Feb. 19, 2008 — Most of us would never think of the earth itself as the planet’s largest heating and cooling unit, but thanks to technology, remarkably, it is. And to find out how well the earth actually works, the Lassen Municipal Utility District has installed a new system at the historic Susanville Railroad Depot, the home of the Lassen County Chamber of Commerce, to help heat the building in the winter and cool it down in the summer.

The project included upgrading the insulation in the building, a solar hot water system and the installation of a heat pump exchange system that takes advantage of the earth’s heating and cooling capabilities.

Theresa Boucher, LMUD’s energy services specialist, said there is no real mystery surrounding the technology used in the system installed at the depot.

“Ground source heat pumps are electrically powered systems that tap the stored energy of the greatest solar collector in existence — the earth.” Boucher wrote in a press release about the system. “Heat pumps are a device which moves heat from one place to another. These systems use the earth's relatively constant temperature to provide heating, cooling, and hot water for homes and commercial buildings.”

Patty Hagata, executive director of the Chamber, said the newly installed system works great.

“It’s working very well,” Hagata said. “It definitely does the trick.”

Hagata said the Chamber has reduced its winter heating bill by nearly two-thirds, thanks to the new insulation, solar panels and the new heat exchange system.

She said the project took longer to complete than expected, so the chamber had an opportunity to see what its winter heating bills would be without the new system.

Hagata said the Chamber will be able to remain open all year long, thanks in part to the big savings on its energy bills.

“In a nutshell, the geothermal loop and heat pump is really a big, reversible refrigerator,” Boucher wrote. “When our homes or businesses are too hot, the heat is removed and carried down into the earth, using the soil as a huge heat sink. Then, when we need heat, the refrigeration process is reversed, and the heat is moved from the earth and back to our homes or businesses.”

LMUD got involved with the project to find out how well such a project actually would work in its service area.

“When we started the project we wanted to get some real numbers on a ground source heat pump,” Boucher said. “The geo-exchange technology has been around forever. They’ve been using it back east for decades.”

Customers who use the technology could enjoy more benefits than simply lower energy bills. LMUD customers may be eligible for a $1,500-per-ton rebate if they install a ground source heat pump system. LMUD installed a six-ton system at the depot.

According to Boucher, the average home would need a three- to four-ton unit and could qualify for a $4,000 to $6,000 rebate.

She said construction costs for an average home would probably be about $15,000. A retrofit on an existing building probably would be more expensive.

The project at the depot is a “demonstration project,” Boucher said, and “a public benefits project” that goes along with LMUD’s Smart Built Home program.

The cost of the project at the depot, according to Boucher, was about $30,000 including new insulation, ductwork, drilling, piping and the new heat exchange pump.

A solar thermal water heating system also was installed as part of the project, allowing the depot to have hot water without using any electricity at all.

Boucher said the project began in November 2006, and they finally threw the switch on the heat pump in August 2007.

A drilling rig installed six closed loops, each 200 feet long along the side of the depot.

The loops were filled with an environmentally friendly fluid and connected to the heat pump.

The environmentally friendly fluid passes over what looks like a radiator. Because the fluid is warmer than the outside air in the winter and cooler than the outside air in the summer, the system uses less electricity to heat or cool the building.

The system works so well, most customers who install one are very satisfied.

According to Boucher, in a recent poll, more than 95 percent of the people who installed a geothermal heat pump said they would recommend it and would do it again. The EPA also has rated geothermal heat pumps among the most efficient heating and cooling technologies available today.

Ground source heat pumps can be categorized as having closed or open loops, and those loops can be installed four ways — horizontally, vertically, slinky or in a pond or lake. The right type for each project depends on the available land areas and the soil and rock type at the installation site.

Open loop systems operate on the same principle as closed loop systems and can be installed where an adequate supply of suitable water is available and open discharge is feasible. Benefits similar to the closed loop system are obtained.

Many environmental benefits also are derived, regardless of which type of ground source heat pump is installed.

According to Boucher’s release, currently installed systems are making a huge difference in our environment. The systems are eliminating more than 3 million tons of carbon dioxide — the equivalent of taking 650,000 cars off the road.

The systems conserve energy and, because they move heat that already exists rather than burning something to create the heat, they also reduce the amount of toxic emissions in the atmosphere.

They use renewable energy from the sun, and because the system doesn't rely on outside air, it keeps the air inside of buildings cleaner and free from pollens, outdoor pollutants, mold spores, and other allergens.

Boucher said the system installed at the depot is basically like a conventional furnace, except that it uses the relatively constant temperature of the earth.

She said once you dig below the frost line, the temperature in the earth is generally about 50 degrees. The ground temperature near the depot is a little bit higher because of the geothermal activity in the area.