Upstairs underfloor heating

[PeterM88]

Hi,

I'm building a pair of semi's. (DIY project got out of hand. ) I want to install underfloor heating, both downstairs and up.

Although experinced with plumbing, I've never done underfloor.

My question is this... I've been recommended to use a screed upstairs to act as an heat sink.

No real problem, I create a 'ledge' with 2x1 put 50mm of rigid insulation, membrane, fix pipes cover with screed.

But I got to thinking, (dangerous) since the screed actually cariies no weight (it being covered by boarding) would sand do the same job?


Anyway, any advice on composition of the screed, (whether my idea would work or not..) depth it needs to be etc would be a big help.


I was planning on mixing my own.


Thanks

 

[DeltaT2]

Even a 40mm weak Pug is good Pete. Of course you need to ensure the joists can take the extra weight & the span etc is OK. A Pug system is a lot better than plates or heating an air gap.

 

[DeltaT2]

Fit Viessmann Vitodens 200-W boilers with weather compensation. You adjust the weather comp to suit the underfloor. Connect the CH flow from the boiler straight to the UFH manifolds. You will not need the UFH manufacturer's pump, blending valve, timer or thermostat. Nothing can be simpler, more efficient or economical.

But MM, he's asking about the UFH install. Are you flogging Viessmann boilers all the time?? Is there no spam control on this forum??

Chances are he's got 2 Heatlines fitted if he's a Developer........

 

[DeltaT2]

I am simply recommending the best boilers and best form of control. There is no sense in fitting cheap constant temperature boilers plus an underfloor pump and thermostatic mixing valve and external controls when it can be done so much better.

Hello!!!!.............The OP is a Developer, so I'd be surprised if he installs over-priced German boilers like that.

 

[ALEC1]

wood is a great insulator, and experience shows that there is no efficiency gain acheived by installing ufh, you end up running it at radiator temperatures!!!

 

[DeltaT2]

wood is a great insulator, and experience shows that there is no efficiency gain acheived by installing ufh, you end up running it at radiator temperatures!!!

That is a statement by someone that has very little knowledge of UFH or Radiant heating of any type.

 

[Agile]

As an independent I can suggest a Viessmann 100 or an Intergas as alternatives to a Viess 200.

As the OP wants UFH then he does not want a cheap job!

In an ideal world my ultimate boiler would have a facility for different WC curves to cater for ground level solid floors and upstairs suspended floors. That could also be achieved using seperate pumps and blending valves. Seperate zone timing would largely overcome this though.

OP, sand does not have the heat transmission like weak concrete so would not be as good.

Tony

 

[Agile]

The Intergas does have an aluminium block heat exchanger!

But the waterways are all copper pipe encased by molten aluminium during manufacture.

I agree the Viess 200 series are very versatile. Such a pity so few customers can understand how to use them!

Tony

 

[DeltaT2]

The Intergas does have an aluminium block heat exchanger!

But the waterways are all copper pipe encased by molten aluminium during manufacture.

I agree the Viess 200 series are very versatile. Such a pity so few customers buy them

That's cause they're over-priced, over-engineered & over here.
Buy British Tony, British products so British jobs. F.cking Krauts & their dodgy Euro!!!

 

[Agile]

I totally agree with you in principle Dick!

However, that leaves you with just Ideal or GlowWorm boilers ( or Ravenheat assembled from foreigh made parts ).

Its very unclear if any other boilers are really to any extent made here!

 

[big-all]

heeelllooo and welcome PeterM88

as long as you realise underfloor is only suitable for well insulated houses or as a secondary heating system in an old draughty house with normal radiators to warm the house
in general underfloor is very ineficient unless you are very well insulated and dont use your heating in a few hours heating morning and afternoon

 

[DeltaT2]

I totally agree with you in principle Dick!

However, that leaves you with just Ideal or GlowWorm boilers ( or Ravenheat assembled from foreigh made parts ).

Its very unclear if any other boilers are really to any extent made here!

Good point Tony and I like most have had many hairy experiences with both.
But I understand there's some good reports on the Ideal Logic range and Opentherm compatibilty.