Gradient heat pumps get innovation to enable retrofitting of old buildings

New York City and others like it are filled with beautiful old buildings for the most part, except that they are not all that comfortable to live in. Built in an era when large boilers were the state-of-the-art technology, the buildings are often too hot or too cold, but rarely perfect.

There are companies trying to fix that using horseshoe shaped heat pumps. Superficially, they are similar to window air conditioners, except they do not block the view and can heat and cool.

Gradient makes one of those heat pumps, but now it adds a twist: In multi-family buildings, it can link all of its window units together. The startup shared with TechCrunch exclusive details about the new Nexus software and service.

“Multifamily real estate is a neglected sector,” Vince Romanin, chief technology officer at Gradient, told TechCrunch. “It’s a place where we can make the user better.”

The startup is mostly targeted at older buildings that need HVAC upgrades. Gradient has worked with the New York City Housing Authority to install its heat pumps in public housing, and is conducting a pilot in Tracy, California, in a new two-story affordable housing complex. It also talks to colleges and universities, many of which have dormitories that aren’t built with warm fall weather in mind.

Older buildings often have a single electric meter, which can tempt residents to overuse their heating or air conditioning. Nexus provides some control to property managers. They can set up guardrails to prevent people from overusing the heat or AC – either intentionally or otherwise – while still allowing them to be comfortable. In one case, the building manager set the heating limit to 78˚F, and the next day energy use dropped by a quarter.

Romanin said Gradient heat pumps are a “cost-effective option” for older buildings with end-of-life boilers, a common occurrence in New York City. As a bonus, units that previously only had a steam radiator now get air conditioning, future-proofing the units against increasing heat waves.

By installing a window unit instead of a small partition, the restoration can be done within hours. And they don’t require electrical upgrades, Romanin said. In buildings with older electrical wiring that can’t support a full 12 amp load in a single outlet, Nexus can reduce the draw, said Mansi Shah, senior vice president of product and software at Gradient.

That strategy can extend beyond the building. When the grid is full of demand, which can happen on hot summer days, Gradient works by dialing down its heat pumps while maintaining the comfort of the person inside. Using information about the building and feedback from sensors on the heat pumps, the company hopes to predict which units can reduce their air conditioning needs, such as those on the shaded side of the building. That kind of demand response can help the grid provide more heat pumps without requiring expensive upgrades.

“Many people said that if we electrify everything, the grid will not handle it,” said Romanin. “I think it’s very possible to electrify everything and make the grid better, make grid work easier, and make electrons cheaper.”