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For that use the 30 gauge should work just fine.
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
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Light gauge is fine. Exhaust is positive pressure, but to be honest, the HFDC doesn't create enough negative pressure, even at or near full stall, to collapse even 6" duct of light gauge construction. And in that case, using short lengths for straight runs reduces the chances of collapse, due to the frequent reinforcement areas and therefore short clear spans, which is the weakest point.
The highest SP I was ever able to read was 8.0" WG, with about 270 CFM flowing*, and that ain't much. But my blower wheel measures 9.8" diameter, which might be a little smaller than others with the same "2 hp HFDC".
*It's common for the highest SP of a blower to occur with some air flowing, rather than at full stall.
Tom
“This place smells like that odd combination of flop sweat, hopelessness, aaaand feet"
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Thanks! I was thinking the 30ga should be fine for my purpose since I'm not actually running any ductwork, just a reducer and a couple elbows on the exhaust.
Jason
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Location: Athens, TN
30 ga works on the suction side most of the time as well.
Rocket Science is more fun when you actually have rockets.
"The Constitution is not an instrument for the government to restrain the people, it is an instrument for the people to restrain the government." -- Patrick Henry
