CPVC Manifold Questions

[thorn_bird]

So I built my CPVC octagonal manifold today and I have a few questions.
I am reading Dave Miller's Brew Like A Pro at the moment in which he states
that he has tried both ways and consistently gets better results with slots up despite
popular opinion. Most on here say slots down but I did find one person on here
that said he achieved better efficiency with slots up.
Has anyone else actually tested this?

Question 2: Just wondering why no one puts slots in the middle section
of the octagonal manifold? Every design I came across only had slots around the outside
of the octagon....what is the reason for omitting them in the middle cross section?

Thanks for your help in advance.

 

[stpug]

Question 1: Very interesting. I have a copper manifold I've just build with slots on all tube sections and holes on all soldered fitting sections and I build it to be slots/holes down. It makes sense that you'll have much less deadspace this way since the siphon should not break until air encounters an opening. I suspect it's about 1/3-1/4 inch lower with slots down which could account for 2-4 cups maybe. I'd be interested in hearing from other folks who have compared up/down methods with manifolds.

Question 2: I slotted/holed everywhere on my manifold except the T fitting that leads to the ball valve, and unsoldered connections. I figure the more consistent the draw from the entire manifold, the better - afterall, a false bottom has consistent holes across the entire bottom surface

 

[thorn_bird]

I agree with you on having the constant draw from all sections.
I was unable to find any theory as to why it was never slotted.
Being in the middle, I don't see the harm in it.

Also, having slots down seems to make more sense given
that you wouldn't be wasting wort. However, Dave Miller's
theory of better efficiency with slots up has me both perplexed
and curious. I can't make sense of it. I am hoping someone out there
has tested this and can explain the theory.