16
Step 10 — Make Outdoor-Air Inlet Adjust-
ments
MANUAL OUTDOOR-AIR DAMPER — All units (except
those equipped with a factory-installed economizer) have a
manual outdoor-air damper to provide ventilation air.
Damper can be preset to admit up to 25% outdoor air into
return-air compartment. To adjust, loosen securing screws and
move damper to desired setting, then retighten screws to secure
damper (Fig. 18).
Step 11 — Install Outdoor-Air Hood
The outdoor-air hood is common to 25% air ventilation,
EconoMi$erIV and EconoMi$er2. If EconoMi$erIV or
EconoMi$er2 is used, all electrical connections have been
made and adjusted at the factory. Assemble and install hood in
the field.
NOTE: The hood top panel, upper and lower filter retainers,
hood drain pan, baffle (sizes 025 and 028), and filter support
bracket are secured opposite the condenser end of the unit. The
screens, hood side panels, remaining section of filter support
bracket, seal strip, and hardware are in a package located
inside the return-air filter access panel (Fig. 19).
1. Attach seal strip to upper filter retainer. See Fig. 20.
2. Assemble hood top panel, side panels, upper filter retain-
er, and drain pan (see Fig. 21).
3. Secure lower filter retainer and support bracket to unit.
See Fig. 21. Leave screws loose on 025 and 028 units.
4. Slide baffle (sizes 025 and 028) behind lower filter retain-
er and tighten screws.
5. Loosen sheet metal screws for top panel of base unit
located above outdoor-air inlet opening, and remove
screws for hood side panels located on the sides of the
outdoor-air inlet opening.
6. Match notches in hood top panel to unit top panel screws.
Insert hood flange between top panel flange and unit.
Tighten screws.
7. Hold hood side panel flanges flat against unit, and install
screwsremovedinStep5.
8. Insert outdoor-air inlet screens and spacer in channel
created by lower filter retainer and filter support bracket.
IMPORTANT: If the unit is equipped with the optional
EconoMi$erIV component, move the outdoor-air tempera-
ture sensor prior to installing the outdoor-air hood. See the
Optional EconoMi$erIV and EconoMi$er2 section for
more information.
Fig. 18 — Standard 25% Outdoor-Air
Section Details
Fig. 19 — Outdoor-Air Hood Component Location
Fig. 20 — Seal Strip Location
HOOD TOP
PANEL
HOOD SIDE
PANELS (2)
BAFFLE
(025 AND
028 ONLY)
LOWER
FILTER
RETAINER
FILTER SUPPORT
BRACKET
HOOD DRAIN PAN
UPPER FILTER RETAINER
BAFFLE
LOWER FILTER
RETAINER
FILTER SUPPORT
BRACKET
Fig. 21 — Outdoor-Air Hood Details