Ground Source Heat Pumps

Ground Source Heat Pumps (GSHPs) transfer heat to and from the earth, heating and cooling buildings without burning fossil fuels. A Ground Source Heat Pump will also provide hot water using either the waste heat from your building or warmth from the earth.

How It Works

Five to eight feet below the earth’s surface, the ground is at a constant temperature. A Ground Source Heat pump makes use of a water loop buried in the ground around the building and a standard vapor compression cycle to transfer heat into the building in the winter, and transfer heat out of the building in the summer.

There are over one million GSHP installations in the United States. The GSHP tubing makes use of the same materials and techniques that are used to install hydronic in-floor heating systems that are permanently built into a building’s floors. The tubes are made of polyethylene, a durable, but flexible plastic. Joints are heat-fused so that the joints are stronger than the tube itself. Tube manufacturers give a 50 year warranty to purchasers.

Polls consistently show that 95% of all GSHP owners would recommend such a system to a family member or friend. GSHP Systems Are Economical The United States Environmental Protection Agency (EPA) determined that GSHP systems were the most energy efficient, environmentally clean, and cost-effective space conditioning systems available. The study found that GSHP systems saved 30% to 70% in heating mode, and 20% to 50% in cooling mode. The same EPA study determined that, while initial costs were higher for a GSHP system, GSHP systems have the lowest life cycle cost of any space conditioning system, paying back the initial investment in 6 to 8 years. In addition to cost-of-energy savings, GSHP systems reduced maintenance costs by 50%.

Benefits

GSHP mechanical systems operate at much lower temperatures and pressures than conventional heating and cooling systems. The heat exchangers are simpler and less highly stressed, and the circulating pumps operate at benign environmental conditions. In fact, since all equipment in a GSHP is installed indoors, maintenance is reduced and service life is extended.

Here are just a few of the benefits of installing a GSHP system.

Energy and cost efficiency

All equipment is installed indoors, reducing maintenance and extending service life.
According to the United States Environmental Protection Agency (EPA), GSHP systems are the most energy efficient, environmentally clean, and cost-effective space conditioning systems available, with cost savings of 30% to 70% in heating mode, and 20% to 50% in cooling mode.
While initial costs are higher for a GSHP system, GSHP systems have the lowest life cycle cost of any space conditioning system, paying back the initial investment in 6 to 8 years.
GSHPs provide free hot water when operating in cooling mode by collecting waste heat from the building and using it to heat water. The system can produce hot water year round by utilizing excess heat collection capacity to heat water at times when space heating demands are low.

Safety and air quality

GSHP systems do not rely on combustion for heating. They require no air intake or venting ducts, and do not produce any emissions such as carbon monoxide, an odorless gas produced by the combustion of fossil fuels. Even small amounts introduced into confined areas over a long term have resulted in documented health problems.

Environmental benefits

The average GSHP installation results in a reduction of almost 6 metric tons of carbon dioxide emissions annually, and a savings of 40 million BTUs of fossil fuels. Each installation also saves on average 8,000 kWh of electricity. These reductions are equivalent to taking 1.2 cars completely off the road, or eliminating 2.1 barrels of imported oil.

Other benefits

GSHP systems:

Have predictable operating costs – no price shocks.
Increase resale values.
Are quiet, with no exposed outside equipment.
Eliminate the need for multiple utility services.
Can be retrofitted onto any existing system.

Polls consistently show that 95% of all GSHP owners would recommend such a system to a family member or friend. And, the United States Environmental Protection Agency (EPA) determined that GSHP systems were the most energy efficient, environmentally clean, and cost-effective space conditioning systems available.

Case Studies

Here you'll find case studies about about Ground Source Heat Pump installations in residential, school, and health care settings from Geoexchange, the Geothermal Heat Source Consortium. You'll need Adobe Acrobat Reader to view the case studies. Click here to download Adobe Acrobat Reader.

GeoExchange Comfort in Princeton, Minnesota: 100 kb
Energy Smart Solutions for America's Schools: 998 kb
The Prescription for Lower Heating and Cooling Costs in Healthcare Facilities: 1.656 mb