Enlarge DC Outlet?

[Matt Schenk]

I have an older Jet DC-1200 mounted in a shed adjacent to my shop which it vents into (no filters, venting outside). I have 6" duct work installed throughout the shop and it seems to work quite well, however, I've noticed that the outlet port on the DC is only 5". Should I take time to cut the reducing ring off the DC to open it (which would result in a ~6.5" square outlet) or would it not make any difference?

[James Gunning]

I'm guessing it would do no harm and would probably increase the flow through the blower. Was there a hose from the blower exhaust leading to the filter on this unit? If so, that's the reason for the exhaust port to transition to a round 5".

[Malcolm McLeod]

I have an older Jet DC-1200 mounted in a shed adjacent to my shop which it vents into (no filters, venting outside). I have 6" duct work installed throughout the shop and it seems to work quite well, however, I've noticed that the outlet port on the DC is only 5". Should I take time to cut the reducing ring off the DC to open it (which would result in a ~6.5" square outlet) or would it not make any difference?

Many blowers use an impeller that in 'free air' (no housing or restrictions at all) will grossly overload the motor. If this is your case, some other component of the 'system' restricts or limits air flow, which reduces the load on the motor, which in turn keeps it from melting and/or tripping the CB. The limiter could be the inlet, outlet, or housing. On the other hand, if the impeller is the limiting factor, you can enlarge at will - - it simply won't move any more air.

Put an ammeter on the power supply to the motor first. You may already be at the rated (safe) load limit of the motor. If so, and you enlarge the outlet, at best the impeller, or inlet is the limiting factor and you gain nothing. Or, you remove the needed limiter and overload the motor.

[Matt Schenk]

Thanks for the advice
I think I'll leave it as-is since it's already working and if I ever upgrade units it'll be easier to sell this one without it being hacked up.