Feed for 2 showers - 15mm series or parallel from 22mm hot and cold feed?

[smarriott]

Just want to check something before I proceed with a re-piping exercise.

I am fitting a new thermostatic shower in the bathroom which is fed from a balanced unvented hot water system.

I have another shower in the en-suite where the hot and cold feeds are both 15mm teed directly from 22mm copper.

For the new shower am I better taking an additional feed off the 22mm copper, or just branching off the 15mm feed to the existing shower?

Presumably taking a new feed from the 22mm will possibly provide enough flow to allow both showers to by run at the same time, less so if I take the feed from the existing 15mm?

Any advice greatly appreciated!

Thanks

 

[AWheating]

probably better to go to the 22mm pipework. it will work ok off the 15mm tho is the flow rates are good. Most mixer showers have flow restrictors which limit the amount of flow through them. dont forget the isolators and check valves.