<VV> Fans/.my take

[ScottyGrover at aol.com]

In a message dated 8/2/2007 11:14:51 P.M. Pacific Daylight Time,  
r.gault at sbcglobal.net writes:

PS:  I had a dream of building an iris like device to decrease the  diameter
of the inlet hole.  The iris would be controlled by pressure  inside the
turkey roaster, so that the pressure was limited to something  like 8 in-H2O.
This would give about 90% of the max flow, but cap the hp  requirement at
somewhere around 8 hp.  Still a lot, but better than  18+.  But, I'm way too
lazy to actually do  this.



Roger,
I looked on the 'Net, found some data on iris dampers; to get the 2500+ CFM  
to pass through, it would take a minimum of a 16" diameter damper; a 12" unit  
would pass over 2000 CFM but would be hard-pressed to take care of a "Vair  
engine operating at high speed.  How you would fit a 16" unit into the  
available space, that I don't know.  
Besides, iris dampers are hard to find; the manufacturers that handle most  
air distribution products don't make them; in fact, most of the lines I found  
came from the UK.  They're not widely used yet; I hadn't heard of them as  of 
May '05 and I read nearly 50 sets of HVAC plans per week.  
 
Scotty from Hollyweird



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