Unearthing Cheaper AC and Heat: Geothermal Heat Pump Technology: Energy for the Future
Jun 03, 2014 07:55PM
● By Doug Wagner
Dating back to the times of ancient Chinese empires, cultures across the globe have capitalized on the knowledge of the Earth’s ability to provide and store heat. Today, technological advances have enabled us to strategically harness this energy in ways that translate to energy savings in the heating and cooling of commercial and residential buildings.
Geothermal heat pump technology and specifically, ground-source heat pumps, have been installed for more than three decades and are presently recognized as the most highly efficient type of heating and cooling system available. Ground-source heat pumps work in concert with either an open- or closed-loop water-source geothermal system of high-density polyethylene pipes installed in trenches (horizontal) or bore holes (vertical) in an outside location near a building or home. Fluid circulating through the underground pipes collect energy in the form of heat, which is either pumped into or out of the building by way of the heat pumps, depending on the indoor climate requirements.
For each unit of electrical energy purchased to power a geothermal, or “geoexchange” system, renewable energy is drawn from the earth and used for space heating and cooling, domestic hot water and heating swimming pools/spas.
The amount of heat energy transferred to or from the earth depends on the thermoconductivity of the soil, the flow rate through the ground loop and the size of the refrigeration system in the heat pump. The simplicity and mechanics of the units allow geothermal systems to be applied to a wide range of installations.
Thanks to the robust efforts of the North American green building and renewable energy movements, today’s building community has a heightened understanding of both the economic and comfort benefits of geothermal systems. As products and technologies continue to evolve in their sophistication, ease of installation and streamlined operation, building professionals are also becoming more expertly trained in geothermal system design, installation and maintenance. Thus, geothermal systems are being incorporated into numerous new construction and retrofit projects throughout the U.S. and Canada, in both residential and commercial applications.
In winter, water circulating inside a sealed loop absorbs heat from the earth and carries it to the unit. In the summer, the system reverses and expels heat from the home to the cooler earth via the loop system. This heat exchange process is not only natural, but is a truly Earth-friendly and highly efficient way to create a comfortable climate in a home.
Depending on property size, the underground loops can be installed in a variety of ways, including horizontal, vertical or within a lake as a closed loop or, if an aquifer is present, as an open loop, virtually suiting any property configuration.
Horizontal loops are installed in areas where the soil conditions allow for economical excavation. Taking up more land area than any other loop type, they are used where space permits. Trenches are normally five feet deep and several hundred feet of trench is required.
Vertical loops are used extensively where land area is limited. A pair of pipes with a special U-bend assembly at the bottom is inserted into a borehole that averages around 250 feet in depth per ton of equipment.
Lake loops are usually very economical to install. If a pond or lake at least eight feet deep is available, lake loops can utilize the water (rather than soil) for heat transfer. Reduced installation costs are characteristic of this type of loop system.
Open loop installations actually pump water from an underground aquifer through the geothermal unit and then discharge that water to a drainage ditch or pond. Discharging water to a pond or lake is considered ideal.
With a geothermal heating and cooling system, the lawn becomes a permanent power plant for your home or business. It’s tried and true, can cut utility bills more than half, and does away with noisy air conditioning condensers. A geothermal system is not affected by the corrosive salt bombardment that coastal climates place on conventional equipment, thus greatly extending operational longevity. Users enjoy the benefits of the most comfortable, reliable, energy and cost efficient heating, cooling and water heating systems available on the market.
Geothermal is now more affordable than ever, thanks to recent changes to the tax code. The change contains long-term tax incentives to encourage the use of renewable energy technology such as geothermal heat pumps in homes and businesses and extends tax incentives for homes and commercial buildings that support the installation of highly-efficient heating, cooling and water heating systems such as geothermal heat pumps until 2016.
On all residential ground loop or ground water geothermal heat pump installations, a one-time tax credit of 30 percent of the total investment, up to a maximum of $2,000 for systems placed in service during 2008, is available. For property placed in service after January 1, 2009, a tax credit of 30 percent with no limit can be claimed. The tax credit can be used to offset both regular income taxes and alternative minimum taxes and can be carried forward into future years. With these changes, a homeowner can now more easily afford a heating and cooling system that will ultimately pay for itself.
ClimateMaster is the world’s largest manufacturer of geothermal heat pumps in their state-of-the-art facility utilizing quality management systems that are ISO 9001:2000 certified. Contact Doug Wagner at 850-244-2665 or [email protected].