Brooklyn Condo Upgrades Rooftop Unit, Cooling Tower, and Fans to Cut Carbon Emissions

1 Grand Army Plaza, a glass-faced 99-unit condo in Brooklyn's Prospect Heights, knew it had a breathing problem. The rooftop unit, which was supposed to bring in fresh air to the hallways, was bringing in hot and humid air, despite the condo spending over $50,000 on repairs to fix the issue. What many thought was a maintenance problem turned out to be a design problem. “I had a conversation with one of the doormen at the building who had been there from the beginning,” recalled Amalia Cuadra, senior director of engineering at En-Power Group, and “and he said the unit never worked correctly.”

The fix turned out to be more than simply replacing the unit. Cuadra advised the board to take a holistic approach and examine how the entire ventilation system worked. "If we replace the unit,” she advised,  “we have to replace the unit in a way that meets the ventilation rate of your exhaust fans, because both are meant to work together." Turns out that the building's rooftop fresh air intake unit was positioned directly above the cooling tower, which meant it was constantly pulling in hot, humid air. Upon investigation, Cuada found that the exhaust fans were also oversized, creating an additional imbalance. 

To address all these issues Caudra encouraged the board to not focus on a replacement, but reimagine the entire system. In this case, that meant replacing the rooftop unit, cooling tower, and exhaust fans in a single coordinated effort, while also sealing the ducts to address leakage. This comprehensive strategy allowed the building to address multiple issues simultaneously, including comfort, energy conservation, carbon emissions, and building operations efficiency. The project also delivered cost savings by combining work that required expensive crane equipment: "You use the crane for an hour, you're still going to pay at least $100,000," Cuadra pointed out.

While the final price tag was close to $900,000, the payoff is a projected savings of 250,000 kilowatt-hours and a full letter grade improvement in energy efficiency. Additionally, 1 Grand Army Plaza is projected to reduce carbon emissions by around 170 tons, which could help the building avoid future penalties under Local Law 97.

"Replacement of A with A sometimes does not solve a problem," Cuadra warns. “You’ve got to think, can this save me energy, operating expenses, or carbon emissions? There are ways to piggyback off capital projects and reduce energy and carbon emissions, especially for such critical, large equipment as a cooling tower, rooftop unit, exhaust fans, or chillers and boilers.” By approaching building systems as interconnected parts rather than isolated components, necessary capital improvements can be transformed into opportunities for enhanced comfort, efficiency, and compliance—turning chronic problems into sustainable solutions.