Switching to heat pumps is one of the most energy-efficient and cost-effective ways to reduce the climate impact of buildings, which account for more than a third of U.S. carbon emissions.
It can also save lives by cleaning the air we breathe, according to new research by Rewiring America, a nonprofit that advocates for home electrification.
The group’s latest report explores what would happen to outdoor air pollution if all U.S. homes installed heat pumps, heat pump water heaters, and heat pump clothes dryers. Researchers found that replacing oil and gas furnaces would eliminate in-home fossil-fuel combustion that vents pollutants like ammonia, sulfur dioxide, and nitrogen dioxide into the outside air. Swapping out inefficient electric resistance heaters, meanwhile, would reduce air pollution from fossil-fueled electricity production by minimizing the amount of power that households use.
In all, those changes would slash 300,000 tons of fine particulate matter pollution each year, equal to taking 40 million cars off the road — and prevent thousands of deaths.
Most people don’t realize that improved air quality is a benefit of home electrification because the connection is less obvious than, say, energy efficiency and utility savings, said lead author and senior research associate Wael Kanj. “We have these appliances in our homes, and so we don’t really think about how they’re impacting outdoor air quality,” Kanj said.
Using data from the National Renewable Energy Laboratory, the Environmental Protection Agency, the U.S. Census Bureau, and the federal Energy Information Administration, Kanj’s team sought to quantify the public health benefits that would result from cleaner air. They found that households would experience 3,400 fewer premature deaths, 1,300 fewer hospital visits, 220,000 fewer asthma attacks, and 670,000 fewer days of missed work and activities each year. Those outcomes would add up to $40 billion worth of annual health improvements.
Not all states would experience the same level of health benefits, though.
The degree of pollution reduction depends on a wide range of local factors, including population density, as well as how clean the electric grid is and what kind of heating and cooling equipment households already use. In cold Northeast states with dense populations that rely heavily on gas and fuel to heat their homes, for example, switching to heat pumps would have a greater impact than in warmer states like Florida, where electric resistance heating is widespread, the report noted.
Another important factor is the clean energy transition. To calculate annual health benefits over the next 15 years — the average lifetime of a heat pump appliance — Rewiring America’s analysis used a grid forecast that assumes a 95 percent decarbonized grid by 2050. In reality, any policy that speeds up or slows down that transition could significantly affect projected health outcomes. Roughly speaking, a faster rate of decarbonization would mean even fewer deaths, hospital visits, and asthma attacks than the group’s modeling.
