A Look at Today’s Geothermal Heat Pumps
New Residential Geothermal Products Feature Higher Efficiencies, Renewable Qualities
According to Energy Star, geothermal heat pumps (GHPs) are among the most efficient and comfortable heating and cooling technologies currently available because they use the earth’s natural heat to provide heating, cooling, and, often, water heating. And manufacturers keep pushing the efficiency envelope, introducing products that feature super high EERs and sophisticated control systems that are designed to keep homeowners supremely comfortable as well as make installation and service a little easier for contractors.
GreenSource: Series Model SM
Bosch Thermotechnology’s Greensource™ CDi Series Model SM geothermal heat pump is designed to cool and heat a home economically and in an environmentally friendly manner. This model is available in cooling capacities ranging from 2-6 tons and features a part-load EER of up to 37 and a full-load EER of up to 28 (ground water). Other features include a tin-plated evaporator coil for long life; a floating base pan and variable-speed motor for quiet operation down to 52 dB; an air-tight cabinet with less than 2 percent air leakage; closed cell fiber-free insulation for improved air quality and energy-savings; multi-position airflow flexibility; and a 10-year parts-and-labor limited warranty.
The Greensource CDi Series SM Split Model GHP features part-load efficiencies of up to 33 EER and a full-load EER of up to 24 (ground water). A split system separates the condenser section up to 75 feet away from the fan coil section to isolate sound, vibration, and unwanted heat from the conditioned space. The condenser may be located indoors or outdoors, and a Bosch communicating thermostat display controls air temperature and humidity levels.
Greensource units are designed to be field-configured for various arrangements, and return air can be customized for the job on the left side, right side, back, or top of the unit. The electrical box can be rotated from front to back for optimal service access. All main components are entirely serviceable from the front of the unit, and the easy-to-read LCD allows for fault codes to be automatically displayed, cutting down diagnostic time and identifying faults as quickly as possible.
Variable-Speed GHP System
ClimateMaster Inc.’s Trilogy 45™ Q-Mode™ variable-speed GHP system provides efficiencies of 45 EER, as well as notable savings via on-demand hot water generation capabilities. The system also offers convenient programming, monitoring, and control for homeowners and dealers over the Internet from any Wi-Fi-enabled device.
Available in vertical-upflow, vertical-downflow, and horizontal configurations, the system is offered in capacities of 930 kBtuh (0.75-2 tons) and 1,860 kBtuh (1.5-5 tons). The patent pending Q-Mode technology reduces hot water operating costs by providing full-time, year-round domestic hot water heating at over 500 percent (5.0 COP) efficiency and also provides no-cost cooling by automatically drawing heat from into the unit’s iGate Smart Tank™ hot water storage tank. The tank’s polyethylene exterior protects it from corrosion.
With iGate Connect™ technology, dealers can retrieve complete diagnostics and operating data via any Wi-Fi-enabled device over the Internet. Through an online portal, dealers can access built-in measurements of all critical system operations and conditions at the past five faults. More than 25 unit settings can be configured from the dealer portal, including airflows and range of unit capacity.
Variable-speed technology provides a wide range of heating and cooling capacities, delivering full-rated capacity across its entire operating range (20°-120°F entering water temperature). The Trilogy 45 Q-Mode can also wholly match loads as low as 30 percent of maximum, providing comfort and humidity control by running longer and slower, and precisely matching capacity to the heating and cooling load.
SC and SD Models
EarthLinked Technologies Inc.’s systems are designed to deliver 100 percent of heating and cooling needs with Energy Star certification. The SC and SD Models offer the onboard Earth Loop Protection System (EPS), which comes pre-configured on every unit. The units also feature built-in secure start; faster startup capability; increased reliability; and Earth Loop service valves, which are standard with the compressor unit for ease of installation.
The SD Model offers the benefit of free hot water with an internal heat recovery system for connection to domestic hot water, which saves time and money for both the customer and installer. The system qualifies consumers for federal, state, and local tax credits and rebates. EarthLinked Renewable Energy Systems can even be designed to integrate into an existing furnace system.
