X8 electric showers on Open Vented system low pressure pump

[Davidalexjeffs]

Ive been asked to remedy the low water pressure at the x8 electric shower outlets at a care home.

Currently its an open vented system, with heat only boiler with CWS and F and E tank.

It appears all the showers are run from the gravity feed and a few off the cold mains? Its hard to know given the extensive refurbishment and pipes in newly plastered walls.

Im going down to site today to take standing pressures.
I will take dynamic pressures with x7 outlets open then x2 outlets.
Then I will take flow rates at outside tap, then with x2-7 cold outlets open at once?

Once I have established these readings, do I need anymore information from site before installing a mains boost cold water pump?

Will a mains cold water mains boost pump be adequate to run x8 electric showers at once?

Or do I need a separate CWS supply to pump from?

Is there a better soloution to running x8 electric showers from the cold mains?

Given its a 1930s mansion, upgrading the cold mains to 25mm MDPE? Or bigger?

Would it be best to rip out all the showers and install thermostatic showers and run a new unvented indirect system with system boiler S plan if readings for flow rate and pressure are within range? Then an accumulator or mains boost pump?

Or shall we keep x3 electric showers from cold mains feed and install x5 thermostatic showers?

Its a lot of questions I know! We just want to ensure the vulnerable residents can shower adequately.
Any other ideas appreciated!

Ho ho ho.....its time to work while all others feast

 

[SimonG]

Forget the mains cold water boost pump. Can only pump 12 lpm. No where near enough.

Must be a canny electric supply for 8 electric showers.

Needs a total rethink imho

 

[Chuck]

Getting eight showers working properly simultaneously is non trivial, particularly if you are trying to upgrade an existing installation at low cost. There have been several discussions of similar projects on this forum over the last couple of years. E.g. here:

Football Changing Rooms

They invariably end up with the conclusion that the upgrade needs to be designed properly by a company that specialises in such commercial installations.

If it's a care home, or similar, there may be extra regulations that need to be complied with.

 

[Riley]

I agree with the above you need some proper design and pipework upgrades in order to get this working properly. Sounds like builders playing at plumbers to me

 

[Riley]

Are you a plumber?

 

[Davidalexjeffs]

Thanks everyone, yes!

The good news is the showers arent electric, they are all thermostatic showers.
The bad news is they have 11 showers and 1 bath!

Ths other good news is we have 6.2bar standing and 5.8 dynamic pressure
Plus flow rate is well over 25lpm
Might need a bigger weir gauge

So the plan is to run x2 unvented cylinders and away with the open vented.

So I need to work out if 11 showers can take these pressure readings, run for a unvented indirect system.

Will I need an accumulator for 11 showers?

 

[Riley]

Quite possibly you will need some sort of booster arrangement unvented cylinders will have a pressure reducing valve to bring it down to acceptable levels Just amazed this was all put in without considering the hot water supply. Are you G3 qualified?? What will be heating the cylinders?

 

[ShaunCorbs]

5.8 with how many open just one ?

 

[ShaunCorbs]

TBH keep the tanks depending on size and feed the showers from a booster set and also feed the cylinders from

What size cylinders you thinking ?

 

[Davidalexjeffs]

Yes with one outlet open.

Agreed with the booster sets and break tank!

Yes my best friend is G3 unvented but we are getting in the big boys as we have never run booster sets or a accumulators.

12 outlets-2x 300litre unvented with x2 system boilers?
X2 3kw immersions
Im checking gas meter type/size for kw output from meter
X2 30kw boilers should be fine-we will need to calculate size of house etc.

Thanks for all your input-the big guns are getting called in!

 

[Riley]

Can I just ask who thought it was going to work on the previous set up??????

 

[ShaunCorbs]

Yes with one outlet open.

Agreed with the booster sets and break tank!

Yes my best friend is G3 unvented but we are getting in the big boys as we have never run booster sets or a accumulators.

12 outlets-2x 300litre unvented with x2 system boilers?
X2 3kw immersions
Im checking gas meter type/size for kw output from meter
X2 30kw boilers should be fine-we will need to calculate size of house etc.

Thanks for all your input-the big guns are getting called in!

That will give you under 10mins of hot water at full load

And reheat time with coil loadings maxed would be around 30 mins and a 50 kw boiler just for hot water

 

[AMGasServices]

Why not put 2/3 Andrews water heaters in they chuck some hot water out.