Confused about underfloor heating tile temp...

[tan8856]

Hi
We have had WarmUp electric underfloor heating in our tiled bathroom for 5 years and we love it. It is set to Floor Temp 32C in morning and evening and it feels just right underfoot. The air temp of the room stays around 21C when its on which is perfect.
We loved it so much we've just had piped underfloor heating fitted in most of the downstairs area. Ive just gone to set the Floor Temp and thought id do some research online to set the right temp as I know piped works differently to electric. The first article ive read says "Floor thermostats are ideally set at 21C - a pleasant temperature for stockinged feet - and the air, walls and furniture will reach that temperature as well." but my tiles are currently at 21-22C with the underfloor heating off and the tiles are flippin freezing underfoot! The article goes on to say "the absolute maximum you should set is 29C for a solid floor". Which makes sense as our new heating has a default floor temp limit of 28C (although it can be set as high as 45C).
So I have 2 questions:
1. Id like my tiles warm underfoot but the air temp around 21C, what shall I set the Floor Temp to? I was going to do 32C but it now seems that is much too high?
2. Have we been wrong to set our bathroom to a Floor Temp of 32C?
Thanks

 

[muggles]

What is the current air temp with the heating on?

 

[tan8856]

What is the current air temp with the heating on?

When the underfloor heating is at Floor Temp 21C the air temp was 20-21C (its not a cold day today and the rooms without underfloor heating are set at 21C)

Earlier I set the thermostat to Floor 28C and it has reached temp. But when I take the tile temp with a thermometer it says 24-25C depending on where in the room I measure. With the floor (allegedly) at 28C the air temp in the room is now 21.5C

 

[ScottishGasMan]

My question is if the underfloor heating fitters are competent why have they not sized the UFH system and set the temp for you?

Heat emitter temperature depends on a number of design considerations, with UFH that would be Floor area, floor type, heat losses from the rooms, Flow/return temps and amount of UFH pipe installed so theres not a one size fits all answer to how to set it.

Remember the idea of UFH is not infact to be warm on the foot, but to not be cold to the foot, and more importantly to act as a large low temperature heat emmiter to warm the room (over a considerable time)