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Energy Dept. pushes heat pumps to reduce greenhouse emissions

Efficiency, though, depends largely on where you live. Experts say they perform better in moderate climates.

8 min

Regular heat pumps are a much less dramatic alternative to geothermal heat pumps — you don’t need a huge yard and you don’t have to dig a huge swath in it.

Whether you should get one depends largely on where you live, as they perform better in moderate climates.

Unlike furnaces, heat pumps don’t generate heat to warm a home. They transfer heat from the outdoors to inside your home. Thus, heat pumps are far more efficient than furnaces, reducing electricity use for heating by 50 percent, according to the Energy Department.

In recent months, home sustainability experts and the federal government have been pushing heat pumps as a way to address climate change and reduce energy consumption. Late last year, Vice President Harris said the government will partner with private companies to “drive innovation in electric heat pumps.”

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Homeowners will spend $820 to $1,550 to heat their homes annually using any type of furnace, according to HomeAdvisor. But if they live in a warmer climate, they most likely will spend from $260 to $850 annually with a heat pump system.

Heat pumps use electricity as their only fuel source, creating significant opportunities to reduce carbon emissions compared with traditional gas heating appliances.

David Nemtzow, former building technologies office director in the Department of Energy’s Office of Energy Efficiency and Renewable Energy, says heat pumps are an essential part of the United States’ response to the climate crisis. The systems reduce exposure to indoor air pollution because homeowners are not burning natural gas or fuel oil, so there are no carbon monoxide or nitrous oxide emissions in the air.

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As climate change drives increasingly extreme and dangerous weather, these devices can play another essential role: keeping people comfortable and safe in their homes, even under the worst conditions.

“Every air conditioner you know of is a heat pump,” Nemtzow said. “They pump heat from inside the house where it’s too warm in the summer, and they pump it and dump it into the outside.”

About half of the homes in the United States use natural gas to heat water and rooms, to cook and to dry clothes. In cold months, rather than creating heat by burning natural gas, fuel oil or propane, a heat pump transfers heat from the outside and pumps it into the home.

“I don’t know if I’m asking for trouble, but if you lived in the Mid-Atlantic area or especially Illinois and you had a heat pump 30 years ago, you might say, okay, that didn’t work as well in the winter as I thought it might,” Nemtzow said.

But newer heat pumps have quieter variable speed motors and they transfer heat by circulating a refrigerant through a cycle of evaporation and condensation.

Nemtzow says the refrigerant helps absorb heat from the outside air, even in cold temperatures, and transfers it to the indoor air.

Still, refrigerants used in heat pumps are not as climate friendly as they should be, said Charles Cormany, executive director of Efficiency First California, a nonprofit trade organization that represents energy-efficiency and clean-energy contractors in California. "Technology is shifting away from these high GHG [greenhouse gas] potential refrigerants to safer alternatives like carbon dioxide, but the transition will take some time,” he said.

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Christopher Roth, CEO at National Technical Institute, a trade school with campuses in the Las Vegas and Phoenix areas that offers training for HVAC, plumbing and electrical careers, said heat pumps aren’t typically used as a space heating alternative in areas that experience extended periods of subfreezing temperatures.

“If that coil outside gets below 32 degrees and there’s moisture in the air, we end up with ice on it,” he said. “The colder it is outside, the more it has to go through the defrost cycle, which makes the heat pump less and less efficient.”

Heat pumps perform best in moderate climates as energy-efficient alternatives to furnaces and air conditioners. The technology delivers two to four times more heating energy than the electricity it consumes.

“Natural gas obviously creates carbon dioxide,” Roth said. “That’s what everybody is concerned about from a climate change perspective. There’s been this conversation that is happening right now that, hey, maybe we move toward heat pumps to get away from that inefficient furnace output. As you’re burning fuel, it’s not 100 percent efficient, so we end up with byproducts.”

In Sun Belt states like Arizona, many areas do not have gas lines, so gas furnaces are not always an option. In many instances, heat pumps are the logical choice.

“Phoenix is a great example,” Nemtzow said. “Phoenix has a pretty mild climate in the winter. But 80 percent of the Phoenix market is for heat pumps as opposed to using an alternative source for heating.”

Bob Robbins is involved in site improvements for custom-home builders in his position as a construction manager and project engineer for underground improvements in Phoenix.

He said some subdivisions have natural gas available, which is what conventional furnaces run on, but within a half-mile, another block of homes will not have natural gas. In that case, heat pumps are the only option for heating and cooling.

When Robbins bought his tri-level home in Phoenix, two heat pumps were included with the air conditioners.

“I’m happy with my home, but heat pumps are not my first choice,” he said. “If we had gas available to our home, and when it came time to replace our air conditioning units, I would much rather go with a traditional air conditioner and a separate furnace that would heat with natural gas.”

Robbins said that if temperatures are ranging in the 60s and it’s damp and cold, or it’s in the 50s during one of Phoenix’s cold spells, it doesn’t feel like his home is getting warm quickly with the heat pumps.

“But give it a few hours and the room temperature warms up to 75 to 78 degrees, and you’re okay,” he said. “However, when you’re doing that, you’re basically running the same thing you do in the summertime, which is air conditioning. So to me, it’s a much more expensive way to heat your house. But fortunately, here in Phoenix, we really don’t need it that much because of where we are located.”

TJ Perkins, a plumbing contractor in the Phoenix area, also observed that a lot of custom homes in the rural area where he lives have heat pumps.

“I had heard from HVAC contractors that heat pumps last longer than furnaces,” he said.

About five years ago, Perkins decided to have a heat pump installed at his ranch-style home, and he’s satisfied with the system. “It does the job,” he said.

In regions where there is not enough infrastructure to support natural gas, heat pump usage is driven by necessity, not choice, according to Cormany. He said he believes heat pumps are clearing the way for a promising future because there are no on-site greenhouse gas emissions.

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“The real advantage of heat pumps is they can be more than 100 percent efficient,” he said, adding that heat pumps that are for space heating are in the range of 200 to 300 percent efficient.

Newer heat pumps in Japan are dramatically more efficient. “They can be 200 to 500 percent more efficient than gas furnaces,” Cormany said. “The most efficient a gas furnace will ever be is where they are now, which is 98 percent efficient because anytime there is a combustion process there’s waste. A gas furnace will never achieve 100 percent efficiency. It’s physically impossible.”

In some areas, the downside of heat pumps is the cost of the fuel source. “For example, in parts of California, where electricity costs are high and gas is cheap, heat pumps don’t pencil out,” Cormany said. “In areas with low electricity rates, or when paired with solar panels, they are the preferred solution.”

An increasing number of utility companies are offering incentives for energy-efficient products such as heat pumps. Nemtzow described the effort as a huge coordinated campaign.

“In my world, it’s very exciting,” he added. “What we ask is that when that furnace starts wobbling, breaking down and it’s time to replace it, we hope people will take a look at heat pumps. And once they take a look, we think they are going to pick heat pumps.”

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