In recent months, home sustainability experts and the federal government have been pushing heat pumps as a way to address climate change and reduce energy consumption. Late last year, Vice President Harris said the government will partner with private companies to “drive innovation in electric heat pumps.”
Heat pumps have the potential to save an average American family about $459 annually when they switch from an electric resistant heating system and about $948 annually when they switch from an oil system, according to the Northeast Energy Efficiency Partnerships.
Heat pumps use electricity as their only fuel source, creating significant opportunities to reduce carbon emissions compared with traditional gas heating appliances.
David Nemtzow, building technologies office director in the Department of Energy’s Office of Energy Efficiency and Renewable Energy, says heat pumps are an essential part of the United States’ response to the climate crisis. The systems reduce exposure to indoor air pollution because homeowners are not burning natural gas or fuel oil, so there are no carbon monoxide or nitrous oxide emissions in the air.
As climate change drives increasingly extreme and dangerous weather, these devices can play another essential role: keeping people comfortable and safe in their homes, even under the worst conditions.
“Every air conditioner you know of is a heat pump,” Nemtzow said. “They pump heat from inside the house where it’s too warm in the summer, and they pump it and dump it into the outside.”
About half of the homes in the United States use natural gas to heat water and rooms, to cook and to dry clothes. In cold months, rather than creating heat by burning natural gas, fuel oil or propane, a heat pump transfers heat from the outside and pumps it into the home.
“I don’t know if I’m asking for trouble, but if you lived in the Mid-Atlantic area or especially Illinois and you had a heat pump 30 years ago, you might say, okay, that didn’t work as well in the winter as I thought it might,” Nemtzow said.
But newer heat pumps have quieter variable speed motors and they transfer heat by circulating a refrigerant through a cycle of evaporation and condensation.
Nemtzow says the refrigerant helps absorb heat from the outside air, even in cold temperatures, and transfers it to the indoor air.
Still, refrigerants used in heat pumps are not as climate friendly as they should be, said Charles Cormany, executive director of Efficiency First California, a nonprofit trade organization that represents energy-efficiency and clean-energy contractors in California. “Technology is shifting away from these high GHG [greenhouse gas] potential refrigerants to safer alternatives like carbon dioxide, but the transition will take some time,” he said.
Christopher Roth, CEO at National Technical Institute, a trade school with campuses in the Las Vegas and Phoenix areas that offers training for HVAC, plumbing and electrical careers, said heat pumps aren’t typically used as a space heating alternative in areas that experience extended periods of subfreezing temperatures.
“If that coil outside gets below 32 degrees and there’s moisture in the air, we end up with ice on it,” he said. “The colder it is outside, the more it has to go through the defrost cycle, which makes the heat pump less and less efficient.”
Heat pumps perform best in moderate climates as energy-efficient alternatives to furnaces and air conditioners. The technology delivers two to four times more heating energy than the electricity it consumes.
“Natural gas obviously creates carbon dioxide,” Roth said. “That’s what everybody is concerned about from a climate change perspective. There’s been this conversation that is happening right now that, hey, maybe we move toward heat pumps to get…
Read More: Dept. of Energy pushes heat pumps over gas furnaces