VENT AND COMBUSTION AIR HOODS
The vent and combustion air hoods are shipped attached to the
blower housing in the blower compartment. These hoods must
be installed on the outside of the gas heat panel to ensure
proper unit function. The necessary mounting screws are
provided in a bag that is also attached to the blower housing.
The screen for the combustion air intake hood is secured to the
inside of the access panel opening with three fasteners and the
screws used for mounting the hood to the panel. The top flange
of this hood slips in under the top of the access panel opening
when installing. Refer to Figure 6. Remove the protective label
covering the opening just prior to installing this hood.
The vent hood (including its screen) is installed by inserting the
top flange of the hood into the slotted opening in the access
panel. The top screw secures the hood to the access panel.
The remaining two side screws must be installed after the
access panel is installed on the unit. These screws engage the
bottom flue box flange.
CAUTION: All three screws in the vent hood must be properly
installed before furnace operation to insure all
combustion products are exhausted from the unit.
OPTIONAL ECONOMIZER RAIN HOOD
The following procedure should be used when assembling an
economizer rain hood onto a unit. Refer to Figure 7. The
outdoor and return air dampers, damper actuator, the linkage
and all the controls are factory mounted as part of the
economizer option.
All of the hood components, including the filters, the gasketing
and the hardware for assembling are located above the top
filter racks within the filter section. The outdoor air sensor is in
the bag of parts located at the bottom of the return air section.
1. With filter section access panel removed, take out hood
components, filters and sensor described above. Remove
and discard outdoor air opening cover on back unit (Upper
right hand corner).
2. Remove the 1/2" knockout (A) in the units rear panel
(located to the right side of the outdoor air opening). Insert
the two loose wires from inside the unit, into the 1/2"
bushing provided. Insert wires and bushing into knockout.
Snap bushing into place.
3. Mount the outdoor air sensor to the rear panel, just below
the knockout described in Step 2. Secure with two self-
drilling screws at dimples (B) provided in the panel.
NOTE: Sensor must be positioned so that the sensing ports
are at the top (louvers pointing downward) and termi-
nal connections to the right.
4. Connect the two wires, indicated in Step 2, to the sensor as
follows:
•
Wire #73 to terminal (+)
•
Wire #74 to terminal (S)
5. Assemble the LH and RH side plates to the top cover (2
screws each side) to form the hood. Apply gasketing to the
flange surface on each side plate. Extend gasketing 1/4"
beyond top and bottom of each flange to insure adequate
corner sealing. Secure this assembly to the unit back panel
(upper right hand corner). First, remove screw (C) on unit
top cover. Then slip flange of hood cover in under flange of
unit top cover, replace screw (C), engaging hole (E) in hood
flange and tighten. Attach the two side plates to the unit
panel by using two self-drilling screws for each side plate at
dimples (D) provided in the panel.
6. Position fillpiece at bottom of hood, between the two side
plates but do not secure at this time. (Slotted openings
MUST be downward for drainage). After fillpiece is properly
positioned, note where contact is made with the unit panel.
Remove fillpiece and apply gasket material to this area to
provide a seal. Reposition fillpiece and secure with 2
screws.
7. Install the two filters into the hood assembly, sliding down
along retainers on side plates, into fillpiece at bottom of
hood.
Unitary Products Group
7
035-14832-003-A-0204
FIG. 6
- VENT AND COMBUSTION AIR HOODS
FIG. 7
- ECONOMIZER RAIN HOOD ASSEMBLY (OPTION)
B
GASKET
C
HOOD
COVER
OUTDOOR AIR
SENSOR
A
FILTER SECTION
ACCESS PANEL
D
GASKETED
FLANGE
R. H.
SIDE
PLATE
D
E
D
D
GASKETED
FLANGE
FILTER
COVER
L. H. SIDE
PLATE
FILTERS
FILLPIECE
OUTDOOR AIR
OPENING COVER
SIDE DUCT
APPLICATION SHOWN
