A confluence of factors has brought heat pumps from the HVAC shadows into the mainstream over the past few years. But things really came together for heat pumps this month when Biden signed off on using the Defense Production Act to spur more heat pump production. With the prospect of more heat pumps on shelves (or wherever heat pumps are stored), now’s as good a time as ever to understand the climate-protecting technology that just so happens to save people money and keep homes comfortable in all seasons.
What is a heat pump, and how does it work?
At its simplest, a heat pump moves heat from one place to another. The concept is relatively ancient history, dating back to 1852, though it took a while before heat pumps came into existence.
Today, there are two main flavors of heat pumps: air source and ground source. They work basically the same way, pumping or dumping heat from the air or ground. For the ground source version, a series of coils or a long pipe are installed underground and filled with antifreeze. The antifreeze circulates and draws on the ground’s constant temperature in the 50s. In the winter, that antifreeze is pushed through a compressor that turns it into a gas, a process that heats it up, before it’s piped over a fan that sends heat into a home while cooler air is drawn out. The system works in reverse in the summer. Neat!
Why are heat pumps good for the climate?
If you read the above explanation, you may have noticed one thing missing in the description of how heat pumps keep a house cozy in winter: fossil fuels. And that is why heat pumps are the stuff of climate dreams.
The Biden administration wants to reduce U.S. greenhouse gas emissions by at least 50% by 2030. There are many avenues to do that, but decarbonizing buildings is a vital one. Buildings are responsible for 13% of American greenhouse gas pollution. While overall building emissions peaked in the mid-2000s, speeding up the decline is vital to protecting the climate.Heat pumps have the potential to replace methane gas furnaces, which use a greenhouse gas 80 times more potent than carbon dioxide for fuel, as well as oil and wood-burning stoves. Getting a heat pump in every single-family home in the U.S. would shave at least 160 million metric tons of carbon pollution off the American balance sheet annually.
So what’s the holdup?
Supply chain woes have also come for the heat pump, sadly. But Biden invoking the Defense Production Act could help make them a bigger priority, opening things up a bit.
The up-front cost of a heat pump is also a challenge. Geothermal heat pumps can run into the tens of thousands of dollars depending on the location. Air source ones are cheaper, and mini splits are cheaper still, though you’ll need one for each zone of your home so costs can add up.
That’s not to say investing in a heat pump is a bad idea; an analysis by Carbon Switch found that a heat pump would save the average household $557 per year on the utility bill. That analysis was done before the Russian war in Ukraine caused gas prices to skyrocket, so the savings could be even greater today.
They’re also not super great in really cold climates, though the Department of Energy has a program to try and fix that.But there’s hope. A number of companies are attempting to help make heat pumps more accessible. Dandelion Energy, a startup that spun out of Google’s moonshot factory, is a one-stop shop for heat pump consultation and installation. BlocPower, another startup, is working on ensuring that heat pumps are accessible in low-income, multiunit buildings. (It’s also helping electrify the entire cities of Ithaca, New York and Menlo Park.) Gradient, meanwhile, is making window unit heat pumps for renters. That’s just the tip of the heat pump innovation iceberg.
What happens next?
The Defense Production Act alone isn’t going to spur heat pump mass adoption. Some states offer incentives already; New York, for example, has an array of incentives, including thousands of extra dollars in rebates for low-income homes. Getting more states — and utilities — on board with policies that help people prioritize installing heat pumps over their fossil-fueled counterparts is essential.The federal government could also have a role to play. The Build Back Better Act included $6 billion for a program that would kick landlords and homeowners money for electrification retrofits, including heat pumps. Most of that money would be targeted at tribal and low-income communities, creating more heat pump justice. That’s particularly important since poor households spend four times more on their utility bills than wealthy ones due in part to inefficient appliances. The act would also boost what’s known as the 25C tax credit, a home efficiency upgrade incentive that currently maxes out at $500. Electrification think tank Rewiring America said those portions of the legislation that’s currently in Senate limbo are “critical to unlocking heat pump adoption.”