Distributing water via manifolds (22mm to 10mm for radiators

[mattandrew]

I am about to totally re-plumb an old cottage. I need to replace all pipe work and radiators, bathroom etc. I have a couple of ideas of what to do.

suplly all hot & cold water in 15mm
For the radiators i was going to supply a 20mm pipe to a central place then use a speedfit manifold (22mm to 10mm branch) then run 10mm to all the radiators. 10 in total
22mm to manifold 10mm return from radiators

Can you see any problems doing this? Would the 10mm supply enough heat to my radiators the 10mm runs could be up to 10metres at a rough quess (not measured properly)

Cheers matt

 

[Agile]

No professional would recommend you to fit any pipework until you have calculated if the flow rate will be adequate.

Supplying a radiator at a distance of 10 m with 10 mm tube sounds like a disaster about to happen.

All professionals that I know use a minimum of 15 mm to supply rads!

Tony

 

[ChrisR]

There are folk using microbore, but it's easy to get it wrong, so somewhat out of favour.

 

[chrishutt]

There's nothing wrong with microbore, provided it's flow limitations are understood. Most rads can be fed by 8mm tube, depending on the length of the run and rad load (kW). 10mm tube will cover virtually everything excepting very long runs with heavy rad loads. Now that the preferred temperature drop across a system is 20 C rather than 11 C, the flow rates through rads are lower and microbore even more appropriate.