According to the (NADCA), National Air Duct Cleaners Association, a professional association based in Washington, D.C., air duct cleaning is a buyer-beware service. Some companies promoting duct cleaning may be either bait and switch operations or companies that do inferior jobs with unprofessional equipment.
Any professional cleaner would question a company that employ only shop-vac sized machines with a single 2-inch hose. To do a good job, powerful machines mounted in specially equipped vehicles with varying types of hoses and attachments will be needed in most cases to adequately reach all duct areas.
But even if the technician is prepared, the above information begs the question: "Is air duct cleaning really worthwhile?" You can check some of your own ducts with a mirror and a flashlight. Unscrew several of your wall or floor vents and, using your mirror, look into the ducts.
If there aren't any large deposits of dust, dirt or mold, or if no one in your home suffers allergies or asthma, having air ducts cleaned is probably unnecessary, according to advice provided by the U.S. Environmental Protection Agency. Also, just because you have dirty return grilles doesn't mean you have dirty ducts. It's normal for dust-laden air to be pulled through the grates leaving telltale black streaks that can often be easily vacuumed or cleaned at the return.
The NADCA notes that ducts are more likely to need cleaning under the following circumstances:
- The home has been remodeled.
- Water has damaged the home.
- There are four-leg pets.
- Someone smokes.
- Your carpeting is old.
According to industry experts, in cases where there are truly dirty ducts in a 2,000-square foot house, duct cleaners may fill three grocery sacks with dirt and debris. Expect to pay $250-500 for a typical home's duct cleaning by a qualified professional. Larger homes with a more extensive duct system will cost proportionately more.
If duct cleaning is done improperly, or needlessly, the outcome can do more harm than good. Disturbing a basically intact and inert dust layer and then not removing the residue creates air borne contaminants that might not otherwise have been a problem. Homeowners should seek the advice and information on the pros and cons of duct cleaning before hiring a contractor.
The EPA advises that a professional cleaning should include:
- Opening duct access points to allow the entire system to be inspected and cleaned.
- Use of only high-efficiency particle (HEPA) air vacuuming equipment.
- Protection of the carpeting and household furnishings during cleaning.
- Use of well-controlled brushing equipment with powerful vacuums to dislodge dust and other particles.
- Taking care to protect ductwork including sealing and re-insulating any access holes.
Fore more information on duct cleaning visit the EPA website: www.epa.gov/iaq/pubs/airduct.html