Any benefit to having different inflow and outflow sizes

[dan4307]

I am in process of my first baffle build and was wounding if there is any added benefit to having a larger 5" outflow (from the blower to the filter and between the tophat and the blower); with a smaller 4" inflow to the baffle.   I was thinking the 5" after the baffle may overcome some internal resistance, but maybe not and therefore not worth the effort.  My tophat is built entirely from PVC and the inflow is 4" sewer pipe (no changing it now as it is welded together).  4" is easy to find locally, but 5" will need to be ordered.

I've attached a photo of the basic design.  Any help and thoughts would be much appreciated.

Thanks

[tvman44]

I don't know but have been thinking about changing those 2 to 5" on my system, then maybe eventually changing the rest of the system.  More than likely just those 2.  :)

[phil (admin)]

The larger outlet pipe will mean the air will be moving more slowly.  Of course, it will be larger and closer to the spinning air mass, too.  Probably a bit of a wash, but having a larger pipe to the blower is undoubtedly a plus, as this will cause lower resistance.

So overall a good idea.

[dan4307]

Thanks Phil.  I really appreciate your insights.  I went ahead and ordered the 5" fitting and will report back in the next few weeks once all is assembled. 

[tvman44]

Phil by "larger pipe to blower" Are you referring to the line from separator to blower?

The larger outlet pipe will mean the air will be moving more slowly.  Of course, it will be larger and closer to the spinning air mass, too.  Probably a bit of a wash, but having a larger pipe to the blower is undoubtedly a plus, as this will cause lower resistance.

So overall a good idea.

[phil (admin)]

Phil by "larger pipe to blower" Are you referring to the line from separator to blower?

The larger outlet pipe will mean the air will be moving more slowly.  Of course, it will be larger and closer to the spinning air mass, too.  Probably a bit of a wash, but having a larger pipe to the blower is undoubtedly a plus, as this will cause lower resistance.

So overall a good idea.

Yep.

[Mad Dog]

Dan, I believe increasing the size of the exhaust port to the filter is a good idea and seems to work very nicely on my conversion.  For the most part, allowing the air expand and slow down just helps reduce back pressure by letting the air fill a larger space before it goes to the filter.  It's not much but every bit helps IMHO.

Mike