too much pressure and flow from 3bar pump

[gthang]

Hi,
I've recently installed a stuart turner Monsoon Standard 3.0 bar Twin pump to boost my shower. The pump is good, in fact it's too good. The pressure / flow rate is just too much for our small bathroom.

Presumably if I swap the 3bar pump (and lose money in the process) for a 2bar pump this reduce the force that the water comes out of the shower by 33%

Will the 2 bar pump have a lower flow rate? at the moment the 3 bar pump fills the bath tub very quickly.

any advice most welcome
thank you

 

[Agile]

If the problem is only the shower then I dont see why you should not fit two pressure reducing valves on the feeds to the shower.

One might ask why you decided to fit a three bar pump?

Tony

 

[misterdubya]

Pressure or flow?

They are two completely different entities.

Mr. W.

 

[gthang]

Pressure or flow?

They are two completely different entities.

Mr. W.

yes,

Pressure is too high, so i should simply swap the pump for a lower pressure model, or fit a reduction valve. I'd rather have the correct pump. lesson learnt 3 bar is too much for a normal shower.

as for flow, it must be moving 15 - 20 litres per minute possibly more. seems silly to use this much water, will one of those small reducing vales in the show hose help? are they ok for pumped showers?

 

[muggles]

If you decide to fit pressure reducing valves, you'll have to wind them down more than you expect - although you have three bar pump, because of the way they work if it's putting out 20 litres per minute it's only actually running at two bar. A two bar pump would be running at about 1.5 bar when delivering 20l/min. The reducing valves you put in the hoses might help, failing that you'll need to change the pump or put something on your supply pipes to the shower.

 

[FoxtrotOscar]

Forgive the no doubt stupid question, but doesn't your shower mixer have a flow control dial? Can't you just turn it down?

 

[muggles]

Forgive the no doubt stupid question, but doesn't your shower mixer have a flow control dial? Can't you just turn it down?

Oh now that would just be far too easy...

 

[CharteredEngineer]

Just a word of warning to the original poster.

If you go from a 3 bar to a 2 bar pump, you will not get a 33% reduction in force. The force you find uncomfortable is the speed at which the water pelts you.

So if you dropped the pressure from 3bar to 2 bar, the velocity drop would only be ~18%, Pressure = 0.5 x density x Velocity^2

Apologies for the maths.

 

[gthang]

Forgive the no doubt stupid question, but doesn't your shower mixer have a flow control dial? Can't you just turn it down?

ha, I wish!

chartered engineer, would a 1.5bar pump be better then? Based on what your post I guess so as 18% reduction does not sound very much

 

[CharteredEngineer]

I would keep your 3 bar pump and buy a larger shower head.

 

[mickyg]

as above, get a bigger shower head, enjoy the nice flow you have. My shower comes out at 22 l/min, cushty

nb: no polar bears were harmed or injured in the making of this shower.

 

[FoxtrotOscar]

3 bar for one shower head!! I hope you've got a big hot water cylinder!

 

[mickyg]

3 bar for one shower head!! I hope you've got a big hot water cylinder!

just turn it up nice and hot I run mine at 70c

 

[FoxtrotOscar]

3 bar for one shower head!! I hope you've got a big hot water cylinder!

just turn it up nice and hot I run mine at 70c

= Cavitation in shower pump.

= No warranty on shower pump.

Sounds good in principle but a bad idea in practice!

 

[ChrisR]

You can just change the shower head.
There are many now designed for about 3 bar which supply only about 10 litres/minute but introduce air into the flow which sort of makes it more volume.
The Grohe Raindance is a good one.
I have a 4.5 bar pump which fills the bath at >30l/min. The shower, I just turn down a bit