"Goedjn" wrote in message
...

For every 90 degree elbow you put in a duct work, it restricks 1/27 th
of the air moving through it. Put 27 -- 90 degree elbow in a ductwork
line and it will be a plugged up air ductand no air will move through
it.

By my figuring, you'd actually get closer to 36% of the original flow.


Figure it correctly, and you need to figure in whats called TEL, and for
every 90, its another 5ft added to it, then you take your ductulator, and
see how it figures with your friction co-efficient and see how bad you
killed flow.