A Green Solution

Mechanical Inc. installing system in lake to save hospital $1 million per year

Edited By Tom Hale -- Associated Construction Publications, 6/2/2008

Mechanical Inc. has a solid track record of successful hospital and green building projects, and that combination made them the mechanical contractor of choice for Sherman Hospital’s $310-million replacement hospital in Elgin, Ill. Scheduled to open in late 2009, the hospital will be mainly heated and cooled by geothermal energy from a 15-acre artificial lake next to the facility.

"The geothermal lake was a wise choice, both economically and ecologically," says Brian Helm, president of Mechanical Inc., Freeport, Ill. "The lake is projected to decrease Sherman’s gas and electric costs by nearly $1 million annually."

Helm adds that Mechanical Inc. is installing the hospital’s intricate heating and cooling system, including 275,000 feet of 2-inch piping in the geothermal heat exchanger – a component that uses the lake’s natural geothermal properties to heat and cool the hospital. Mechanical Inc. is also installing the medical gas piping and the plumbing in the facility.

Mechanical Inc. is working with Walsh Construction, the construction manager for the replacement hospital.

"Sherman Hospital will be the first hospital in Illinois to build a geothermal lake," says Selena Worster of Mechanical Inc., project manager for the geothermal lake. "This lake will also be the largest of its kind in the nation."

Saving Energy

According to Worster, solar energy absorbed by the Earth gives the ground below the 17-foot-deep geothermal lake a consistent temperature of 55 degrees.

The lake will have a natural clay liner and be filled with rainwater. Water-bearing coils of piping, or barges, are stationed at the lake’s floor. The steady temperature at the bottom of the lake will be the heating and cooling source for water passing through the barge coils. This water, in turn, is circulated by a lake loop heat-pump system.

When the circulating water reaches the geothermal heat exchanger, the energy is converted to warm or cool air to regulate the temperature of the majority of the hospital’s rooms. The emergency room and surgical suites will employ a traditional heating and cooling system, since they require cooler temperatures.

"The geothermal lake will give Sherman flexibility to grow," says Worster. "It will be easy to expand the geothermal system along with the hospital."

Worster sees this project as the beginning of a greener future for the Midwest, and ultimately the nation. "More and more businesses are embracing green building," she says. "Hopefully this project will inspire other businesses to pursue their own green solutions."