One for dia - break dancing

[ChrisR]

A colleague has got himself in trouble, specifying a Megaflo where the water supply wasn't really up to it.
The static water pressure is usually about 4 bar, and the total flow from three ground floor mains taps is 24 l/min.
Unsurprisingly, if you run a shower on the first floor (fed by 15mm), then nothing else will work without collapsing the flow at the shower.
It transpires than while part of the incoming water main is new, there's still some lead, probably 1/2" I suppose. Not sure how much, but it means a 35m detour in poly to bypass it.

The garage is fairly big (enough for the Porsche and the Ferrari) so a break tank and pump set could be a possibility. There are 2 bathrooms, and a couple of cloakrooms. Family, 3 kids.

What spec would you specify for such a thing, and what sort of cost would it be for the kit?

 

[blahblah]

What about the accumulator route Chris? http://uk.osohotwater.no/Products/dualstream/index.html
Not sure about prices.

 

[ChrisR]

It would certainly help. I've not used one tho have made enquiries in the past. Around £500. You can get 120 llitre pressure vessels for about £100. I'd love to try one of those, I'm not sure if the diaphragm would like being stretched so far so often though. A break tank would hold a lot more water.

Anyone here used one?

 

[ChrisR]

Just tried Oso - they don't sell the accumulator bit without the HW tank bit.

Does anyone know a supplier ??

 

[kevplumb]

dunno if this is any good chris

 

[blahblah]

Won't do one without the other? Seems a bit daft sales wise. Shame. It stuck in my mind because when I did my uv cert they had one set up on a deliberately restricted inlet. Worked really well.

 

[ChrisR]

INdeed Zilmet and Flamco do make vessels which look as though they'd do. I was surprised to learn though that if you or I used one as an accumulator, it would be an infringement of patent!! SO Flamco for one wouldn't sell one for that purpose. Bizarre or wot.

 

[blahblah]

Think the OSO uses the accumulator to supplement the existing mains flow -along the lines of a storage combi I guess. I'm there doing my Water Regs thing tomorrow, I'll have another look.

 

[brumylad]

why not Tee off the shower supply nearest the hot draw off at the cylinder then a place a pressure reducing valve ahead of the rest of the hot draw off's set at about 1/2 bar less than the PRV before the cylinder.

I've never tried this

 

[Eugene]

try this
Dualstream Accumulator www.gahheatingproducts.co.uk

 

[ChrisR]

That page doesn't display, for some reason. Dualstream IS Oso though.

Brumylad - I see that would reduce the hot flow other than to the shower but thet isn't the problem (though it would be if another HW were turned on for long)
With a shower running, the pressure remaining on the CW supplies is not enough to fill the loo cistern!

FOr those not familiar - an accumulator is basically a pressure vessel say about 2/3 full of water, the rest squashed gas. Mains in has a one way valve so it charges up in its own time when there's no draw-off, to full mains pressure. Then when a tap is opened, there's an amount of water available at mains pressure. The pressure obviously reduces, but it doesn't seem to show too much. When the pressure matches the mains dynamic pressure, that's all you get. Until the tap is turned off and the thing repressurises.
How the heck anyone can patent a tank and a valve I don't know!

 

[doitall]

Chris.

Having given it some thought following your phone call.

Why not simply connect the cylinder via a Monsoon 3bar single pump, with a cold feed from the storage tank.

Photo's if required

 

[ChrisR]

Photo - why not! Good thought that. Bit complicated in this case because, due to unfortunate/uncertain pipe runs the balanced CW from the Megaflo isn't used, but it should be possible to get some Hep through.

The 3 x 50 gallon cisterns are still up there.

This was done to get rid of tanks and pumps but hey. If they sort their mains pipe out it could be changed later.

I thnk it might be impractical to get pumped or balanced CW just to the 2 showers which are miles apart, so it would have to go back up to the loft, or a passing CW pipe, to connect to all the old outputs from the loft cisterns.

Or, if the output pipes from the cisterns were joined together, then they could all go through the pump, then separate again. One of the 3 outputs goes to the megaflo. Then the HW and the CW would all be fed via the pump, at 3 bar. Only snag I can see is that that puts the pump on the loft floor by the side of the cisterns, not ideal. You might be getting another phone call. Have I lost you? Sketch required!

 

[Eugene]

this is probably to late to be of any use to you


he quoted me part no: col80 £310 retail 80Ltr accumulator
no metion of not being able to buy this item seperately. got this information from www.gah.co.uk/GAHThermecon/

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[htgeng]

It transpires than while part of the incoming water main is new, there's still some lead, probably 1/2" I suppose. Not sure how much, but it means a 35m detour in poly to bypass it.

Myself, I would tell them the best option is to dig that 35metres and do it properly. I do understand the accumulator option but it really is a second best solution. How long does is the membrane good for and you only have a finite store. As for pumps, well again, not my favourite.