ICP PGN324 Installation instructions manual - Warning
10
Step 9—Install Duct Connections
The unit has duct flanges on the supply-- and return--air
openings on the side and bottom of the unit. For downshot
applications, the ductwork connects to the roof curb (See
Fig. 3 and 4 for connection sizes and locations).
CONFIGURING UNITS FOR DOWNFLOW (VERTICAL)
DISCHARGE
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing or servicing system, always turn off
main power to system. There may be more than one
disconnect switch. Turn off power supply to the unit and
install lockout tag.
!
WARNING
1. Open all electrical disconnects before starting any
service work.
2. Remove horizontal (metal) duct covers to access
vertical (downflow) discharge duct knockouts in unit
base.
3. Use a screwdriver and hammer to remove the panels in
the bottom of the unit base (See Fig. 9).
4. If unit ductwork is to be attached to vertical opening
flanges on the unit base (jackstand applications only),
do so at this time.
PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in property
damage.
Collect ALL screws that were removed. Do not leave
screws on rooftop as permanent damage to the roof
may occur.
CAUTION
!
5. It is recommended that the base insulation around the
perimeter of the vertical return--air opening be secured
to the base with aluminum tape. Applicable local codes
may require aluminum tape to prevent exposed
fiberglass.
6. Cover both horizontal duct openings with the provided
duct covers. Ensure opening is air and water tight.
7. After completing unit conversion, perform all safety
checks and power up unit.
NOTE: The design and installation of the duct system must
be in accordance with the standards of the NFPA for
installation of nonresidence--type air conditioning and
ventilating systems, NFPA 90A or residence--type, NFPA
90B; and/or local codes and ordinances.
FIGURE 8
Supply and Return Duct Opening
SUPPLY
DUCT
OPENING
RETURN
DUCT
OPENING
VENT HOOD
SHIPPING
LOCATION
FIGURE 9
Vertical Duct Cover Removed
DUCT COVERS REMOVED
Adhere to the following criteria when selecting, sizing, and
installing the duct system:
1. Units are shipped for horizontal duct installation (by
removing duct covers).
2. Select and size ductwork, supply--air registers, and
return--air grilles according to American Society of
Heating, Refrigeration and Air Conditioning Engineers
(ASHRAE) recommendations.
3. Use flexible transition between rigid ductwork and unit
to prevent transmission of vibration. The transition may
be screwed or bolted to duct flanges. Use suitable
gaskets to ensure weather--tight and airtight seal.
4. All units must have field--supplied filters or accessory
filter rack installed in the return--air side of the unit.
Recommended sizes for filters are shown in Table 1.
5. Size all ductwork for maximum required airflow (either
heating or cooling) for unit being installed. Avoid abrupt
duct size increases or decreases or performance may
be affected.
6. Adequately insulate and weatherproof all ductwork
located outdoors. Insulate ducts passing through
unconditioned space, and use vapor barrier in
accordance with latest issue of Sheet Metal and Air