boosting my pressure

[Technotim]

You have not stated the size of the tank so it could well be big enough.

Why not install them and do a flow test, I would guess that the jets you would get 4-6liters per min from each and the head depending on the size and the type lets say 8" modern rub clean type 14- 18 liters @3.0 bar.

You have plenty of hot stored water so share it out well.

There are always good solutions to getting a good system design.

Eg
Basins flow restrictors to 6 liters per min
kitchen tap 9liters per min
bath unrestricted unless could be used at same time as shower then restrict to 18 liters per min assuming you have standard size bath.

By doing this you will have enough water for your shower even when the missus decides to wash up.


Remember that pressure and flow are not related.

thought i'd use pressure adjustable reducing valves as you can set them easier to 1bar in order not to trigger the pressure switch on the pump however if you think flow restrictors would be better then i'll consider it thanks,

If you reduce the pressure but still use 12 liters per min then the pressure will drop faster than if you use a flow restrictor @ 6liters and the pump will come on quicker.
I am not sure why you are worried about the pump coming on as that is what it is designed for all you want to achieve is it not cycling on off quickly as this will hurt the pump. but you will want it to react else you will turn on the shower and then it will die a bit then boom your big boy multi-stage will peel your skin off.

 

[mrrigidtool]

thanks for that makes sense, will get it rigged up next week, should not take long as the gravity fed pipes are going to be utilised. any suggestions on best height to mount pump, above cylinder or on floor.

 

[simond]

I can't believe you are putting this in when an accumulator could have just been installed next to the unvented cylinder. No noise, no electricity, no airlocks. No phantom runs of the pump in the middle of the night.

But as long as you are having fun

 

[Technotim]

If you mount the pump below the Cold stored water less chance of air problems, I assume you have the Pressure switch that plumbs directly on top so allow good space. pressure vessel on pipe work after pump before cylinder.

I can't believe you are putting this in when an accumulator could have just been installed next to the unvented cylinder. No noise, no electricity, no airlocks. No phantom runs of the pump in the middle of the night.

But as long as you are having fun

Simple because an accumulator will not increase the pressure from 2.0bar up to the require 3.0bar, they will only improve initial water flow and to use one with a high flow rate for this use will be too expensive and large.

 

[simond]

The 3.0 vs 2.0 bar pressure comment is true (but not significant in my view), however the rest is speculation, ill informed at that.

 

[Agile]

Simon, do you know of anyone who uses an air pump to force water out of an accumulator?

That would enable the whole volume of a cylinder to be utilised but would need a powerful compressor ( or an air tank! )

Tony

 

[mrrigidtool]

I can't believe you are putting this in when an accumulator could have just been installed next to the unvented cylinder. No noise, no electricity, no airlocks. No phantom runs of the pump in the middle of the night.

But as long as you are having fun

Hi did not go for the accumiltor route on the basis that at peak times with only 15mm and under 2 bar it would not give me a ott shower, probably would be acceptable, but why settle for that if you can have a luxary shower for a days plumbing and the cost of a pump, as most of the original gravity fed pipes will be re routed and utilised and the cwsc is existing however i did think of adding an accumilator arfter the pump but thought i'd give it a go without, wont take long to tap into circuit later. As far as the noise is concerned i have a 1hp swimming pool pump in the garage where the new pump will be sited thats running 24hrs a day filtering my 500gallon marine tank, that should drown out the noise of this.

 

[simond]

Fair enough, Mr RT. However the 15mm pipe won't be of any consequence if it is upstream of the accumulator. If it is downstream then it will have a similar effect on your pump, of course.

Agile I have considered this in the past but the air pump would be noisy and it would need to know how much water was in the tank at any point in time. If you boosted the air pressure after the tank had filled, after a drawoff the tank would not refill again until the air pressure dropped.

 

[gordonspants]

Bit late for loads of typing but we've had an accumulator in for a week now - 200 litre - and it rocks!
Silly big flow rates, better pressure in the mornings (got gauges on it to monitor it), and when the mains is turned off, it takes an age to empty out and the flow to tail off - so my mums argurment of 'what if they cut your water off - with no header tank you'll be stuck" doesn't apply!
Recommended.
Did have shower pumps off a vented cylinder before - no comparison.

 

[Agile]

Bit late for loads of typing but we've had an accumulator in for a week now - 200 litre - and it rocks!

If its unstable on the legs and is rocking then you need to pad out the one that too high with a piece of thin plywood selected for the task.

Tony

 

[doitall]

I'm not happy with any off what I've seen so far.

How is the pump connected, I assume to the cylinder cold feed with some sort of check valve to protect the mains

 

[mrrigidtool]

I'm not happy with any off what I've seen so far.

