Brochure

Provide (82%, 83%) high-efciency, separated-combustion, power vented, gas-red unit heaters manufactured
as Reznor
®
brand units. The unit shall be designed for use in a building with negative pressures up to 0.15 “
w.c. and for use in building where a non-explosive atmosphere exist that is dust laden and/or contains mildly
corrosive fumes.
Each of the 14 sizes in the Model UDAS series shall be equipped for use with (natural) (propane) gas. Gas
connection shall be external to the cabinet.
The heater shall be equipped with a multi-cell, 4 pass serpentine style steel heat exchanger. Heat exchanger
tubes shall be press fabricated of (titanium stabilized, corrosion resistant aluminized steel) (409 stainless steel)
(316 stainless steel). All heat exchangers shall be fabricated with no welding or brazing, only tool pressed
mechanical joints. All heat exchanger cells shall be designed with an aerodynamic cross section to provide
maximum airow.
The units shall incorporate a single, one piece burner assembly with a single orice. The burner shall have a
continuous wound close pressed stainless steel ribbon separating the ame from the burner interior. All units
shall have a single venturi tube and orice supplying fuel to a one-piece burner housing. Each heat exchanger
cell shall use balanced draft induction to maintain optimum ame control.
Controls shall include a (single-stage) (two-stage) gas valve; direct spark multi-try ignition with electronic ame
supervision with timed lockout integrally controlled via a printed circuit control board. The control board shall
also incorporate diagnostic lights, DIP switches for fan overrun settings, and a relay for fan only operation. All
units shall be equipped with a safety limit switch.
All controls shall be enclosed in the sealed control compartment to protect them from accidental damage, dust,
and atmospheric corrosion.
The unit shall have a factory-installed power venter device to draw combustion air from outside of the building.
The outside air shall enter the unit through a factory-installed round inlet air terminal on the rear of the heater.
The control compartment shall be sealed and the access door shall be gasketed to prevent dirt, lint, dust, or
other contaminants present in the heated space from entering the unit. The control compartment door shall be
equipped with a safety interlock switch to prevent operation when the door is open.
The combustion air supply pipe and ue exhaust pipe shall be run in parallel from the heater to a factory sup-
plied concentric adapter assembly, which allows for a single wall or roof penetration, to the (horizontal) (verti-
cal) air inlet and vent terminal.
The combustion air/venting system shall include a vibration isolated power venter motor and wheel assembly
and a combustion air pressure switch. Unit Sizes 30-125 shall include a ame rollout switch.
Operation shall be controlled by an integrated circuit board that includes LED diagnostic indicator lights. Supply
voltage connections shall be made in a sealed junction box. 24-volt control connections shall be made on an
externally mounted terminal strip with connections (W1, W2, R, and G). All internal wiring, both line and control
voltages, shall be terminated by insulated terminal connectors to minimize shock hazard during service.
Each unit shall be equipped for use with 115/1 volt power supply. (Stepdown transformers shall be available to
be eld installed for use with (208) (230) (460) volt power supply.)
All units will be equipped with a built-in disconnect switch.
The cabinet shall be low prole with a pre-coat or powdercoat RAL 1001 white paint nish. Finish shall be a
minimum 80 gloss on G30 galvanized steel. The cabinet shall be constructed so that screws are not visible
from the bottom, front, or sides, except for service panel and accessories. Unit construction shall incorporate a
beveled front corner on control side for additional cabinet rigidity. All units shall be manufactured with a tooled
drawn supply air orice on the rear panel to reduce fan inlet noise.
The unit shall be designed for ceiling suspension featuring 3/8”-16 female threads (hanger kits for 1” pipe)
at both 2-point and 4-point locations with no additional adapter kits. (Hanger kit for ceiling mounting shall be
available for Sizes 30-125.)
The cabinet shall be equipped with RAL 3005 burgundy painted, roll-formed horizontal louvers. Louvers shall
be spring held and adjustable for directing airow. (Vertical louvers) (downturn nozzles) (downturn nozzles with
vertical louvers) shall be available.
The cabinet shall be equipped with a full safety fan guard with no more than ½ inch grill spacing on Sizes 30-
125 or no more than 1 inch on Sizes 150-400. The (open dripproof) (enclosed) motor and fan assembly shall
be resiliently mounted to the cabinet to reduce vibration and noise.
The unit shall be designed with a full opening service access panel complete with screw closure attachment
and lifting handle for removal. Service panel shall be fully gasketed and equipped with a safety interlock switch.
All components in the gas train, all standard electrical controls, and the power venter shall be within the sealed
service compartment.
Minimum top clearance from combustibles shall be 1” for Sizes 30-125 and 4” for Sizes 150-400. Minimum
bottom clearance from combustibles shall be 1” for all sizes. Minimum clearance from combustibles on non-
service side shall be 1” for Sizes 30-125 and 2” for Sizes 150-400.
GAS-FIRED, SEPARATED
COMBUSTION UNIT HEATERS
Fuel
HeatExchanger
Burner
Controls
CombustionAirandVenting
Electrical
Cabinet
SampleSpecications
Model UDAS
Form RZ-C-UH (Version H) Page 47
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