Water flow rate and unvented cylinder question

[wwwebber]

This all sounds quite expensive and id still be running two water tanks/accumulators/pressure vessels

Have i understood this correctly ?

 

[Dan Robinson]

No you haven't understood.

You replace the cold tank with an accumulator(s) depending on volumes needed.

Hot water cylinder is replaced with an unvented cylinder.

You then get mains pressure balanced hot and cold with no pumps.

The cost is dependent very much on what is needed and what grade you go for and how much work is involved.

This system cost a fair few sheckles:

But unless you are showering 4 or 5 people simultaneously, you can do things cheaper.


The example in my videos which does a family of 4 and included a boiler installation was just over £5K+VAT.

Plumbing was pretty straight forward though and prices vary heavily with location etc. (I hate giving figures online because of this).

 

[dilalio]

There was a time (and I’m “just” old enough to remember) when a shower was a saucepan, full of the bathwater you were sitting in, poured over your head; and said bath was underneath the kitchen worktop, which was on a hinge and pivoted up out of the way... to be filled via the only hot tap in the house... supplied by a water heater!

It was my nan’s house... I don’t miss those facilities

 

[Dan Robinson]

Go to my dad's house and a saucepan would be more effective and comfortable that the shower.

Waiting for a quiet patch with work to go and fit him an accumulator in the basement.... he's only been waiting 11 years

Speaking of showers... did you get that text?

 

[dilalio]

Speaking of showers... did you get that text?

I did... I thought you were just quoting me excerpts from the diary of Dan Robinson!

 

[wwwebber]

Not got much of a budget and I believe a larger hot water cylinder & a larger cold water tank in conjunction with the twin pump that I already own will deliver what I need for much less than the pressurised solution above.

Thank you all for the responses anyway

 

[bernardgreen]

and said bath was underneath the kitchen worktop, which was on a hinge and pivoted up out of the way

An indoor bath......Such decadent luxury, our tin bath hung in a hook outside and was brought into the kitchen when needed.

Hot water from a

which at Christmas was used to boil Christmas puddings, never did have a bath in pudding flavoured water.

 

[muggles]

Not got much of a budget and I believe a larger hot water cylinder & a larger cold water tank in conjunction with the twin pump that I already own will deliver what I need for much less than the pressurised solution above.

Thank you all for the responses anyway

You might believe that, but you'd be wrong. Still, it seems you'd decided on your own "solution" before you posted, which does rather beg the question of why you bothered

 

[bernardgreen]

If you have a cold water storage tank then removing that in favour of accumulator(s) will by definition result in a balanced supply as that is where you cold is fed from as well as the hot.

But if both hot and cold are supplied from the cold water storage tank then they will both be at the same, balanced, pressure.

Isn't a cold water storage tank providing the same function ( storage ) as an accumulator but with out the complication that a pressurise vessel has to have safety devices such as pressure relief valves. As I see it the only advantage of using accumulators is that they are not confined to being installed in the loft or other high location.

 

[Dan Robinson]

What safety devices do you think are on accumulators?

 

[Dan Robinson]

Interestingly enough I was battling with a cold water sotrage cistern this morning changing a rather stubborn ball valve. Could have serviced an unvented cylinder more quickly.

The water damge from the overflow pipe pizzing down the building for the weekend was significant too.

 

[bernardgreen]

What safety devices do you think are on accumulators?

I would have thought a pressure relief or pressure control valve may be needed to deal with the unlikely event of the mains water presure exceeding the accumulator's safe working pressure.

Also don't accumulators have to have a membrane separating the air chamber from the water and doesn't that air chamber have to be pressurised to an optimum pressure using an air pump. What happens when the mains water pressure is lower than the air pressure and the accumulator is empty of water. ?

 

[wwwebber]

You might believe that, but you'd be wrong. Still, it seems you'd decided on your own "solution" before you posted, which does rather beg the question of why you bothered

Not so sure I deserved such a response

So show me a reputable 210L unvented indirect hot water cylinder, a cold water pressure vessel, necessary electrics, pumps and safety valves etc etc that's cheaper than £500 in total to buy (incl vat) !!. This is the price I can pick up a new 210L indirect vented copper cylinder + 200L water tank for. I'm guessing my solution is also very much cheaper to fit, as I don't need a G3 plumber.

If I'm wrong I'll hold my hands up and say so. Either way your response is out of order.

 

[wwwebber]

No, the flow rate is too low. Say your shower is 10 lpm (and some can run to 30 lpm), then if its running, there's only 2 lpm for anything else and its not enough.

However, if you really have 3 bar pressure, the low flow rate may be caused by obstructions / restrictions. Test what the pressure is at an "open pipe" outlet, with one other outlet (kitchen tap) running. If its over 2 bar you might be in with a chance after some pipework changes. If your kitchen tap has an isolation valve on it, unless it's a full bore one, it will restrict the flow rate to what 3 bar can push through a 10mm diameter.

Hi, I spoke to a plumber last week and he checked out the 15mm pipe coming into the house. It seems that I have 3 isolation valves !!. Two quite old ones before the water meter and another new blue winged valve after the water meter that was recently installed as part of out kitchen plumbing work. He says that the two old ones are almost certainly restricting the flow. The giveaway being that one has failed and they've simply installed a new one above it.

So a good shout there @oldbuffer - thank you. He's coming back tomorrow morning to take out the two old isolation valves and will re-test pressure to see whats what. Cheers.