Comfort-Aire, a registered trademark of Heat Controller, recently introduced its packaged HEV Series geothermal heat pumps. The Series features self-contained units that combine a small footprint with two-stage operation and integrated digital communication controls. As an added benefit, the unit includes a hot water generator that provides domestic hot water.
Available in 2-5-ton models, the two-stage HEV Series is rated as high as 29.4 SEER/4.6 COP (part load) and 22.3 SEER/4.3 COP (full load) for a 3-ton unit in a ground-water installation. A two-stage scroll compressor runs at 67 percent capacity most of the time to maintain constant temperature and humidity levels. When there’s demand, the compressor instantly shifts to 100 percent capacity. The ECM blower motor also automatically adapts to system requirements for consistent delivery of conditioned air.
A digital electronic controller links the thermostat, fan motor, and compressor staging to provide setup and diagnostic data, saving time during installation and service calls. A 4-wire connection between the controller and the communicating thermostat also saves installation time. A port for a separate diagnostic tool is built into the unit to access the data if a communicating thermostat is not used.
Built into all models is a performance monitoring system that acts much like a vehicle’s check engine light. It signals a potential problem so service can be scheduled before a lockout occurs. Additional included safety features guard against high pressure, loss of refrigerant charge, condensate overflow, and freezing of the coaxial heat exchanger and air coil. All components can be accessed through the conveniently located control box and the removable side panels. Brass swivel connectors make water hookup quick and easy.
EnerTech LLC’s GeoComfort Compass Series multi-positional two-stage vertical packaged models are rated as high as 4.3-5.4 COP/21.1-35 EER (open loop) and 3.6-4.8 COP/17.1-29.1 EER (closed loop). Available in sizes from 2-6 tons, the multi-positional cabinet is field convertible to upflow or downflow configuration with left or right return, making installation easier for dealers and inventory management simpler for distributors.
Top-mounted, eye level controls are also a primary feature of these models, as is a composite antimicrobial drain pan. The control panel can be easily relocated, depending on the unit’s configuration. Condensate drain connections, TXV, filter-drier, and desuperheater pump are located to make installation and service more convenient. An all-aluminum microchannel heat exchanger air coil eliminates failures due to formicary corrosion, while improving overall efficiency. It also requires less refrigerant charge, reduces unit weight, and is fully recyclable.
EnerTech LLC’s Hydron Module’s Revolution Series multi-positional two-stage vertical combination models are rated as high as 4.2-5.2 COP/20.2-32.7 EER (open loop) and 3.6-4.6 COP/16.2-27.3 EER (closed loop). Available in sizes from 2-6 tons, these models merge a forced-air geothermal heating and cooling system with radiant floor heating capabilities in a single unit.
These combination models use an innovative multi-positional cabinet design that is field convertible to upflow or downflow with left or right return. This design reduces the number of models that dealers and distributors need to stock. The conversion process is simplified with a rail-mounted blower and multiple mounts for the control box. Many additional features were designed with the installer and servicer in mind, such as eye-level controls and easy-access desuperheater pump.
To reduce service calls, these models utilize a foamed-in water-to-refrigerant coaxial heat exchanger, which prevents condensation. The product line now features an all-aluminum microchannel heat exchanger, which eliminates formicary corrosion, significantly reducing air coil failure. A 10-year part- and-labor warranty, plus a limited-lifetime microchannel air coil and compressor warranty come standard.
Hydro-Temp Corp. Inc.’s VStar Series units feature EERs reaching into the upper 40s and are available in sizes from 2.5-6 tons. All units utilize Bristol’s VStar variable-speed compressor and a proprietary control package that features the most current microprocessor and communicating thermostats available.
Available in vertical, horizontal, and corner console configurations, the VStar unit is well suited for climates all over the U.S. All VStar units can use the patented Priority hot water recovery option as well as built-in zoning. The Protostar advanced control monitoring system offers diagnostics as well as real-time temperatures throughout the house along with relative humidity and even optional CO2 levels. Installing contractors can access system diagnostics and look at trending records without removing a panel.
