Boost flow rate via cold water storage

[EvilDonut]

I have a new combi now and am just refitting the house to have two showers.

Flow rate will be a fairly big problem, especially with two showers running at once.

My peak flow rate is 8.6 l/m, measured by my boiler with kitchen hot tap open.

Looking for ways to boost flow rate. Hot water storage is tricky to integrate into existing combi system.

Can I store cold water in a (pressurised?) tank BEFORE the boiler, with a dedicated pump feeding in to the boiler’s cold input? It would act as a kind of battery that, when empty, would simply allow cold to flow through it at the normal rate. Does this thing exist?

If this idea is rubbish, how about hot water storage? What’s the best way to integrate that?

I know a system boiler+cylinder would have been the ideal solution. Retrospect is a wonderful thing!

 

[ivixor]

Remember you can't pressurize water, only air. So you would need a pressure rated tank and a pressure vessel.

A cheaper (and more legal) approach would be to put a normal open storage tank in the attic, and feed the boiler from that with an automatic 1.5 shower pump run in 22mm.

 

[Dan Robinson]

and the boiler is?

 

[ivixor]

Also just because you have a combi, doesn't mean you have to USE the hot water heater. It would be quite happy heating a conventional vented cylinder.

Don't bother with unvented cylinder as that will again be limited to your mains water pressure & flow rate.