The project, completed in 2008 by Legow Management, is a 50-year-old multifamily apartment building in Caldwell, N.J. Steven Winters Associates combined Aeroseal duct sealing with self-balancing Constant Airflow Regulators from American Aldes to reduce energy usage. The company was able to create a ventilation retrofit design that optimized both energy performance and indoor comfort and air quality.

Aeroseal was used to seal leaks throughout the building’s 25 individual ventilation shafts, a move that, together with the new regulators, improved the effectiveness of the building’s exhaust fans and reduced the consumption of gas used to heat the individual apartments by 30 percent.

“Aeroseal sealed 90 percent of the duct leakage and was instrumental in dramatically improving the floor-to-floor balancing of the ventilation system as well,” said Marc Zuluaga, vice president and director of multifamily energy services for Steven Winter Associates. “Soon after the retrofit was completed, we heard from one tenant who thanked the building manager for fixing his heat. While we didn’t touch the heating system per say, by sealing the shaft leaks we were able to lower the use of exhaust fans — and that, together with the dampers, resulted in more even heating throughout the building.”

According to utility records, since the project was first completed gas usage was reduced by approximately 30 percent. The retrofit also allowed the property owners to downsize each of the roof fans, resulting in additional electricity savings.

“Before the retrofit, we were running 25,300-watt belt-driven fans. We were able to replace them with compact 140-watt units direct drive fans. This alone resulted in a utility savings of about $7,000 each year, and reduced maintenance costs” said Zuluaga.

The Ebie Award was created by the Urban Green Council and the U.S. Green Building Council to recognize environmental performance in existing buildings.