If you or someone in your family suffers from asthma or allergies, you may be considering getting your home’s heating and cooling ducts cleaned. But even if you have no special health concerns, cleaning your ducts may appeal to you at an intuitive level. After all, if your ducts are clean, all that air flowing out of your vents should come out clean, too, right?

Well, actually, no.

Although duct-cleaning operations may insist duct cleaning is essential for your health, the evidence does not support their claims. Companies that perform duct cleaning often advertise health benefits or suggest duct cleaning will lower your power bills by improving your system’s efficiency. Some ads even use language like, “Studies have shown . . . ” but no data back up these claims. Even if your ducts are dirty, cleaning them probably won’t provide any measurable benefits. In fact, the little independent research performed on duct cleaning indicates that the process stirs up so much dust that it creates a bigger problem than it solves.

Although it intuitively makes sense to clean ductwork — after all, you dust and clean the rest of your house — the fact is dust that settles in your ventilation system generally stays where it is, unlikely to become airborne unless disturbed. Under most circumstances, the dust is inert and harmless, and stirring it up with cleaning equipment actually creates bigger issues.

Little research has been done on the effects of duct cleaning. Government studies from the United States and Canada and health professionals who have investigated duct cleaning stop short of recommending against it, but they also don’t endorse it as a routine measure.

A study done by U.S. Environmental Protection Agency researchers measured dust levels and HVAC system efficiency in test homes during a one-week period during the cooling season and found duct cleaning did not significantly improve dust levels or system performance. Based on that report and other independent research, the EPA’s official advisory on duct cleaning concludes:

“Duct cleaning has never been shown to actually prevent health problems. Neither do studies conclusively demonstrate that particle (e.g. dust) levels in homes increase because of dirty air ducts. This is because much of the dirt in air ducts adheres to duct surfaces and does not necessarily enter the living space. . . . Moreover, there is no evidence that a light amount of household dust or other particulate matter in air ducts poses any risk to your health.”

The Canada Mortgage and Housing Corporation (CMHC), a government agency, conducted a study in the 1990s to investigate two claims: Duct cleaning makes indoor air healthier; and it reduces energy costs by improving airflow. After testing 33 homes in Montreal before and after duct cleaning, the study found that there was no significant improvement in air quality and that duct cleaning alone did not improve airflow or energy efficiency. In some cases, measured particle levels actually increased immediately after a cleaning. In other cases, particle levels decreased immediately after cleaning but returned to previous levels within weeks.

Source: https://wapo.st/2scOR70