pans should be made with stainless steel to prevent corrosion and rust. Also, stainless steel is nonporous, so they are easy to clean and difficult for mold to grow on.

3) Check the incline of your drain pan to make sure condensate water can easily run across it into the drain line. Often the drain pan is only slightly sloped or entirely flat. The best drain pans are sloped in two directions so water can drain from both sides with no chance of pooling.

HVAC is a complex system that requires more attention and maintenance than it is often given. But following these drain pan tips may save you problems in the future.