Daikin O-WCP16-SEP21-2, Installation Operation & Maintenance

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Issue: O-WCP16-SEP21-2 Page 24
5.5 SUPPLY AIR BLOWER ADJUSTMENT
The RPM of the supply air blower will depend on the required CFM, the unit accessories and the static resistances of
both the supply and the return air duct systems. With this information, the RPM for the supply air blower can be
determined from fan performance curves.
Knowing the required blower RPM and the blower motor horsepower, the supply air motor and pulley can be
determined. When supply air blower motor is operating, adjust the resistances in both the supply and the return duct
systems to balance the air distribution throughout the conditioned space.
The standard unit is provided with a fan outlet collar for connection of supply ductwork. It is recommended that a
straight duct having the same dimensions as the fan outlet be used. This duct should be at least 3 equivalent duct
diameters in length prior to installing any elbows or transition. See the following
Table 6 for the minimum length of
straight duct required for particular unit.
Insulate duct work that passes through unconditioned space during cooling. Insulation should include a vapor barrier
to prevent absorption of moisture.
Table 6: Minimum Straight Duct Length
Model
Fan Supply Size
(mm) x Qty of
Blower
Duct Size (mm)
Minimum Length
for Straight Duct
(mm)
A B
UCQ60 229x1 262 298 763
UCQ90 229x1 262 298 763
UCQ140 381x1 404 471 1191
UCQ180 381x1 404 471 1191
UCQ240 381x1 404 471 1191
UCQ280 457x1 478 557 1409
UCQ320 450x1 569 569 2026
UCQ360 450x1 569 569 2174
UCQ400 500x1 638 638 2103
UCQ520 500x1 638 638 2382
UCQ570 560x1 715 715 2272
UCQ710 450x2 569 569 3923
UCQ870 500x2 638 638 4386
UCQ940 500x2 638 638 4665