System Benefits

The geothermal heat pump system consists of:

• a water-source heat pump
• a closed loop ground heat exchanger made of high density polyethylene pipe (guaranteed 25 years or more by many manufacturers)
• a low wattage circulating pump(s)

In the heating mode, the closed-loop heat exchanger absorbs heat from the earth (typically 50 F to 70 F) and transfers the heat to the refrigerant via the water-to-refrigerant heat exchanger. The compressor concentrates the heat absorbed by the refrigerant before it flows to a coil in the supply air stream. The coil heats the air moving across it and heats the house. An antifreeze solution may be added to the ground-loop heat exchanger to prevent system freeze-up when heat pump leaving water temperatures drop below the freezing point of water, 32 F.

In the cooling mode, the heat pump extracts heat and moisture from the air and rejects the heat into the refrigerant. The heat is transferred to the fluid in the ground loop system via the heat exchanger. The ground then absorbs the heat from the ground loop.

As a benefit of the system, unwanted heat in the cooling mode can be captured by a desuperheater and used to produce virtually free hot water by reducing the hot water heater's run time. The desuperheater can also be used to greatly reduce the cost of producing hot water in the heating mode by reducing the hot water heater's run time.

Trane's high efficiency residential water-source heat pumps offer EERs up to 20. Moderate earth temperatures translate into the highest comfort levels in cooling from increased dehumidification and higher supply air temperatures in heating.

Another benefit is that the system requires no defrost cycle and little to no supplemental heat.

The GSUF unit is located entirely within the home, much like a refrigerator. By avoiding outside weather extremes, the unit's life span is expanded. Field refrigerant connections, and an outdoor air conditioning unit are no longer needed.

The unit is compact enough to be installed just about anywhere. It can be placed in an attic, basement, or tucked away in a closet.

Design Features and Benefits

Cabinet
The cabinet is constructed of heavy gauge galvanized steel. In addition, the cabinet has a Soft Dove electrostatic powder-paint coating for a longer lasting and corrosion-resistant finish.

Sound
These units operate quietly, with noise ratings of NC 40-45 in typical installations. All units have a thermal/acoustical insulated partition between the blower and compressor compartments to attenuate any compressor noise. Fan motors and compressors are internally isolated to reduce vibration. Compressor base plate and full-length channel stiffeners also help reduce vibration. The ICM-2 variable-speed blower motor, with a soft start at 50% capacity, helps reduce start-up noise and enhance comfort.

Compressor
A high efficiency scroll compressor helps assure quiet, reliable, and efficient operation.

Condensate Pan
Each unit has a removable, cleanable condensate pan to improve indoor air quality. This condensate pan allows any condensate from the coil to drain freely, discouraging condensate buildup and microbial growth in the pan.

Filter Rack and Filter
Each unit is equipped with an accessible filter rack, which houses 1-inch standard sized, disposable, fiberglass filter.

Filter Drier
This unit has a filter drier to dehydrate and clean the refrigerant circuit, adding to the life of the unit.

Desuperheater and Pump
The factory installed, internal, double-wall vented desuperheater uses heat rejected from the unit to preheat a home's domestic hot water. Hot water is provided at virtually no cost to the user during the cooling operation, and very efficiently during the heating operation, by reducing the amount of time the hot water heater runs. The desuperheater is controlled by two temperature control sensors. One sensor monitors the temperature of the compressor's discharge line. The desuperheater pump cannot operate until the compressor line reaches 145 F. The other sensor monitors the water temperature of the hot water heater. The desuperheater will automatically shut off if the water reaches 125 F to prevent scalding and the pump from overheating.

Brazed Plate Heat Exchanger
The stainless steel brazed plate water-to-refrigerant heat exchanger has a low-hydronic pressure drop and it has a high corrosion resistance because of its stainless steel construction. The brazed plate heat exchanger provides a larger amount of surface area for heat exchange between the water and the refrigerant than traditional tube-in-tube heat exchanger designs.

Tubing
All low-side tubing in the refrigeration circuit is insulated to prevent condensation inside the unit.

Expansion Valve
All units are equipped with a balanced port, bi-directional thermal expansion valve. The valve precisely meters the refrigerant flow through the circuit. Only a single expansion valve and no check valves are required on the unit.

Safety
The GSUF was designed with safety and maximum protection in mind. High- and low-pressure cutouts are included to protect the compressor. A freezestat is included to protect the unit from unusually cold fluid-flow and low fluid-flow conditions. The lockout relay is designed to turn off the compressor, loop pump, and the desuperheater pump, if a problem is detected.

Easy Installation

Duct Collar

Return air duct collar is provided with each unit. Ductwork can be easily fastened to the unit, eliminating extra sheet metal work. Easy access filter rack is provided with one-inch throwaway filters.

Blower
The unit is equipped with either a two or a three speed direct drive blower or an ICM-2 blower motor with soft start. The two and three speed blower motors offer flexibility to change the speed of the blower to adapt to various duct designs. The ICM-2 blower motor offers a ramp up/ramp down process for better humidity control and noise reduction.

Brass Connections
One-inch brass swivel connectors on the units are included, eliminating any need for a backup wrench during installation.

Return Air Configuration
The GSUF may be ordered with a left or right hand return increasing installation options.

Field Installed Internal Electric Heat
The GSUF unit is designed for simple field installation of internal backup heat.

Easy Serviceability and Maintenance

Filters
The GSUF filters are removable from both sides of the unit, offering added flexibility for placement of the unit and replacement of the filters

Access Panels
The unit has four access panels for easy access to components. Most components can be readily reached through the front access panels.

Control Box
The control box can be serviced by removing a control drawer from the front of the unit. The control box is amply sized to facilitate any troubleshooting or service work that might be required.

Service Ports
High and low side service ports are provided for servicing the unit.

Click here for performance information on the GSUF.

As part of our continuous product improvement, The Trane Company reserves the right to change specifications and design without notice. Read important energy cost and efficiency information available from your dealer.