2022 WCIA Series: Gradient Comfort's A/C unit shrinks heating and cooling emissions by 75%

One cruel paradox of the climate crisis is that, as the world gets warmer and people crank up their air conditioning, those air conditioners emit greenhouse gasses, warming the planet further. Heating systems emit harmful gasses, too: Heating and cooling buildings accounts for 15% of global greenhouse gas emissions, slightly more than transportation does. (When energy use is added in, building operations account for 28% of global CO2 emissions.) Keeping our homes and workplaces comfortable ends up making the world even more uncomfortable. 

“There’s this vicious cycle, but there doesn’t need to be,” says Vince Romanin, CEO of Gradient Comfort. The San Francisco-based startup spun out of Otherlab, a research and innovation lab focused on energy, robotics, and manufacturing. “The emissions that come from HVAC can be decoupled from the service it provides. That technology exists, and it’s not being deployed at the rate that it needs to be or the extent that it needs to be—but we can fix that.” 

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Gradient’s first product, geared toward improving HVAC systems, rethinks the standard window air conditioner. Gradient’s version combines a cooling system with a heat pump, which uses climate-friendly refrigerants to reduce heating and cooling emissions by up to 75%. If users power their unit with renewable energy, that footprint could shrink by 99%, the company estimates. Called Gradient Comfort, it’s the winner of the consumer products category of Fast Company’s 2022 World Changing Ideas Awards. 

The redesigned window AC unit fixes some essential flaws widespread in existing products—primarily, the harmful refrigerants, high cost, cumbersome installation, and the fact that most units are just plain ugly to look at, with the tendency to block half of users’ windows. Gradient Comfort has a slimmer profile and sits below the window, letting in more light. While most window units use refrigerants that still have a high environmental impact—the standard refrigerant still in use today has a global warming potential 2,088 times higher than CO2, Romanin notes—Gradient uses low-emissions refrigerants like R-32, a refrigerant deemed to have a “low global warming potential,” that go beyond the current regulatory requirements.  

And whereas most dual heat pump/air conditioners, which heat as well as cool, cost around $5,000 for professional installation, Gradient’s unit needs no technicians. While the company hasn’t yet announced a price for Gradient Comfort, it’s working to make the units competitive with other standard window AC systems, conceding that it will require manufacturing scale and time. (Announced in summer 2021, the unit is expected to launch summer 2022.) “The fact is most of the growth in AC use is happening in emerging economies where people are finally getting economic access to the service,” Romanin says. “If we don’t look at that market as well, we’ll never solve the climate problem.” 

Gradient says the interest in a new kind of heating and cooling system is clear: The company has a 30,000-plus email wait-list for its product. It next plans to work on a cold climate heat pump strong enough to heat a home on the coldest winter day in New York, for example. (The Gradient Comfort will also have a heat pump, but is currently suited for warmer climates, so would mostly supplement other heat sources.)

“We always talk about our mission as to cool the world, because we want to look at not just the mitigation side of climate change, which is removing emissions, but the adaptation side of climate change, and that’s where the need for AC and heating in many climates comes in,” Romanin says. “There are a lot of areas that need building heating and cooling for people to be healthy and productive. And it’s just becoming more true as heat waves increase.”