Water flow question about Megaflow

[Brownjamesa]

Hi,

I have had a couple of plumbers around to quote me for a new bathroom and to install and new en-suite and have asked them what do i need to have in installed to be able to run two showers at the same time for a maximum of 5 mins.

Both of them have recomended a megaflow, but they did not check my mains water presure/flow?

I know I have a 15mm mains comming in from the road (3 meters away from stop cock) and have mesured the time it takes to fill a bucket of water (10 ltr).

Tap in Garage near stop cock = 0.36 seconds
Utility Tap = 0.57 seconds
Kitchen tap = 0.56 seconds.

Do I have the minimum requirements to have a megaflow?

Cheers
James

 

[Brownjamesa]

can anyone help ?

 

[lufcmark]

I wouldn't install a Megaflo on those flow rates...My advice would be upgrade your cold water storage capacity to 100 gallons, check your hot water storage capacity and upgrade too if need be and fit a 3 bar shower pump (Stuart Turner if possible) to run both showers.

It is imperative to install the shower pump to the manufacturer's instructions.

 

[Newcastle88]

see the link http://www.heatraesadia.com/hs/heatraes.nsf

the tests you have done really don't prove anything.

You need a Weir Cup to measure the flow and a pressure gauge to test the working pressure.

 

[transam]

are your flowrate figures correct e.g 0.36 secs for 10 litres ?? unless I am misunderstanding the figs that is 10 litres in under 1 second ?

 

[seco services]

are your flowrate figures correct e.g 0.36 secs for 10 litres ?? unless I am misunderstanding the figs that is 10 litres in under 1 second ?

oh come on 36 seconds.

 

[Brownjamesa]

are your flowrate figures correct e.g 0.36 secs for 10 litres ?? unless I am misunderstanding the figs that is 10 litres in under 1 second ?

Sorry,

The times are in seconds.


Tap in Garage near stop cock = 36 seconds
Utility Tap = 57 seconds
Kitchen tap = 56 seconds.

 

[transam]

for unvented cylinders I would expect a min of 1 bar dynamic or running pressure , & a min flowrate of 20 litres a min ', your flowrates are at the min' i would go with storage . you could of course use an accumulater with an unvented cylinder , which is a way of storing mains water .

 

[Brownjamesa]

for unvented cylinders I would expect a min of 1 bar dynamic or running pressure , & a min flowrate of 20 litres a min ', your flowrates are at the min' i would go with storage . you could of course use an accumulater with an unvented cylinder , which is a way of storing mains water .

OK Cheers,

I was looking at a 210l megaflow, so will a 60 x 18 hot water cylinders do me, with a 3 bar pump?

I know I will need to increase the cold water storage in the loft, I think I currently have a 25 gallon one, will a 50 gallon tank do instead?

By the way if you are in the black country area of the west midlands, I would be happy to have a quote from you.

Cheers again.

James

 

[Brownjamesa]

Just looking at the flow rates, would the following combi boiler be OK, if the presure was right at my house?

http://www.worcester-bosch.co.uk/homeowner/products/gas-boilers/greenstar-highflow-550cdi


Central heating output: 30.6kW

Domestic hot water flow rate: 25 litres per minute at 35 degree temperature rise (provided adequate mains pressure is available)

James

 

[rojaca]

Think I worked your flow rate out last night as being 16.6 lmin at your stop cock. Combi's not going to give you 25l/min if you've only 16l at the stopcock.

 

[Brownjamesa]

Think I worked your flow rate out last night as being 16.6 lmin at your stop cock. Combi's not going to give you 25l/min if you've only 16l at the stopcock.

Cheers Rojaca,

So would the following cobi be OK?

http://www.worcester-bosch.co.uk/homeowner/products/gas-boilers/greenstar-42cdi#features-benefits

Also would this be able to power two showers at the same time?

James

 

[transam]

combis , dont know if this helps ? but when you are dealing with instantaneous type combis the H.W flowrate can be worked out by the following formula , convert the combis output into kilo calories , 1 kw = 14.3 k. calories , e.g a 24 kw x 14.3=343 divide by a given temp ' e.g 35 = 9.8 litres a min at a temp' rise of 35 degs C . If you only got 16 L coming in , u can only get 16 l out , storage or an accumulater , Oso do an accumulater system the dualstream or ariston do there are others do.
an accumulater works on kinetic energy , (water) no pumps !