Every other Friday, the Outside/In podcast team answers a listener’s question about the natural world.

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This week, Brian from Canaan, New Hampshire asked: “When a family is preparing to transition from one heat source to another (such as replacing an aging stove), what is the best way to reduce its carbon footprint?”

To help us answer this question, we interviewed Nate Adams, who is also known as "Nate the House Whisperer". Nate said that in terms of emissions, heat pumps are the best home heating system because heat pumps do not generate heat like oil or gas stoves—they transfer heat from one place to another. Heat pumps use significantly less electricity than traditional electric heating options, such as electric skirting and space heaters. Therefore, as the grid continues to shift from fossil fuels to renewable energy, heat pumps—along with electric vehicles and induction furnaces—have become part of the "Electrification of Everything" strategy.

The working principle of a heat pump is to absorb heat from the outside and transfer it to the room. "Extracting heat from the cold seems really counterintuitive," Nate said when explaining how the heat pump works. For example, some of his customers were surprised to find that heat pumps can still operate at temperatures below zero, and some models have temperatures as low as -15 degrees Fahrenheit.

"But now you probably have one running in your house. It's called a refrigerator."

Nate says that refrigerators and air conditioners are technically heat pumps-they transfer heat from inside the refrigerator or in the case of air conditioners from your home to the outside. However, although refrigerators and air conditioners can only transfer heat in one direction, heat pumps can transfer heat in both directions, whether entering your home or outside your home, so they can be used as both heaters and air conditioners .

Therefore, heat pumps are more efficient and help keep your home at the right temperature throughout the year-but there are a few important things to note.

Emily Mottram, founder of Mottram Architecture in Maine, said: “They are not always installed correctly, so we have the problem of refrigerant loss.” In terms of its warming potential, refrigerants are a more effective way than carbon dioxide. greenhouse gas. Emily said to hire qualified professional installers to ensure that the equipment is installed correctly to prevent refrigerant from leaking into the atmosphere.

Second, Emily said that before replacing the heating system, you should conduct an energy audit to see if your house has weathered. Joe Lajewski, the energy solutions project manager for the New Hampshire Electric Cooperative, said heating a house without weathering is like scooping water from a ship with holes.

"A better solution is to plug the leak first, and then drain," Joe said.

This means sealing cracks and penetrations, such as wires or pipes running through walls or floors. A compact house reduces the total energy required to heat the house, and your system will operate more efficiently.

Therefore, if your home needs a new heating system, experts say that a heat pump is the best choice. But even if you don’t plan to replace that old furnace, there are good reasons to consider switching.

After all, climate experts tell us that by 2050, we need to achieve net zero emissions of greenhouse gases. Getting a heat pump, like getting an electric car, is part of the strategy to achieve all electrification and get rid of fossil fuels. Refuel as soon as possible.

Caring about the climate is not the only reason to buy a heat pump. Their operating costs are generally cheaper than any other heating system, and many heat pump owners think they are just better: they are quieter, the temperature is more stable, and the air quality is better. This sounds like a win-win for home comfort and climate.

If you want to submit a question to the external/internal team, you can record it as a voice memo on your smartphone, and then send it to externalin@nhpr.org or call the hotline 1-844-GO-OTTER.

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