A: Because the Revolution® HVLS Fan uses the air from above it, there is a minimum clearance required between the industrial fan blades and the ceiling. Revolution® HVLS Fans have different minimum clearance requirements based on diameter.



If the ceiling support structure is an open-web design, all hanging dimensions can be taken from the underside of the ceiling. If the ceiling's support structure is a solid beam or solid channel, all measurements must be taken using the bottom of the beam as the basis point for the hanging dimension. If the roof is pitched, this must also be accounted for above the tips of the blades. Failure to follow these guidelines will result in limited air movement by the industrial fan.



 

HVLS Fan Diameter	Minimum Clearance to Blade Tips at Full RPM
8'	2'
12'	3'
16'	4'
20'	5'
24'	5'

The 30" drop tube will help when installing 20' or 24' industrial fans in applications with a 24" open-web ceiling support. By using the 30" drop tube, you will have at least 63" clearance for full air delivery. Be aware that other hanging dimensions are possible by using the field adjustable 31" to 84" drop tube assembly.