Aeroseal Sparks Trend in NY High-Rise Retrofitting

Sealing from the inside allows engineers to fix ventilation in older buildings where access is limited, resulting in lower energy costs and improved IAQ.

Like most older buildings throughout the United States, the Carlyle Towers in Caldwell, New Jersey suffered from poor ventilation. Leaks in the duct work prevented the huge rooftop fans from effectively drawing air out of the many bathrooms, hallways and living spaces within the 55-year-old multi-family apartment building. Limited access to the duct work made manual duct sealing methods impossible without severe demolition to the building’s walls and ceilings.

Several years ago, the engineers at Steven Winters Associates decided to tackle the problem using a new technology developed by the U.S. Department of Energy that seals leaks from the inside of the duct work. The success of that project has resulted in the technology’s use to solve similar ventilation issues in thousands of apartments throughout the New York City area alone.

In Brief

  • Building: Carlyle Towers apartment building
  • Location: West Caldwell, New Jersey
  • Property Owners: Legow Management
  • Engineering Contractor: Steven Winters Assoc.
  • Goal: Improve ventilation, lower energy costs, improve indoor air quality and HVAC comfort
  • Before Aeroseal: 250 CFM average leakage/shaft
  • After Aeroseal: 15 CFM average leakage/shaft
  • Results: 90% reduction in leakage; $26,000/year energy savings; even room-to-room comfort. 

It took engineers just 4 weeks to Aeroseal all 25 of the building’s individual ventilation shafts. With the leaks sealed and the pressure within the shafts balanced, contractors were able to replace the 25 300-watt roof exhaust fans with 140-watt units. The fan optimization alone resulted in an annual energy savings of $7,000. In addition, the improved HVAC efficiency afforded by the leak-free ductwork decreased gas use by approximately 30% – from an average of 57,000 therms (EC)/year to 41,000 therms (EC)/year for an additional savings of approximately $19,000 annually.

Since the completion of the Carlyle Towers retrofit project, hundreds of similar New York-area multi-family apartments with central ventilation have been similarly retrofitted for higher energy performance.


Soon after the retrofit was completed, we heard from tenants who thanked the building manager for fixing the heat. While we didn’t touch the heating system per se, by sealing the shaft leaks and automating the damper adjustments, the furnace was noticeably more efficient and effective” (David Legow, President, Legow Management).

Aeroseal sealed on average 90% of the duct leakage, and that had a significant impact on the ability to properly balance ventilation and reduced the use of both gas and electricity” (Marc Zuluaga, Vice President, Steven Winters Associates).

Source: Aeroseal

Aspen Air Duct Cleaning is an approved Aeroseal Dealer, licensed and ensured, and a member of the National Air Duct Cleaners Association (NADCA) and National Organization of Remediators and Mold Inspectors (NORMI).

Please contact Aspen Air Duct Cleaning at 1-800-931-6653 for an Air Duct System Inspection and to learn more about how sealing air duct leaks can improve indoor air quality and reduce energy costs. Or email