I am about ready to figure out the manifolds for my polybutylene to PEX repipe.

The manifold will be in the garage. The water heater is also in the garage.

I will need a cold water manifold with seven ports:

(1) Incoming 3/4"
(2) 3/4" to 1st floor bathroom
(3) 3/4" to 2nd floor bathroom
(4) 3/4" to kitchen
(5) 1/2" to washing machine
(6) 3/4" or 1/2" to hose bibb
(7) 3/4" to water heater

On the hot side I need five ports:

(1) 3/4" from water heater
(2) 1/2" to washing machine
(3) 1/2 to 1st floor bathroom
(4) 1/2" to 2nd floor bathroom
(5) 3/4" to kitchen

I am wondering what type of manifold is best. I have seen those copper manifold and I suppose I can use two of those one for cold one for hot. Something like this:



I have also seen the cold/hot integrated ones like this:



What if you want to mix 3/4" and 1/2"? Do you get all 3/4" ports then adapt to 1/2" for individual ports or are there some out there with combinations of hot and cold ports?

Would you get more ports then you need? Say you need 7 ports get at least 10 so you can expand in the future?



Edited 2 times.

Not sure why you want to run 3/4 to the kitchen but the 2nd manifold is made of plastic and stainless steel tubing on the inside and I've seen them go bad within a couple years the copper manifold is you best bet for 3/4 port home runs to the bathrooms then 1/2 branches to the fixtures

sum, the hot could be a copper manifold similar to the one pictured except get it with the end closed. why 3/4 to the kitchen? 1/2 inch would be plenty.
as for the cold use the one pictured (one inch) with a bushing in the supply down to 3/4 then 1/2 to the kitchen and solder on a 1 x 3/4 x3/4 copper tee with a couple of 3/4 ball valves.

Packy are you saying it may be better for me to solder on ball valves for each branch myself then to get those manifolds that comes with factory ball valves on all the branches ready for the PEX connections? I think the advantage of doing my own valves is I can mix and match 1/2" and 3/4" branches the way I see fit where a factory one it's the same size and if I have to adapt I have to adapter downstream of the ball valves?

If my incoming supply is 3/4" from the meter, is there still an advantage to use a 1" manifold with 3/4" branches?

I saw some installations on the internet where they put the manifolds inside a box, like an electrical panel enclosure like this:



What is the point of doing it this way? I do not see an advantage I am thinking mine will be surface mounted (not recessed into the wall).

sum, no... just install your own valves on the 3/4 branches.
i would use a 1 inch manifold with a bushing on the inlet to accept 3/4.

WOW plastic pipes going thru metal sides??? no plastic sleeves ?

just seems like way too much work to have a manifold. too much pipe. too much crawl time.

I would simply bring 3/4" or 1" lines as needed and use tees and be done.

Sum, instead of using manifolds so, why don't you use or consider multi-port tees. These are used with What's called the logic Plumbing and it's almost like a remote manifold system but since the multi-port tees are not considered a manifold you don't have to have access points to them. The Uponor kind is the prototype but I think they're available for all the systems now

[www.uponor-usa.com]