Commercial Building Duct Sealing Market Characterization

The California investor-owned utility San Diego Gas & Electric commissioned a study to evaluate duct sealing technologies in commercial buildings, comparing traditional methods like manual taping and mastic application to advanced aerosol sealants. The research, based on literature reviews and expert interviews, revealed that HVAC airflow leakage—often 10 to 20 percent and up to 35 percent in older systems—wastes fan, cooling, and heating energy, leading to higher costs and reduced performance. Effective sealing can cut leakage to 5 percent or less, with manual methods best for large leaks and aerosol sealants optimal for smaller gaps. Large markets like healthcare, hotels, and schools actively adopt duct sealing retrofits, though other opportunities exist, especially for older systems or those never tested for leakage. Key barriers include implementation costs and limited industry awareness. Incentivizing duct testing and sealing could yield annual HVAC energy savings of 15 to 30 percent, addressing a persistent efficiency challenge that occurs year-round.