The ultra quiet corner console system requires no ductwork and is often used in school retrofit applications where units need to be in the classroom. The corner console configuration also comes with an optional energy recovery ventilator (ERV) capable of handling up to 450 cfm of outside air through the desiccant wheel system. This unique unit allows the ground-loop pump and check valve to be mounted internally for decentralized loop or individual loop applications.
Key components include a brazed plate stainless steel heat exchanger, ECM blower, stainless steel sloped drain pan, detachable electrical panel, full condensing on-demand hot water recovery, and optional dual priority for DHW and radiant applications.
Modine Residential and Light Commercial
Modine Mfg. Co.’s Energy Star-rated residential and light commercial geothermal product line — with operational efficiencies up to 30.3 EER and 5.3 COP — includes water-to-water, water-to-air, water-to-air/water combination, and split condensing/air-handling systems.
Water-to-water models are available in reversible and non-reversible sizes from 2-12 tons; water-to-air models from 1.5-6 tons in both vertical and horizontal configurations; and split condensing/air-handling systems, which are well-suited for new and retrofit applications, from 2-6 tons. Water-to-air/water combination units are available in 3-6 tons in both vertical and horizontal configuration and provide forced-air heating and cooling. They are ideally suited for use as the heat source for radiant-heated floors, domestic hot water, pools/spas, snow melting, and radiant cooling.
All Modine geothermal systems feature the Orb controller, designed specifically for installers. The easy-to-use, onboard control system provides integrated equipment intelligence with complete operating, monitoring, control, and diagnostic capabilities. Other Orb features include an LCD touchscreen for simple control and menu navigation; a commissioning menu that provides text-based notifications; configuration settings for all components; a system maintenance/alarm analysis tool; and comfort zoning capability, which provides up to four zones of precise control utilizing two-speed fan control.
The efficiency ratings of the WaterFurnace Intl. Inc. 7 Series 700A11 surpass 41 EER and 5.3 COP, and the system features a soft-start variable-capacity compressor, in concert with a variable-speed ECM blower and variable-speed loop pump. This allows the unit to scale output to exactly the level needed rather than the high or low speeds. The unit can ramp down to 20 percent of normal operation for efficient conditioning of up to 130 percent output using SuperBoost™, for periods when extra cooling is needed.
The 7 Series utilizes Aurora controls to continuously monitor and optimize operation. Aurora provides a platform of two-way communication between components, robust troubleshooting capabilities, and advanced communication protocols. This includes integration to home automation networks and whole-home energy monitoring. The Aurora Interface Diagnostic (AID) port allows service and diagnosis of the unit without having to open it, plus it provides easy-to-use troubleshooting features with fault lights, onboard diagnostics, and a hand-held AID tool.
The Aurora system also includes advanced loop and hot water generator pump controls, as well as service, performance, and energy monitoring sensor kit capability. A swing-out control box provides serviceability. Configurations include vertical units with top, bottom, or rear discharge (left or right return), and horizontal units with left or right return and side or end discharge. Heavy-gauge metal cabinets are fully insulated and coated with a durable gray paint for long-lasting protection.
Enertech LLC’s Thermal Energy Transfer Co. (TETCO) recently introduced the ES-4W Series two-stage water-to-water models featuring efficiencies of 3.4-3.8 COP/19-24.5 EER (open loop) and 2.8-3.1 COP/14.6-20.6 EER (closed loop) and are available in 3-10-ton sizes.
ES4-W units feature advanced compressor isolation utilizing elastomeric insulation blocks, which provides superior sound and vibration absorption. Hydronic models have digital controls with automatic fault retry, individual fault LEDs and remote fault indication. The controls also feature strip connections for convenient low-voltage wiring. A copper or coaxial water heat exchanger is available, and the unit comes standard with a factory-installed desuperheater. All cabinet panels are removable to simplify installation and service.
Publication date: 7/28/2014