Cutting-Edge Aerosol Duct Sealing Technology
Denair HVAC brings a lab-proven method, born at Lawrence Berkeley National Laboratory, to commercial ductwork across NYC — sealing leaks up to one inch wide from the inside, without opening a single wall.
How Aerosol Duct Sealing Works
Aerosol duct sealing traces back to 1994, when the Energy Performance of Buildings Group at Lawrence Berkeley National Laboratory developed a method for sealing air distribution ducts from the inside out. Denair HVAC has built this technology into our own sealing process, because it solves a problem that hand-sealing every joint and seam simply can't: reaching leaks that are buried inside walls, ceilings, and chases.
The process works by injecting a fine mist of sealant particles into a pressurized duct system. The particles are engineered to stay suspended in the airstream rather than sticking to duct walls — until they reach a leak. There, the physics of the leak itself does the work of finding and closing it.
Supply and return grilles are temporarily sealed, forcing all air in the system — and every suspended particle in it — to travel out through the leaks.
Continuous airflow keeps the lightweight aerosol particles floating through the ductwork instead of settling on interior surfaces.
The sharp turn air makes as it exits through a leak causes particles to collide with the leak's edges and drop out of the airstream there.
Particles bond to one another and to the leak's edges, building a solid seal that closes gaps up to one inch in diameter.
Advantages Over Traditional Duct Repair
Traditional duct sealing relies on a technician physically reaching and taping or mastic-sealing every joint — a method that gets significantly harder, and less reliable, once ductwork is buried behind finished walls or ceilings. Aerosol sealing sidesteps that limitation entirely, which is why it's become a core part of how Denair approaches whole-building duct performance.
Comprehensive Coverage
Seals leaks that are physically inaccessible to a technician, including gaps hidden inside finished walls and ceilings.
Efficiency
One sealing run addresses an entire duct run's worth of leaks at once, cutting the time Denair's crews need on site.
Cost-Effective
A high first-time success rate means building owners avoid paying for repeat sealing visits down the road.
Not sure how much your building is losing to leaky ductwork?
Denair's team can run a duct leakage assessment across your system.
MASIS: Built for Large Commercial Buildings
Standard aerosol equipment works well for smaller duct systems, but large commercial buildings need a different scale of tool. That's where the Mobile Aerosol-Sealant Injection System, or MASIS, comes in. Denair HVAC uses MASIS on extensive commercial projects that call for simultaneous sealing across multiple zones.
MASIS centers on a compact, high-output aerosol-sealant injector, paired with a mobile cart carrying an air compressor and a computerized monitoring device that tracks the sealing process in real time as it runs.
Why it matters for NYC buildings: Less energy lost to duct leakage means less energy an HVAC system has to generate in the first place — a direct, low-disruption lever for buildings tracking their Local Law 97 carbon performance.
MASIS Features
Compared to standard commercial aerosol injectors, MASIS offers several concrete advantages for large-scale sealing projects:
Increased Sealing Rate
Seals five to ten times faster than standard commercial injectors.
Concentrated Sealant
Uses a more concentrated sealing material for stronger, faster closures.
Reduced Heating Power
Runs on less energy than earlier-generation injection systems.
Compact Design
Easy to maneuver and set up across varied commercial building layouts.
Minimal Invasiveness
Disrupts day-to-day building operations as little as possible during installation.
Ease of Maintenance
Simplified servicing keeps the equipment ready for the next project.
Why NYC Buildings Choose Denair
Denair NYC HVAC leverages aerosol sealing and MASIS to deliver measurable performance gains without the disruption of a traditional duct overhaul. For facility and building managers across Brooklyn, Manhattan, Queens, the Bronx, and Staten Island, that means fewer surprises, tighter energy bills, and one less item standing between your building and its compliance targets.
Frequently Asked Questions
Aerosol duct sealing is a process, originally developed at Lawrence Berkeley National Laboratory, that seals ductwork leaks from the inside. A mist of sealant particles is injected into a pressurized duct system while the supply and return grilles are temporarily closed off. The particles stay suspended in the airstream until they reach a leak, where the sharp change in airflow causes them to collide with the leak's edges and bond there, closing gaps up to one inch in diameter.
MASIS, the Mobile Aerosol-Sealant Injection System, is a commercial-scale version of aerosol sealing equipment built for large buildings and multi-zone projects. It pairs a mobile cart, an air compressor, and a computerized sealing monitor around a compact, high-output injector. Compared to standard commercial aerosol injectors, MASIS delivers five to ten times the sealing rate using a more concentrated sealant, runs on less heating power, and is easier to maneuver and service on site.
Aerosol duct sealing reliably closes leaks up to about one inch in diameter. Larger openings or structural duct damage typically need to be addressed with a direct repair before the aerosol process is run, so Denair's technicians inspect the system first and flag anything outside that range.
Yes. Sealing duct leaks reduces the energy an HVAC system needs to condition a space, which lowers overall energy consumption and the emissions tied to it. For NYC buildings managing their Local Law 97 carbon footprint, aerosol duct sealing is a comparatively low-disruption step that supports broader efficiency and compliance goals.
Very little. Because the sealant is introduced from inside the existing ductwork, there's no need to open walls, ceilings, or floors to reach individual joints. MASIS was specifically designed to minimize invasiveness on large commercial projects, so most buildings can keep operating with minimal interruption while the work is done.
Ready to Stop Losing Energy to Leaky Ductwork?
Denair HVAC brings aerosol duct sealing and commercial-scale MASIS technology to buildings across Brooklyn, Manhattan, Queens, the Bronx, and Staten Island — delivering measurable energy savings without opening a single wall.
