Ufh Mat Advise

[J.C.E]

Morning guys

1st time I have been involved in ufh if I am honest.

Nearly complete 1st fix of a part re-wire plus double extension job- and now customer/builder has decided they want electric UFH throughout whole of ground floor!

Originally it was just in upstairs small bathroom- which is supplied by 13a switch fuse spur off of upstairs ring.

But now for downstairs!!:

The builder is using 150w/m2 topps tiles mat.....

So kitchen is 16.26m2- so after taking off 10% (for slight gaps around perimeter etc) =9.5amps
-not too hard having this on own 10/16a circuit and one wall programmer for this zone

Then Breakfast area is 11.19m2
And Dining room is 15.85m2

-but they want both of these mats/zones to be controlled by 1 wall programmer (max load 16a)

so for both zones -10% (for slight gaps around perimeter etc) around 15.77amps
-again not to hard to get own circuit over to here (rather than put on ring)
just stick on 16a/20a mcb and have a 20a dp switch rather than 13a spur?

cheers guys!

 

[J.C.E]

ps- not sure if I can/have to apply diversity etc...so look forward to your advises

 

[Dan]

Make sure you have a word with our resident ufh guy @Uheat – Jake

What flooring are the having downstairs? As the cable is only meant for under tiles.

 

[Dan]

@J.C.E Here's your original thread.

 

[Taylortwocities]

In my opinion, and experience. Electric UFH is OK to warm your tooties as you walk to the shower, but no good for space heating. For large rooms it's expensive and you'll need a couple of hours to get up to heat.

Also, any fault with element or temp probe and you are in to chopping up the nice tiled floor.

If they MUST have under floor heating, then get a wet, zoned system. That the only way to go.

BTW. There is NO Diversity for floor and ceiling heating.

 

[Dan]

You can get 200w/m2 which isn't too bad but you still want central heating.

 

[J.C.E]

cheers guys

the house has central heating- the ufh is just i guess a secondary luxury to show off with...

just wanted advise on my math and as one zone (2 mats) would >13amps- would a 16a/20a circuit with a local 20amp dp switch be fine?

 

[Dan]

Should be mate yeah.

They might want more control though. If you split the floor into sections and have the stats far apart (and more of them) you tend to find it's more economical because not all will need to kick in all the time.

 

[J.C.E]

cheers Dan

will be one circuit and 1 controller for living room
one circuit and 1 controller for dining room/breakfast area
one circuit and 1 control for kitchen

and upstairs bathroom is spurred of of upstairs ring with one controller

 

[J.C.E]

Should be mate yeah.

They might want more control though. If you split the floor into sections and have the stats far apart (and more of them) you tend to find it's more economical because not all will need to kick in all the time.

or sorry did you mean....you can have >1 stat to one controller? and have a few zones on each mat?

 

[Dan]

I'd take the two mats maximum (16amp) to each individual stat controller. And where the floors are greater than 16amp, have say two 10amps (if it's 20 say) and have the stat controller at either end of the room.

So one floor probe at one end and one at the other. Meaning the whole floor doesn't need to turn on, just because a door opened at one end of the room and made that bit of the floor and / or air cold.

 

[Taylortwocities]

Topps Tiles sell the Warmup product IIRC.
When I have had to do a UFH I have always preferred that.

 

[Dan]

Warmup is expensive. Especially in topps.

Go speak to uheat our sponsor. You get special discount with being a forum member. And if you do somehow manage to find a better price because of some promotion or something elsewhere, I'd bet my Sunday dinner they'd try to beat the price and deliver it faster with their better product.

(I get really really fussy about my dinner)

 

[J.C.E]

Topps Tiles sell the Warmup product IIRC.
When I have had to do a UFH I have always preferred that.

that's what he is using

their 150w/m2 for tiled rooms and there 140w/m2 foil mat for wooden floors

 

[Dan]

that's what he is using

their 150w/m2 for tiled rooms and there 140w/m2 foil mat for wooden floors

You want to speak to our man. He'll be paying well over the odds for that heating.

Also, we get cheaper tiles from a tile outlet on our tile forum.

I know it sounds like I'm touting for business, but I use our buying power of 56,000 sparks, 42,000 plumbers, and 23,000 tilers, to get us cheaper prices from firms we already use.

So it's wise to at least get a price.

 

[Uheat – Jake]

From reading through it seems like you've got multiple mats for one area and they're totalling more then 16amps?

We normally say if the total watts in between 3000-3600w then a 20A DP Switch can be used but for anything over 3600 then a contactor would be needed to switch the load.

Running multiple zones on one thermostat can be done however you've got to think about the temperature difference in the zones and where the thermostat is placed.

A kitchen & dining room for example, control them both off one thermostat and place the thermostat in the kitchen. When appliences are on creating heat the thermostat will read that and then kick off leaving the dining room with no heat at all.