Recent Applications of Aerosol Sealing in Buildings

This paper describes two recent applications of aerosol sealing techniques in buildings for improving indoor air quality and reducing energy required for heating, cooling, and ventilation. One application applies a commercially-available duct sealing technology, which has typically been used in single-family applications, to large-building exhaust systems. The initial leakage rates, percent leakage sealed, and issues encountered are presented for several large buildings. The reasons for having this leakage sealed are presented, as are some of the techniques applied when conducting this type of sealing. The average duct leakage for these buildings was 28% of fan flow and the aerosol process sealed over 90% of that leakage. The second application is the use of aerosol sealing techniques for building envelope leaks. The process is similar to that used for sealing leaks in ducts; however it does not depend on injection of the sealant into a carrier flow to transport the sealant to the leaks, and therefore has to address the likelihood of particles settling to the ground, as well as the possibility of particles depositing on vertical surfaces. Laboratory tests investigating the impacts of pressure and particle size on the sealing process are described, as are the results of selected field tests showing how well the process performed when applied at two different stages of new multifamily construction. These tests suggest that the process should be able to achieve better levels of air tightness as compared to manual sealing methods, while including the added benefit of automated air-tightness verification.