Should You Really Clean Your Air Ducts?



A Difficult Question

In your home, office, or commercial space, you may have wondered how often you should clean your air ducts. Researching the topic will bring up information saying the procedure should be done every few years. However, many of these results have been written by air duct cleaning companies trying to sell their services. Read on for a balanced take on answering this not-so-simple question.

Debunking Several Air Duct Cleaning Myths

various air ducts
various air ducts

You may be surprised to learn that decades of research have not given warrant to clean your air ducts. A 2010 reviewopen_in_new on duct cleaning studies did not find that the practice benefits indoor air quality, HVAC performance, occupant health, or energy savings. The U.S. EPAopen_in_new and Division of Occupational Health and Safety (DOHS)open_in_new clear up several air duct cleaning myths with the following facts:

air duct facts
  • Contrary to popular belief, air duct cleaning should not be part of routine maintenance.
  • The EPA neither sets duct cleaning standards nor certifies duct cleaning companies.
  • Dusty air vents are normal, caused by dusty air being pulled through the grates. They do not indicate that your ducts are contaminated with heavy dust or debris.
  • Duct cleaning has never been shown to prevent health problems.
  • While proper air duct cleaning has not been shown to be harmful to human health, improper air duct cleaning can cause indoor air problems. Inadequate cleaning can simply stir up dirt and microbes and release them into the home. According to the study cited aboveopen_in_new, post-cleaning levels of contaminants were often higher than pre-cleaning levels.

What About UV Air Duct Disinfection?

AeroLogic installed on duct

While air duct cleaning may not prevent health problems, there is evidence to support UV duct disinfection as a means to help prevent disease. One study conducted at office buildings in Montrealopen_in_new exposed certain workers to ductwork equipped with UV systems. Those individuals experienced less headaches, coughs, congestion, and respiratory issues when UV air duct disinfection was running.

On surfaces within these UV-equipped ventilation systems, there was a 99% reduction of microbial and endotoxin concentrations. Another studyopen_in_new conducted in homes of mold-sensitized, allergic children found that UV-C air duct systems produced “significant alleviation of several asthma outcomes.”

99% reduction of microbes

The American Society of Heating, Refrigerating and Air-Conditioning Engineers states:

The effectiveness of a UV-C system to inactivate microorganisms in the air and/or on surfaces has been amply demonstrated; the best results were obtained for the long-term irradiation of downstream coil surfaces.

—ASHRAE, in its position documentopen_in_new on Filtration and Air Cleaning

ASHRAE cites the findings of a 2017 studyopen_in_new confirming this evidence, while also highlighting reduced maintenance cost and energy use. The U.S. EPAopen_in_new and Rensselaer Polytechnic Instituteopen_in_new have found our AeroLogic® Air Duct Disinfection models to be efficient, safe, and effective in reducing contaminants in air duct systems.

When is Air Duct Cleaning Really Needed?

Since conditions in every home or building are different, making a general statement for or against air duct cleaning is impossible. While the practice is not necessary in most cases (and may even be more harmful), the EPA and industrial hygienists agree it is proper in the following circumstances:

Does duct cleaning cause more harm than good?
  1. Permanent or persistent water damage appears in your air ducts.
  2. Slime or microbial growth is present in ducts.
  3. There is substantial, visible mold growth inside your ducts or on other components of your heating and cooling system.
  4. Debris build up in your ducts that restrict airflow.
  5. Ducts are clogged with excessive amounts of dust and debris that are coming out of your air vents.
  6. Offensive odors are coming from ductwork or HVAC components.
  7. Your ducts are infested with rodents or insects.

How to Prevent Air Duct Contamination

Whether or not you decide to clean your air ducts, good preventive maintenance practices are essential to minimize duct contamination. Follow these recommendations from the EPA and DOHS and avoid the potential hazards and cost of air duct cleaning:

HVAC professionals working on ducts
HVAC professionals working on ducts
  • Use the highest efficiency air filter recommended by the manufacturer of your heating and cooling system.
  • Follow manufacturer schedules for changing filters. If your filters become clogged, change them more frequently.
  • If renovating, seal ductwork to prevent construction dust and debris from entering you air ducts.
  • Maintain good housekeeping in occupied spaces to help prevent excessive debris from entering your ducts. Use a high efficiency, HEPA filter vacuum or the highest efficiency filter bags your vacuum cleaner can take.
  • If your heating system includes in-duct humidification equipment, operate and maintain the humidifier as the manufacturer recommends.
  • Prevent moisture due to condensation from entering your HVAC system, by making sure ducts are properly sealed and insulated in all non-air-conditioned spaces (like attics and crawl spaces).
  • Ensure that air vents are located away from any sources of contamination.
  • Consider routine inspections of your ducts. The National Air Duct Cleaning Association (NADCA)’s standard, “Assessment, Cleaning and Restoration of HVAC Systems ACR 2013,”open_in_new recommends that HVAC systems be visually inspected for cleanliness at regular intervals, depending on building use. For healthcare facilities, the standard recommends annual inspections of air handling units and supply/return ductwork.
  • When having your heating and cooling system maintained or checked, ask the service provider to clean cooling coils and drain pans.

In their technology evaluation reportopen_in_new, the U.S. EPA documents the efficiency and safety of the AeroLogic® Air Duct Disinfection System in reducing the presence of microorganisms within air duct systems. Shop AeroLogic® on AtlanticUltraviolet.comopen_in_new.

Learn More & Shop AeroLogic®

Made in the USA from U.S. and imported parts (since the 1950s), our AeroLogic® UV-C Air Duct Disinfection models are constructed of the highest quality materials and use germicidal UV lamps to purify HVAC Ducts. Models have many optional accessories available, making them flexible systems for residential, commercial, and industrial applications.

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