NYC tests window-mounted heat pumps to cut emissions
NEW YORK — For 27 years, the heat in Regina Fred’s Queens apartment building came from a noisy steam radiator that she couldn’t control and sometimes didn’t come on at all, leaving her shivering. Sometimes, the radiators ran so hot that residents had to keep their windows open in the middle of winter for relief.
That all changed a few months ago, when she got a window-mounted heat pump as part of a pilot project run by the New York City Housing Authority aimed at cutting energy costs and lowering emissions. Suddenly, all Fred had to do is touch a dial to adjust her temperature, and she found herself enjoying “a very good silence.”
“They did a demonstration for me and I was thrilled,” Fred said. Now, her grown children call the heat pump “the best thing” she has in her apartment, and her neighbors have knocked on her door to check out the unit.
Heat pumps, a highly efficient technology that has grown in popularity in recent years to rival gas furnaces, have mainly been an option for owners of houses. But new designs also are making them practical for apartments, which often rely on inefficient centralized steam boilers powered by oil or gas. That represents a promising climate solution for buildings, whose operations account for 26% of global energy-related carbon emissions, according to the International Energy Agency.
The IEA said last year that installing heat pumps in apartment buildings and commercial sites should “be a priority area” to maintain the growth necessary to meet national climate pledges worldwide. The U.S. has 23 million apartment units, according to the National Multifamily Housing Council, representing a huge sector of people who could use less energy with heat pumps.
New York law requires buildings to make big cuts in greenhouse gas emissions over the next decades. To comply, NYCHA is targeting heating and cooling, the largest source of emissions for the agency, which houses about 528,000 people across more than 2,400 buildings — or about 1 in 17 New Yorkers, said Shaan Mavani, the agency’s chief asset and capital management officer.
Centralized steam boilers powered by natural gas or oil typically provide the heat, and they are wasteful — the NYCHA’s climate mitigation road map calls steam heat “19th-century technology incompatible with 21st-century needs.”
Mavani said 30% and 80% of heat is lost through old and leaky ductwork before it reaches apartments. And that doesn’t account for the waste when residents have to open their windows to dissipate excess heat from a system they can’t control.
Eric Wilson, a senior research engineer for the Department of Energy’s National Renewable Energy Laboratory, led a team that analyzed heat pump performance in various electric grid scenarios and found even the lowest-efficiency pump would cut greenhouse gas emissions and save on operating costs in every state in the nation.
Most heat pumps require ductwork, which isn’t an option for renters in a unit they don’t own. And ductless systems typically require extensive installation that includes wiring, making a hole in a wall and a sizable external compressor.
Gradient and Midea, the two companies making the units in the pilot project at Woodside House, downsized it all into something that looks a bit like a window air conditioner but with a much lower profile. Exterior and interior halves drape over a sill to leave the window mostly unobscured. Gradient, one of the companies, says its unit installs in 15 minutes and plugs into an ordinary wall outlet.
Wilson said the interior portion of the units “take up more space on the inside than you might be used to,” but Fred called it “very beautiful.”
The NYCHA will evaluate results of the pilot project, with plans to eventually install more than 4,000 heat pumps over two years if all goes well.