How is the pump connected, I assume to the cylinder cold feed with some sort of check valve to protect the mains

its not pumpimg from the mains its pumping from the storage tank, would have a job contaminating the mains unless it could climb up the ball cock.

 

[mrrigidtool]

Bit late for loads of typing but we've had an accumulator in for a week now - 200 litre - and it rocks!
Silly big flow rates, better pressure in the mornings (got gauges on it to monitor it), and when the mains is turned off, it takes an age to empty out and the flow to tail off - so my mums argurment of 'what if they cut your water off - with no header tank you'll be stuck" doesn't apply!
Recommended.
Did have shower pumps off a vented cylinder before - no comparison.

Hi what brand did you use and what sort of pressure do you have on your mains to start with, not familair with them however am i right in saying the mains pressurisies the cylinder and the the diaphram pushes it back out, if i have say 1.5 bar during peek hours will it only pressurizes it to this amount, sorry if i am wrong like i say no experiance with accumiltors and mixed answers every where ive looked, like i said was originaly going to go for the accumilator and was going to pump the water into it from header tank as i thought the mains was n't man enough, then i thought as i'm installing a pump any how i'd try without it first if not happy then place the accumilator between the pump and cylinder. What you running with it unvented or combi.
thanks

 

[gordonspants]

Bit late for loads of typing but we've had an accumulator in for a week now - 200 litre - and it rocks!

If its unstable on the legs and is rocking then you need to pad out the one that too high with a piece of thin plywood selected for the task.

Tony

Many thanks for that, the problem did appear to be a lack of shimming, but despite using three bits of 18mm ply stacked under the offending leg, movement was still evident, shimming in the order of approximately 3 inches being required. Instead, we have used our plumbers wallet as a temporary solution

 

[gordonspants]

Bit late for loads of typing but we've had an accumulator in for a week now - 200 litre - and it rocks!
Silly big flow rates, better pressure in the mornings (got gauges on it to monitor it), and when the mains is turned off, it takes an age to empty out and the flow to tail off - so my mums argurment of 'what if they cut your water off - with no header tank you'll be stuck" doesn't apply!
Recommended.
Did have shower pumps off a vented cylinder before - no comparison.

Hi what brand did you use and what sort of pressure do you have on your mains to start with, not familair with them however am i right in saying the mains pressurisies the cylinder and the the diaphram pushes it back out, if i have say 1.5 bar during peek hours will it only pressurizes it to this amount, sorry if i am wrong like i say no experiance with accumiltors and mixed answers every where ive looked, like i said was originaly going to go for the accumilator and was going to pump the water into it from header tank as i thought the mains was n't man enough, then i thought as i'm installing a pump any how i'd try without it first if not happy then place the accumilator between the pump and cylinder. What you running with it unvented or combi.
thanks

We have maybe 3.5 bar max dipping to 2 bar during peak hours (this is measured by a fixed pressure gauge by the way, so it's fairly accurate). Prob we have is flow - wanted big huge showers similar to yours - the bodyjets and a raindance head, and without digging the drive/road/garden up to get a big plastic mains supply to replace the 15mm existing, an accumulator seemed a good way to boost flow when required. We (well, plumber/plumbers merchant and me) decided an accumulator is the way to go whether you use an unvented cylinder of a thermalstore. With a combi, unless you have a very good one, it might not help that much, as the combi may not give you the hot water flow you need, certainly not in the winter when the cold water is really cold.

Accumulator is a big blue 'zilmet' vessel, just checked and its 250 litre, diaphragm is pressurised to 2 bar, so our 2 to 3 bar incoming fills the vessel up as much as possible, then forces it out when a tap is opened. If you have 1.5 bar minimum, you may have 2.5 bar or above during the night - this is when the accumulator does it's job, nicking the pressure from the mains to blast out at you when you turn the shower on in the morning.
It's just tee'd into the supply feeding the bathrooms with a non return valve between the vessel and the incoming supply. The supply splits for hot and cold - hot goes via a plate heat exchanger similar to a combi but much bigger (we have a thermal store - will post about that seperately) and TMV blender, cold goes straight to the thermostatic showers.

Vessel was under £300 inc vat, and scares everyone who sees it - looks a bit 'industrial', but I'd recommend one if you're unvented and don't want to dig your garden up to replace the mains pipe. Different world from shower pumps as well - no noise, no moving parts.

OSO do a twin pack (£££) with an unvented cylinder that we looked at, but it's way cheaper to get the two halves separately if you want to go unvented.

Note I'm not a plumber, but have done a lot of reading, asked a lot of people a lot of questions (plumbers merchants hide when they see me now) - and I reckon we've got it spec'd right for our application.