Going Geothermal with Ground Source Heat

E.B. Boyd by E.B. Boyd | March 29th, 2012 | 1 Comment
topic: Green Living, Green Tech

geothermal heat

Sure, you’ve thought about adding solar panels to your roof as a way of reducing your home’s carbon footprint. Maybe you’ve even given wind power a gander. But what about ground source heat pumps?

OK, here’s the deal. Ground source heat pumps (GSHPs) — sometimes called “geothermal” or “geoexchange” systems — essentially use the ground outside or under your home to bring heat inside in the winter and take heat out in the summer. These systems are about 400 percent more efficient than conventional (read: fossil fuel-based) heating and cooling systems. Yes, they’re expensive to install. But with most, you’ll break even within five to 10 years — a good deal when you consider that most pumps tend to last 25 years (the loops installed in the ground can last 50 years or more). About 50,000 families and businesses install GSHPs every year.

How they work

About five feet underground, the earth’s temperature remains consistent all year-round — about 50-70 degrees Fahrenheit, depending on where you live. With a geothermal system, water circulates through tubes run into the ground outside your home. In the winter, the temperature of the ground heats the water, then the tubes pump the water back up and through a heat exchanger to bring the air in your home to a warm, comfortable temperature. In the summer, this process is reversed. Heat in your home gets sucked down into the tubes and sent out into the ground, leaving your home nice and cool.

This simple video does a great job of explaining the basic principles involved:

(Source: newgroundwork)

How much they cost

According to the Department of Energy, GSHPs cost about $7,500 for a typical home (not including labor) compared to $4,000 for a traditional heating/cooling system (also not including labor). If you decide to go this direction, however, remember to check for federal, state, and local energy efficiency rebates. Start here: Dsireusa.org.

How they compare to solar and wind

Here’s how geothermal stacks up against other green energy options:

Pro: GSHPs can be installed anywhere and are not dependent on the supply of a natural resource, like sun or wind.

Con: GSHPs are not completely energy independent. You still need to use electricity from the grid to run the system. But they do use 30-60 percent less energy than a conventional HVAC system.

For More:

Learn more about green energy with sustainability videos on GaiamTV.com.

Photo: U.S. Department of Energy

Comments

  1. A very informative article explaining the inner working of heat pump systems, and the processes they use. Many articles explain the benefits and uses of heat pumps, etc, but they never go into the inner working of the apparatus itself, so potential buyers may be somewhat left in the dark, or even dissuaded completely from investing.
    It’s great that you’ve added a visual aid too with the video.

    A very useful article, keep up the great work.

    BenG | February 1st, 2013 | Comment Permalink

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