The Basic Science of Geothermal Heating and Cooling

More than a few people here in Alaska, Alaska, have hired Energy Efficiency Associates to turn their homes into geothermal homes. Still need convincing about geothermal heating and cooling yourself? Understanding a little of the science behind it – and the mechanics as well – would likely help.

We’ve discusseded elsewhere the merits of geothermal heating and cooling. It’s enough to say here that hardly any other means of maintaining a comfortable home environment all year long are as efficient, reliable, or economical, particularlly when you gauge the energy savings.

Here’s how geothermal makes that a reality.

Thar’s Gold Heat in Them Thar Hills!

We tap the earth for precious metals. We tap the earth for oil. Now, as never before, we’re tapping the earth for a commodity likely just as valuable to many of us: the energy to heat and cool our homes that doesn’t entail oil.

You see, right beneath the earth’s crust – that would be in the neighborhood of 33,000 feet under our feet – is a mantle of magma. This is a molten and semi-molten brew, for the most part comprised of silicates, in which temperatures vary from 1300 degrees Fahrenheit to 2400 degrees Fahrenheit and hotter the deeper you go (not that you’d want to go there!). What this does is keep the ground immediately under the earth’s surface at a reasonably stable year-round temperature of between 45 and 75 degrees Fahrenheit. Meaning? Underground temperatures in Alaska (and most places stateside, anyway) are warmer than the ambient air above ground in Winter and cooler than the ambient air above ground in Summer.

Time to Get Pumped!

What geothermal heating and cooling systems do, then, is transfer heat from the ground  to your home or heat from your home to the ground, in accordance with the season. Either way, your home’s interior remains at the optimum temperature to keep you and your family comfy month after month.

The device that handles the transfer is a geothermal heat pump. It continuously circulates water or some mixture (commonly antifreeze) between your home and loops of piping (commonly fashioned of polyethylene, high-density polyethylene, PVC, or CPVC) placed in the ground. In Winter, the liquid is cold when it enters the ground. As it flows through the loops, it sucks up heat from the earth and is reintroduced to your home warm. In Summer, the process is reversed: warm liquid goes into the loops, where it absorbs the cooler ground temperatures before it’s returned to your home. Want details? You’ll find more specific information on ground loops here.

The key point is that geothermal heating and cooling systems don’t produce energy. They don’t work like central heating systems, which generate heat themselves. Instead, geothermal systems heat and cool your home by making use of the energy already richly available beneath the earth’s surface. That’s why geothermal systems not only run quieter but also are considerably more trustworthy, need less maintenance, have far longer lifespans, and are more environmentally friendly than traditional HVACs. That’s also why, ultimately, you’ll save lots more more money by going geothermal.

Curious now? Get hold of Energy Efficiency Associates, your Alaska geothermal heating and cooling professional, today.