Top hat size

[Holsterguy]

Hi guys, newbie here, so be kind. Been searching for a few days, but can't seem to find the answer. My BIL just brought me a new HF dust collector. (Guess he thought my shop was a real mess). Oh yeah, it is, he he.
Anyway my first mod after trying it out, was decided to make a top hat on a 55 gal drum.
Is there any hard set rule as far as how tall to make it for a given inlet size? ( I'm gonna use 5") Also, I think I recall reading to keep the inlet as high as possible, correct?
Thanks a lot

[retired2]

There are no rules or hard data to support a given separator height.  Separators with the height of the chamber roughly equal to the height of the inlet are generaly referred to as 1X.  In recent years, some people have started building deeper separators, generally the height is 2X the inlet height.  But again, there are no hard rules about either.  The consensus seems to be that for chambers with heights exceeding the height of the inlet, the inlet should be at or close to the top.

As I said before, I do not believe there is hard data to prove the benefit of one versus the other, however, most people who have built a 2X say it works better.  It is a tremendous amount of work to build two different separators for the sake of comparison testing, and to the best of my knowledge no one has done it.  And that is why there us no hard data.  One thing for sure is they both work, so if you have the headroom and don't have to lift the weight of a 2X separator to empty the drum, then go with a 2X.  Or try 1-1/2X!!

[Holsterguy]

Thanks, retired 2, really appreciate your input!