[BLDG-SIM] Question about Fan Power

[David S Eldridge]

Assuming an approximate conversion at 746 W per BHP - numerator, which is divided by some motor efficiency corrections (all the logarithmic stuff) to get your Pfan in Watts.

 

For instance with 50 BHP, your numbers might give you something similar to:  746 / 0.929 x 50 = Pfan = 40.2 kW

 

David

 

 

From: BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] On Behalf Of Vikram Sami
Sent: Thursday, July 05, 2007 3:12 PM
To: BLDG-SIM at gard.com
Subject: [BLDG-SIM] Question about Fan Power

 

So I'm trying to calculate fan power, and came across this mindbender 

Pfan = 746 / (1 - e[ -0.2437839 × ln( bhp ) - 1.685541 ]) × bhp 

Having done the hard part (I figured out how to automate the process in XL with just the CFM input using the natural log function ), I have only one question - does the bhp (highlighted at the end) go in the numerator or denominator of the equation?

i.e. - Should the equation read 

Pfan = 746 / [(1 - e[ -0.2437839 × ln( bhp ) - 1.685541 ]) × bhp] 

Or 

Pfan = [746 / (1 - e[ -0.2437839 × ln( bhp ) - 1.685541 ])] × bhp 

 


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