Copper pipe sizes.

[vdp1]

Will it matter if the flow to a towel radiator is 15mm and the return is 22mm or visa versa, as I want to utilse the old hot and cold copper pipes that are still under the floor and run the exact way I need them too.

Also Will a 700x600 (2200BTU) and a 500x600 (1700BTU) be ok on the same 15mm supply/return feed.

I am ok doing the physical side of plumbing, just not too clued up on the calculations.

[Rickyy]

All three will be fine.