By Starrla Cray
INDEPENDENCE, MAPLE PLAIN, MN When Dawn Reidinger discovered that her furnace was on its “last leg,” she decided it was time to start looking into alternative heating/cooling sources.
“My house was really an energy hog,” said Reidinger, whose house in Independence was built in 1968.
In January 2010, she and her husband had a geothermal home comfort system installed by UMR Geothermal in Maple Plain.
“I’m really just tickled pink with the geothermal so far,” Reidinger said. “My house is so comfortable.”
In the winter, geothermal systems capture heat from the ground (which naturally stays at about 50 degrees) through a series of pipes. Warmth is delivered to an indoor heat pump, which transfers heat into the home.
During hot weather, the same ground source heat pump simply reverses, and pulls heat from the building. Heat is then carried through the pipes and deposited into the ground.
“The summer was exceptional,” Reidinger said. “It’s so quiet, so nice.”
In 1997, when UMR Geothermal began, geothermal was a little-known technology in the area. Since that time, geothermal has been gaining in popularity, as businesses and homeowners strive to reduce long-term cost and environmental impact.
“If you’re looking to replace your furnace, and you’re planning to be in the house awhile, geothermal can have a really good payback. It all depends on where the price of energy goes,” said Brian Nowak of Maple Plain, who is involved with a climate crisis organization called 350.org.
The cost of geothermal compared to traditional methods of heating and cooling also depends on the weather, which varies from year to year, Reidinger added.
In Reidinger’s house, a backup furnace was installed along with the geothermal system.
“The main source is geothermal, and there’s very little use on the furnace,” Nowak said.
Typically, geothermal heat pumps are sized to supply 80 to 100 percent of the heating load, and a furnace is used to supply extra heat as needed.
According to the UMR Geothermal website, sizing the heat pump to handle all heating needs might result in slightly lower heating costs, but the savings might not offset the added cost of the larger pump and loop installation.
Also, an oversized unit could cause dehumidification problems in the cooling mode.
“Each house has to weigh the economics of what they need,” Nowak said.
For Reidinger, geothermal is just the beginning of a more energy-efficient home.
“I really believe in using technology as much as we can to cut down on our use of fossil fuels,” she said. “We’re actually converting our house over to LED lighting.”
The bulbs are initially more expensive, but they last longer and run more efficiently.
Reidinger’s outside yard lights are left on 24/7, and she only pays about $7 per year in electricity costs.
“They add a nice little touch in the winter,” she said.
The Reidingers also use LEDs inside the home.
“The bulbs look more modern,” Reidinger said. “LED lights are much nicer than fluorescent, and they’re actually more similar to the sun’s spectrum.”
Reidinger is also considering adding solar voltaic panels to her home in the future.
“That’s kind of the perfect complement to geothermal,” Nowak said, explaining that it helps a home become “carbon neutral.”
Nowak is an advocate for 350.org, which aims to help reduce carbon dioxide in the earth’s atmosphere.
According to the 350.org website, the atmosphere contained 275 parts per million of carbon dioxide for many years. Now, it’s up to 388 parts per million, and climate experts are saying that 350 parts per million is the safe upper limit.
Nowak said that protecting the environment can be done in many ways, and that solar panels and geothermal systems aren’t for everyone.
“What we recommend first is conservation,” he said.
Many energy companies offer a service for evaluating energy efficiency in a building. Reidinger had this done about five years ago, and she said it was very useful for determining the location of air leaks.
The personal evaluation can provide an analysis of energy consumption and recommendations for energy efficiency improvements.
“That’d be good for everybody to do,” Nowak said.