No of radiators on a spur

[dd2005]

Can anyone advise on the number of radiators which can be run from a 10mm spur off the 22mm main ring (probably the wrong terms, sorry). We have a system with 22mm feed and return pipework in the upper floor of the house (ceiling of the ground floor), there is then a 10mm feed and return off this main pipework to each radiator.

I am moving/installing additoinal radiators to improve heat distribution and rather than installing additional feed pipework for each radiator would like to run 3 rads off one 10mm feed and return. Is this possible or will this increase pressure on my pump and/or will the radiators be ineffective due to lack of flow?

Any help greatfully received before I set about making a mess! Can upload sketches if it will help.

 

[Kev F]

can only run one rad off 10mm, some wont run on 10mm at all

 

[Morris40]

eaton is quite correct, DO NOT run more than one rad off 10mm pipe, can you not increase the size of this pipe to 15mm then you'll get 2 rads running nicely from that

 

[dd2005]

I read somewhere on this forum that they suggest a maximum of 2.3kW per 10mm feed? Therefore 2 smaller radiators could run off one spur. My only problem with putting 3 sets of 10mm downpipes in is the connections to the main 22mm ring and whether these should be staggered by any distance? I do have an area to box the pipes in so this is not a worry. Can I run 2 rads off a 15mm downpipe and the other off a 10mm?

 

[Kev F]

could try, wouldnt take any notice of the kw advice, its simple really you can have a 22mm pipe and come off it straight away for up to roughly 20 rads and be fine, but 10mm will and should only do 1 rad max. Some plastic fittings ie speed fit have a 22mm fitting called a manifold and it has 4 holes to take 2 rads

 

[D_Hailsham]

Small Bore Heating Systems explains it all.