Human Journey

Heat Pumps: (Yet Another) Global Warming Solution?

Walking through the Copenhagen climate conference‘s exhibit hall last December, one might have wondered why negotiations were so deadlocked: Dozens of booths were advertising too many climate solutions to count.

Some of the ideas would make you raise your eyebrows, since they seem like expensive ideas that are unlikely to ever come to fruition.

But one flier I picked up touted a logical technology to cut carbon: Heat pumps. As an alternative to furnaces or air conditioners, which burn natural gas or fossil fuels, heat pumps draw out heat or cool air from the air and ground to warm or cool homes and other buildings. And unlike going totally off-the-grid, heat pumps might be a good place for someone to jump-start a plan for a lower carbon household.

For instance, compared with traditional heaters and air conditioners, heat pumps can reduce carbon dioxide emissions by about 70 percent, according to the flier, produced by the Heat Pump & Thermal Storage Technology Center of Japan.

If the G7 countries mostly installed heat pumps, carbon dioxide emissions could fall by 40 percent on average, the flier claimed.

That might be unrealistic, but it’s clear heat pumps save money: The U.S. Department of Energy (DOE) says that heat pumps can shave off as much as 30 to 40 percent off a household’s electricity used for heating. (Related: “Small Steps at Home Can Combat Climate Change, Study Says.”)

The most common type of heat pump, the air-source heat pump, transfers heat between a house and the outside air. Because the pumps move heat instead of generating it, they can provide up to four times the amount of energy they consume, according to the DOE.

But hands-down, the superstar among heat pumps is the geothermal, or ground-source, pump, which draws heat or cool air from the ground or water. Though they’re more costly to install, geothermal pumps end up costing less in the long run, and last 25 years.

Although temperatures aboveground vary, temperatures under Earth’s surface are relatively constant. In most regions, soil temperatures are usually warmer in than surface air in winter and cooler than the air in summer, according to the U.S. Energy Information Administration. So geothermal heat pumps can transfer this stable heat into buildings during winter, and cool air in the summer.

Geothermal pumps have been catching on in the U.S. in recent years, with about 50,000 new pumps installed yearly. It’s not a do-it-yourself-project, so the DOE offers a helpful Web site for getting started. There are also some rebates, special financing, and incentives around installing geothermal heat pumps, so it’s wise to look into those.

Of course there are downsides: Waiting the five to ten years to recoup the costs of a geothermal-pump installation, for instance. And air-source pumps, more common than geothermal pumps, don’t really work as well in really extreme climates.

But if it can keep that dreaded energy bill down, well, I’m pumped.

–Christine Dell’Amore

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Christine Dell'Amore, environment writer/editor for National Geographic News, has reported from six continents, including Antarctica. She has also written for Smithsonian magazine and the Washington Post. Christine holds a masters degree in journalism with a specialty in environmental reporting from the University of Colorado at Boulder. Her book, South Pole, was published in 2012.

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