The Basic Science of Geothermal Heating and Cooling

Scores of residents here in Hattiesburg, Mississippi, have signed on with BC's Heating and Air to upgrade their homes to geothermal homes. Still need persuading about geothermal heating and cooling yourself? Knowing a little of the science behind it – and the mechanics as well – would undoubtedly help.

We’ve talked elsewhere about the advantages of geothermal heating and cooling. It’s enough to say here that few other manner of maintaining apleasant home environment throughout the year are as efficient, trustworthy, or affordable, particularlly when you gauge the energy savings.

Here’s how geothermal works its magic.

Thar’s Gold Heat in Them Thar Hills!

We dig in the earth for precious metals. We dig in the earth for oil. Now, more than ever, we’re tapping the earth for something likely just as valuable to many of us: the energy to heat and cool our homes that doesn’t involve oil.

You see, just below the earth’s crust – that would be about 33,000 feet under our feet – is a mantle of magma. This is a molten and semi-molten brew, for the most part made up of silicates, in which temperatures range from 1300 degrees Fahrenheit to 2400 degrees Fahrenheit and hotter the deeper you go (not that you’d want to go there!). What this serves to do is keep the ground immediately under the earth’s surface at a year-round temperature of between 45 and 75 degrees Fahrenheit. Meaning? Underground temperatures in Hattiesburg (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!

This, then, is what geothermal heating and cooling systems do: they 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 stays at the perfect temperature to keep you and your family happy year-round.

The apparatus that effects the transfer is a geothermal heat pump. It continuously circulates water or some mixture (usually antifreeze) between your home and loops of piping (usually fabricated of polyethylene, high-density polyethylene, PVC, or CPVC) buried 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 enters the loops, where it’s cooled by the cooler ground temperatures before it’s returned to your home. Looking for details? You’ll find more comprehensive information on ground loops here.

The principal point is that geothermal heating and cooling systems don’t produce energy. They aren’t like central heating systems, which generate heat themselves. Instead, geothermal systems heat and cool your home by putting to use the energy already amply available beneath the earth’s surface. That’s why geothermal systems not only run quieter but also are considerably more dependable, need less maintenance, have far longer lifespans, and are more environmentally friendly than traditional HVACs. That’s also why, over time, you’ll save a lot more more money by going geothermal.

Curious now? Consult with BC's Heating and Air, your Hattiesburg geothermal heating and cooling specialist, today.