With the increasing public awareness of indoor air pollution I often get asked if duct cleaning is a good idea. As with most questions, there is usually not a yes or no answer. To help you make a decision, here is a short Q&A on the topic of duct cleaning.

Q: What are ducts?

A: The ducts or ductwork are the large pipes that carry the heated or cooled air from the furnace (air handler) to the rooms of your house.

Q: Can dust and other debris get caught in the ductwork?

A: Yes: dust, pollen and other debris can become lodged on the interior surfaces of ducts.

Q: Do these contaminants cause health problems?

A: Yes. If the interior of the ducts have become wet it can promote the growth of molds which may have an adverse effect upon people with allergies.

Q: Will cleaning the ducts reduce the contaminants in the living space?

A: There are no studies to demonstrate conclusively that dust or particle levels inside the home increase because of dirty ducts.

Q: Are there any conditions under which I should definitely consider having my ducts cleaned?

A: Yes: The U.S. Environmental Protection Agency recommends that you consider cleaning your ducts if any of the following conditions exists.

1. There is substantial mold growth on the interior of the ducts or other parts of the heating/cooling system.

2. The ducts have become infested with vermin (rats, mice, or insects).

3. You are able to determine that particles are being released into your home from the ductwork system.

4. If members of your household are experiencing unusual or unexplained symptoms or illnesses.

Q: Can cleaning ducts make the indoor air quality worse?

A: No: There is no evidence that proper cleaning of the ducts has any detrimental effects.

Q: How do I know that my ducts have been cleaned properly?

A: The best way to ensure that you get is good job is to hire a professional. In choosing a contractor, look for someone that adheres to the standards of the National Air Duct Cleaners Association. More information about NADCA is available from their Web site, www.nadca.com. Be wary of people who claim to be certified. The EPA offers no certification for duct cleaners. Also be wary of suggestions to treat the ducts with chemicals or biocides. The EPA does not recommend the use of chemicals or biocides unless the homeowner completely understands the pros and cons of their use.

Q: How much should I expect to spend to have my ducts cleaned?

A: The cost of duct cleaning will vary, but you can expect to spend between $450 and $1,000 per heating and cooling system. For additional information of indoor air quality, visit the EPA Web site at www.epa.gov.

Do you have a home repair question? Send e-mail to Ask the Inspector at

homeandgarden@ajc.com.