Need expert advice/opinions for AHT - Tile Advice

[discjockeyr]

Hi,

This is the first year that i am using my underfloor heating. I have install the AHT ribbon. The company that install it is one of the bigger installers in my country with many years experience. They insist that by installing the ribbon cables in-screed and not just below the tiles is better as the screed can hold temperature for more ours. Actually my AHT is 3-4cm below cement then there is an adhesive and then the tiles. What is your opinions regarding this type of installation? Also my second question is regarding the thermostats. I am using the XSTAT from warmup company. What i would like to ask is about the settings. There are some options regarding the subfloor like screed, Concrete, IBB, WBP Ply, Backer Board. What i cannot understant what difference can make to the heating mats those settings? The thermost actually switch ON or Switch OFF the power to the Heating mats, so what the usage of those settings?
Thanks in advance

 

[jay]

hi sounds interesting i can understand it holding heat longer but it will also be slower warming up as for settings might have something to do with the amount of diff in temp when temp drops below set temp it must work out how much power is needed to bring back to set temp safely:8:

 

[Dan]

You've used Ribbon under floor heating for an in-screen application?

My understand is ribbon underfloor heating is for carpet, directly under the low tog underlay.
Cable or cable mat is for under tile adhesive, usually just with a thin coat of self levelling compound under that.
And actual thicker cables for in-screed, often called "in-screed underfloor heating cable" is for in-screed applications. Both cable/cable-mat or in-screed for tiles.

Then under laminate flooring there's 'foil' or 'carbon' underfloor heating which is a really thin sheet.

And all of them will do a better job and be cheaper to run if you use the right insulation directly underneath the UFH.

I don't think I'd want to use Ribbon as in-screed under tiles at all to be honest.

 

[discjockeyr]

Hi Dan,

AHT manufacturer (israel) for many years was advertising ribbon for all floor types (Ceramic, wood, carpet etc). Now some companies that using ribbons and also have the wire type advertise that ribbon is better for laminate and cable for ceramic tiles. The installer in my country insist that after several years experience by installing AHT in screed getting better results. As i told you this is the first year that i am in my house. After some months i found that the AHT needs about 1-1:30 hours to start generates heat but when you switch it off the tiles need several hours to cold as the cement hold temperature for several hours.

 

[Dan]

With In-Screed cable you'd find less energy and time is required to heat up, and you'd still benefit from a slow cool-down too. That's all mate.

AHT have marketed it for all applications, but I've found, and many others have found too, that cable is best directly under tile, and proper in-screed cable is specially designed just for in-screed applications.

Under carpet however, I don't think there's a better system than Ribbon. Problem is, warm carpet contains more bugs and grubs than any other floor surface type, and asthma sufferers suffer more around heated carpet than not heated. And to be honest, asthma sufferers are probably better off going with laminate or tile or some other flat easy to clean surface.

Sorry I can't help with your original questions though, I don't really know much about the XSTAT.

 

[discjockeyr]

Hi Dan,

As i told you the installer here after several years of experience he found that is better to use ribbon under 30mm screed. Now if this is a mistake what can i say, i will have a problem in this case. I was not an expert so i trust him. Also in his personal house i saw a photos he also install it under screed. To be onest after several test. it need about an hour to increase the temperature of the tile about a degree but i have also test the temperature of the tile after 15hours were the aht was switched Off and i found 4 degrees (celsious) more than a point next which do not have a ribbon cable below. So what can i say hope that i will not have a problem.

 

[Olz]

To answer your original question, I beleive that the different subfloor settings are there to adapt for the different thermodynamic? properties of the different subfloors.

For example if you want your concrete floor to be at 20 degrees at 0730 the system would need to come on earlier to heat the floor.

If instead the system knew it was only heating a tile backer board much thinner that a concrete screed it may not need to come on as early.

Just set it to the relevant sub floor and enjoy having toastie warm feet.