Deep Energy Retrofit at Clinton Hill Co-op

As fans of March Madness basketball know, a full-court press by the defense can turn into a devastating offensive weapon. In its effort to defend against high energy costs, the massive Clinton Hill Cooperative has mounted its own full-court press – a deep retrofit of its buildings’ systems. The goal is to reduce the co-op’s carbon dioxide footprint, save on energy costs, make residents comfier, and show the way for other co-ops and condos to go green. 

“They’re way ahead of the game,” says Haym Gross, an architect and founding member of the NYC 2030 District, the local arm of a nationwide nonprofit that educates building owners on energy efficiency. “They have an experienced and engaged co-op board and a management that takes energy efficiency seriously.” 

Built in the 1940s as housing for workers at the nearby Brooklyn Navy Yard and converted to a co-op in 1984, the Clinton Hill Co-op consists of 12 brick towers on two neighboring campuses. An energy audit revealed that the co-op was wasting about $150,000 a year on energy costs due to its inefficient heating system, leaky windows, balky radiators, and improperly sealed entry doors. Rather than attack these problems piecemeal, the board decided to mount a full-court press. 

First, the master electricity meter was replaced by submeters for all 1,200 apartments, resulting in an immediate 30 percent drop in consumption, says George Switzer, an architect who serves on the co-op board. “Some people would run the air-conditioning all the time,” he notes. Submeters put a damper on that practice. 

Spurred by a grant from the New York State Energy Research and Development Authority, the board installed a cogeneration system on its north campus. Cogen cuts costs by generating electricity and then using waste heat to heat domestic hot water. More recently, an audit conducted by Mosto Technologies suggested modifications to the heating system. After consultations with Steven Winter Associates, an architectural firm that helps clients improve building performance, the co-op replaced about 500 steam traps, vacuum pumps, and the boiler controls system. 

Now it was time to tackle the 7,000 windows. The NYC 2030 District recommended the board consult with Fentrend, a company that finds and compares windows based on acoustics, air and water infiltration, and thermal values. Fentrend recommended a German product, but the co-op, wary of working with an overseas manufacturer, ended up with models by Kelly Window Systems that fit the co-op’s budget and provided higher performance. Since the south campus is situated in the Clinton Hill Historic District, the co-op had to get approval from the Landmarks Preservation Commission. “We had to change the specs a few times,” says Steve Greenbaum, director of property management at Charles H. Greenthal/MGRE, the co-op’s management company. 

Then came the problematic radiators. Typical of older New York City buildings, some apartments were under-heated while others got too hot. “The spread was 60 to 85 degrees,” says Greenbaum, which prompted some residents to open windows in wintertime to regulate the temperature. With advice from Bright Power, the co-op is currently installing “The Cozy” on radiators. Manufactured by Radiator Labs, this insulating enclosure includes a temperature sensor and a built-in fan that circulates warm air out the bottom of the radiator whenever the room temperature drops. 

The co-op has reduced energy costs, made apartments more comfortable, and improved the health of the planet. “Everyone wants a nice lobby,” says Gross of NYC 2030 District, “but not everyone is looking at the long-term impacts of climate change on the environment.” 

“People want to do it,” says Switzer, “but they don’t know how to begin.” Clinton Hill Co-op began by mounting a full-court press. The result was a slam dunk. 

PRINCIPAL PLAYERS – PROPERTY MANAGEMENT: Charles H. Greenthal/MGRE. WINDOWS: Kelly Window Systems. CONSULTING ENGINEER: Steven Winter Associates. STEAM TRAPS: GS Dunham. BOILER AND COGEN: East Coast Mechanical. RADIATORS: Radiator Labs. SYSTEM AUDIT: Mosto Technologies.