When it comes to air ducts in Arizona, the landlord must ensure they are kept in an adequate and habitable condition. The National Association of Air Duct Cleaners (NADCA) recommends that ducts be cleaned every three to five years. To find companies that offer duct cleaning services, you can look in the Yellow Pages under the Duct Cleaning section or contact NADCA directly. It is best to leave duct cleaning and repairing to HVAC professionals who have the specialized equipment and knowledge of HVAC systems.
No matter what you decide to do about air duct cleaning, it is essential to commit to a good preventive maintenance program to minimize contamination. The EPA does not recommend that air ducts be cleaned except when necessary, due to continuing uncertainty about the benefits of duct cleaning under most circumstances. This is because much of the dirt that can accumulate inside the air ducts adheres to the surfaces of the ducts and does not necessarily enter the living space. On the other hand, if a service provider does not follow proper duct cleaning procedures, it can cause problems with indoor air.
You might consider cleaning your air ducts simply because it seems logical that they will get dirty over time and should be cleaned from time to time. Some service providers may also suggest applying chemical treatments (sealants or other encapsulants) to encapsulate or cover the inner surfaces of air ducts and equipment housings, believing this will control mold growth or prevent the release of dirt particles or fibers from the ducts. While many of these products can be legally used inside uncoated ducts if all instructions on the label are followed, some of the instructions on the label may not be appropriate for use in ducts. If no one in your home has allergies or unexplained symptoms or illnesses and if, after a visual inspection of the inside of the ducts, you see no evidence that they are contaminated with large deposits of dust or mold (there is no musty smell or visible mold growth), it is probably not necessary to clean them. Whether you decide to clean your home's air ducts or not, preventing water and dirt from entering the system is the most effective way to avoid contamination.
Most organizations that deal with duct cleaning, including the EPA, NADCA, NAIMA, and SMACNA (the National Association of Metal Plate Contractors and Air Conditioning), do not currently recommend the routine use of sealants to encapsulate contaminants in any type of duct. Duct cleaning methods vary, although industry associations that deal with air duct cleaning have established standards.
