4" Inlet/Outlet + 2 1/2" Hose + Adapters = Crazy?

[epic]

Firstly, Phil, you've done a tremendous thing with this lid design.  Thank you for sharing it.

This may be a stupid idea since I've not seen anyone else try it:

If I were to create a [Phil Thien] separator lid with 4" inlet/outlet and hook up 2 1/2" hose using 4"->2 1/2" adapters, would there be any negative impact on airflow?  Would the size of the baffle need to be adjusted to work with 4" ports?  I'm in the planning stage of my separator lid design and want to create something that will stand the test of time.  Currently I'm running with a small 3hp shopvac with 2 1/2" inlet/hose but a true dust collector is on my wishlist, so the ability to go to 4" ducting would be beneficial if my wish ever comes true.

Thanks in advance!

Edit: I should also mention that a 5.5hp shopvac is a possible replacement in the interim if it would perform better than the 3hp.

[phil (admin)]

Yes, you can do the 4" ports w/ 2.5" adapters.  The larger the shop vac, the better.  But it will work w/ a 3-HP just fine.

[epic]

Thanks, Phil.  In that case would doing the same thing with 6"->4" adapters work the same way?  Call me more crazy: what about 6"->4"->2 1/2" to make use of existing 2 1/2" hose but maintain a forward thinking 6" port?

[phil (admin)]

Thanks, Phil.  In that case would doing the same thing with 6"->4" adapters work the same way?  Call me more crazy: what about 6"->4"->2 1/2" to make use of existing 2 1/2" hose but maintain a forward thinking 6" port?

Okay, first of all, you're crazy.   ;D

Second of all, as you increase pipe size, you reduce the velocity at which the debris shoots out of it.  As the velocity drops, the separation drops, too.  That is because slower moving debris-laden air can move from inlet to outlet without having to enter rotation (called "short circuiting").

So it is a bit of a balancing act.  2.5" to 4" can be done.  You'll give up a small amount of separation.  But 2.5" to 6" may be more compromise than you're ready to accept.

Also, keeping in mind that 6" ports on TOP of a typical garbage can is a tight fit.