The Gradient All-Weather 120-volt Window Heat Pump was on full display earlier this year at CES 2025, pumping out cool, refreshing air onto the convention center floor from a demo window at a booth alongside BioLite and Copper.

But this sleek machine is far from the clunky, noisy window units of the past. Unlike traditional window air conditioners that only cool (and loudly at that) this device can also heat your space, even in freezing temperatures. Its larger size and higher price tag reflect that added power and versatility, making it a serious upgrade for year-round comfort.

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Rather than sitting inside the window and taking up all of the space, like most window units, the Gradient unit straddles the bottom of the window, with the outdoor and indoor units hanging below, like a horseback rider’s legs dangling from the saddle.

A powerful heat pump for small spaces

The All-Weather model was designed to boost the heating performance of Gradient’s primary model meant for moderate climates. The moderate climate model can keep a home warm when the mercury outside drops to 40 degrees Fahrenheit. The All-Weather model, built to meet the needs of the New York City Housing Authority, is rated for weather down to minus-13 degrees.

Gradient’s heat pump can heat and cool up to 500 square feet, with 9,300 BTUs of cooling power and up to 9,000 BTUs for heating. But perhaps the coolest part is that this big device (it weighs 140 pounds) can run off a standard 120-volt outlet — no electrical work needed. A Gradient rep told CNET by email you won’t need to hire a professional to help install it. The All-Weather 120V Window Heat Pump can be installed on your own. 

Mist, Wi-Fi and more heat pump perks

The unit has some nifty features. The outdoor unit has a diffuser that turns any condensate into mist, meaning no water is pooling up underneath it or dripping onto the ground below. The heat pumps are Wi-Fi enabled and can be controlled either from the app or from a touch thermostat on the indoor unit. 

The heat pump also doesn’t block the view of the window. Because it hangs below, you can still open and close the window, see outside and use the top of the heat pump as a small table surface.

So far, Gradient’s heat pumps have been mostly available only to specific buyers — namely the New York City Housing Authority. But company reps told me business customers can buy direct from Gradient. A few units were made available to individual consumers through a distributor in the New York area, but those quantities were very limited, and the company mostly sells to businesses. A Gradient rep said the company believes that’s the fastest way to scale up electrification, and it means you might see these heat pumps in businesses, schools or multifamily housing. 

The All-Weather model has an MSRP of $3,800 — a lot more than your typical window AC, but for something with a lot more capability. And because it doesn’t require any permitting, ductwork or electrical work, expect the installation cost to be a lot smaller than other ways to heat and cool your home.

Correction, Jan. 29: Updated to clarify that direct-to-consumer sales are limited to one contractor.