[quote=Graywolf]
the cfm is directly proportional to the fan rpm, but an increase in rpm requires the cube of the increase in horsepower.QUOTE]

Isn't horsepower increase the cube root of RPM2 minus RPM1?
Hempsouth Reviewed by Hempsouth on . Static Pressure Question - Ducts and Carbon scrubbers Hello friends, I am in the process of designing a 400 watt grow cabinet, and I've got a couple questions. I am planning to use an Elicent inline fan to suck through a DIY carbon filter, through a 6" (probably Hydrofarm) cool tube, and blow out of the cabinet. I found the spec table for the Elicent fans. It gives flow rate (in m3/hr) versus pressure (in pa). This information would be priceless if I only knew how much static pressure would be generated by my DIY carbon scrubber... The Rating: 5