Pipework for a multi zoned system

[natwill]

Hi,
Just need some help with a system im working on. Its a four storey house and each floor is being zoned individually. My question is with the returns. Can i run one return and pick up each floor in turn or do i have to common them all in? Obviously im trying to avoid reverse circulation when the system is up and running.

 

[Gray0689]

Well you can take your 2 primary's up to the 4 floors and tee off and zone from there(mot valve) or you can take your 4 zones back to a central point and do a header (with mot valves)
Both will work fine the first is less pipework but primary's will be bigger pipe I don't know what size each floor is so not sure pipe size (I'd guess at 35mm)
And will need a pump big enough to cope with this size of house(I'd go for a grundfos magna modulating pump expensive but worth it) the second option would be my preferred take each zone back to boiler room and make header looks better and very easy to zone and control and I'd go for a buffer tank to feed everything as will probably need more than one boiler to feed (as said I don't know size of house but 4storeys would be quite big)
Hoe this helps any more info you might need let me know
(Ps I'd go more a smart controller like a honeywell smile)