Provide KEES Model DFG Direct Fired Heater designed for (indoor) (outdoor) installation with (down) (end) (top) discharge. Performance shall be as scheduled on the plans.
The direct fired gas heater shall be ETL listed to conform with the latest ANSI standards for efficient and safe performance and shall be compliant with IRI (FM) requirements. It shall be 100% combustion efficient and equipped for use with (natural) (propane) gas.
The burner will have stainless steel combustion baffles that use the kinetic energy of the airstream to ensure proper combustion well below OSHA permissible levels.
Main gas pressure regulator, main gas safety solenoid valves, pilot ignition system, air flow safety switches and high limit switch shall be included.
The output of the heater shall be controlled by an electronic modulating gas valve with (discharge ductstat) (discharge ductstat and room override thermostat) (space temperature controller) (DDC compatible controller).
The housing shall be fabricated from heavy-gauged G90 galvanized steel with all joints caulked for weather-protection. Base rail to run the entire length and width of the unit excluding the intake hood and will form a curb cap. Gasketed panels will provide access to all of the components. Exterior of unit to be painted if specified.
The unit shall be lined with 1” thick matte faced fiberglass insulation that is in accordance with NFPA 90A and UL 181. Foil faced insulation or double wall construction shall be provided if specified.
Blower, Motor and Drives
The entire blower and motor assembly shall be mounted on a common base with vibration isolators to prevent noise transmission.
The unit shall be provided with a forward curved, DWDI centrifugal blower that has been statically and dynamically tested. The fan shaft shall be ground and polished steel designed for a maximum operating speed not to exceed 75% of its first critical speed. Bearings are heavy duty and pre-lubricated
V-belt drives are to be cast iron, sized for 150% of driven horsepower and are adjustable up to 10 HP.
(Single speed) (Two speed) motor in (ODP) (TEFC) enclosure shall be energy efficient, EPACT compliant, matched to the fan load and furnished at the specified voltage and phase. Motors shall be inverter duty rated and have class B insulation.
All electrical components shall be UL listed, recognized or classified. A motor control center shall include a main fusible disconnect switch, motor starter, fused control transformer with all necessary wiring completed in accordance with NEC and pre-wired for single point power and control connection to numbered terminal blocks.
Filters shall be provided in a (V-bank section) (flat filter rack in the intake hood) and shall be easily accessible. Velocities across the filters shall not exceed 500 FPM. (1” thick) (2” thick) (fiberglass throw-away) (aluminum cleanable) (30% efficient pleated) filters shall be provided. High efficiency filters with a pre-filter mounted in a flat bank in the filter section shall be provided if specified.
Intake Hood (Optional)
Intake hood shall be fully assembled and provided with (birdscreen) (moisture eliminators) (filters) at the intake. Extended intake with filters shall be provided when NFPA 96 requirements must be met.
The unit will be mounted on a factory supplied (roof curb and support rail) (full perimeter roof curb) (modular roof curb and support rail) (set of support rails).
The unit will be (ceiling hung) (vertically mounted on a wall) (vertically mounted on an angle frame base) (mounted on a slab).
Outside Air Damper (Optional)
The unit shall be provided with a low leakage damper and a two position spring return actuator mounted directly it. The damper shall be (factory mounted at the intake) (sent loose for field mounting at the discharge of the unit).
Return Air (Optional)
Return air section shall be provided with a damper and:
Variable Air Volume (Optional)
The unit shall be provided with a:
Cooling Coil (Optional)
Chilled water or direct expansion cooling coil shall be built, tested and rated according to ARI 400. Sloped stainless steel drain pan with drain fitting shall extend 12 inches downstream of the coil. Construction shall consist of copper tubes and aluminum fins spaced from 8 to 12 FPI. Direct expansion coils shall have distributors and nozzles selected for the exact application.
Evaporative Cooling (Optional)
Evaporative cooling section shall contain 12” deep Munters CELdek (GLASdek) media for 90% efficiency. Self-cleaning corrosion resistant design with water distribution plumbing, re-circulating pump, bleed off and float assembly. Freeze protection and automatic drain and fill kit shall be provided if specified.
The unit shall be provided with the following accessories: