Under floor heating

[Richardthe3rd]

With screeded floors individual room thermostats in each room are a waste of money, the floor doesn't react quickly enough. Loads of controls are sold by UFH companies as the only way they can make a profit. There's a large Skool of thought that view weather compensation being a much better control.

Don't over complicate the controls side, it's just not worth it with UFH. One central thermostat operating on preferred daytime temperature & night time setback.
With UFH it mainly heats by radiant heat & very little convection, so 17degC can feel like 21.
HTH

 

[doitall]

The room stats are controlling the manifold stats and therefore the water temperature.

Are they needed, in my opinion Yes they are.

 

[ALEC1]

I have whole houses of up to 200m2on one outdoor sensor and no indoor sensing with Viessmann vitodens 200 series.

You can also run the rads on the UFH circuit, just up size them...

Much less to go wrong, one constant flow at a variable temperature..

Lower cost to buy, lower cost to install.,

 

[Dan Robinson]

Higher cost to run though

 

[ALEC1]

Well gas usage depends on occupancy hours among other things, and these type of controls give as many off options like normal on off controls...

 

[Dan Robinson]

But for a given occupancy and set point, your set up appears to cost more to run?

 

[ALEC1]

haha dan... I run my heating at 21c 20 hours a day...its not going to be cheap..

but my energy consumption over winter is only a tad more than others ... whose heating is on 7-8 hours a day.


Most people have heating to be comfortable... not to save gas...if they wanted to do that they would not have a gas boiler...

 

[Norcon]

I have whole houses of up to 200m2on one outdoor sensor and no indoor sensing with Viessmann vitodens 200 series.

You can also run the rads on the UFH circuit, just up size them...

Much less to go wrong, one constant flow at a variable temperature..

Lower cost to buy, lower cost to install.,

It would be easier and cheaper to provide wc flow from the boiler with the curve set for rads. Then let the blender lower the temp for the ufh.

Great big clonking rads are an eyesore.

 

[ALEC1]

there is no blender, direct from the boiler...curves set at about 0.7-9

sometimes even lower on new build

 

[Norcon]

So slightly over 50c into the floor slab at times. If we look at BS EN 1264 it states 50c "Not recommended"!

I think it will average cooler return temps over the year the way I've suggested and a lot cheaper to implement.

 

[ALEC1]

its weather compensated so the flow varies between 20c and probably about 45c, which is what I normally set the max flow temperature too...