Posted by chriscase on Saturday, September 17, 2005 at 9:44PM :
In Reply to: Re: 7 hp moves 18,000 cfm in my spray booth posted by MoparNorm on Saturday, September 17, 2005 at 3:39PM :
Yes, but an electric fan will never whistle like the one on my 1/2t command car with a honeycomb core did. One of the unique sounds of a power wagon. Along with playing "Popeye the Sailor man" on the squeeling brakes.
I guessed their 7 hp is from a hi po motor, turning 7,000. A flathead does 3500, so I used 1/4 of the horsepower, or 1 3/4. Perhaps I'll try extrapolating from a Grainger catalogue for a 20in 1/4hp fan, 1725 rpm, so 3500 would take 1 hp? (Yes, doubling the speed takes 4x the hp, but only moves 50% more air. More air requires bigger fan)
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