Frequently Asked Questions
Are incentives available from the state or federal government?
YES. Home and commercial building owners who install geothermal heating and cooling systems are now eligible for federal tax incentives under the American Recovery and Reinvestment Act of 2009 (H.R. 1: Div. B, Sec. 1122, p. 46), which removed the maximum credit amount for all eligible technologies (except fuel cells) placed in service after 2008. The legislation offers a one-time tax credit of 30 percent of the total investment for residential ground-loop or groundwater geothermal heat pump installations, with no limit on the maximum credit. To qualify for the tax credit, residential systems must meet Energy Star requirements. The contractor who sold and installed the product should list the purchase as a “geothermal heat pump” on the invoice and note that the unit “Exceeds requirements of the Energy Star program currently in effect.” The home served by the system does not have to be the taxpayer’s principal residence. The act also provides incentives for residential wind and solar systems, biomass, and efficient appliances and vehicles. Some states offer tax incentives, and some utilities offer rebates or special electric rates. You should check with a contractor to find out what's available in your area.
OK, so geothermal can provide cheap heat. Can it cool too?
It can do more than cool; it can make hot water, too. A simple switch at the thermostat reverses the process, allowing the geothermal system to provide cooling twice as efficiently as any other air conditioning system. In the process, the system provides virtually free hot water and superior home dehumidification plus, some units can make all of your hot water.
Are we going to be comfortable?
Probably more comfortable than ever. A geothermal system moves warm air throughout your home via a standard duct network. Because the system moves a larger volume of air, heat is more even throughout the home and the initial cold air blast common with fossil fuel furnaces is eliminated. It's also a great comfort to know that you've reduced your energy consumption while using a renewable source - the earth. And geothermal means a cleaner house because there is no soot from combustion, and increased air flow means increased filtration.
Can a geothermal system be added to my furnace?
Split systems can easily be added to existing furnaces for those wishing to have a dual- fuel system. Dual-fuel systems use the geothermal unit as the main heating source and a fossil fuel furnace as a supplement in extremely cold weather if additional heat is needed. Your electric utility may provide special rates for dual-fuel installations.
Do I need separate loops for heating and cooling?
No. The same loop works for both. All that happens when changing from heating to cooling is that the flow of heat is reversed.
How do geothermal owners feel about them?
State and national surveys show that over 90 percent of owners are very satisfied with their geothermal units. More than 95 percent said they would choose the system again and recommended it to others.
Electric utilities like them because they use a lot of electricity, right?
Actually, utilities like geothermal systems because they use electricity in a way that benefits them and the customer. Because of the way they operate, geothermal systems provide a steady base load for utilities, pretty much avoiding the sharp peaks of electricity usage that require expensive reserve power sources. Those savings often are passed on to the customers in the form of special rates. And yes, geothermal systems use electricity, but because they only use it to move heat already available in the ground, they use a lot less than other electric heating systems. Geothermal systems operate at efficiencies 3 to 5 times higher than electric resistance heat. That is, a geothermal systems will provide 10,000-14,000 BTU's (British Thermal Units) of heat per kilowatt-hour compared with 3,413 BTU's per kWh produced by 100% efficient electric resistance heater. This also means that geothermal systems cost less-as much as 60 percent less to operate than propane or fuel oil furnaces.
How much groundwater does an open-loop system need?
Geothermal heat pumps used in open loop systems need differing amounts of water depending on the size of the unit and the manufacturer's specifications. The water requirement is usually expressed in gallons per minute (g.p.m.) Your heating contractor should be able to provide this information. Generally, the average system will use 6-10 g.p.m. An extremely hot or cold day might result in usage of 6,000-10,000 gallons of water. Your well pump combination should be large enough to supply the water needed by the geothermal unit and your domestic water requirements.
I wouldn't want to be a guinea pig for some new gadget.
The technology has been around since the 1950s. Tens of thousands of the units have been installed in all parts of the U.S. and Canada. An estimated 25,000 are working in Michigan, with more than a thousand installed every year.
Is a geothermal heat pump difficult to install?
Most units are easy to install, especially when they are replacing another forced air system. They can be installed in areas unsuitable for fossil fuel furnaces because there is no combustion, thus, no need to vent exhaust gases. Ductwork must be installed in homes that don't have an existing air distribution system. The difficulty of installing ductwork will vary and should be assessed by a contractor.
If I have a pond near my home can I put a loop in it?
If it is at least six feet deep, a pond is a perfect heat exchanger.
My friend has a backhoe. Can we put in the loop ourselves and save a few bucks?
It's not recommended. In addition to thermal fusion of the pipe, good earth-to-soil contact is very important for successful loop operation. Nonprofessional installations may result in less than optimum system performance, and may void manufacturer's warranty. Look for qualified installers who guarantee their work and tell your friend to watch.
Should I buy a system large enough to heat my home with no supplemental heat?
Your contractor will calculate the heating and cooling load (heat loss/ heat gain) to guide equipment selection. Some new generation systems can be sized to meet optimum heating and cooling requirements without additional supplemental heat. Other models will supply 80-100 percent of your design heating load. Sizing the system to handle your entire heating needs may result in slightly lower heating costs, but the savings may not offset the added cost of the larger unit.
Is this magic? You can't get heat out of cold well water or the frozen earth.
The earth is a wonderful source of heat. Just ask the burrowing animals that depend on it for warmth in the winter. In fact, the earth stores 47 percent of the solar energy that reaches us, making it a natural source of heat for our homes, if we can get it out. And we can. Geothermal heating and cooling systems, also called earth loop, or ground-coupled heat pumps, move the heat from the ground into your home using the same technology your refrigerator uses to remove heat from food. When a cat curls up at the bottom vent of a refrigerator it simply is enjoying the warm result of the refrigeration process.
So what is this open-loop, closed-loop stuff?
The heart of the geothermal systems is the ground loop. An open-loop geothermal system uses well water as a heat source. As the water passes through it, the system extracts heat, reducing the water temperature about 5 degrees F. The water is then returned to the earth, usually by running it on the ground and letting it seep into the aquifer. A closed-loop system extracts heat from the earth by a series of liquid-filled pipes buried in the ground. The plastic pipes are filled with water and antifreeze. The pipe used in closed loop systems is buried beneath the frost line. The pipe can also be run vertically in bored holes. A typical home will have about 2,000 running feet of pipe in the earth loop. The pipe can have a guaranteed lifetime of 50 years or more.
How much does a geothermal system cost?
We get into trouble with dealers when we mention prices, because total installation cost depends on so many variables: unit size, type and style of loop, modifications to existing ductwork, among others. And the initial cost is more than offset by operating cost savings, which could be way more than half your current heating bill if you use propane or fuel oil.
Will an earth loop affect my lawn or landscape?
Well, digging a trench can get a little messy. But experience has shown that loops have no adverse effect on grass, trees or shrubs. Most horizontal loop installations use trenches about two feet wide. This of course, will leave temporary bare areas that can be restored with grass seed or sod. Vertical loops require little space and result in minimal disruption.