The Finksburg branch of the Carroll County Public Library, already designated as the county's first "green" building, may also become the first one to use the earth's temperature to heat and cool the facility.
The county commissioners are considering adding a geothermal system to the plans, which would heat and cool the building using the earth's core temperature, thus reducing energy costs. The $3.8 million facility would become the first county building to run on such a system.
The Bureau of Building Construction is preparing to test the thermal conductivity in the soil surrounding the building and should decide if such a project is feasible in the coming weeks, said Thomas J. Rio, the bureau's chief.
Rio is optimistic.
He expects the ground temperature to be consistent enough - about 52 to 53 degrees -to sufficiently cool the building in summer and provide warmth in the wintertime. "I really would be flabbergasted if there's poor conductivity," Rio said.
Officials from Carroll County Public Schools first heard about implementing geothermal systems about six or seven years ago, said Ray Prokop, director of facilities for the school system. But engineers weren't convinced the equipment was well-developed at the time, Prokop said.
Since then, many school systems across the country have gotten on board. In Maryland, new schools in Montgomery and Dorchester counties must include geothermal heating, Rio said.
A geothermal system is also planned for Carroll's Ebb Valley Elementary School, scheduled to open in the northeast corner of the county in August 2008. That system is expected to pay for itself in less than six years, when the county realizes savings in energy costs, Rio and Prokop said.
The Ebb Valley geothermal system is budgeted at $2.9 million, about $300,000 more than the cost of implementing the conventional air conditioning and furnace format, Rio said.
Rio expects a similar cost and payback period for the 15,000-square-foot library, planned for the intersection of Old Westminster Pike and Green Mill Road in the Sandymount area.
As energy prices continue to rise, the systems - and other environmentally friendly features - have become more prevalent in publicly funded buildings. The presence of a geothermal system could also help the Finksburg library gain official certification from the U.S. Green Building Council, Rio said.
However, Keith Leonard, the project's architect, isn't convinced that the complicated certification process is essential.
"It's just a methodology of proving that you've done what you said you have done," Leonard said.
Rio has presented the county commissioners with more than 30 examples of public buildings around the country that use geothermal systems. Most systems were expected to achieve cost savings in about seven years.
A longer payback period of 20 years was predicted for the Glenwood Community Center that Leonard also designed in Howard County. But with a large gymnasium, that building, which will be four times the size of the Finksburg Library, would be much more expensive to cool and heat, Leonard said.
Estimates for the Glenwood center, which has yet to be completed, were based on old utility rates obtained from Howard County, said George Ribas, a mechanical engineer working with Leonard on the project.
"Now with these new rates, the story will be different," said Ribas, who also worked on the Finksburg project. "The cost of energy is going to continue to increase, so basically a geothermal system does make sense. The balance would be in its favor."
About 60 wells would have to be dug, some 400 feet deep, to pump geothermal energy into the Finksburg library, Rio said. The wells eliminate the need for a boiler or chiller.
In winter, heat is pulled from the earth or groundwater into the building. In the summer, heat is transferred from the building and discharged into the ground.
Redesigning the library to include a geothermal system will set the project back about three months, Rio said. He expects the county to receive bids on the project in late fall. The library, with the geothermal system, would be set to open in December 2007.
Hopefully, the county will continue to tap into geothermal energy in the future, Prokop said. "It's a better type of a system in terms of the environment, but it also makes sense economically, when you look at the thing over the long term," he said.