Efficiency of residential duct cleaning

This report presents the results of a study on the efficiency of residential duct cleaning. The study was performed In 33 houses and describes the results of measuring duct flows, fan amperage, dust, and micro-organisms before and after duct cleaning. The study concludes that there were no significant improvements in duct flows, fan amperage, duct airborne dust, house airborne dust, or supply duct dust levels. Only dust concentrations in the return ducts and the concentrations in airborne micro-organisms have significantly improved after the duct cleaning. The reductions in airborne microorganisms could not be attributed directly to the cleaning operations.