“Archaeological evidence shows that the first human use of geothermal resources in North America occurred more than 10,000 years ago with the settlement of Paleo-Indians at hot springs.” Thus states the U.S. Department of Energy, Energy Efficiency & Renewable Energy’s webpage titled “A History of Geothermal Energy in the United States.” Various other peoples throughout history have used this type of energy as well.

Today, geothermal can be used to not only heat baths, the way the ancient Romans did, but also to heat and cool homes and other buildings. Interest in and use of geothermal is growing again, and a variety of HVAC units and components are available to meet the rising demand. Listed below are a sampling of the geothermal products currently offered.

HEAT PUMPS

The Bard GeoTec Geothermal Heat Pump is ideal for residential and light commercial applications and suitable for open or closed loop applications, says the manufacturer. The GeoTec is available in 2- to 6-ton capacities. Features include a Copeland step-capacity scroll compressor and variable-speed ECM motor. Increased dealer-friendly installation and service features include left- or right-side water connections, left- or right-hand access to control panel, slide-in electric heat packages, and simplified wiring and troubleshooting. www.bardhvac.com

The Century HWW Series water-to-water geothermal heat pumps can provide both hot and chilled water, as well as domestic hot water, making them viable options for such installations as radiant floors, snow and ice melting, chilled water for fan coils, and other types of residential and industrial applications. Available in 3-, 5-, and 10-ton capacities, the units can be installed as part of a ground loop, ground water, or water loop (boiler/cooling tower) system. The solid-state microprocessor controls have a performance monitoring system to signal when the system is not operating at peak performance so maintenance can be scheduled. www.century-hvac.com

Comfort-Aire GeoMax2® Series geothermal heat pumps have an extended operating range of 20 to 120°F entering water temperature, making them suitable for virtually all applications and climates, says the company. The two-stage system saves energy by shifting between part load and full load, automatically adjusting to optimize comfort. Upflow, downflow, and horizontal models are available in 2- to 6-ton capacities with EERs as high as 30.8 on a partial- load, ground-water installation. Features include a hot-water generator with built-in pump and solid-state microprocessor controls with a performance-monitoring system to signal a potential problem before a lockout can occur. www.comfort-aire.com

Earthlinked® commercial water heating system Model CWH-072-2B is a heat pump designed for commercial water heating. It typically provides preheated water to standard 120-gallon water heater tanks. According to the company, the system’s most economic water heating application is to heat or preheat water for users such as motels, multifamily dwellings, dormitories, pool heating, health care facilities, and restaurants. It has a capacity of 6 tons (72,000 Btuh), and uses R-407C. It is a 230-V, three-phase unit. www.earthlinked.com

The Invictus gas absorption heat pump is a natural gas- or propane-fired heat pump that is incorporated and piped into a traditional hydronic heating system alongside either condensing or noncondensing boilers. The unit uses a solution comprised of two-thirds water and one-third ammonia within a small, closed system. Models include air-, ground-, and water-source units. Invictus units have both heating and cooling capabilities. It features 95,500-Btuh inputs and 135,000-Btuh outputs. The manufacturer says it can custom design systems that achieve up to 149 percent efficiencies. www.fulton.com

OTHER SYSTEMS AND COMPONENTS

The VRV®-WIII by Daikin AC (Americas) Inc. is a compact, water-cooled condensing unit designed to provide the ability to operate geothermal and cooling tower/boiler combination applications. When used in geothermal applications, the relative stability of groundwater temperatures results in optimum system efficiency regardless of outdoor temperatures. According to the manufacturer, the unit is an energy-saving alternative to traditional centralized equipment that can serve any-size commercial application. Its six system capacities range from 6 to 21 tons and in unified heat recovery and heat pump condensing units. www.daikinac.com

The next-generation Copeland Scroll UltraTech™ modulating compressor by Emerson Climate Technologies is designed for high-efficiency performance in water-to-air, geothermal applications, and will aid geothermal manufacturers in reaching Energy Star 3.0 standards, says the company. The compressor offers an easy-to-apply solution to enhance system efficiency and reliability for both air conditioners and heat pumps. It offers modulating two-step capacity design, 100 percent at full-load and 67 percent at part-load. According to the company, the compressor offers the ability to provide impressive full-load EER performance. www.copelandscroll.com

The Enertech Manufacturing Hydron Module Revolution® Series vertical multipositional geothermal system packaged unit is designed for residential and light commercial applications in new construction and retrofit installations. It can be field converted from upflow to downflow, right-hand return or left-hand return, all in the same cabinet. Sizes range from 4 to 6 tons; all sizes are Energy Star®-rated. The quadruple compressor isolation is designed to absorb a wide range of sounds and vibrations. www.hydronmodule.com

The Enertech Manufacturing Compass Series by GeoComfort® are hydronic (water-to-water) geothermal units that can provide hot water for such uses as radiant floor heating and snow melting. It can provide chilled water for forced air conditioning through a separate fan coil unit. The hydronic units can be used in residential and light commercial applications and in retrofits or new construction. Sizes range from 2 to 12 tons; all but one of the models are Energy Star®-listed. www.geocomfort.com

The GeoSystems LLC Econar® GeoSource™ Ultra Split system is available as a dual-fuel or standard split unit. They are available as forced air 3- and 4-ton units. The dual-fuel split system helps homeowners get more from their conventional heating systems by using ColdClimate™ technology, which provides more heating for every cooling Btu, says the company. Using the homeowner’s existing ductwork and furnace blower, the dual fuel/split system can become the primary heating source, as well as providing a/c and dehumidification. For new or existing homes, a standard split system can use new or existing ductwork, depending on where it is mounted. Warm or cool air can be transmitted through an AHU that can be installed anywhere in the home. www.econar.com

Publication date: 07/26/2010