Mixing ufh electric systems (ditra, prowarm etc) - small kitchen ufh

[gambo]

I'm tiling kitchen and am expecting the floor to be colder in winter than it it's with LVT, so I want to put around 1.5-2m2 of electric ufh with an output of roughly 150W total. The idea is that it will be nicer to walk on warm tile but the kitchen will keep its radiator as the main source.

Firstly, lots of different systems and I like ditra heat mat as it give a (very) little bit of insulation. Next I can get ditra heat cable but do I need thermostat from ditra too or is everything so simple in design that I can put a Mapei heat cable into ditra mat and link it with prowarm thermostat?

Given I'm heating tiles not the room how radiant the heat from the cable is? Can I cover 4sqm of kitchen with a 150W cable (normally intended for 1-1.5sqm) and still expect nicely warm floor?

[MikeGrahamT21]

You can use any UFH thermostat with heating mat/cable, as long as it’s rated more than the load you are wanting to run, which for your area will be every one in existence.

The worse the insulation underneath the floor, the less heat you’ll get out of it, but any heat which does go into the tiles which radiate into the room, it’ll certainly make a difference but how much depends on your insulation levels.

be warned as well, it can be quite expensive to run.

The cable itself isn’t 150w/m2, it’s the spacing of the loops that determines that, so by making 2m2 worth of cable span 4m2 your just making it 75w/m2, which will need some serious insulation to make a difference.

 

the other side to look at is how much you want the warranty, mixing systems will most likely void any warranty 

[gambo]

Insulation level is low, standard late 80s build. That's the reason the radiator stays and the ufh will be warming up the tiles rather than heating the room.

Any recommendations for cables, uncoupling mat, thermostat?

 

[Nickfromwales]

10 hours ago, gambo said:

Given I'm heating tiles not the room how radiant the heat from the cable is? Can I cover 4sqm of kitchen with a 150W cable (normally intended for 1-1.5sqm) and still expect nicely warm floor?

You can expect you left foot to be warm and the right cold. DO NOT do this! Just buy a 50w/m2 kit on a mat and do it properly plz!!!

[Nickfromwales]

6 hours ago, gambo said:

Insulation level is low, standard late 80s build. That's the reason the radiator stays and the ufh will be warming up the tiles rather than heating the room.

Any recommendations for cables, uncoupling mat, thermostat?

 

If you want a brand, then Warmup for cable/mat and a very good controller. The 3ie and 4ie (iirc) are good, with learning algorithms to predict how long it takes to get the floor to the desired temp at the desired time, so if it takes an hour to get to the temp you want at 07:00, it'll learn to switch the floor on at 06:00 etc, same for turning off (again iirc). Speak to their technical guys to get more clarity.