Geothermal heat pumps boost water conservation by millions of gallons

By: Deborah Johnson Wood

Did you know that a 200,000-square-foot office building that uses a conventional heating system and cooling tower—the stack that emits a plume of steam on cool mornings—can use two million gallons of water per year and sends another 20,000 gallons to the sanitary sewer?

geothermal heat pump, by contrast, uses the earth’s constant temperature to heat or cool water (depending on the season) in buried closed-loop pipes, recycling the same water through the loop over and over. No water is wasted, no heat releases into the atmosphere, and the pipes can last up to 100 years.

“The type of soil makes a difference,” says Steve Hamstra of Holland-based GMB Architects-Engineers. The company has installed geothermal heat pumps for over a decade, but is doing more of them now than ever before, including installations at Caledonia High School, which has one of the largest geothermal heat pump systems in the state, Zeeland West High School, Quincy Elementary, two schools in Kentwood, and Davenport University’s Lettinga Campus Academic Building and Residence Halls.

“We do a test bore to determine the type of soil, and then put polyethylene pipes vertically about 400 feet into the ground, it makes a U-turn and comes back up,” Hamstra adds.

“We built Zeeland West High School. It's 200,000 square feet and has 120 of these holes for the heat system. It’s a $2.2 million system, comparable to a conventional HVAC system, but it will save them $80,000 to $100,000 a year and won’t waste any water.”

In addition, GMB just completed the school’s new indoor pool building and is looking at ways to heat the pool by using the geothermal heat system to capture the heat exhausted by the building’s air conditioning.

Source: Steve Hamstra, GMB Architects-Engineers

Deborah Johnson Wood is the development news editor for Rapid Growth Media. She can be contacted at [email protected].

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