Taking hot water feed from expansion pipe.

[malx42]

I fitting a new Mira shower in a slightly different position in the bathroom. It’s going to be easier to feed it with cold water from main cold cylinder feed and from a connection to the hot water cylinder expansion pipe. These are just above the shower position.

the pipes are both 22mm and I will add a t junction to each and then a 22mm isolation valve..

the shower works down to 0.1 bar. So I will have enough pressure.

 

[Ric2013]

The 0.1 bar pressure stated is working pressure at shower inlets, which means 1m head of standing pressure minus any losses due to frictional resistance to flow through the pipework, and you'll lose even more pressure if you use a tee from the cold cylinder feed than if you give it a dedicated distributing pipe (and won't have anti-scald protection if the cistern runs dry). Plus, do consider that, while the shower will work at 0.1 bar, the flow will be less than if you had, say, 0.3 bar, so if you've based your purchase off flow rates calculated at 0.5 bar, you may be disappointed.

But if you have 0.1 bar working pressure at inlets, you will get the flow the manufacturer states at 0.1 bar.