March 26, 2010

Geothermal efficiency

Geothermal efficiency
New Town schools adding heating and cooling technology


In a word, efficiency is what New Town schools are getting now that geothermal heating and cooling systems are being installed.
And when the closed loop circulation systems are in place, the school district is expected to save 50 percent of its annual costs on energy, which is currently coal to heat the school and electricity to cool it.
Late last week, Donovan Meuchel, Dave Beerost and Jared Pederson of Earth Energy & Water Systems from Mandan and New Salem, were boring holes near New Town High School to install circulating pipe.
A similar system will be installed later at Edwin Loe Elementary School.
When the Morton County trio was finished, they had dug 18 holes, each 200 feet deep that will have a black pipes containing a food grade propylene glycol water and antifreeze solution.
Bentonite was dropped into the holes with the pipe to help transfer heat through the pipes.
Meuchel said the best way to describe a geothermal system is to think about a car radiator and how the antifreeze circulates.
He said in a closed loop circulating system, the liquid, which remains a constant temperature underground, draws heat through the pipes in winter and draws cool during the summer.
Meuchel added the deeper the holes are bored, the warmer the temperature. But in general terms, a geothermal system is normally 54 degrees Fahrenheit.
He said there is an efficiency factor that he tries his best to meet. He can make it so the pipes get hotter, but the cost then begins to rise more than the equivalent efficiency of the heating and cooling.
“These holes give off available heat,” Meuchel said. “I call them mini gas wells that will never go dry.”
Once this system is completely installed, it will take care of 100 percent of the high school’s heating and cooling needs.
“And all we’re doing is taking heating out of the ground,” Meuchel said. “We’re drilling these geothermal wells and installing loops.”

The Weather Network