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Old 2014-08-23, 2:10pm
LarryC LarryC is offline
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Join Date: Mar 07, 2011
Location: Northern California
Posts: 2,023
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Quote:
Originally Posted by Dale M. View Post
Larry, my statement stems from I have never seen a duct system setup, and that there seems to be no standard on duct size and how many CFM fan should be.... I do remember stating that a funnel of some sort be used on end of duct, the duct material not be corrugated (for same static pressure reason as for duct on hood setup), and that a minimum of 6 inch duct be used and use a minimum of 500CFM fan.... However NOBODY ever came back to me with actual number and efficiency report....

Only feed back I got was "whoosit" is using a "similar system" and it seems to work.....Including you.... Don't mean to start a fight this late in game, a long time ago I tried to establish parameters that were practical and efficient, I asked for feed back, but no body contributed their expediences....

I tried to work something out for safe set of parameters, but the "community" did not seem to want to support the efforts.... Oh well....

This is why I have backed way, way, way, out of the glass arena as people still seem to what to go their own way....

Dale
Dale, I am not looking to start an argument either but I also realize that there is a theoretically perfect system where all of the rules of thumb are met, and a practical system which will vary based on the situation. In my new shop I have a full overhead hood system with 12 inch ducting etc. but this is not always practical. So many funnel systems are in use and I would hope that good judgment is used in building them and that they get tested well. Mine worked very well. How did I choose the components? I SWAG'ed it, tested, and adjusted until I was happy with the performance. I dont think most folks here have the judgment to do this and that is why I often suggest that a local HVAC person be consulted.
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