Ask Mr. Answer Person: What is the status of the geothermal project at Decorah High School?

1. It all starts here - a 65 foot well.

OK, Mr. Answer Person is going to tackle this one, despite being severely challenged in terms of understanding all the complexities of the engineering involved in geothermal systems. You might call it "geothermal for dummies."

First, the system is all up and go; all zones have been operational since December.  (The only areas of the high school not included in the geothermal heating and cooling are the gymnasium and locker rooms.) The steam boilers that had long worried school officials were removed last spring. Back up hot water boilers have not yet been installed. They would be rarely used, but would be needed for system cleaning shut downs.

Our pictures attempt to tell part of the story.  Water is pumped from a 65 foot well behind the high school. It comes into the mechanical room, where the heat from the ground water is transferred to a closed loop glycol/water circulation system via a plate cooler.  Ground water is then dumped back into the pond behind the high school. The glycol/water solution is then pumped to various heating/cooling zones via complex heat pump units.  The heating/cooling system is not simply water pumping around the building, but is enhanced by ERVs (energy recovery ventilators) that temper needed fresh outside air by interface with 68 degree air that has been re-circulated from classrooms.

What is not operational are all the automated systems that tell units when they should be shutting down, starting up or redirecting flows, so the full efficiencies of the system are yet to be experienced. Ultimately, the system should be able to provide both heating and cooling for a cost equal to or less than the operation of just the old heating system.

Thanks to Decorah Schools Buildings and Grounds Director Greg Schaller for helping us!

2. Ground water comes into building

3. Heat transfer via plate cooler

4. Heat pumps circulate closed loop glycol solution

5. Happy classroom campers!