Just had new bathroom, gravity fed shower not powerful enough as expected so going to install a pump, very straight forward as it backs onto the airing cupboard, electrical supply there, just need to put pump in line on hot and cold feeds to shower.
Any experiences with different makes of pump?
Also we want a timer, i.e. you turn the shower on, the pump starts though only runs for a preset length of time - any ideas?
Thanks.
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>> Any experiences with different makes of pump?
Avoid Salamander, go for Stuart Turner, brass pump chambers where ever possible.
You need head of water, plenty of it and temps of no more than 60c to avoid cavitation. Cavitation will knacker a pump in less than a year.
>> Also we want a timer, i.e. you turn the shower on, the pump starts though
>> only runs for a preset length of time - any ideas?
Why? Pump starts when you turn tap on, pump stops when you turn tap off.
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>> Why? Pump starts when you turn tap on, pump stops when you turn tap off.
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Want to stop one son spendng an hour in there ...
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He'll just turn it off and on again.
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>> He'll just turn it off and on again.
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Depends on how sophisticated the timer is, the ideal would be on 10 mins, off 5 mins ...
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Take the towels out of the bathroom, tell him you'll only leave it ouside the door for 10 minutes. After that its gone.
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>> >> He'll just turn it off and on again.
>> >>
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>> Depends on how sophisticated the timer is, the ideal would be on 10 mins, off
>> 5 mins ...
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Use a push button time delayed off switch outside the bathroom. He will soon get fed up with coming out of the shower naked to reset it.
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Turn the stopcock off?
Pat
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>> Want to stop one son spendng an hour in there ...
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Fit a switch in the cupboard with the pump, he will soon get the message. Do you switch off the WiFi to wind him up as well? :-)
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>> Want to stop one son spendng an hour in there ...
>>
That's against the laws of the universe!
It gets worse when they get a girlfriend!
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You won't have to worry about that if you fit a big pump - it will empty the tank in much less than an hour. A cold shower will turf him out!
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I have an Aqualisa, now about 5 years old. It's been a good shower. No timer as far as I know but there is a remote on/off option which you could mount outside somewhere. Won't stop him turning it on again though...
Last edited by: smokie on Mon 29 May 17 at 23:12
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As Zero said. Stuart Turner.
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Yep thanks, will probably get a Stuart Turner pump.
Though re the timer, I am not sure anyone other than Smokie is taking it seriously ...
I need a timer that enable the following taps turned on, pump runs, timer disconnects the supply after 10 mins and reconnects the supply after another 5 mins or so.
Something like this will do part of it.
uk.rs-online.com/web/p/lighting-time-switches/6658194/
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Some of the water companies offer 'shower timers' as part of their water saving offer to customers:
www.anglianwater.co.uk/environment/how-you-can-help/using-water-wisely/we-products/
I suspect though they're just rebranded clockwork kitchen timers.
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Thanks Bromp, we have got an egg timer from out local water co, I am after a little more sophistication even if I have to make it myself.
Anyone have any thoughts on pump spec, 1.5bar or 2.0bar for a 200mm dia shower head?
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Regarding the timer is this something you could use?
www.showermanager.com/conservation-store/shower-timer-home.shtml
I take it you've spoken to the person that's created this requirement?
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>> Regarding the timer is this something you could use?
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>> www.showermanager.com/conservation-store/shower-timer-home.shtml
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Thanks, I came across that when Googeling, no it won't do the job, its a fully fitted plumbed in shower, chrome goose neck and head, separate hand held head. The timer and pump will go in the airing cupboard behind the shower.
>> I take it you've spoken to the person that's created this requirement?
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Not sure what you mean?
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>> I take it you've spoken to the person that's created this requirement?
>> >>
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>> Not sure what you mean?
Sorry i was obviously a bit cryptic, i mean spoken to your son about his water usage?
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>> Sorry i was obviously a bit cryptic, i mean spoken to your son about his water usage?
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Aha, yes, it's a longstanding issue, if he has a shower when we're around we can bang on the bathroom door though at other times he'll just stand there and let it run cold without realising how much time has passed, we have put alarm clocks and egg timers in the bathroom though he has to remember to set them.
Thought about a coin slot meter as per campsites and sailing clubs, 50p a shower ;-)
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Good job he doesn't belong to me!
I'd sit him down and give him a talk about self discipline and responsibilities to others.
If that didn't work then the shower door would be locked and he would have to have a strip wash in the kitchen sink!
That would cure him.
Pat
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Aha, yes, it's a longstanding issue, if he has a shower when we're around we> can bang on the bathroom door though at other times he'll just stand there and let it run cold without realising how much time has passed, we have put alarm> clocks and egg timers in the bathroom though he has to remember to set them.
