You’ve heard that the new Sherman Hospital’s 15-acre lake not only provides beautiful views from the patient rooms, but it helps to heat and cool the entire hospital, saving $1 million in energy costs per year. And you know it’s a pretty big deal–it’s the largest geothermal system in Illinois and one of only 2 currently heating and cooling medical centers in the US. But you might not know the answer to the most basic question about the lake: How exactly does it work?
What is Geothermal Energy?
Geothermal energy is energy that is derived from the temperature of the earth. The earth absorbs 50 percent of all solar energy and traps it as heat just below the frost line. Using a heat pump, this natural and renewable resource trapped below the earth’s surface is transformed into a harnessable form of energy. This energy –geothermal energy– provides buildings with a dependable, eco-friendly and economic heating and cooling system.
The tools that make it happen:
- The temperature at the bottom of the lake—a constant 55 degree F in all climates. The ground absorbs almost 50% of the sun’s heat as it hits the earth’s surface. Regardless of the season, this solar energy maintains a relatively constant 55 degree temperature at the bottom of the lake, around 17-18 feet deep.
- A lake loop heat-pump system under the water, including 185 miles of pipes that are placed at the bottom of the lake to harness the energy. The pipes hold a heat-absorbing solution, and the heat pumps move heat from one place to another.
- A “manifold” building that houses over 170 pressure gauges connected to the pipes. This piping is channeled into supply and return pipes that are run to the building and fan out to individual heat pumps.
- Heat pump units housed just outside patient rooms that allow each room to be temperature controlled individually.
In the winter, the 55 degree temperature at the bottom of the lake is absorbed into a heat-absorbing fluid that constantly runs through the pipes. That heat is harnessed from the pipes through the pressure gauges, and pulled into the building. There it is concentrated and released into the building at a higher temperature. The heat is distributed through a conventional duct system as warm air. In the summer, the process is reversed–the heat from inside the hospital is pushed back down and stored in the cooler earth. Like in a refrigerator, cold air is not pushed into the hospital–rather, the heat is removed from the air.
Learn more about Sherman’s geothermal lake.
November 3, 2009
Recently, our aerial photographer got the chance to shoot the new Sherman Hospital as the sun was setting. The coming darkness brought out the interior lighting of the hospital, which gave it a new look that we hadn’t seen before. The shots turned out great, so we wanted to share them with you!
The new hospital opens on December 15th, just six short weeks from now. Be on the lookout for details on the December 6th Community Open House Celebration, in which we’ll celebrate the new hospital with food & drink and public tours.
October 20, 2009
The new hospital opens in less than two months. With the grand opening approaching quickly, the new building is really taking shape, both inside and out. Here are seven new photos of the interior of the hospital at Randall and Big Timber Roads.
For the latest news, press releases and photos on the new hospital, be sure to visit the brand new Future of Sherman page!
October 6, 2009
One of the main features of the brand new Future of Sherman website is the dedicated page solely devoted to the geothermal lake. The lake will use geothermal energy to heat and cool the new hospital, which will save around $1 million per year in energy costs. It’s the largest geothermal system in Illinois and one of only two systems heating and cooling a medical center in the entire United States.