Under Floor Heating

[DeltaT2]

Best way to control UFH?? Well, it depends if you have a large thermal mass ie pipes in concrete screed, overlay or thin screed.

Most common systems are concrete screed, so I'll explain that; Because it's radiant heat, 17 feels like 21C, so set your room thermostats to 17C for when you want heat & 5-8C overnight or periods when you don't want heat on 'set-back'. Large thermal mass UFH is very cheap to run, but running it 24/7 is plain daft, use 'set-back' room thermostats on thermal mass systems or even better on a WC system.

Of course overlay or thin screed systems are more expensive to run & are controlled more like a radiator system.

Having UFH in a Bedroom zone is also daft, much better to have standard emitters in these areas.

 

[snb]

the bills do seem a little high but that depends on how far out they were withthe previous estimates.

Bear in mind that nov/dec/jan/feb will account for around 75% of your yearly gas consumption.

I would alter the blending valve down to 35 and see after a week if the house is still warm enough. If it is then you could possibly drop it down to 30 if your system will let you do it.

The bigggest reason that causes high consumption with underfloor is having the system switching between comfort and setback. This causes the system to put too much heat into the floor and then causes temp overshoots.

 

[DeltaT2]

the bills do seem a little high but that depends on how far out they were withthe previous estimates.

Bear in mind that nov/dec/jan/feb will account for around 75% of your yearly gas consumption.

I would alter the blending valve down to 35 and see after a week if the house is still warm enough. If it is then you could possibly drop it down to 30 if your system will let you do it.

The bigggest reason that causes high consumption with underfloor is having the system switching between comfort and setback. This causes the system to put too much heat into the floor and then causes temp overshoots.

100% agree mate.

 

[paulpa]

Ok, i will do this for a week see how it goes.
Set blending valve to 35 degrees.
Set comfort to 19 degress on from 8am - 9pm, then eco mode 17 degrees from 9pm to 8 am.
See how it goes.
Many thanks.

 

[snb]

don't have eco mode for more than 8 hours or it will cause the system to put too much heat in to underfloor to catch up and then 12- 18 hours later you will have overshoot.

 

[paulpa]

overshoot.

What is that?

The bigggest reason that causes high consumption with underfloor is having the system switching between comfort and setback. This causes the system to put too much heat into the floor and then causes temp overshoots.

And how would you set the stats?

Is my suggestion
"Set comfort to 19 degress on from 8am - 9pm, then eco mode 17 degrees from 9pm to 8 am" Not the correct way.

I assume i,m understanding comfort and eco correctly.
Comfort is the desired running room temp, and eco is the night (off) setting where should the temp fall below the setting it will fire up