Is eletric radiant heat worth installing for a bathroom floor?
January 19, 2018 11:11 AM   Subscribe

We are remodeling our second floor master bath in northeastern Illinois and are considering including electric heat under the tiled floor. Is it worth the cost? What temperature do you set it for? Is it on all the time? Does it heat the whole room? Do things on the floor get warm or hot? What brands should we consider or avoid?
posted by grahahw to Home & Garden (17 answers total) 5 users marked this as a favorite
We just bought a house that has this for several rooms, including the main bathroom. We love it. I wish the downstairs bathroom had it too. Ours is gas, not electric, but I imagine function will be the same. It's set to 68 during the day and 66 at night, which is what the seller had it set to and we find works well. We were told by the seller (who is a plumber) and my BIL (who works on renovations) that you're supposed to leave it on all the time. It is the only source of heat in the rooms that have it (except for a fireplace in the living room) and they are more comfortable than the rooms that have radiators. Things on the floor do get warm, but not crazy warm. Our dogs love low profile beds on the floor now. One of ours spends all day in the kitchen (which has it too) now, instead of on the couch like she used to.
posted by disaster77 at 11:28 AM on January 19, 2018 [1 favorite]

We live in an apartment and do not have it, but my boss has radiant heating in his bathroom and he tells us about it AD NAUSEAM, so...he does have it on all the time and uses a combination of "smart home" devices like Sense to keep tabs on it. He discovered that what works for him is to have the temp go up to 70 degrees just before he gets up in the morning so the floor is warm when he walks in for his morning shower, turns it down a smidge for his wife (who prefers it a little cooler), then drops it down to 65-66 once everyone has left the house for the day.
posted by briank at 11:49 AM on January 19, 2018

We installed one when we redid our master bath about 6 years ago. I can't remember the name brand (something with 'sun' in it). It was a great decision! It is always on, but has not noticeably increased our electric bill. It operates from a wall-mounted thermostat that has some pre-programmed schedules (or you can program your own). The one we chose turns the heat up around 5am, then down around 9am, then up again for a while bracketing bedtime. It makes the tile comfortable all year round. You can choose a lower setting for the Summer months, or turn it off completely during that time. Highly recommend.
posted by Don_K at 12:11 PM on January 19, 2018

We installed radiant heat so we could remove a large radiator in our small bathroom. Ours doesn't work perfectly; the room can still feel chilly even when the floor is set to 80 degrees. It also uses a good amount of electricity. But it was well worth it to get the additional space.
posted by Winnie the Proust at 12:37 PM on January 19, 2018

We built a house with radiant heating on the main floor, but had to forego the radiant heating in the tiled bath upstairs for budgetary reasons, which was a big mistake in retrospect. I think it's one of those things that once you've had it you don't want to live without it. I listen to a home improvement show and the host talks about his radiant bathroom heating that he has on a timer.
posted by sarajane at 12:46 PM on January 19, 2018

If you know anyone who has radiant heat and would let you experience it, you should see what it feels like to you.

I personally don't like it, it feels really unnatural to me and makes me feel like I'm in a pot being slow-cooked. Other people love it.

The point is, you should find out if you like how it feels before you spend a bunch of money on it.
posted by under_petticoat_rule at 1:06 PM on January 19, 2018

We are in the process of renovating our basement and opted to put in electrical radiant though the whole space, less the mechanical room. Ours is under a newly laid polished cement floor. The electrician told us to leave it set to a steady 74 in the winter, and it warms that whole space nicely. It seemed high to us but he said the floor heat is set higher than the desired air heat, and the space itself is at about 72. We will turn it off when the weather warms up. It feels neutral on my feet, neither warm nor hot. Friends who have it in their bathrooms have distinctly warm floors. This article seems to suggest it depends on the insulation/energy waste in the space. As part of our basement reno we gutted the space, and put in all new very high quality insulation, so I guess that make sense.

In our case radiant floor heating came recommended by family who had taken the plunge and the architect we hired We liked the idea of getting rid of the wall heaters that used to heat that space. That part of the house is already our favourite over the forced air that we have on the upper floors. It is a very pleasant warmth. We went with electrical though there are water versions as well.
posted by Cuke at 1:15 PM on January 19, 2018 [1 favorite]

We had to totally gut and finish a bathroom in our older house a couple years ago. We put in an electric heating system under the tile floor and don't regret it a bit. We have forced air heat in that room, but use it in the morning and evening (on an automatic thermostat) to make barefoot Minnesota winters more tolerable.
posted by nordic_hammer at 3:20 PM on January 19, 2018

We installed it in our bathroom during a remodel about 2 years ago. The room is otherwise unheated (SoCal).

We have a timer and set it to turn on just before we wake and then off about the time we shower. It takes a long time to heat the floor & then the room, it's on for about 3 hours a day.

It makes the room comfortable, but not hot. I think it gets to 95 at its peak.

Here's what we learned though: you must account for the height the radiant floor panels add to your floor when doing your subfloor and rest of your design. And you also should not put it too close to a toilet that uses a wax seal for the drain.

Our flooring install guy was different from our plumbing/tile folks, so when they roughed in the plumbing they didn't account for the extra two inches the floor added, so our sink is probably a little lower than standard (our faucets are wall mounted).

