Shower mixers - maximum possible flow rate? FAQ

Jun 15, 2024 Last reply: 2 years ago 1 Replies

I am already well down the rabbit hole on water flow, shower mixers etc.



I've established that I have a Triton Aire on the bath, and a Triton Dove in the downstairs wet room.



The specifications give a minimum and maximum running pressure and a maximum static pressure.



For the Dove (shower room), this is:



Maximum static water pressure 10 bar Running water pressure 0.5 bar minimum and 5 bar maximum. [Pressure taken at the outside tap is about 2.6 bar and doesn't seem to drop when a tap is turned on.]



Recommended minimum flow is 8 litres/min available at both inlets. [I tentatively assume that this could deliver 16l/min of lukewarm (both hot and cold at max) litres/min.]



Testing (see previous thread) suggests 10.23 l/min cold and 7.28 l/min hot which is not quite up to minimum spec but not far off.



[I will draw a veil over the bath shower/mixer for the moment.]

The issue I have at the moment is what is the expected maximum flow rate? Testing suggests that where the mains enters the house I can get nearly 30 litre/min.



The combi can heat up to 19.1 l/min by 30C.



Say I restricted (as an assumption) the hot flow to 15 l/min to get a higher temperature, I would expect to see perhaps 20 l/min at the shower head and more with a tepid shower.



We are a long way off this target, but I have no data at the moment what the maximum flow the mixer can offer all other things being optimum. The installation instructions don't say. Most Internet searches don't give a figure.



The only one I have found so far is

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which quotes 20 l/min for a Triton Dene Cool Touch Bar.



This kind of figure is very helpful in sizing the system - the combi can easily handle this with some spare, and so there is the potential to run both showers at once.



It would be nice to know if you could get a more powerful option - say 25 l/min - for a luxury rather than basic shower. However I am struggling to find sizing information.



The Expertreviews site quotes maximum flow rates for the reviewed showers (where does it get these?) which vary widely.



I am as usual chasing my tail.



I need to know



(1) what is the maximum flow rate my system will theoretically deliver via a mixer.



(2) will my current mixers demonstrate this prior to ordering a new bathroom, or will they bottle out at a lower flow rate?



(3) the minimum, average and maximum flow rate for any proposed new system.



I assume that there is a source of technical data somewhere with more in depth detail than the sales web sites and installation manuals.



Any pointers more than welcome.



Cheers


Dave R


<snip>

Update:

The plumbers did a simple test of disconnecting the incoming hot from the mixer and just turning the water back on and letting it gush out of the hole.

A lot more water than was coming through the mixer!

So it looks as though I may have had a duff mixer tap from new.

That means that although the flow isn't massively fast, it isn't an impediment to fitting a new better quality shower!

I don't think fitting a new mixer at this point would cost in (unless for some reason we don't progress with the new shower this year) but at least we have some idea of why we don't have the expected flow.

Cheers

Dave R

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