Good enough for an unvented cylinder?

[doitall]

Evening all.

Scores on the doors.

Static 7.5bar.
flowrate 18lpm
dynamic 5.5bar.

28mm ish incoming, going straight to a 15mm stopcock/pipework.

I guess I should see the flow increase with 22mm? More importantly is that good enough for a unvented jobbie?

For those that can't read very well

As i keep saying.

Piiss poor flow rate at that pressure.

Hell of a pressure drop between static and dynamic.

Both together indicates a problem with the service pipe being blocked, crushed or a lot smaller than 28mm

 

[jason61c]

To measure flow at 1bar would that involve opening multiple taps till standing pressure is one bar? or reducing to 1 bar then measuring? What would the need be for this measurement? Thanks for the input.

 

[jason61c]

Evening all.

Scores on the doors.

Static 7.5bar.
flowrate 18lpm
dynamic 5.5bar.

28mm ish incoming, going straight to a 15mm stopcock/pipework.

I guess I should see the flow increase with 22mm? More importantly is that good enough for a unvented jobbie?

For those that can't read very well

As i keep saying.

p**s poor flow rate at that pressure.

Hell of a pressure drop between static and dynamic.

Both together indicates a problem with the service pipe being blocked, crushed or a lot smaller than 28mm

Would the readings just not be indicative of a 15mm stopcock and pipework in the house currently? The incoming isn't crushed as I can follow it all the way to the meter. I was under the impression that every house/area will vary depending on source/location/geographical placement?

 

[doitall]

Smaller the pipe, the greater the dynamic pressure to a limit.

just saying with the numbers you posted it doesn't add up, is there a water meter or blockage in the pipe before the stopcock.

 

[jason61c]

Smaller the pipe, the greater the dynamic pressure to a limit.

just saying with the numbers you posted it doesn't add up, is there a water meter or blockage in the pipe before the stopcock.

The incoming comes straight off the meter, into the house then straight down to a 15mm stopcock, a very very old one!

 

[Agile]

To measure flow at 1bar would that involve opening multiple taps till standing pressure is one bar? or reducing to 1 bar then measuring? What would the need be for this measurement? Thanks for the input.

Yes, that the way to measure the dynamic flow rate.

Its important because to get a good shower you need about 1.0 bar of pressure in the pipework to force the water out of the small holes to give that tingly feeling on your body.

But many heating installers don't understand it either so you are not alone!

Tony

 

[jason61c]

To measure flow at 1bar would that involve opening multiple taps till standing pressure is one bar? or reducing to 1 bar then measuring? What would the need be for this measurement? Thanks for the input.

Yes, that the way to measure the dynamic flow rate.

Its important because to get a good shower you need about 1.0 bar of pressure in the pipework to force the water out of the small holes to give that tingly feeling on your body.

But many heating installers don't understand it either so you are not alone!

Tony

I've measured the dynamic at 5.5 bar ish with one tap fully open. I'll check with as many open as possible.

 

[Agile]

Yes, but 5.5 bar is way too high for a domestic supply as it will cause all basins to splash.

Most of those who understand what dynamic pressure is will use 1.0 bar as that's what all showers will work on as well as combi boilers ( in most cases ).

Anyone with over 3 bar incoming supply would best need a pressure reducing valve!

It also risks bursting flexible hoses on WMCs etc.

Tony

 

[jason61c]

Yes, but 5.5 bar is way too high for a domestic supply as it will cause all basins to splash.

Most of those who understand what dynamic pressure is will use 1.0 bar as that's what all showers will work on as well as combi boilers ( in most cases ).

Anyone with over 3 bar incoming supply would best need a pressure reducing valve!

It also risks bursting flexible hoses on WMCs etc.

Tony

They do splash quite a bit!!