Air Sealing & Duct Sealing

Air sealing and duct sealing stop the conditioned air a typical NYC home wastes, cutting heating and cooling energy use by 20 to 30 percent. We caulk, weatherstrip, and foam gaps to reduce infiltration, then duct-blaster test and mastic-seal every ductwork joint. Most projects run $800 to $2,500 and pay for themselves in 1 to 3 years.

Duct leakage is equally important and often invisible. In a typical NYC home with central HVAC, 20–30% of conditioned air leaks out of ductwork before it reaches the registers. Joints, connections, and flexible duct runs all leak. We test duct systems with a duct blaster — pressurizing the ductwork to measure total leakage — and then seal every joint and seam with mastic sealant or foil tape (not standard duct tape, which fails over time). After sealing, we re-test to verify the improvement.

Air sealing and duct sealing are the fastest-payback efficiency upgrades available. Most projects cost $800–$2,500 and pay for themselves in 1–3 years through reduced energy bills. They also improve comfort immediately — fewer drafts, more even temperatures between rooms, less dust and allergens entering through gaps. We recommend combining air sealing with insulation for maximum effect, but air sealing alone delivers measurable results.