Duct Cleaning Q & A

Q: What is duct cleaning?

A: If your home is heated and cooled by a central system, boxes or pipes carry air between an air handler and each room. These pipes, called ducts, are made of sheet metal, fiberglass or wire-reinforced plastic and may become contaminated with debris including dust, dirt, pollen, mold or even construction materials, like sawdust.

Proper cleaning includes more than ducts. The contractor should clean all parts of the system, including grills, heat exchangers, coils, drip pans, fan motors, housings and inside air handling units.

During cleaning, the contractor uses tools on the inside of the ducts to dislodge this debris. Then, a high-power vacuum system sucks the loose dirt out. Beware of companies that use a vacuum as the only means of cleaning.

Some companies also recommend the introduction of a biocide and/or sealant into the system as the last step in cleaning. Make sure these chemicals are approved for duct applications and the contractor follows label directions in applying them.

Q: Should I have my ducts cleaned?

A: Each home is different. If you don't smell musty odors and have no air quality concerns, you may not want to worry about duct cleaning. Dust accumulation on the outside of return air registers is normal.

If, on the other hand, you have family members with allergies or other problems you think may be related to your home environment and indoor air quality, duct cleaning may be one step of a comprehensive plan to remedy the situation. Talk to your physician and the regular heating and air contractor who services your system.

If the contractor uses shoddy workmanship, duct cleaning can actually cause more indoor air quality and energy efficiency problems than it solves.

Q: How often should I have my ducts cleaned?

A: Your preference is one of the biggest factors in determining how often ductwork is cleaned. Other factors in the home that may warrant more frequent cleaning include smokers, pets that shed large amounts, water contamination of the cooling system and allergy or asthma sufferers.

It may also be a good idea to have ducts cleaned after remodeling. One study showed cleaning the ducts of a brand new home yielded 17 pounds of debris, including saw dust, chunks of drywall and other dirt, including pieces of workmen's sandwiches.

Q: Who should clean my ducts?

A: Use the same savvy you use before hiring any contractor. See if they're members of industry associations. The National Air Duct Cleaning Association actually has a contractor testing and certification program for duct cleaning specialists.

Check the Better Business Bureau. Get proof that the company is insured (liability and worker's comp) and licensed (Georgia requires special licensing for duct cleaning). Get references. Ask about the company's experience. Get several estimates. And beware of companies that make sweeping claims of health and energy savings from duct cleaning.

Q: How much will it cost to clean my ducts?

A: The Environmental Protection Agency says "services typically-but not always-range in cost from $450 to $1,000 per heating and cooling system, depending on the services offered, the size of the system to be cleaned, system accessibility, climatic region and level of contamination."

Avoid "$99 whole-house specials" and other sales gimmicks, as well as "blow and go" contractors. These companies charge a nominal fee and do a poor job. High-pressure sales and unauthorized work are other frequent trademarks of these companies.

Q: How long will it take to clean my ducts:

A: A typical three bedroom home will require four to eight hours depending on the type of home, accessibility to the ducts and number of workers.

Q: Will duct cleaning lower my energy bills?

A: In a few cases, ducts or coils may be so clogged that increased air flow resulting from cleaning will significantly lower energy bills. In most cases though, you'll probably notice little difference.

Q: How can I help keep my ducts clean?

A: Use a high-efficiency air filter on your cooling system and clean or change it regularly. Make sure the joints and seams in your duct system are sealed. Dust and vacuum your home frequently. If you're remodeling, cover return and supply grills of those rooms and remove saw and sheet rock dust before uncovering.

Q: Where can I find more information on duct cleaning?

A: Try these web sites: www.epa.gov/iaq/pubs/airduct.html, and www.nadca.com

Contractors should use one of these two methods in addition to a vacuum system to clean your home's ducts.