Disconnect the water a few times when your not there. Or pats plan, there won't be very many hour showers after that ;-)
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You've got a lad that likes washing - and your complaining ! ;-))
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Good job he doesn't live round here, all that dragging the bath in out of the yard once a week and boiling kettles on the range every month.
Some kids don't know they're born ! Pah !
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>> Anyone have any thoughts on pump spec, 1.5bar or 2.0bar for a 200mm dia shower
>> head?
1.5 bar is ample, dont get flow and pressure mixed up they are not the same. More pressure doesn't get you more water, just makes the little jets out of the shower head sting!
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>> 1.5 bar is ample, dont get flow and pressure mixed up they are not the
>> same. More pressure doesn't get you more water, just makes the little jets out of
>> the shower head sting!
>>
Thanks, I have ordered a 2.0 bar pump, there is not a lot of difference in performance though at 10ltrs/min the 1.5 is running at about 1.1 bar whereas the 2.0 is running at 1.4 bar and reckon with a 200mm showerhead, which has lots of nozzles, the extra pressure might be useful.
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Intrigued by that. Surely the higher the pressure the more water will be forced down a pipe and out of the shower. Am I missing something?
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There must surely be a limit where you need a larger pipe to increase the amount of water?
Isn't bar a bit like bhp, and related to the force needed to stop it, rather than necessarily the amount of water flowing?
But then I've never thought it through before either.
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I guess there must be a finite limit to flow through a given pipe but I would have thought that generally speaking if you increase the pressure more water will flow down the same pipe. I stand to be corrected though.
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Everything else being equal, yes.
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Or perhaps the idea is that if the pressure remains stable at 2bar, then the pipe size will govern flow - 2bar through a 1cm pipe as opposed to 2bar through a 2cm pipe.
Though I would have thought that pressure would have dropped in a larger pipe.
Come on Zero, help us through this.
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>> Come on Zero, help us through this.
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He'll no doubt have something to add.
The pump rating is maximum head, the pressure the pump can achieve pushing against a closed valve. 1.5 bar, 2.0 bar etc.
Thereafter as the valve is opened and the flow increases the pressure drops and this change varies from pump to pump depending on its capacity or volume rather than pressure.
Last edited by: Hard Cheese on Tue 30 May 17 at 17:29
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Pressure does not equal flow. Flow is volume of water. There is a finite amount of water you can get through a pipe diameter, regardless of pressure. There is a reference work with all pre calculated tables that all water engineers use to calculate flow and pressure and pipe diameter
The huge fountain at Chatsworth works on flow/pressure calculations and no pump. There is a very large diameter pipe at the reservoir in the hill, the pipe diameter steps down in stages during the fall, till it emerges at a small diameter nozzle at the huge fountain. The reduction in diameter and flow increases pressure. Its all self limiting. But if you put a pump at the fountain end, and tried to force it up the pipe it would barely get to the reservoir.
Last edited by: Zero on Tue 30 May 17 at 18:32
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Yes I get that but all things being equal the higher the pressure the more you will force down a pipe no?
I suspect that there the rate of flow does not increase proportionally with the pressure but It surely must increase.
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>> Yes I get that but all things being equal the higher the pressure the more
>> you will force down a pipe no?
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>> I suspect that there the rate of flow does not increase proportionally with the pressure
>> but It surely must increase.
till it reaches a limit There is a point where you can increase pressure as high as you like, the flow will not increase. you get back pressure. The tables include the length of pipe as well as diameter.
Last edited by: Zero on Tue 30 May 17 at 18:48
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If I was running a shower with a 1bar pump and whilst I was ok with the pressure I wanted more water;
In the real world would I;
1) get a more powerful pump
2) increase the pipe bore
3) both
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>> If I was running a shower with a 1bar pump and whilst I was ok
>> with the pressure I wanted more water;
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>> In the real world would I;
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>> 1) get a more powerful pump
>> 2) increase the pipe bore
>> 3) both
2, tho pressure would drop.
Last edited by: Zero on Tue 30 May 17 at 18:56
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>> If I was running a shower with a 1bar pump and whilst I was ok
>> with the pressure I wanted more water;
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>> In the real world would I;
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>> 1) get a more powerful pump
>> 2) increase the pipe bore
>> 3) both
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1/ Up to a point, if still not satisfactory then 3/.
In reality I suspect that a standard 15mm pipe would be more than adequate and increasing the pressure would be all that would be needed in a domestic shower.
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>> In reality I suspect that a standard 15mm pipe would be more than adequate and
>> increasing the pressure would be all that would be needed in a domestic shower.
You'll find that most domestic shower mixers have 22mm pipe fittings for a reason.
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Here in this last bastion of Spanish supremacy plumbing fittings are imperial. I know not why. But, in true South American style, not always.
Mind you, plumbing is also called "gasfiteria".
