Heating, ventilating and air conditioning (HVAC) ducts must be properly installed, operating and maintained in order to avoid Indoor air pollution. Ducts that are not properly installed or maintained can become contaminated with dust, allergens, and other debris.  If moisture becomes present and is not properly cleaned, mold can begin to grow.

Ask yourself a couple of questions:

- Does my home have a musty odor? And

- Is anyone in the home suffering from allergies or unexplained symptoms or illnesses?

If you suspect there might be a problem, just do a simple visual inspection of the inside of the air ducts to see if they are contaminated with debris, dust or mold.  If you see debris of any kinds then it would be in your best interest to have your ducts properly cleaned.

If you choose to have your HVAC system cleaned, it is important that the technician agrees to clean ALL components of the system and is QUALIFIED to do so. Failure to clean any part of your HVAC system properly can contaminate the entire system and result in costly repairs or replacement of the system.  Methods of cleaning HVAC Systems vary, although standards have been established by industry associations concerned with air duct cleaning.
 
EPA does NOT recommend that the air ducts be cleaned routinely, but only as needed.  If any company recommends routine duct cleaning and makes claims that it is recommended by the EPA or it will benefit your health, you should write the EPA.

Here is a great article from the EPA as well as other information about Deciding Whether or Not to Have Your Air Ducts Cleaned.