A visual inspection is the best way to determine the cleanliness of your heating and cooling system. Some service providers use remote photographs to document the conditions inside the ducts. All parts of the system must be visibly clean; you should not be able to detect any debris with the naked eye. Show the service provider the consumer checklist after cleaning before work begins.
When it comes to duct cleaning, it is important to understand that there are certain standards that must be met in order for it to be done correctly. Industry associations that deal with the cleaning of air ducts have established these standards, and it is important to make sure that any service provider you hire is following them. You may have seen an advertisement, received a coupon in the mail, or a company contacted you directly to offer to clean your air ducts as a way to improve your home's indoor air quality. On the other hand, if a service provider doesn't follow proper duct cleaning procedures, it can cause problems with indoor air. As long as the cleaning is done correctly, there is no evidence to suggest that such cleaning is harmful.
While there is debate over the value of regular duct cleaning, there is no evidence to indicate that it is harmful, provided it is done properly. However, there is little evidence to indicate that simply cleaning the duct system will increase its efficiency. Products designed for use in ducts or as ducts themselves 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). Most organizations that deal with duct cleaning, including the EPA, NADCA, NAIMA, and SMACNA, do not currently recommend the routine use of sealants to encapsulate contaminants in any type of duct. If you are considering having your air ducts cleaned, it is important to find a reputable company that follows all of the necessary standards and procedures. To find companies that offer duct cleaning services, check the Yellow Pages in the Duct Cleaning section or contact the National Air Duct Cleaners Association (NADCA) at the address and phone number listed in the information section at the bottom of this guide.
You can also contact professional duct cleaning service providers and ask them about their services. You may consider cleaning your air ducts simply because it seems logical that they will get dirty over time and need to be cleaned from time to time. If no member of your family has allergies or unexplained symptoms or illnesses and if, after a visual inspection of the inside of the ducts, you don't see any signs that they are contaminated with large deposits of dust or mold (with no musty smell or visible mold growth), it is probably not necessary to clean them. Preventing water and dirt from entering the system is the most effective way to prevent contamination (see How to Prevent Duct Contamination).Cases in which it might be appropriate to use sealants to encapsulate duct surfaces include repairing damaged fiberglass insulation or combating fire damage to ducts.
