Using The Earth To Heat and Cool Your Home

Ever thought about using the ground to heat and cool your home? It’s called geothermal heating and cooling, and it’s a fantastic way to use the earth’s energy to maintain the temperatures inside your home.

It used to be that technologies, like geothermal heating and cooling, were outliers, but now my clients seem to be looking at the energy efficiency of every home they’re considering. Almost any existing home can be converted over to geothermal, and new construction can incorporate it into the HVAC system, as well. I remember talking with an HVAC installer a couple of years ago, who told me that the cost to install a geothermal system was nearly the same as that of a traditional heat pump system, and the savings recouped made it a no-brainer.

Progress_Street_BuildersProgress Street Builders talked about this technology in a recent newsletter, which I’ve quoted below. I’ve made a comment, in bold.

“The temperature of the ground is about 68 degrees (Things I’ve read put this between 55-degrees, and 68-degrees – if you can confirm what it actually is, please let me know). Conductive, non-toxic fluid is pumped through the pipe and is heated or cooled (depending on its temperature) by the constant temperature of the ground. When that fluid returns to the surface, it transfers its temperature to the air being blown into the home’s ductwork.

That’s exactly how conventional, air-sourced heat pumps work, except that those systems use the temperature of the ambient outdoor air, which is far less predictable and constant than underground temperatures.

In winter, for instance, if the thermostat is set at 72 degrees, the heating coils in the pump only need to boost the incoming ground-conditioned, 68-degree fluid by a few degrees to achieve the desired temperature. The outdoor air temperature that day, however, is likely much colder, which requires far more energy from the pump’s heating coils to warm it sufficiently.

Because this type of ground-source system requires far less supplemental heating or cooling measures to achieve desired indoor temperature and comfort levels, it uses less energy. In turn, there’s less wear and tear on the heat pump, allowing it to operate at optimum efficiency for a longer period of time and with less maintenance.

Cost and payback: Until 2016, the Federal Government is offering a 30% tax credit on geothermal systems with no upper limit. This covers both the cost and installation of the units. These credits apply to both new construction and existing homes. The cost to install a geothermal system and the savings vary. Hypothetically, if a Geothermal system costs twice as much as a conventional air-sourced system, and cuts the monthly energy use and cost in half, there will be a substantial return on investment within a few years.

People with geothermal systems also report better and healthier indoor comfort, especially in the height of summer or winter when a conventional heat pump has a hard time conditioning the outside air to the desired indoor temperature.

Geothermal heating and cooling systems may not be for everyone or every new-home condition, but they are a proven, energy-efficient option that delivers better performance and lessens environmental impact.”

Looking for a way to cut your energy-costs, either on a new or existing home? Check out geothermal … your wallet will thank you, and truthfully, the greater good may be in using resources more effectively.

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5 thoughts on “Using The Earth To Heat and Cool Your Home

  1. Phil

    We got one installed about 2 years ago. My parents have one also. My thoughts:

    -most geothermal systems also have a desuperheater that will heat or preheat your hot water as well as heating air for your house. This is an added benefit. I know of folks that use that warm water for radiant heat in their tile floors or even in a driveway during the winter.

    -in our experience, the install costs were about twice as much as a good heat pump. However, the tax credit gives you a third of the total cost back within a year. The energy savings will recoup the remaining cost within 4-8 years depending on usage.

    So if you know you’re going to be in the house for a while, you will recoup the cost and then the additional savings is just gravy.

  2. Bob Peek

    I am certain the overall cost over the life of a geothermal system would be lower than that of an air-source heat pump system, but the lion share of the cost is paid up-front. That’s not a good bet for most people.

    I see, on average, two geothermal systems each year.

  3. Jeremy

    I forgot to ask, Bob – you do more home inspections than just about anyone in the New River Valley. How many geothermal units do you think you see in a typical year?

  4. Jeremy

    Thanks Bob – 55 kept coming up in the things I was reading, but then I saw 2 articles that referenced 60+ and I wasn’t sure.

    I would assume that the cost of a geothermal unit would be somewhat location-dependent, based on utility company costs, etc., but I wonder how, with tax credits and the like,the overall costs associated with a geo unit compare to a traditional heat pump system.

  5. Bob Peek

    Three things:

    1-The temperature of the ground below the frost line is about 55 degrees.

    2-The cost of installing a ground-source heating system is significantly higher than that of an air-source system, otherwise, we would all have one.

    3-Geo-thermal is worth more than it costs, but most folks aren’t willing to make the up-front commitment to get the back-end, long-term savings.

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