The prophecy is coming true. The moment is here. Heat pumps are taking over, at least in Washington State.
Washington is now the first state in the country to mandate energy-efficient (and possibly fossil fuel-free) electric heat pumps, over traditional furnaces and water heaters. The rules apply in new commercial and multifamily residential buildings with four or more stories.
On Friday, the Washington State Building Code Council voted 11-3 in favor of a new statewide update to the commercial building energy code. The legislation summary spans more than 330 pages and includes lots of different provisions, including new requirements that air and water heating and cooling systems use electric “heat-pumps” (sort of a misnomer, because the pumps both heat and cool) in most new buildings.
“We passed one of the most energy-efficient building codes in the U.S. last Friday,” wrote Kjell Anderson, a member of the Building Code Council and a sustainable design architect in Seattle, in an email to Gizmodo. The code is a win for building decarbonization and could help Washington meet its state goal of reducing building energy consumption to 70% of 2006 levels by 2031. The change goes into effect July 2023.
“We need climate action and this [was] one opportunity to do that,” Anderson added in a phone call with Gizmodo.
The new rules effectively ban some standard HVAC systems, which generally run via furnaces that burn natural gas (largely methane), as well as less efficient heating systems that use electric resistance (like floorboard heaters) in most cases. The few exceptions are for supplemental heating and for certain added heating systems in some of the coldest parts of the state. Further, under the updated code, 50% of the hot water in new commercial and large residential buildings needs to be warmed via heat pumps.
Heat pumps work to cool or heat (depending on the context and season) a space by moving air across temperature gradients. They exchange heat between the inside of a building and the outside air, a body of water, or underground.
For example, in geothermal heat pumps, which rely on the consistent 50 degree temperatures below ground, refrigerant is pumped through pipes in an array, either deep into a single, vertical well or across a system of more shallow loops. An electric compressor transfers heat from between the ground and the piped refrigerant, and fans move either that newly warmed or cooled air inside of a building. The same general set-up can be used to heat water.
Whether it’s a geothermal heat pump, or an air or water source heat pump, they’re all 2-4 times more efficient than furnace or electric resistance heaters, said Anderson via phone.
The Biden Administration has instituted a couple of federal programs to boost the uptake of heat pump systems, and related policies have been attempted in other states. New York state, for example, has had a subsidy program for a few years and tried and failed to institute a building gas ban. And last year, California passed codes incentivizing all-electric (i.e. no gas furnace) construction in all new residential buildings and some businesses, but the Golden State stopped short of an all-out requirement.
Methane-burning appliances are bad for your heath and the environment. Heating and cooling buildings using fossil fuels accounts for a huge amount of carbon emissions. A 2020 UN analysis found that buildings (including construction) accounted for 38% of energy-related carbon dioxide emissions globally. And a 2019 report from the Rocky Mountain Institute, an environmental nonprofit, concluded that about 10% of all U.S. carbon emissions come from heating and cooking in buildings. Switching over to heat pumps alone could chop 3% of emissions out of the U.S. carbon budget.
In a lot of cases, though, electric heat pumps do still rely on fossil fuel consumption. This is because the electricity that powers heat pump compressors and fans generally comes from an electric grid dependent on burning oil, coil, and methane gas. But Washington has one of the cleanest and greenest energy grids in the country, running largely on hydroelectric power from the state’s many dams. Dams have their own issues, but for Washington they mean that most of the power running the newly mandated heat pumps won’t be coming from fossil fuel sources.
The new required shift toward electric heat pumps could prevent an estimated 8.1 million tons of carbon emissions by 2050 (the equivalent of nearly 1.6 million cars taken off the road for a year), according to a Rocky Mountain Institute analysis. Plus, those state mandated 70% reduction energy targets “would be impossible to hit without heat pumps in buildings,” said Anderson over the phone.
Similar requirements for residential buildings in Washington are currently up for public comment and will be put to a council vote later in the year.
Update 4/26/2022, 4:51 p.m. ET: This post has been updated with additional comment from a phone conversation with Kjell Anderson, as well as clarifying information about the different types of heat pumps.