ABSTRACT
Research and studies on subject of duct cleaning are unfortunately limited. One, reported in Annals of Allergy, involved eight homes in northern Texas sampled to determine fungal colony forming units prior to and after duct cleaning. The three common technologies for cleaning air ducts were to be tested—contact vacuuming, air washing, and power brushing. A second year of research was to study nine existing homes, and would include energy analysis to determine whether or not duct cleaning had any impact on energy conservation or equipment efficiencies. Any Indoor air quality problem or evaluation should include evaluation of ventilation system. Most heating, ventilation and air conditioning systems have few existing access or entry points for duct cleaning and/or visual inspection. Coatings were tried with little success, and attempts to reduce moisture in ductwork also met with failure. The final solution was a combination cleaning, application of an EPA-registered biocide, and use of the mechanical insulation repair coating to internal lining.