They get easily confused, these colonials.
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>> You'll find that most domestic shower mixers have 22mm pipe fittings for a reason.
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Yes when un-pumped though with a pump, 15mm pipe on the hot and cold would be fine.
To use No's example if it were already 22mm pipe then 1/ would be the only viable option.
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BTW it was timer ideas I was mainly after?
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But presumably a 22m pipe at 2bar through a shower head is likely to pin me up against the wall and drill holes in my skull anyway?
Here the water struggles up the climb to the shower head and then falls out.
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>> Here the water struggles up the climb to the shower head and then falls out.
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That's the problem that requires solving. Anyway I am confident in the pump. It's the timer next on the agenda.
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>> But presumably a 22m pipe at 2bar through a shower head is likely to pin
>> me up against the wall and drill holes in my skull anyway?
Depends on the diameter, and number of the shower head outlets. A single 22m gush will give you a slap, a single shower pimple will drill your eye out. All at the same pump pressure.
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We have a Thermo-thingy type shower run directly from the combi, supplied by 15mm cold and a 15mm hot pipes. The shower head is 8in Diameter and has 540 holes (think i counted them all correctly!) and i feel like i'm being drowned! ;-)
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We had a new bathroom 18 months ago. At the same time we had a shower bar fitted taking cold water from the rising main and hot from the boiler. Much better than all the electric showers we've had fitted over the years. Much neater too. SWM loves it. Shower head is about 6 inches but I've not counted the holes, I have what passes for a life !
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>> There is a very large diameter pipe at the reservoir in the hill, the pipe diameter steps down in stages during the fall
As the flow rate increases, doesn't the pressure fall, as in a venturi? What keeps aircraft wings supporting the plane?
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As the flow rate increases, doesn't the pressure fall, as in a venturi?
Depends which end of the duct, convergent or divergent. At normal speeds in a convergent duct as pressure falls, velocity increases, divergent ducts the opposite is true.
What keeps
>> aircraft wings supporting the plane?
>>
Normally a load of big nuts and bolts ;-)
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>> As the flow rate increases, doesn't the pressure fall, as in a venturi? What keeps
>> aircraft wings supporting the plane?
Not applicable when we are talking flow and pressure in a constrained volume i.e. pipe.
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You are, for once, almost completely wrong, Zero....
Pressure and flow in hydraulic systems are inextricably linked. Whilst there is a limit to what you can get down a pipe, it's very high - being the speed of sound in the fluid. However, pressure drop increases in proportion to the square of the flow, and also to the length of the pipe, and the number of fittings (which all add pressure drop). So to get there you need an awful lot of available pressure drop. Whilst there is no pump at Chatsworth there is a lot of static head (ie pressure due to gravity) and this is what is pushing the water down the pipe and out of the nozzle. If there was a pump in the system you could get away with a smaller pipe as you would have more available pressure drop. The nozzle is there to reduce the pipe size, which increases the velocity of the fluid so it spurts out (finger on the end of the hose like) - if the whole pipe was that small the flow would be much lower as the pressure drop would be higher. The nozzle does not create pressure - there will a pressure drop across the nozzle equivalent to the static head in the inlet pipe, minus the operating pressure drop.
Centrifugal pumps, as being talked about here, have a curve which is a relationship between developed head (pressure - although strictly this is related to density, the same pump operating on hot water will produce less 'pressure' as it produces the same head, but the density is lower) and flow rate - and they always operate somewhere on that curve. More head = less flow and vice-versa. I'm not sure how the S-T pumps are rated - it may be that the pressure is the shut off head (ie developed head at no flow) or it may be a nominal flow at some pre-determined flow. In order to know how much flow one would get out of the shower you would need to know the relative heights of the header tank, pump and shower, and the pipe routing. This would allow you to calculate a system curve for for the pipework (ie relationship between pressure drop and flow) and then plot this over the pump curve - where they intersect is where the system will operate. Suffice to say a 2 bar pump will almost certainly produce more flow than a 1 bar pump - although not twice as much (it will depend on the curve, and pressure drop is proportional to flow squared, remember).
S-T example curve here: www.stuart-turner.co.uk/media/479523-Performance-Kennet-B.pdf It appears that the 1.4 is the shut off head (14m on cold water = 1.4 bar).
Simples.... all first year engineering degree stuff!
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I'm off for a cold shower :S
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I disagree with you, you need to go check the log tables for pressure/flow/pipe length/diameter. And thats before we consider bends in pipe, and the back pressure that causes.
Last edited by: Zero on Wed 31 May 17 at 21:10
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Disagree all you like, but MEng CEng MIChemE and 20 years designing this stuff on an industrial scale says I know what I am talking about, and you are wrong.... :-)
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Shower pump and timer - Zero
