IBC AHU 800, Installation & Operating Manual

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Supply / Return Air Trunk Size CFM at 0.25"wc external static pressure (galvanized duct)
Round Rectangular CFM range
8"
8 x 6 160-190
8"
8 x 7 190-230
9" 8 x 8 230-275
10" 10 x 8 275-360
11" 12 x 8 360-460
12" 14 x 8 460-570
13" 16 x 8 570-650
13" 18 x 8 650-750
14" 20 x 8 750-850
14" 22 x 8 850-950
15" 24 x 8 950-1050
Table 7 Supply air trunk size CFM at galvanized duct .25"wc ESP for return and supply air
2.3.2 Ducting installed in conditioned space
If a cooling system is connected to the appliance, we recommend insulating the supply air ducting
with a minimum of 1" thick fiberglass insulation with a vapor barrier. All insulated joints must be sealed
with tape designed for this purpose.
2.3.3 Ducting installed in un-conditioned spaces
Supply air and return air ducting should be insulated with a minimum 2" thick fiberglass insulation with
a vapor barrier. All insulated joints must be sealed with a tape designed for this purpose.
2.3.4 Making the return air openings
Both sides as well as the bottom of the appliance provide markings for the maximum return air
opening. Use suitable metal cutters to perforate the marked area for the return air supply. Ensure that
you cut within the marked area.
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2.3.2 Ducting installed in conditioned space