open loop


Geothermal Installation Types: Open Loop Vs. Closed Loop Systems


The loop system in your geothermal installation is the extensive network of pipes buried in the ground (in a ground-source system) or submerged in water (in a water-source system) where the temperature stays consistent year round. An antifreeze solution or water is circulated through the loop. The heat pump components of the geothermal installation extracts heat from the loop for indoor heating and transfers heat from your indoor environment to it for home cooling.There are two main types of loop systems available for your geothermal installation:

  • Closed loop:Closed loop systems are used in both ground and water-source applications. They are, as their name suggests, closed off, which means the antifreeze solution stays within the pipes. Horizontal closed-loop systems are the most common. These use a loop system that covers several square feet of horizontal ground area. Vertical loop systems are used where there is not a lot of open ground available for installing the loop system. The loop is installed in a series of deep vertical holes drilled into the ground, usually about 100 to 400 feet deep and set 20 feet apart. Vertical loops are also used where the soil is rocky, where the topsoil is thin or where horizontal loops are impractical.

  • Open loop: In an open loop system, water from a well, pond, lake or aquifer is used instead of the antifreeze solution within the loop. The water circulates through the heat pump. After heat is extracted from or transferred to the water, it returns to the original source, to a recharge well, or to a surface discharge and drainage system. To use an open-loop system, you must have a sufficient supply of water available to sustain its operation. In addition, the water must meet local regulations covering groundwater discharge and pollution.

For nearly three decades, Air Assurance has been a leading source of professional HVAC services in Tulsa and the surrounding communities. Contact us today for more information on the options available for your geothermal installation and for expert advice on whether an open loop or closed loop system will work best for your needs.Our goal is to help educate our customers in the Tulsa and Broken Arrow, Oklahoma area about energy and home comfort issues (specific to HVAC systems). Image courtesy of Shutterstock