Don’t do it. 10 years ago we applied numerous 60” 70,000 cfm cast axial upblast fans in a large Sony warehouse. Sections of the warehouse had bar joists on 52”centers. Fans were on 11” curbs with butterfly dampers on outlet. Thus the fan had a 6” bar joist obstructing one side of the inlet. After 6 months of operation, numerous blades failed. Parts of the blades were found on the warehouse floor. Failures were at 6” in from the tip and at the hub. The mfg inspected the failures and the application. Based upon metallurgical inspections, the blade to found to flex up and down due to loading / unloading during a revolution. We changed to a steel blade with less flow and slower rpm. Lucky no damage was done to people or equipment.
Fans require even flow to load the wheel or blade evenly. Look at old style IGVs on cent. fans, the vortex damper allows to even out the flow.
