pipe sizing.....

[D_Hailsham]

Small Bore heating Systems explains how you calculate the heat carrying capacity of a pipe. It's not an absolute figure but depends on the velocity of water through the pipe: too low and there is a danger of sludge settling; too high and you get flow noise.

Copper Tubes in Domestic Heating Systems explains how you size the pipes of a system. It depends on the wattage being carried and the losses due to friction.

 

[CBF]

well you can't argue with the above, Big Bang Theory anyone ?

 

[CBF]

no based on experience, so you feed 40k of rads on 15mm then wonder why they don't work, plus Lee you are talking about pipework rads work on a delta t of 50 degrees not 20

i didn't know a pop band knew anything about heating calcs

experience is variable. Physics is constant. You cant argue with correct calculations because you have always done it that way.

so how many btu's would you feed on 15mm ?

 

[mickyg]

no based on experience, so you feed 40k of rads on 15mm then wonder why they don't work, plus Lee you are talking about pipework rads work on a delta t of 50 degrees not 20

i didn't know a pop band knew anything about heating calcs

experience is variable. Physics is constant. You cant argue with correct calculations because you have always done it that way.

so how many btu's would you feed on 15mm ?

depends on the length of the circuit and the water speed, but most calculations with domestic steamers and pumps will give you at least 8-9kw.

 

[ALEC1]

from domestic heat sizing guide from CIBSE

15mm @ 11c delta t 6kws, @ 20c delta t 11kws

22mm @ 11c delta t 13kws, @ 20c delta t 23kws

28mm @ 11c delta t 22kws, @ 20c delta t 40kws

thats the quick pipework sizng table

 

[gaswizzard]

plus Lee you are talking about pipework rads work on a delta t of 50 degrees not 20

And your point being.................?

Must dash got a LLH to size.

 

[Biggles..]

So where did we end up.

11-12 ish Kw from 15

That's without someone confusing radiator/air delta t which we tend not to use 50 for either anymore, but then we don't use BTU's either.

Adam it'll be massive if you only get 4kw from 15....you might need a load leveling cylinder.

 

[gaswizzard]

Adam it'll be massive if you only get 4kw from 15....you might need a load leveling cylinder.

, might size it for a 5 delta T.

 

[Biggles..]

Maybe a fact and figures guru maybe along later to help you out with it pal.

 

[gaswizzard]

Hope they come along soon as getting impatient now.

 

[newbuildinstaller]

Its great when people are told an answer, then shown the reason why its the answer, then shown industry specs confirming the answer and yet STILL disagree with it. Then back up their arguement with the fact that they dont THINK its right!!! Some people cant be helped

 

[twgas]

Ok, I got it a tad wrong, in my defence it was back in the 70s when I started.

 

[Dan Robinson]

CBF is rather conspicuous by his absence

 

[Biggles..]

I'm sure he can explain why we're wrong especially his 50deg ΔT knowledge

 

[CBF]

sorry i was rather tied up with that microgenius & the seeming lack of flow but i'll check tomorrow if the whole house is 15mm from the boiler, but's it's only 32kw so it should be ok if it is