Geothermal Heating and Cooling: Understand the 4 Types of Systems

Geothermal heating and cooling is a unique and extremely cost-effective way of using solar energy that’s collected in the ground as the medium of exchanging thermal energy for your home. In the more common closed-loop systems, a water/anti-freeze mixture is pumped through underground tubing, where it collects heat from the earth and brings it inside (or deposits it back outside for cooling). A heat exchanger transfers heat between the liquid mixture and refrigerant in the heat pump system in your home, which then provides comfortable and affordable geothermal heating and cooling. While there are three main types of closed-loop systems, an open-loop system is also available in situations where there’s a nearby source of clean water that meets certain conditions.

An open loop system uses well or surface water as the exchange fluid that circulates through the geothermal heating and cooling system. When it has run through the system, it’s either returned to the well or routed to a recharge well or surface discharge. This is only a good option if there is a generous supply of clean water nearby.

The three types of closed-loop systems include:

Horizontal loop

This common geothermal system uses trenches that are at least 4 feet deep, with two sets of piping either at different depths or side by side. They run in a shallow pattern underground, using quite a bit of space. The “slinky” style of laying the pipe or tubing maximizes the amount of underground heat that can be extracted.

Vertical loop

The vertical loop system uses holes drilled about 20 feet apart and 100 to 400 feet deep. This system uses u-bends at the end of the tubes to move the fluid through the closed loop. This is best used in situations where the soil isn’t appropriate for a horizontal loop system or yard space is limited.

Pond/Lake

If the building site has a pond or lake, this system is a great option. A supply line runs from the unit underground to the water source.  The tubing must be at least 8 feet under the water’s surface to prevent freezing. This is probably the cheapest type of closed-loop system.

Though the initial investment in a geothermal heating and cooling system may be high, this cost is usually returned within 5 to 10 years through energy savings. A generous federal tax credit of 30 percent is also available to help defray the cost. The inside part of a geothermal heat pump system may last around 25 years and the external loop system 50 years. To learn more, please contact us at Rinaldi’s Energy Solutions. We provide excellent HVAC and plumbing services to the Orlando area.

Our goal is to help educate our customers in Orlando, Florida and surrounding areas about energy and home comfort issues (specific to HVAC systems).  For more information about Geothermal Heating and Cooling and other HVAC topics, download our free Home Comfort Resource guide.

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