When to Clean Air Ducts, According to EPA

If you’re putting together a late-summer home maintenance checklist, you’ve likely taken your home’s HVAC system into consideration. Replacing filters and having it checked at least once a year is always a good idea to keep things running smoothly. While cleaning the grates on the vents can help prevent dust build-up, the ducts themselves do not need to be cleaned annually. According to the EPA , there are no proven health benefits from air duct cleaning. While there is no harm in properly cleaning your air ducts, if you don’t have air duct problems, you can check this task right off your list.

Before cleaning thoroughly, check for mold.

While in some cases the air ducts need to be cleaned, such as when mold grows inside, in most cases this type of cleaning is unnecessary. If you don’t know if something is mold or not, you should obtain a sample of the suspected mold and submit it for testing for confirmation. Lab testing costs about $50, as opposed to duct cleaning, which can cost thousands depending on your system. Since testing is the only way to know for sure if your ducts have mold, you should be suspicious of any contractor who looks at your vent and tells you it has mold in it.

Clean the vents if they are clogged

If there is visible blockage in your air ducts, or particles or dust coming out of the vent when your HVAC system is running, that is definitely a concern and a good reason to clean your air ducts. However, if you don’t address the underlying problem causing material buildup in the channels, you will likely have a permanent problem that cannot be solved with a single cleaning.

Check for infection

Another possible reason to clean the air ducts in your home is the presence of rodents. Because mice, rats, and squirrels can leave potentially dangerous germs in their droppings if you suspect you have an infestation, calling a professional to clean your air ducts is a good idea.

Check the insulation

If you are planning to clean the air ducts due to a noticeable smell, you should also check the insulation on the air ducts. If the insulation becomes damp, it can cause odors and even mold. Solving the insulation problem should take care of the smell, although cleaning the air ducts won’t hurt either.

Don’t Apply Cleansing Agents Too Much

While duct cleaning has not been proven to benefit your health, there are some cleaning methods that can actually be harmful. Because there are currently no approved cleaners for cleaning the inside of HVAC vents, it is also impossible to know the potential health effects of inhaling any cleaner that enters indoor air. In certain circumstances where mold growth is observed, or where rodent excrement is found, biocides may be used, but should not be applied to vents in general.

Close vents to prevent problems

The best way to keep your air ducts clean is to keep moisture and particulates out as much as possible. Make sure your air ducts are properly sealed and that all of your humidifier and dehumidifier equipment is working properly to prevent condensation from forming inside your air ducts and help keep them dry. Checking and replacing air filters and using the most efficient filter your system can use will help keep particles from entering the vents.

When doing repairs or even deep cleaning, you can raise additional dust that can get into air ducts and air intakes. Be sure to shut down the system and cover the vents for any dusty activity. Vacuum with a HEPA filter device to remove as much dust as possible before opening the vents and turning the system back on.