There are examples of ducts that have become badly contaminated with a variety of materials that may pose risks to your health. The duct system can serve as a means to distribute these contaminants throughout a home. In these cases, duct cleaning may make sense. However, a light amount of household dust in your air ducts is normal. Duct cleaning is not considered to be a necessary part of yearly maintenance of your heating and cooling system, which consists of regular cleaning of drain pans and heating and cooling coils, regular filter changes and yearly inspections of heating equipment. Research continues in an effort to evaluate the potential benefits of air duct cleaning.
In the meantime
Educate yourself about duct cleaning by contacting some or all of the sources of information listed at the end of this publication and asking questions of potential service providers.
Are duct materials other than bare sheet metal ducts more likely to be contaminated with mold and other biological contaminants?
You may be familiar with air ducts that are constructed of sheet metal. However, many modern residential air duct systems are constructed of fiberglass duct board or sheet metal ducts that are lined on the inside with fiber glass duct liner. Since the early 1970’s, a significant increase in the use of flexible duct, which generally is internally lined with plastic or some other type of material, has occurred.
The use of insulated duct material has increased due:
- to improved temperature control
- energy conservation
- reduced condensation
Internal insulation provides better acoustical (noise) control. Flexible duct is very low cost. These products are engineered specifically for use in ducts or as ducts themselves, and are tested in accordance with standards established by Underwriters Laboratories (UL), the American Society for Testing and Materials (ASTM), and the National Fire Protection Association (NFPA). Many insulated duct systems have operated for years without supporting significant mold growth.