Geothermal Heating

One of the easiest and most reliable types of geothermal energy that just about everyone, regardless of location, can use circulates the heat of the Earth through your house with the use of geothermal heat pumps. Water or glycol is circulated through the thermal mass of your house on one end and either an outdoor pond or simply a lot of pipe buried in the ground on the other.

Such systems do not require you to be sitting on top of a hot spring in the mountains, though you certainly can be. The main advantage of using ground source heat pumps is that they can be used anywhere, even in areas that seem quite cold. In fact, the greater the differential between the ground and air temperatures, the more useful and cost effective they are.

This is because the Earth stays at a rather constant 45-50F (8-10C) no matter where you are and no matter the season. In a sense, the entire planet is a contiguous mass, so it has even more ability to retain heat than the oceans do. This means that by coming into contact with enough ground will heat or cool a pipe and whatever is in it.

Since water (and in some cases, glycol) is a very good conductor and storage for heat (or the absence of it), it is usually pumped through pipes to act in those capacities. When the pipes are colder the liquid transfers heat to the metal that is a good conductor but a poor storage media. Air is a terrible conductor and storage media as evidenced by the massive amount of electricity required to heat a room through a space heater. As such, most pipes make physical contact with the foundation of the house.

Keeping the liquid circulating is the key to the whole operation. It's like keeping your blood moving, and in this case, the heart is a heat pump. Pumps themselves can be electric, or diesel or even wind generated. In climates that freeze it is a good idea to have a back up pump as part of the system, just in case, since you don't want burst pipes underground in the middle of winter.

The amount of pumping required is often not as large as you might think, since the rate of flow doesn't have to be great. Also, since the system is always running, there's no need to prime or otherwise start moving liquid from a resting state. Once the system is going, it's going and doesn't usually stop for anything.

Passive geothermal energy has the potential to be a major part of weaning North America off heating oil for good because it can be used just about anywhere and is the most trouble-free of "renewable" resources.

Geothermal Heating |