Ground Source Heat Pumps offer great benefits:
• Simultaneously heat & cool different parts of the same building
• Very quiet--users do not know when the system is operating
• Can be set up in multiple zones, with each zone having an individual room control
• Greater freedoms in building design due to 50-80% less mechanical room space
• No outside equipment to hide, eliminating vandalism and roof top units
• Pipes have 50-year life expectancy
• All electric, which eliminates multiple utility services
• Expel boiler and chiller maintenance
• Ground heat exchanger is maintenance free and will last 40+ years

GSHPs offer great savings:
• Very competitive on initial costs and lower lifecycle costs than most HVAC systems.
• Savings of 25-50% on energy consumption
• Lower peak demand, lowering your operating costs
• Water heated with waste heat from air conditioning at no cost in the summer and at substantial savings in the winter
• Some utilities offer rebates or incentives to their customers who purchase GSHPs. None are currently available in California.

GSHPs are environmentally friendly:
• Conserve natural resources by providing efficient climate control and thus lowering emissions
• Minimize ozone layer destruction by using sealed refrigeration systems, which seldom or never have to be recharged
• Use underground loops to transfer heat, with no external venting and no air pollution
• Very energy efficient, with the earth providing over 70% of the energy required to heat and cool

How Ground Source Heat Pumps Work
A heat pump is a mechanical device that transfers heat from one source to another. Ground-source units pull heat from the earth and transfer it to homes or buildings. Heat pumps (despite their name) can provide both heating and cooling. The cooling process is simply the reverse of the heating process: heat is taken out of a building and returned to the Earth.

Typical ground-source heat pumps transfer heat using a network of tubes, called "closed loops." Basically, the loops are filled with either water, refrigerant or an anti-freeze solution. They run through the ground in the vicinity of a building and the liquid absorbs the Earth’s heat energy. Then, this warmed liquid is pumped back through the system into the building. This process provides heat to the building space. Once the fluid passes through the building and transfers its energy, it flows through the loop system back to the Earth and the process repeats itself.
In the summertime, these systems "reverse" into cooling mode. Technically, the system does not "run backwards." Instead, a series of valves enables the system to switch the "hot" side and the "cold" side. The heat from the building is transferred to the liquid in the loop and this liquid is pumped back into the ground. When the ground source heat pump is in cooling mode, it usually has an excess of warmed liquid in the system. This liquid can heat water for the building and basically eliminate the use of the hot water heater during the summer months.
Saving Energy

Ground-source heat pumps can use 25%-70% less electricity than conventional electric heating and cooling systems. First, in winter heating mode, a ground-source heat pump uses energy from the Earth to provide heat, whereas air-source heat pump try to extract the last bits of heat energy out of cold winter air. Because of the long, cold Wisconsin winters, air-source heat pumps are not effective or efficient.

Second, ground-source heat pumps are more energy efficient than conventional electric heaters because they maximize the thermodynamic advantage of a heat transfer fluid. This benefit enables the ground source heat pump to produce more heat energy output than electric energy input. Conventional electric heaters on the other hand don’t quite produce as much heat output as electric input. (Under some conditions, a ground source heat pump cannot meet the required heating needs. In these cases, supplemental heat must be provided from another source–usually conventional electric units.)

Third, during the summer, the ground source heat pump "reverses" into cooling mode. This fact makes the ground-source heat pump more energy efficient for cooling than a traditional air conditioner.
Finally, when a desuperheater is installed, energy from the ground source heat pump can be transferred to the hot water tank. As a result, building occupants receive "free" hot water in the summer and very low-cost hot water in the winter.

Most of a ground-source heat pump’s electrical energy requirement (70% to 80%) is consumed by the compressor and pump that combine to move heat energy to or from the ground, through the loop system, and into or out of a building. The remaining 20% to 30% of the electricity is used for fan(s) and controls to distribute the conditioned air throughout the building.

Saving Money
A ground source heat pump system, including the underground loops, costs about $2,500 per ton of capacity, or roughly $7,500 for a 3-ton unit (typical residential size). Approximately half of this cost is related to the geothermal loop configuration. It can be expected to last from 20 to 30 years with minimal maintenance. A conventional heating and cooling system costs up to $4,000.

At first glance, this price difference of $3,500 may seem impractical and too costly. However, buyers must carefully consider monthly energy costs over the life of the equipment when making a decision. As the school administrators in Fond du Lac and Evansville learned this past year, rising energy prices can destroy annual budgets and geothermal systems are a good way to minimize future price shocks.

Since these systems use from 25% to 50% less energy than conventional systems, users will spend less on their monthly energy bills. In fact, many homeowners could spend from $35 to $70 less per month, meaning that most ground source systems will "pay for themselves" in 2 to 10 years. The additional cost of $3,500 will be recovered from the monthly energy savings. After the "payback" period, the owner will simply pay much-reduced utility bills.

Ground-source heat pumps can be retrofitted in existing homes that have traditional forced-air systems. In most cases, the heat pump can be connected to the existing ductwork while the loop system is installed outside in the ground adjacent to the home.

Interested? Take Advantage of Available Incentives!
• Many brands of ground source heat pumps carry the Department of Energy and the Environmental Protection Agency's ENERGY STAR label. It qualifies them for an ENERGY STAR loan from banks and other lending institutions. (Visit www.energystar.gov for more information.)

• When upgrading a home’s energy efficiency, these retrofits can be financed through "energy efficiency mortgages." (For more information, read the EnergyMatch feature article titled New Ways to Finance Home Energy Efficiency Improvements.)

• Many lending institutions recognize that ground source heat pumps reduce monthly utility bills and will approve higher loan amounts. Visit www.energyloan.net for more information.

Find a licensed geothermal system installer in your county or state:
The International Ground Source Heat Pump Association is a non-profit organization that works to advance ground source heat pump technology on local, state, national and international levels. IGSHPA utilizes state-of-the-art facilities for conducting GSHP system installation training and geothermal research. The IGSHPA website has an extensive directory of licensed designers and installers.