Underfloor heating pumped/manifold or un-pumped small area

[lchris21]

Hi All,
I'm at the stage of researching the underfloor heating I'm putting in my small 3x6m extension.
The total floor space to be heated minus kitchen cabinets etc will be appox 10m2.
I've got a rad in an adjacent/connected room which I'm keeping and was wondering whether to go with a pumped/manifold type of UFH or just use Uponor's small area kit (up to 14m2) which uses a feed off the exisiting rad ciruit and limits temp via a limiting valve?

Any con's with going with the unpumped system? I'm all googled out and need to make a decison !!!
I'm edging towards the un-pumped system with a view to buning in a pump and manifold at a leter date if its not performing as planned.

Cheers

 

[ianniann]

If your existing pump provides sufficient spare head and the pipework to the area is appropriate then you shouldn't have a problem. Otherwise either the new room won't heat properly or existing radiators will be starved. That's a quite a complicated thing to calculate accurately, but you can get a rough idea from the number of radiators and the pump power.

I'm not keen on this type of valve for controlling the flow temperature, but people seem to use them without too much trouble.

 

[mysteryman]

I would think it will be OK to add the system you propose as it is so small.