Both open loop and closed loop systems are available.

‘Pump and dump’ geothermal is an open loop system using a well or other ground aquifer to supply water to a geothermal heat pump. Well water is channeled through the heat pump, where heat is extracted from the water using a refrigeration process. This extracted heat is then used for forced-air heating or radiant floor heating, maintaining a comfortable temperature at very little cost.

The water used is then returned to the Earth’s natural water table via a separate well referred to as an injection well. This type of system is very efficient for large-scale projects and where ample ground water exists.

Closed loop geothermal uses a self-contained supply of water (commonly mixed with antifreeze) to circulate constantly, either through vertical bores or horizontal trenches in the ground. After the water absorbs its heat underground, a geothermal heat pump (or ‘ground source heat pump’; GSHP) extracts heat from the warmed water, returns it to the home and pumps the liquid back underground to rewarm.

With both types of geothermal systems, an automatic flip of the switch reverses the flow to initiate the cooling process for the summer months.

Ground water maintains a constant temperature year round, depending on depth. In many areas (primarily in those with large, relatively fast-flowing aquifers), ground water can be used to effectively cool even large structures quickly and efficiently.

Cool water is pumped from ‘supply’ wells and throughout a building’s HVAC system, providing uniform, cost-effective and near-zero emission cooling.

Water used in this way is not consumed or contaminated and is allowed to drain back into the water table through an ‘injection’ well once its cooling power is spent.

According to the EPA, a household leveraging geothermal energy saves between 30% and 70% in heating costs, and 20% to 50% in cooling costs (where applicable).

That number is probably low, because fuel and energy costs are skyrocketing with no signs of slowing. Investing in geothermal heating and cooling is a smarter choice than ever, whether your primary goal is to create comfort or to add value to your property.

In many jurisdictions, geothermal users benefit from tax credits, providing added incentive to make the switch.

In a word, yes.

In theory, there’s more thermal energy already stored inside the Earth than we’ll ever need, with more building up every day thanks to a combination of radioactive decay, gravitational friction, and plain old sunlight.

The forces that drive geothermal heating and ground water cooling are present everywhere around the world, and evolving technology makes them more accessible to more people every day.

With zero emissions (offsite electricity generation notwithstanding) and a renewable source, geothermal is one of the most promising prospects we have to create a cleaner, brighter future.