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A powerful vacuum unit with a HEPA exhaust filter is attached to the duct system.
Question: When my furnace was serviced, the technician asked if I wanted the ducts cleaned, too. How can I tell if they need it, what’s involved in this process and how much does it cost?
Answer: Over time, dust and indoor pollutants can accumulate in ductwork, potentially lowering the efficiency of your heating and cooling systems and diminishing the air quality in your home. But according to the U.S. Environmental Protection Agency (EPA), much of the dust in heating and air-conditioning ducts tends to adhere to the duct surface, and doesn’t circulate throughout the house. So don’t be alarmed if you see some dust collecting on the grill over an air register.
What should concern homeowners is any buildup in ductworks that contains mold spores, bacteria or the very fine particles from cigarette and fireplace smoke as these can cause respiratory problems. Test kits are available that allow homeowners to take a sample of the dust inside their ducts and have it tested for harmful contaminants. However, if you suspect a problem, it’s best to have your system inspected by an HVAC technician who is certified by The National Air Duct Cleaning Association (NADCA). These professionals use mirrors and, in some cases, miniature video cameras to thoroughly explore all the nooks and crannies of your ductwork for potential problems. In addition to NADCA-certification, look for a company that will deduct the inspection cost from the total project cost should you need to have your ducts cleaned.
Although it is commonly referred to as “duct cleaning,” it is important to have the entire HVAC system cleaned. This includes the furnace and air-conditioner blower, heat exchanger and coils, and drain pans. The typical cost for a complete cleaning ranges from about $500 to $1,000, depending on the size of your home and the complexity of the duct system. Before hiring a contractor to clean ducts, ask about the equipment they use. If they employ an indoor vacuum unit, be sure it has a high-efficiency particulate arrestance (HEPA) filter on the exhaust to prevent particles from being blown into the open air of your home. Another good option is a truck-mounted vacuum unit, but be aware that these systems are very powerful, and during winter they may suck quite a bit of the heated air out of your house during the cleaning process.
In extreme cases, some duct-cleaning companies may suggest spraying a chemical biocide inside the ducts to kill any mold and bacteria present or to prevent future growth. If you opt for this procedure, make sure they use EPA-approved chemicals designated for the type of ducts in your home.
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