Small scale under floor heating using simple limiting valve

[garyo]

I'm building a kitchen extension that's 3M by 6M. By the time the wall thickness and kitchen units are taken in to account, the exposed floor area will be around 2M by 5M. I'd like to conserve wall space by avoiding traditional radiators, and don't like the under-plinth fan type heaters.

I've read some articles that say you can plumb small scale UFH loops in to the existing CH pump and then use a limiting valve such as this one: https://underfloorparts.co.uk/product/underfloor-heating-injection-valve-return-limiting-rtl/

Does anyone have any experience or recommendations? I've also seen some recommendations to fit a single small rad in the room in series with an UFH loop and then let the thermostatic rad valve control the flow along with the rad balance valve. That approach feels like there'd be too much risk of the system running too hot to me, though.

The current CH set up has two pumps - one for the upstairs and one for downstairs.

Thanks

Gary

 

[Agile]

I would be more worried about getting enough heat output.

Typically UFH gives about 100W per square meter which will be about 1 kW. Possibly enough if it is well insulated.

But the difficulty with UFH is the long warm up/cool down times. I hope you realise you will need to start it earlier than the rest of the house? I wonder how you plan to achieve that!

Because kitchens with cooking can get hot quickly then the heat needs to be extracted and that's rather wasteful to loose all the heat you have built up over a couple of hours.

Surely you can squeeze in a vertical rad?

What do you have against plinth heaters? They have a very rapid heat up and are so efficient.

 

[garyo]

Surely you can squeeze in a vertical rad?

Yes, I reckon I could get a 600mm vertical double in, so that'd probably be 1kw too. Perhaps I should do both. The kitchen will be open plan to a 4m x 4m breakfast room that has a radiator that I'd say is 2kw so the two rooms together will probably be able to dampen down the spike of heat generated from having the oven on.

But the difficulty with UFH is the long warm up/cool down times. I hope you realise you will need to start it earlier than the rest of the house? I wonder how you plan to achieve that!

Mmm no idea!

 

[Agile]

I think that you can get vertical tube rads about 1800 high and only about 400 wide that can give about 2 kW output.

I would want to significantly over size when the room may want to be warmed up quickly. As soon as that area is warm the TRV will turn it off anyway.

A typical UK lifestyle is to get up upstairs and then come down to the kitchen to make coffee/breakfast so having the kitchen nice and well warm quickly is good!

 

[Steelmasons]

I think that you can get vertical tube rads about 1800 high and only about 400 wide that can give about 2 kW output.

Really??...what type of 'tube' radiator would that be?
Average heat output for a 400x1800 vertical radiator would be around 800 watts (2730 BTU's).

 

[ianmcd]

Really??...what type of 'tube' radiator would that be?
Average heat output for a 400x1800 vertical radiator would be around 800 watts (2730 BTU's).

I do not understand why some inferior engineers state outputs in BTUs, we have been Metric for a long time and all quoted outputs should be in KWs