General
The water source heating/cooling units shall be vertical upflow air discharge. Units shall be AHRI/ISO/ASHRAE 13256-1 (ground- source closed-loop) performance certified and listed by a nationally recognized safety-testing laboratory or agency. Each unit shall be water run-tested at the factory. Each unit shall be pallet mounted and shipped with appropriate protective packaging to help avoid damage in transportation.The units shall be warranted by the manufacturer against defects in materials and workmanship for a period of 10 years on all parts, and 10 years on the compressor and refrigerant circuit parts with a service labor allowance for five years on refrigeration components and two years on other parts. An optional extended warranty is available for the GT-PG Series units, which increases the labor allowances to 10 years on all parts.The water source units shall be designed to operate with entering fluid temperature between 20°F and 120°F.
Casing & Cabinet
The cabinet shall be fabricated from heavy-gauge galvanized steel and painted with an epoxy powder coating.The interior shall be insulated with 1/2" thick, multi-density, coated glass fiber. Insulation in the air handler section shall be foil backed for ease of cleaning.Two (vertical) or one (horizontal) blower compartment and three compressor compartment access panels shall be provided and shall be removable with supply and return ductwork in place.The internal component layout shall provide for major service with the unit in-place for restricted access installations.
A duct collar (Field installed) shall be provided on the supply air opening. 2" high efficiency MERV11 pleated filters shall be provided with each unit. Units shall have filter frames.The units shall have an insulated divider panel between the air handling section and the compressor section to minimize the transmission of compressor noise, and to permit operational service testing without air bypass. Units shall be supplied with left or right air inlet.
Refrigerant Circuit
All units shall contain Puron® (HFC-410A) sealed refrigerant circuit employing a hermetic motor-compressor, bidirectional thermal expansion valve, finned tube tin plated air-to-refrigerant heat exchanger, reversing valve, coaxial tube water-to-refrigerant heat exchanger and service ports. An optional Hot Water Generator (desuperheater) coil shall be provided.
Compressors shall be Copeland scroll type designed for heat pump duty and mounted on dual level compressor vibration isolation. Compressor motors shall be single phase PSC with internal overload protection. A factory installed bidirectional filter drier shall be provided on all models.The finned tube coil shall be sized for low-face velocity and constructed of lanced aluminum fins bonded to rifled copper tubes in a staggered pattern not less than three rows deep. Entire air coil surface shall be tin-coated for corrosion protection.
The coaxial water-to-refrigerant heat exchangers shall be designed for close approach temperatures and be constructed of a convoluted copper (optional cupro-nickel) inner tube and a steel outer tube.The thermal expansion valves shall provide proper superheat over the entire fluid temperature range with minimal “hunting”.The valve shall operate bi-directionally without the use of check valves.
The water-to-refrigerant heat exchanger and refrigerant
suction lines shall be insulated to prevent condensation at low liquid temperatures.
Fan Motor and Blower
The fan shall be a direct drive centrifugal type with a dynamically balanced wheel.The wheel and housing shall be designed for quiet, low outlet velocity operation.The fan housing shall be of galvanized steel construction and shall be removable from the unit without disconnecting the supply air ductwork for servicing of the fan motor. The fan motor shall be of 3-speed permanently split capacitor (PSC) type.The fan motor shall be high efficiency and provide high static capability, and shall include three on-motor selectable air flow options. An optional variable speed electronically commutated (ECM) fan motor is available with permanently lubricated ball bearing construction, and it has no less than four operational speeds online.The fan motor shall be isolated from the housing by rubber grommets.The motor shall be permanently lubricated and have thermal overload protection.
Electrical
CXM Control - A microprocessor-based compressor controller shall be provided to monitor and control unit operation.The control shall provide compressor and electric heater sequencing, high and low pressure monitoring, field selectable water and air coil low temperature protection sensing, condensate overflow sensing, over/ under voltage monitoring, and unit performance sentinel (UPS).The control shall also provide for water valve connection, a test mode, short cycle protection, random start-up, as well as fault LED, fault memory, and intelligent fault retry.
The control shall employ quick attach harness assemblies for low voltage connections to the control board to aid in troubleshooting or replacement. An integral terminal block with screw terminals shall be provided on the control for all field low voltage connections. A circuit breaker protected 75VA transformer shall be employed. Line voltage box lugs shall be provided for unit wiring. Units shall have knockouts for entrance of low and line voltage wiring.The fan motor and control box shall be harness plug-connected for easy removal.
Residential models shall have a dual circut-breaker protected power block for the connection of external flow controller pump module.
Piping
Supply and return water connections, as well as Hot Water Generator (desuperheater) connections shall be 1" FPT brass swivel fittings which provide a union and eliminate the need for pipe wrenches and sealants when making field connections. A thread by sweat fitting shall be provided for connection to the water heating. All water piping shall be insulated to prevent condensation at low liquid temperatures.
The condensate connection shall be a 3/4" PVC glue (socket) with internal-trap (Vertical Models).
