Plumbing Manifold help needed

[Jb9]

Hello,

I am building a house with 2 1/2 bathrooms stacked around a single wet wall. I am trying to keep the plumbing simple. I have a few questions about manifolds that I am struggling with:

-Do I need one manifold per floor? (2 full bathrooms on 2nd floor, half-bath on first floor)

-How do I size the number of lines for the manifold (exactly what I need or have an extra few lines)?

-Are manifolds noisy? (I am wondering if one might not want one close to a bedroom)

-What is an optimal location and how big of a wall cavity is required? (given I am using a single wet wall). Could a manifold go under a cabinet sink?

-I am also going to be using manifolds SEPARATELY for a radiant heat floor so let me know if any suggestions for conventional plumbing (potable) might not apply to a radiant system.

Thanks in advance. I really appreciate all the kind folks here.

 

[Terry]

You can put a manifold anywhere you have space.
Sizing pipes is according to a chart like this
Pipe sizing chart

Normally you can have up to two plumbing fixtures on a single 1/2" line depending on what they are.
The chart uses fixture units, which then get converted to the chart for how many "fixture units" you can use for a certain size pipe.