Geothermal Closed Loop Pond Installation

Excavate a trench leading from your home to the pond. This trench will need to be at least four feet deep and provide access to the foundation wall of your home to connect the piping. Try to make the trench as directly routed to the pond as possible. You can, of course, dig the trench by hand, depending on the amount of time and energy you have.

Drill two holes of the same diameter as the geothermal tubing through your foundation wall. These two holes will be be used to feed through the tubing that will receive and return coolant pumped through your underwater pond loop.

Lay the piping into the trench and into the pond. In closed loop systems, you will use one long section of tubing, with the ends installed through the holes drilled through your foundation wall and the loop laid in the trench and onto the bottom of the pond. The length of the pond loop will be determined by the BTU requirements of your system, which will be dictated by the kit you purchase based on the size of the home and the climate conditions of your area. You may make your own kit, but the calculations for sizing should be copied from a pre-assembled kit.

Backfill the trench, burying the piping to insulate the heat transferred from the underwater pond loop.

Install the included water pump and heat exchanger into your furnace. The heat exchanger typically mounts after the fan assembly in a central heating system, before the heating element in the furnace. The water pump may be installed on either exposed pipe from the pond loop. The pump will cycle a glycol solution through the closed loop, through the heat exchanger coil, and back into the other pipe, completing the circuit.

Fill the loop system with a glycol solution. Glycol transfers heat more efficiently than water and will not freeze. This must be done at the highest point in the system to avoid the formation of air bubbles. You may need to run the water pump and periodically top the system off to remove any residual air in the piping system.