Roberts Gorden Combat IDF-Series - Manual (Page 3)

PART 2: PRODUCTS
2.1 MANUFACTURERS
A. COMBAT ® IDF-Series which can incorporate one of the
following air control schemes:
• 100% outdoor air (MUA Style)
• Manual modulation of 0% - 100% outdoor air (FR Style)
• Automatic modulation of 0% - 100% outdoor air (AM Style)
2.2 MANUFACTURED UNITS
A. Unit: Constant volume [outdoor] [indoor] indirect-fi red air
handler.
2.3 FABRICATION
A. Casing and Components: Units to have a welded steel frame.
Th e casing shall be constructed of a minimum of 16 gauge, cold
rolled steel and the panels shall be fabricated into self-framing,
standing seam type construction. Th
e panels shall [form a self-
framing casing] [be properly supported with welded structural
angle, channel and tubular steel framework]. Th
e exterior
roof panels shall be a minimum of 16 gauge, cold rolled steel.
Th
e top wearing surface of the fl oor of each section shall be a
minimum of 16 gauge, cold-rolled steel. Th e cabinetry of the
heat exchanger section shall have internal heat shields to protect
the exterior unit skin and allow air to travel between the exterior
and the shield.
B. Fan Support: Fan housing(s) shall be welded to the casing and
reinforced with structural angle or tubing to reduce vibration
and sound.
C. Access Doors: Doors in the unit housing shall be provided
to permit ready access to all internal components. Th e access
doors shall be of 16 gauge cold rolled steel. Th e doors shall be
designed to swing out with a hinge. Th e door shall be framed by
the wall panels of the unit casing.
D. Outdoor Installation (Optional): A service vestibule shall
encase the unit control panel, power burner and gas train. All
joints and seams are to be caulked and weather proofed. All
access doors to be fully gasketed. Roof panels shall be pitched
(optional on IDF-35 through IDF-125; standard on IDF-150
through IDF-450).
E. Lift ing Points: Th e lift ing channels/tubes shall be provided on
the base on the corners of each section of the air unit.
F. Finish: White air dry enamel is standard fi nish.
G. Observation Port: A permanent observation port shall be
provided in the burner to allow observation of both the pilot
and main fl ame.
2.4 POWER BURNER AND GAS TRAIN ([Gas][Oil[Gas/Oil
Combination])
A. Burner: Furnish and install one [on/off gas burner] [high/
low/off gas burner] [3:1 turndown gas burner] [8:1 turndown
gas burner] [10:1 turndown gas burner] [on/off oil burner]
[high/low/off oil burner] [fully-modulating oil burner] [on/off
combination burner] [high/low/off combination burner] [fully-
modulating combination burner]. Th
e burner shall incorporate
a stainless steel fl ame retention type combustion head.
Combustion head shall be symmetrically round with internal
gas pilot. Primary-secondary air control shall be a design
function of the combustion head.
B. Burner Assembly/Gas Train: Th e gas train piping shall include
a 1/4" NPT pressure tapping with 1/4" pipe plug upstream
and downstream of valve and regulator in the gas train, one
manually operated ball valve upstream of all valves, one main
gas pressure regulator with vent, one safety shutoff valve which
shall be proven closed during pre-ignition by proof of valve
closure interlock switch on valve on FM gas trains over 5 million
Btu/h input, primary and secondary automatic gas safety shutoff
valves to operate simultaneously, manually operated gas valve
which shall be located downstream of both automatic gas valves
to permit leakage testing of the valves and [a normally open,
fully ported, electrically operated valve shall be provided in a
vent line connected between the two safety shut off valves.] Th
e
vent pipe shall be run outside to atmosphere. Electronic safety
combustion controls shall be supplied complete with ultra-
violet fl ame scanner to monitor the pilot and main fl ame. A
programming relay shall be furnished. It shall be so utilized as to
provide intermittent type gas electric ignition and pre-ignition
purge timer.
C. Pilot: Automatic electronic ignition system.
D. Damper (Optional): Motorized with end switch to prove
position before burner operation.
2.5 INDIRECT-FIRED HEAT EXCHANGER
A. Heat Exchanger: Heat exchanger drum and front header is to
be made entirely from 409 stainless steel. Th e secondary heat
exchange surfaces shall be made from [carbon steel] [stainless
steel]. Heat exchanger is to incorporate primary surface drum
and secondary surface tubes in a [three][four] pass design.
Baffl
es are to be utilized to assure proper air distribution on the
heat exchanger at low air volumes. Th e primary surface is to be
no less than 16 gauge, the secondary tubes are to be no greater
than 3" in diameter and no less than .055" wall thickness. Th
e
front and rear headers, as well as the intermediate headers are
to be a minimum of 16 gauge. Th
e front and rear collector
boxes shall be a minimum of 8" deep. Th e front and rear
collector boxes shall overhang the drum and include an integral
directional baffl
e to direct air to cover the entire box as well as
the box to tube joint.
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