Radiant electric heat beneath tile....

[thefed]

Anyone have one of these mats installed? Im looking at the Suntouch system from Home Depot.

Any input, information, or advice? Im planning on putting it in a new basement bathroom im constructing.

 

[heyyou]

Wouldn't you need some insulation under the heat source to keep from heating the concrete floor? Is the visible floor raised above the concrete? I'm skeptical of the energy use if the seller is the only one saying their product saves energy over some other method. It may well be comfortable but at what cost? Ask your electric company for their opinion of that product.

For floors not in contact with the ground, that may be a good way to go.

 

[cute fuzzy bunny]

Its not much of a problem. You use a radiant barrier and if the slab warms up a little its no big deal...most of it will end up back in the house anyhow. Wood floors over a crawlspace or basement presumably have some insulation under them, and wood isnt too bad of an insulator.

Hot water radiant is more efficient than electric, but man are radiant heated floors the bomb.

My old 1950's era house back in Boston had radiant heat...cast iron hot water pipes running right through the slab. Worked great until the slab cracked a little too much and the rusty pipes broke. In 1991.

Get out of bed and damn the slippers. The floor is toasty warm.

 

[samclem]

Well, it's a luxury. It is electric resistance heat, which is the very most expensive way to make heat. It will make the floor nice and toasty, but you will also be heating that big concrete slab underneath, which is not very efficient. Also, it won't be instant heat--it will take some minutes for the floor to get warm. That would seriously reduce it's utility in my mind--I wouldn't want to run an inefficient electric heater all the time, and when I enter the bathroom, I don't want to wait 10 minutes after I turn the heater on to feel the heat (unlike a heat lamp or one of those old-style resistance heaters that they used to put into bathroom walls--turn the dial and feel the heat right now).
It will only save you money if it allows you to leave the furnace set to a lower temp.
I don't know how long it will last. All electric resistance elements I'm aware of eventually burn out.

 

[Telly]

I looked into the concept last year. I researched the SunTouch system in particular. This was for a bathroom on a concrete slab in TX. Samclem has covered the problems well.

The relatively good heat conduction of concrete, coupled with the large thermal mass of the concrete, will require a large amount of heat for a long time to do any good. From Suntouch's own charts, maybe I could get a 10 degree F rise after quite a while of running it. 10 degree rise over ambient ain't much. And the usual use of a bathroom is counter to a long warm-up interval.

The only way it would work for me is if I insulated the slab first. No way was I going to build up some big thick sandwich and then mortar big porcelain tiles over that. Concrete by itself makes a great base for tile, though a thin crack-isolation membrane can help longevity, particularly in bigger rooms. People who have no choice but to put tile over a wood sub-base who do it right want at least a 1/720 flexing moment, and they do a lot of work to get the floor that stiff. Since I have a concrete slab, it's bending moment is extremely high, no way do I want to lower it to wood-construction levels by making a squidgey sandwich

So for my application, radiant in-floor heat just isn't worth it. So I just refurb'ed the IR Heat Lamps, they give instant toasty on the few mornings it is needed. And since it is simple and overhead, what little maintenance that may be required is easily performed... and cheap!

True, all of the floor area is not covered by the IR lamps, so if one gets the urge to do a fan-dance on a cold morning, just stay in the spotlight on the stage

 

[Martha]

When we redid our bathroom floor we put in one of those electric radiant heat mats. We put down cement board over the subfloor, the mat and then marble flooring. We hooked it up to a timer so we could set it to start up about 4:00am so the floor would be toasty at 5:00am when I got up. We also have a thermostat hooked up to it. This turned out not to be necessary as we just use the timer and always have it on high.

 

[OAG]

Throw rugs are cheaper. Just a few will improve your agility on cold mornings.