The Basic Science of Geothermal Heating and Cooling

Scores of people here in Traverse City, Michigan, have engaged D&W Mechanical to upgrade their homes to geothermal homes. Still need convincing about geothermal heating and cooling yourself? Understanding something of the science behind it – and the mechanics as well – might help.

We’ve noted elsewhere the merits of geothermal heating and cooling. Suffice it to say here that few other methods of maintaining a comfortable home environment throughout the year are as efficient, dependable, or ultimately low-cost, particularlly when you size up the energy savings.

Here’s how geothermal works that magic.

Thar’s Gold Heat in Them Thar Hills!

We mine the earth for precious metals. We drill the earth for oil. Now, to an unprecedented degree, we’re tapping the earth for a treasure no doubt just as valuable to most of us: the energy to heat and cool our homes that doesn’t call for oil.

You see, close beneath the earth’s crust – no more than 33,000 feet under our feet – is a mantle of magma. This is a molten and semi-molten brew, principally of silicates, in which temperatures run 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. The upshot? Underground temperatures in Traverse City (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, depending on the season. Either way, your home stays at an optimal temperature to keep you and your family in comfort year-round.

The device that handles the transfer is a geothermal heat pump. It continuously circulates water or some blend (predominantly antifreeze) between your home and loops of pipe (predominantly fabricated 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 takes in heat from the earth and is reintroduced to your home warm. In Summer, the process is reversed: warm liquid is brought into the loops, where it takes in the cooler ground temperatures before it’s returned to your home. Want details? You’ll find more specific information on ground loops here.

The primary 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 much more trustworthy, need less maintenance, have much longer lifespans, and are more environmentally friendly than standard HVACs. That’s also why, ultimately, you’ll save considerably more more money by going geothermal.

Curious now? Get together with D&W Mechanical, your Traverse City geothermal heating and cooling professional, today.