kilowatts along 10mm/15mm/22mm copper.....

[fred]

.... at typical combi flow rates?

I've seen this mentioned somewhere but damned if I can find it. Just trying to get a ball-park figure for rads feedable from each size. TIA

[Pete C ukdiy]

Might be in here:

cheers, Pete.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "fred" saying something like:

Approximations:

22mm 24kW 15mm 12kW 10mm 6kW

[fred]

Many thanks.

[Donwill]

Strange!!!, For a flow velocity not exceeding 0.75 m/sec (recommended for domestic)

22mm 7.6kW 15mm 3.07kW 10mm no figures.

For a flow velocity not exceeding 1m/sec (recommended for industrial)

22mm 14.65kW 15mm 4.7kW 10mm no figures

These carrying capacities are calculated on a temperature drop of 11deg C in the system.

The figures are so far apart from the previous contributor there must be an error somewhere.

Don

[dennis]

11 deg C drop.. condensing boilers need a bigger drop so the water has to give out more heat.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Donwill" saying something like:

28mm 24kW 22mm 12kW 15mm 6kW 10mm 3kW

Used as a quick and dirty rule of thumb I've found this to be good enough for general purposes. It tallies much better with your figures (and no, I'm not just correcting them to look better).

[Dave Plowman (News)]

Interesting; my new 28kW system boiler has 22mm outlets. Either it's pushing the water round rather fast or it's not going to work when it's cold.