In spite of the fact that it rotates soundlessly around the Sun in a void so cold it can only be compared to a spurned lover’s icy glare, the Earth, as we all know, is quite temperate. In fact, the deeper you penetrate into the Earth’s mantle, the warmer it gets – topping out at a balmy 10,800°F (6,000°C) in its iron-rich core.
Aside from making the proliferation of life that much easier, the heat radiating from deep within the Earth can be harnessed to maintain a building’s ambient temperature, in a way that poses little risk to the environment, certainly far less than coal or gas. The best part is, as long as the world continues to turn, so too will its inner power plant, making it one of the most reliable sources of renewable energy currently at our disposal.
What Does Geothermal Technology Mean for the Homeowner?
While there are certainly some broader applications that are worthy of discussion (snow removal and desalination come to mind) geothermal technology is equally beneficial on a much smaller scale. For homeowners, geothermal technology provides the opportunity to heat and cool their home without having to rely on an outside system, effectively reducing the need to draw energy from the grid in order to power some of their more energy-hungry appliances.
In addition to feeling less of an impact from energy price volatility, the eco-minded homeowner can rest easy knowing that their home is responsible for producing far fewer greenhouse gases.
So, How Does a Geothermal Heat Pump Work?
The neat thing about heat pump technology is that it takes full advantage of the fact that the temperature below ground remains relatively constant, no matter how hot or how cold it gets on the surface.
Using a series of liquid-filled underground pipes, the heat pump draws energy in the form of heat from the ground in the winter, and banishes excess heat in the summer. This system, which can work in conjunction with a home’s current HVAC system or as a standalone heating and cooling system, requires far less electricity to operate, which explains why it is being used so prolifically in the construction of office buildings.
Before beginning the installation process, it’s important to know your annual heating and cooling loads. Essentially, you’re looking to see if there’s a balance between hot and cold external temperatures throughout the year to determine just how beneficial a geothermal heat pump will be for your home.
For example, if you want to install a geothermal heat pump at your home in Arizona, it’s safe to assume that it will principally be used to keep the space cool given that annual temperatures in the American southwest tend to be on the warm side. This means that more heat will be rejected into the earth than will be drawn from it, which in the spring and fall will be feasible; but in the hottest months the system stops being reasonably feasible.
Granted, this doesn’t mean that the system would be 100% ineffective, but it will mean that, the liquid within the pipes will need to be circulated over a greater area in order to achieve the same effect, reducing the system’s overall energy efficiency during the hottest or coldest months depending on where you are.
That being said, geothermal heat pumps make the most sense in regions that tend to see a 50/50 hot/cold split when it comes to seasonal temperatures.
Another thing to consider is what kind of soil or bedrock your home is sitting on. Different rock and minerals conduct heat differently and thus can impact the heat transfer, or, the efficacy of the system. An assessment of your property may be in order, and this can be expensive – but it would behove the responsible homeowner to know how effective a geothermal system will be on their property will be before taking the plunge.
While these may sound like reasons to not even bother considering a geothermal heat pump, the financial merits of this technology have been extolled time and again. It may not be the solution for everyone, but given the right conditions and enough research, a geothermal heat pump can significantly reduce your monthly heating and cooling costs, and allow your home to stay green.