Difference between Top hat and double top hat separator

[JimmyTheHand]

I'm planning on building a top hat Thien baffle. The only thing I have not decided yet is whether to build a double top hat or a "normal" top hat separator.

I'm going to use 6" ducting throughout  my system. I will probably use the 44 gallon Brute trashcan (or perhaps the 32 gallon one).

So, the diameter of the baffle is either 24" or 21.9" (not sure if that's the inside or outside diameter of the trashcan).
I'm making a transition (in sheet metal) to go from 6" to 8" x 3.5". This means the minimum internal height of my baffle will be 8".

So, the internal height for a double height baffle would be 16" (2H of square duct), or 12" (2H of 6" round duct). Not sure how I should count.

I will vent outside. So I'm not after 99.9% separation. I'd rather get more CFM's than perfect separation, as the small amount of dust that makes it through the separator, will blow away in the wind, once outside.

Does the 2H top hat promise better separation or better throughput? I've been reading loads of threads, but I'm still not sure if I should go for the 2H build or not.

[alan m]

double height will give better seperation but will hurt cfm a tiny amount