Reducing the permeability of residential duct systems.

In this paper, we investigate the potential of an aerosol-based technique to significantly reduce the leakiness of residential air distribution systems (ADS). The first part is dedicated to a short review of theoretical analyses of particle transport and deposition in an ADS as well as particle removal in the leaks. The purpose of this review is to pre-determine the ranges of the flow rates, pressure differentials and miscellaneous characteristics of the particles that would allow plugging of the leaks in a relatively short time. The remainder of the paper deals with our experimental investigation and includes a description of experiments performed to assess the feasibility of the technique. We found that an aerosol alone made out of a liquid suspension of a vinyl polymer can plug 16 cm² of Effective Leakage Area in a branch in less than 30 minutes. Based on our theoretical and experimental results, we designed a field device and performed laboratory experiments on a small-scale duct system. We showed that with this portable unit, the Effective Leakage Area of a typical duct network in California can be reduced by about 80%.