Electric UFH The real difference between different wattage per m - Tile Advice

[Flintstone]

What are your opinions on electric underfloor heating outputs? I always go for the 200w option. A few of the uncoupling systems seem to be 160w ish, I’m not sure why that is? The elektra one and the varme one spring to mind. I know warmup dcm pro can go up to about 230w. In a normal kitchen dinner environment or bathroom, is the difference in power really going to be noticeable, Thoughts?

 

[Andy Allen]

Always thought 200w was more for rooms with no other heating in them to heat the room rather than just the floor.
150w for rooms with radiators just to heat the tiles.

 

[Dumbo]

Surely it can only be noticeable during warm up after all 30 degrees is 30 degrees .

 

[Time's Ran Out]

It’s all to do with the substrate.
You should not be using a wattage over 120-140 for wood and 150-200 for concrete.

 

[Flintstone]

What’s the reason for that, John?

 

[Time's Ran Out]

Overheating the wood - risk of fire?
At CTD they always ask which do you want for wood or concrete.
Devi, Raychem, Thermonet all differentiate between the two substrates.
From what I understand the cables are arranged closer to each other for the higher output .

 

[Flintstone]

I wouldn’t advise anyone to install direct to wood. Always insulation before wires, so the heat won’t get to the wood! They all reach the same temp I think, just the time it takes to get there ?

 

[Flintstone]

DEVI 200w Mat



The new DTIF-200 is a high output mat with 200 Watts per m² which makes DEVI´s new heating mat a decisive winner, when it is speedy heating that counts.
Excellent when there is great demand for rapid response time and high output.
High output per m² resulting in instant warmth gives the DTIF-200 a number of possible uses:
• when renovating areas such as conservatories and cellars, which loose a large amount of heat
• in small bathrooms with a relatively small floor area compared to the size of the room
• with timer control
Areas of application and technical specifications


DTIF-200 is designed for installation in floor constructions of concrete or with tiles and where the heating element is installed close to the floor surface.

 

[Time's Ran Out]

Yes - just for concrete.

 

[Flintstone]

I think it means on concrete, or as long as it has tiles on top. You can use Lino and karndean over slc.

 

[Flintstone]

Thermonet say there 200w won’t get any hotter just heat up faster

 

[Time's Ran Out]

The heat is governed by the thermostat.
The mats usually have a 10 year plus guarantee and the thermostats 12 months. A failure in the thermostat will allow the mat to heat up above a safe level if a 200 mat is used over a wood substrate.

 

[Uheat - Jake]

There's different wattages for different floor finishes, bases and rooms.

100w/m2 mats are generally used only to give you a warm floor, these mats can be laid directly onto a timber base as they wouldn't cause it to warp. These can be used with any floor finish, however with a Wood or Carpet you'd need a 10mm Flexible SLC over the top.

160w/m2 mats are used for a primary heat source within a standard insulated room. (That's floor and wall insulation) These mats are the most popular as they offer a primary heating source without the need for any other heating source within the room. These are mainly used with tiles however can be used with Wood or Carpet restricting the floor temperature to 27 degrees.

200w/m2 mats are designed for high heat loss areas like a conservatory, these mats give off a higher output due to the cables being spaced closer onto the mesh. These mats will also heat up quicker as well due to the way they're spaced.

Generally all these mats will reach your desiered temperature however in different times but also the high wattages will maintain the heat for longer due to closer spacings on the mat. The reason the decoupling options can't be used at 200w/m2 is we only supply a 10w/m loose wire and the options on the membrane are to closely spaced for one spacing, this could cause the cables to burn out due to being to close. Our minimum distance between cables is 50mm.

 

[Flintstone]

Thanks Jake. Is the 200w suitable On a timber floor, overboarded with insulation board as per what John said is dangerous ?

 

[Uheat - Jake]

Thanks Jake. Is the 200w suitable On a timber floor, overboarded with insulation board as per what John said is dangerous ?

To use anything over 100w/m2 on a timber substrate you have to install a Backerboard. This is then fine to lay a 160w or 200w mat on top of with a tiled floor finish. Or a 160w mat with engineered wood or laminate with a 10mm SLC over the mat.