How To Install A Geothermal Heat Pump System

Geothermal heat pump system is energy efficientIf you are planning to live “off the grid” or just minimize your carbon footprint, you may be thinking about adding solar panels to your roof. Perhaps you want to install a storage battery in your basement as well, so you can charge up for free on sunny days and use that stored electricity for your own personal use later.

Those are good steps to take, but you still have to provide for heating and cooling your home. For that, the most energy efficient system you can buy is a geothermal heat pump. Yes, such a system will cost more than a traditional system powered by oil, propane, natural gas or electricity. But it will more than pay for itself after a few years and put money in your pocket every year thereafter. It will also add value to your house when it comes time to sell.

What is a geothermal heat pump? It is a system that takes advantage of the fact that the temperature of the earth around your home only varies a few degrees with the seasons. By contrast, an atmospheric heat pump has to deal with ambient temperatures that may be more than 100 degrees in the summer or below zero in the winter. Normal atmospheric heat pumps aren’t very useful at temperatures below freezing, so they need an auxiliary furnace during cold weather.

There are two kinds of geothermal systems. One, called a horizontal system, involves digging a series of trenches about 6 feet deep around your property. Pipes are laid in the trenches then covered over with dirt. Water is circulated through the pipes where it is heated or cooled to the temperature of the earth. Then it is pumped to the heat pump mounted inside the house. In North America, the temperature of the earth is usually between 45 and 72 degrees Fahrenheit.

A vertical system uses a number of holes bored up to 80 feet deep into the ground. Pipes are then installed in the holes and fed through the foundation to the heat pump located inside. In either system, the temperature of the water coming in from outside remains nearly constant throughout the year, allowing the heat pump to operate as efficiently as possible.

Heating and cooling costs are often 50% less with a geothermal heat pump system. And because you already have that marvelous solar energy system on your roof, you can operate the heat pump almost for free, saving even more money. The more you know about a geothermal heat pump system, the more sense — and cents — it may make to install one for your home.

And speaking of saving money, don’t forget to upgrade the windows and insulation in your home to save even more money and reduce your carbon footprint even further. Using modern caulking can cut air infiltration (and energy loss) by another 4%.

With some careful planning, you can reduce the energy need to heat and cool your home significantly. That’s not only good for your wallet, it’s good for the environment as well.


About the Author

writes about the interface between technology and sustainability from his home in Rhode Island. You can follow him on Google + and on Twitter.

  • A geothermal heat pump is a central heating and/or cooling system that pumps heat to or from the ground. It is similar to an ordinary heat pump, but instead of using heat from the outside air, it relies on the stable, even heat of the earth to provide the heating, air conditioning, and even hot water.

  • Janet Cook

    What climate zones does the ROI make sense? Or the reverse, which ones would it not make sense?

  • Derek Marshall

    Interesting, how would this work in hot countries, or countries that it is warm most of the year. Sure hot water for showers. How to calculate water consumption per person basis? I am more interested in very green way to cool down building 10 months of the year and heat up remaining two (only at night time) how would Geo thermal work for me?

  • JohnCBriggs

    Can it make hot water warm enough to work with baseboard radiators, or is it only for forced hot air systems?

    • No way

      Absolutely no problem with baseboard radiators, assuming your house stand on ground suitable for geothermal heating that is. There is no problem to have a system that gets you all the heat for both heating the house and you and your family’s hot water needs for showering etc.
      About 400k households in sweden have a geothermal heat pump system, or about the eqvivalent of 25% of all houses (villas, not multi-family buildings).

      • JohnCBriggs

        Thanks kindly for the reply.
        I have 1/2 acre here in the Boston suburbs, so I should have enough room for it. Currently using home heating oil (aka diesel) to heat my home. Really need an alternative.
        We have solar electric and solar hot water, but really need to find a way to dump the diesel consumption.

        • No way

          It’s a brilliant solution that should be used more across the world. The problem is often the price. Here it’s pretty stream-lined considering the decades of experience, large numbers of installs in a mature and transparent market.
          It’s about $12k-$17k here for a normal villa, everything included.
          It’s worth at least looking into. And since you got such a large lot then near surface geothermal is also a viable option if drilling is not economical or even viable.

          I have friends who have done geothermal from vertical (drilling), horizontal (near surface) and water based (in a lake or a pond) and the one thing in common is how satisfied they are with the solution. Non-emitting, zero maintanance and super easy.

          But in the suburbs of a major city isn’t any district heating offered?

          • JohnCBriggs

            I’ll look into it some more. It is not very common out here.

            As for district heating, I have only seen that in cities and it is very rare. Co-generation in the USA is not very common.