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.
FIG. 6 - VENT AND COMBUSTION AIR HOODS
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
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.
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| OUTDOOR AIR | C |
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| HOOD | OPENING COVER |
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| COVER |
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| OUTDOOR AIR |
| FILTER | D |
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| COVER |
| SENSOR | |
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GASKETED | E |
| A | D |
| D |
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FLANGE |
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| GASKET | |
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| B |
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| D |
L. H. SIDE
PLATE
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| FILTER SECTION |
| GASKETED | ACCESS PANEL |
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| FLANGE |
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FILTERS | R. H. |
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| SIDE DUCT | |
| SIDE | |
| PLATE | APPLICATION SHOWN |
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| FILLPIECE |
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FIG. 7 - ECONOMIZER RAIN HOOD ASSEMBLY (OPTION)
Unitary Products Group | 7 |