Underfloor Heating (Water)

[The_Scotty]

Hi folks,

Working on site just now the spec for heating in the Extension is underfloor heating.

Does anyone have any info on what effect adding underfloor heating has on the existing boiler. ie is a certain sq m of underfloor heating equivilant to adding X amount of radiators? We have had a couple of heating engineers out to estimate to do the work for us but both were unsure whether or not the existing boiler would be able to cope as they have no experience of underfloor heating

Whilst I'm on the subject does it really take long to heat up? Reading up about it a little bit it seems that it would only be on when the rest of the heating is on meaning the rooms with rads heat up as normal but the underfloor heated room takes longer.

Cheers

 

[The_Scotty]

Anyone?

 

[Balenza]

What sized area are you talking about ?.

I would suspect your existing boiler will cope unless seriously undersized previously.
Yes ,you have a delay especially with a screed system (perhaps up to 2 hours) and if you decide on UF heating then you have to live with this delay or have appropiate controls fitted and time the system to start earlier than the rads.

 

[The_Scotty]

Balenza, thanks for that.

Its not my house. We are the main contractor and will be subcontracting the heating work out.

Area's in question are 2 seperate rooms ( 12sqM approx in each)

If it was timed (it more than likely will be) how would it be possible for the UF heating to come on at a different time than the existing heating if the UF heating had been added to the existing (ie flow and return extended to new manifold for UF heating)

 

[Balenza]

A danfoss return temperature limiter (FHV-R) is ideal for 12 sq meters.
Their about £40. (bes)
Bes also supply a conservatory pack for about £300 which includes this valve and piping suitable for an area up to 15sq meters.
To run this independantly then you need to fit a zone valve and use a programmer/timer with the necessary channels to control this ZV.
Wirsbo also sell a pack utilising the FHV-R.

 

[The_Scotty]

Cheers. Thats pushing the limits of my knowledge so I'll leave it there

I was as much interested for myself as for knowing what'll happening on site when I find someone capable of installing it.

I saw a few of the packs for sale. A bit more complicated than I thought it would be but quite simple and clever nonetheless

 

[bengasman]

Make sure your installer puts in separate timer and stat, otherwise your customer will be complaining no end. Lag of 2, sometimes 3 hours is common