MOVING toward

Changing energy markets and evolving technology make it possible to heat, cool, and ventilate homes of any age with (mostly) clean, all-electric power—and less of it. Heating home water, formerly an energy hog, is turning into an energy sipper, too.

- MARY ELLEN POLSON

A self-described early adopter,

Kendall Christiansen previously had helped lead a movement to permit solar panels on the roofs in his historic Brooklyn row-house neighborhood. As his 35-year-old hot-water boiler neared the end of its life, it was a natural decision to convert to a more efficient heating and cooling system—one that was as close to fossil-free as possible.

Christiansen and his wife, Carol Shuchman, chose to replace the old hot-water boiler with a whole-house, air-source heat pump system. Commonly referred to as mini-splits and more accurately as inverter systems, air-source (or air-to-air) heat pumps run solely on electricity. Typically operating at lower temperatures than traditional forced-air or hot-water systems, they can be three to four times as efficient. Some work in temperatures as low as -20°F, too.

“They call them cold-climate heat pumps,” says Matt Crowley, the crew chief for Green Team Long Island, the installer for Christiansen’s 1910 limestone row house. He has seen a flood of residential and commercial customers moving to the all-electric heat pumps. “Basically, we try to get people off fossil fuels.”

THE PRO TIP

A 2018 study in California found that air-source heat pumps could reduce household greenhouse-gas emissions from heating by as much as 54 percent. So besides homeowner savings on fuel costs, the environment also benefits.

Once, we heated our homes with coal.