Down to earth
Fuel-free heating and cooling via geothermal
When David and Elizabeth Taylor’s three children and two grandchildren visit their spacious old home in Fresno, the monthly utility bill can reach $2,000.
That’s in California, where it’s considerably warmer most months than in Northern Michigan, where the Taylors are in the process of building a 7,000-square-foot stunner on the coast north of Harbor Springs.
To help control utility expenses, David began looking into alternative energy options for heating systems, and he decided on geothermal.
“The primary thought was energy savings,” said David, “but I think the environmental aspect is important, too.”
“I needed to have a warm environment,” said David, an orthopedic surgeon who enjoys California’s warmer weather. His wife, a Michigan native, had long hoped to build a home in the Harbor Springs area, where they’ve visited for decades.
Geothermal was the answer to the Taylors’ concerns about energy consumption. Their home has been under construction for some time, with part of the process involving installation of the network of tubing and manifolds controlling the geothermal system that powers the home’s heating and cooling.
It’s a big task; the home has a large indoor lap pool, in-floor heating throughout and cavernous rooms.
Handling the installation of the geothermal system is Great Lakes Plumbing and Heating of Harbor Springs. Sales manager Ken Ashton said more homeowners are looking to geothermal for energy savings in the face of rising oil prices and also for the impact on the environment.
“We are extracting heat out of the earth. It is nothing more than a heat pump that is using the earth as the source of its energy,” Ashton explained.
In a geothermal system, loops filled with a water/antifreeze or alcohol solution are buried five feet underground, where the earth’s temperature remains about a steady 50-56 degrees, despite the season (even up North). The liquid is circulated through the loops and into the home where the warmth is extracted and transferred through the home. Geothermal also controls a home’s air conditioning.
For the Taylor’s installation, because of the lot dimensions, the loops were installed vertically into the ground 150 feet deep, which is an alternative to the more common method of laying loops horizontally under the yard.
The basement utility room looks like a ship’s belly with the various heat exchangers, pipes and tubing required for the system. Plus, a back-up boiler is needed for heating water up to 120 degrees for showers, laundry and other hot-water needs, Taylor said.
For homeowners who choose geothermal, the system works the same as a conventional set-up, with thermostats controlling temperature. Manifolds containing the tubing in each room inside the Taylor home will allow the couple to adjust the temperature individually as well.
“We set it up so we are able to adjust for 17 different zones,” Taylor said.
Geothermal is more expensive to install; in Taylor’s case, he estimated it cost two to three times more than choosing a conventional heating/air conditioning system powered by natural gas. He expects, however, to recoup the additional installation expense after about seven years, with considerably lower monthly utility costs.
“I think it’s actually going to happen faster than that,” Taylor said.
Ashton said when homeowners are looking into geothermal, a software program calculates projected energy costs, taking into account the rising price of fuel sources, based on the size of the home.
“There are two things to look at, the price for the installation and the cost overall. What is this going to cost me monthly and yearly?” Ashton said. “The price I pay today might not be the lowest cost down the road.”
He offered an example using a 2,400-square-foot home. Annual heating cost using a high-efficiency propane furnace is estimated at $1,900 a year. The annual heating cost with a geothermal system is about $530.
The installation of the gas furnace is $16,000; the geothermal installation is about $23,200. In about four years, the difference in the system will have been paid off, Ashton noted.
With an increasing international dependence on fossil fuels for everyday living, geothermal is one option for homeowners interested in reducing the size of their carbon footprint.
Geothermal does require electricity to operate the system, but since its main source of heat and cooling is water, a house with geothermal reduces overall environmental emissions by 40 percent as compared to conventional natural gas and central air systems, according to earthcomfort.com. And the heating and cooling comes from the temperature in the ground, a renewable resource courtesy of the sun.
A house with geothermal also has no flames, no fumes and no propane tank on the lawn.
Using a 7,000-square-foot home as an example, Ashton said the energy consumption is equal to a house about a third of that size when it comes to impact on the environment.
“It’s good for the environment and at the same time it’s going to save them money,” said Ashton. “You get the environmental aspect of it as a bonus if you’re doing it only for the economics. It’s a win-win, no matter what.”
Some homeowners question whether geothermal systems can operate effectively in the cooler Northern Michigan environment; Ashton says yes, because the earth’s temperature down five feet does not vary much region to region.
“Geothermal has been a small percentage of the market, but it’s a growing trend because … people realize that if it’s going to hit me hard at the pump,” Ashton said, “it eventually hits us hard in the way we heat our homes.” HL
Why it’s green
• Geothermal energy resources are renewable because the system uses heat from the earth that will not diminish like fossil fuels.
• Geothermal also produces minimal air emissions and offsets the high air emissions of fossil fuel-fired power plants, like nitrous oxide, hydrogen sulfide, sulfur dioxide, particulate matter and carbon dioxide.
Source: geo-energy.com
