Window heat pumps will help electrify New York City’s apartments

A $70 million initiative will deploy 30,000 electric heat pumps to bring climate-friendly comfort to residents of NYC’s aging public-housing units.
By Maria Gallucci

  • Link copied to clipboard
An illustration shows Gradient heat pumps hanging from an apartment building. (Gradient)

The sleek white machine straddles an apartment window in Queens, New York City, blowing cool air inside the narrow bedroom. Unlike the boxy air-conditioning units that drone loudly and drip water from buildings across the city, this device hums softly and spares passersby from overhead leaks. And when the sticky, sweltering August heat gives way to bone-chilling winter weather, the machine can warm the room instead.

The startup Gradient showcased its new heating and cooling unit — a type of device called a heat pump — this week as part of the Clean Heat for All Challenge. Late last year, city and state officials in New York invited manufacturers to develop new electrified technology that would both improve living conditions and begin to decarbonize public-housing buildings, many of which still rely on outdated heating-oil systems and gas-fired boilers.

window with heat-pump unit
Gradient demonstrated its window heat pump at the Woodside Houses public housing project in Queens, New York City. (Maria Gallucci/Canary Media)

On Tuesday, New York leaders announced a $70 million initial investment to deploy 30,000 window-sized electric heat pumps in apartments citywide. Gradient and another company, the global appliance maker Midea America, each won seven-year contracts to develop and produce devices for the New York City Housing Authority (NYCHA), which provides affordable housing. Leaders in other cities, including Jersey City, Boston and Seattle, say they’re tracking the project’s progress closely.

We’re going to spur innovation for brand-new technologies here in New York that the rest of the nation will be looking at,” New York Governor Kathy Hochul (D) said at a ceremony from a sunbaked basketball court at Woodside Houses, a complex of 20 brick buildings in Queens. 

woman on stage in front of crowd
New York Governor Kathy Hochul is flanked by two novel heat pumps at a ceremony in Queens. (Gov. Hochul)

The Clean Heat challenge is part of a broader effort by city and state governments to reduce greenhouse gas emissions from buildings 40 percent by 2030. Buildings account for nearly three-fourths of New York City’s emissions, compared to just 13 percent of total U.S. emissions. 

The initiative also comes as NYCHA grapples with a massive backlog of repair and maintenance work at its deteriorating properties, which together house nearly 536,000 people in some 178,000 apartments. At Woodside Houses, where the Gradient heat pump is on display, residents went months last winter without reliable heat and hot water after flooding from Hurricane Ida damaged the complex’s boilers in September 2021. City officials attributed the delayed repairs to a lack of federal funding.

Annie Cotton-Morris, president of the Woodside Houses Tenant Association, said the heat-pump initiative puts NYCHA at the cutting-edge of clean energy while finally giving tenants the comfort of a warm home.” She added that it sends a powerful message on behalf of public housing residents: We deserve better.”

Designing heat pumps that keep rooms warm — and cool

Heat pumps warm homes by pulling heat from the outside air and moving it indoors. To cool rooms, the devices work much like air conditioners, using a condensing liquid to absorb the excess heat indoors and transfer it outdoors. The window-sized units that will be installed in public housing apartments are meant to supplant a building’s centralized heating system, giving individuals more control over the temperature inside their living space. Ideally, this avoids the need to open windows in the middle of winter to let out extra heat, or to plug in small space heaters in underheated rooms, which risks sparking deadly fires.

The $70 million investment is a collaboration between NYCHA, the public utility New York Power Authority, and the New York State Energy Research and Development Authority (NYSERDA), which promotes energy efficiency and renewable energy across the state. 

For the design challenge, the agencies asked companies to develop electrified systems that don’t require specialized technicians to put in place, cost no more than $3,000 per unit and can operate in cold climates, meaning when outside temperatures hit 0 degrees Fahrenheit or below. The challenge also involves replacing old, leaking windows in public housing apartments with new windows designed to better accommodate the heat pumps and prevent air from escaping.

We’re looking for something that is simple to install and is easy to maintain,” Doreen Harris, president and CEO of NYSERDA, told Canary Media from Woodside Houses. But it’s also able to be installed in a way that has no disruption to tenants.” 

Brick apartment building with trees outside
Residents in Woodside Houses, Queens, lost heat and hot water after Hurricane Ida flooded the public housing complex in 2021. (Gov. Hochul)

She added that, while the 30,000 heat pumps will increase electricity use in the city’s buildings, the agencies don’t expect that local grid infrastructure will need upgrades to handle the extra demand.

Initially, Gradient and Midea America will develop 60 heat pumps, which they’ll install in dozens of apartments during the fall of 2023 and monitor throughout the winter months. After the trial period, the companies expect to ramp up production and deploy thousands of units in 2024.

Vince Romanin, CEO of Gradient, said the San Francisco–based startup’s technology can curb planet-warming emissions in two ways: by shifting buildings away from fossil-fuel heating sources and by using an alternative refrigerant. Most air conditioners use a class of coolants called hydrofluorocarbons, many of which are thousands of times more damaging to the climate than carbon dioxide. Gradient’s system uses a refrigerant called R-32, which has a significantly lower global-warming potential.

We wanted to figure out a way to get better refrigerants and get heat pumps deployed way faster than they were currently on track to be deployed,” Romanin said of his company’s window-straddling units. 

And the reason wasn’t just because of carbon emissions — it’s a public-health issue,” he added. People need access to air conditioning to protect against the worst effects of heat waves,” just as they need a reliable source of heating to protect against potentially deadly winter temperatures.

heat pump in a window
A Gradient window heat pump. (Gradient)

Gradient is already developing a $2,000 window heat-pump unit that’s designed to supplement an apartment’s main heating system. For New York, the company is designing a slightly larger unit with a higher heating capability that can cover an apartment’s full heating needs and is built specifically for cold climates.

NYC public housing needs billions of dollars’ worth of repairs

While the novel heat pumps could make life more comfortable for apartment dwellers, they only scratch the surface when it comes to fixing the city’s public housing properties. 

NYCHA has said it would cost more than $40 billion to fully restore and renovate all of its buildings, many of which are plagued by toxic mold, lead paint, burst pipes, pest infestations and elevator outages. The agency must change every single piece of equipment that it currently has,” Greg Russ, NYCHA’s chair and CEO, said at the Tuesday ceremony.

At Woodside Houses, an elderly woman pushing a metal shopping cart expressed frustration following the event, which was also attended by New York City Mayor Eric Adams (D). The resident, who declined to give her name, said her stove had been without gas for weeks, and the complex was still relying on temporary boilers installed in the courtyard after Hurricane Ida — large green tanks bracketed by wood planks. When are they going to fix those things?” she asked.

For all the fanfare this week, it will still take another couple of years for a sizable number of residents to start seeing the benefits of the new electric heat pumps. 

Harris of NYSERDA said that focusing on public-housing properties for the Clean Heat challenge is key to ensuring the equitable development of climate-fighting technologies like heat pumps.

Starting here is the most critical part of it all,” she said at the event in Queens. We need to realize the benefits here, perhaps more so than other places, because of the fact that these communities have not always been served in the same way as others.”

Maria Gallucci is a senior reporter at Canary Media. She covers emerging clean energy technologies and efforts to electrify transportation and decarbonize heavy industry.