Air Connection Projects
College may use geothermal holes to heat, cool new building
By Dana M. Nichols
Record Staff Writer
February 01, 2007
COLUMBIA - A new science lab set to rise soon at Columbia College may be the first large building in the region to be heated and cooled with the help of holes bored hundreds of feet into the bedrock below. A drilling rig Tuesday began grinding its way through dark metamorphic rock to create a test well that will determine the feasibility of the plan.
As early as next week, engineers will pump water into a loop of pipe installed in the hole to see how efficiently it can cool hot water and heat cold water.
Although the technology to heat and cool using the constant temperatures below ground has been around for decades, its use is growing as businesses and governments seek ways to cut back on fuel and electricity bills.
"When we found out that Feather River College had this, we looked into it," said Jeff Tolhurst, a geoscience instructor at Columbia College.
Feather River College officials estimated that the geothermal system they installed in 1998 for about $218,000 saves them about $50,000 a year in energy costs.
Although the 24,000-square-foot science building planned at Columbia is about half the size of the buildings served by geothermal heating and air conditioning at Feather River, Columbia officials expect the savings here to be substantial as well.
"We're seeing more interest in these as the price of fuel goes higher and higher," said Mark Morelli, principal of Air Connection, the Santa Rosa-based company that is scheduled to install the system at Columbia College. Morelli said his firm has installed 200 such systems, including a few in large, upscale private homes in the Bay Area.
According to the Federal Department of Energy, holes bored in earth help to heat and cool buildings at about 500 schools nationwide, mostly in Texas, Missouri, Kentucky and New Jersey.
Geothermal systems work because it takes less energy to get rid of heat on a hot summer day by pumping it into the 55-degree rock below ground than by trying to discharge it into the 90-degree or 100-degree air above ground. Likewise, it is easier for a heat pump to suck heat from that same 55-degree bedrock on a winter day than to struggle with sucking heat from above-ground air that may be freezing or colder.
Geothermal systems take up less room in buildings, on rooftops or next to buildings.
Also, "it's a quieter system," Morelli said. "We don't have the outdoor fans running like a conventional system would."
The drawback is the upfront cost of drilling holes. And such systems don't work in locations with poor soils such as sand that don't allow heat to dissipate effectively.
The $18.5 million science building at Columbia College is funded by Measure E, a $326 million bond measure that Yosemite Community College District voters approved in 2004. The district includes Columbia College and Modesto Junior College.
The building is tentatively scheduled for completion by May 2009.