American homes need heat pumps, not space heaters

If you want to ditch your gas furnace and heat your home more cleanly and efficiently, you need to scale up one of your kitchen appliances. The first option is “electric resistance heating,” better known as a space heater, which acts like a giant toaster to warm a room instead of bread. The second is a heat pump, which extracts warmth from even freezing outdoor air and pumps it indoors, like a refrigerator moves heat from inside the box to the kitchen. (That’s why the back of your fridge feels warm, by the way.) Energy experts say that to bring down greenhouse gas emissions and improve human health, we need to replace toxic gas furnaces and boilers with heat pumps ASAP. Less talked about, though, is that we also need to replace those giant toasters with giant reverse refrigerators, which would make homes more comfortable and more efficient, and therefore cheaper to heat. According to a new report from the nonprofit energy group RMI, one in five homes in the United States is heated primarily with electric resistance heating. Replacing those devices with heat pumps would save households an average of $1,530 a year, or $20 billion annually across the country. (The calculations included only single-family homes, not multifamily units like apartment buildings.) At the same time, demand on the electrical grid would fall significantly, while total carbon emissions from homes making the switch to heat pumps for climate control and water heating would plummet by about 40 percent. “There’s a lot of benefits to the grid, which translate to lower rates as well,” said Ryan Shea, a manager in RMI’s carbon-free buildings program. “Then, of course, there’s using less energy.” Electric heat pumps work their magic with a trick of physics: By changing the pressure of refrigerants, they draw warmth from outdoor air or liquids coursing underground, then bring it indoors. (In the summer, the process reverses, cooling an indoor space like a traditional air conditioning unit.)