Ritters hope to use ground-source heating

By Bill Scanlon, Rocky Mountain News (Contact)

Published November 30, 2007 at 7:09 p.m.
Updated November 30, 2007 at 7:09 p.m.

Text size

Engineers will drill into the back yard of the Colorado Governor's Mansion in two weeks, hoping to find groundwater at a consistent 55 degrees that can be pumped into the house to lower heating and air-conditioning costs.

If the tests find easily accessible water, production will start next spring, and Colorado will be the first state in the nation with a ground-source heating and cooling system in its governor's residence, said Lance Shepherd, the manager of design and construction programs for the Office of the State Architect.

First Lady Jeannie Ritter can't wait. It's usually either too hot or too cold, stifling or drafty, in the family's living area at the mansion on East 8th Avenue, she says.

Last summer, she didn't turn on the air conditioner for three months, partly because of a malfunction in the lines, partly because she's such an energy conservationist that she couldn't bear to see the kilowatt hours add up.

Ground-source heat pumps tap the earth's relatively constant temperature — ideally, 55 degrees year-round — to bring heat, cooling and hot water to homes and buidings.

Water or antifreeze will circulate in plastic pipes that stretch from inside the house to deep underground at about the level of the groundwater.

When it's 10 degrees outside, a conventional heating system has to start at a bitter cold temperature and work its way up to a comfortable 70 degrees — or maybe 65 degrees if the family is willing to wear sweaters.

And when it's 95 degrees, the air conditioner has to buzz and hum overtime to get the temperature down to 70 or 75 degrees.

With a ground-source system, the 55-degree temperatures from beneath the ground help ease the work the heating and cooling systems must do, by mitigating the extremes of hot and cold.

Jeannie Ritter on Friday looked out a magnificient, but single-paned, window on the second floor of the mansion onto the east lawn. She said she's thrilled at the prospect of mining the constant 55-degree temperature underground to make heating and air-conditioning easier in the 98-year-old house.

Shepherd, the architect from the state office, said ground-source systems "are very common on the Western Slope. Colorado is a good area for it.

"In summertime, you take cooling out of the ground and bring it up to supplement the air conditioning."

In the winter, "instead of using mechanical means to raise the temperature to 55, you get it right out of the ground."

"We need to get a certain heating or cooling load of BTUs," he said. The quicker they can find the groundwater, the faster they'll get those BTUs, and the less costly the project will be.

The project shouldn't cost the taxpayers any extra money. Because of a guarantee of energy savings — it may take a dozen years for the cost of the project to pay for itself in lower energy bills — the project can be amortized over the years and still fit into the utilty-bill line-item of the mansion's budget, Shepherd said.

Subscribe to the Rocky Mountain News