And as you asked, things on the floor do get warm, so if it's a larger room and you have a potted plant or perhaps set down your make up kit on the floor, that may cause things to dry out or melt.

We only use it about 12 weeks out of the year, but it means we don't have to run the heat in other parts of the house or even the bedroom.

As for whether it's worth it ... I would do it again. I prefer the gentleness of the warmth on my feet to forced air.
posted by typetive at 5:06 PM on January 19, 2018

There are two different technologies you may be considering: Radiant heat and a heated floor.

Radiant heat is sized to heat the room and is pretty glorious. This usually isn't an add on but part of central heating system.

A heated floor is sized to heat the floor to make it comfortable for bare feet.

The latter isn't really designed to heat the room. The mats the electrician installs will typically be around 12 W/sq ft so a typical bathroom with about 15 sq feet of bare floor will only contribute 180W of heating to the room (less than all but the smallest electric baseboard and about the same as 2 -100W bulbs or 1/10th the output of a typical electric space heater). The systems are pretty cheap to install if you are already installing tile and because of their low output don't cost much to run intermittently. In mild climates they may provide all the heat one needs in that room.
posted by Mitheral at 8:58 PM on January 19, 2018

We have an electric heated floor in our bathroom. It's perfect for cool San Francisco weather. It's on a wall-mounted timed thermostat control. It takes a while to warm up -- I think ours is set to go on at 5 am and off at 9 am. Try different temperatures to see what works for you. It's about like walking on a tiled floor that's been heated by the sun -- warm and comfortable. Things on the floor don't get hot. It doesn't really heat the whole room but definitely takes the chill off and it still feels luxurious to me to step out of the shower onto a warm floor.

The cats love it and take full advantage of it. It was definitely one of my best ideas when I had the bathroom re-done.
posted by gingerbeer at 11:45 PM on January 19, 2018

We put it in under the tile in our basement bathroom in a DC rowhouse. It's great and keeps the floor warm, but our version isn't powerful enough to actually heat the room. During the recent severe cold snap, we needed to use the ceiling mounted exhaust fan/electric heater combo unit to make the room comfortable, but that was an unusual situation.

We leave it at 82 degrees all winter and then turn it off once it warms up outside. It hasn't added anything noticeable to our electric bill. The room is small, maybe 60 sq ft, so the total cost wasn't bad, between $1,000 and $1,500 (I don't remember exactly). In retrospect, I wish we had installed it under all the basement floors, not just the bathroom.

One shortcoming, is that the mat must not extend all the way to the wall, so the floor gets very cold close to the exterior wall, which is unfortunate...

I do hear the wall mounted thermostat click on and off, even from the next door room. Doesn't bother me, but might annoy people who are more sensitive to noise.
posted by jindc at 5:49 AM on January 20, 2018

We have it and love it! Best thing ever! Be sure to install at least two sensor wires with it so if one is damaged the other will work.
posted by stewiethegreat at 6:34 AM on January 20, 2018

We've installed both whole-house hydronic and electric radiant heat, and comfort-oriented electric radiant heat in bathrooms. We like it.

>Is it worth the cost?

Depends. What do you pay for electricity, how many square feet do you intend to do, is your bathroom on an exterior wall and if so how well insulated is it, and how hot would you run it?

>What temperature do you set it for?

If the thermostat is in the floor itself, about 80 degrees is pleasant. If you aren't going to use a floor thermostat, then a timer is probably the way to go. Controlling the temperature of a radiant floor in a bathroom with a thermostat on the wall is an inferior solution.

>Does it heat the whole room?

Generally not, but it depends on how big your bathroom is and how fast it bleeds heat to the outside world, and what your climate is at what time of the year. A bathroom that is fully contained in the house (no exterior wall surfaces, including floor slab and/or unheated attic) will be more easily heated by the electric floor than one that bleeds heat to the Illinois winter through a wall or floor.

On average, you'd need about 60 BTU per square foot of floor space, on average, for home heating in a cold climate. A hundred square foot bathroom would need 6000 BTU, or about 2 kilowatts of installed floor heat. Electric floor heat generally runs about 15 watts per square foot, or about a quarter what you would need for the heating requirements of the bathroom.

>Do things on the floor get warm or hot?

Yes. If it an item with a high insulation value, like towel or a pile of laundry, it'll get warmer. If it is a shoe, it'll just get a little warm. It's nice.

One thing you might consider is installing it in the walls of your shower and/or bath, where you get naked and wet. It's glorious, and greatly reduces mold problems.

Don't forget to insulate the walls and floors where you install the radiant heat, with a radiant barrier first, and then conventional insulation: the losses due to infrared radiation in the other direction can greatly reduce the power going through the tiles. Although it doesn't sound like you will be installing it yourself, you will have to use GFCI protected circuits for the power for electric radiant heat. Remember also, thermostat sensors fail, and need to be installed in a serviceable location.
posted by the Real Dan at 12:59 PM on January 20, 2018

> Controlling the temperature of a radiant floor in a bathroom with a thermostat on the wall is an inferior solution.

Why do you say that? Inferior to what? I find the wall-mounted thermostat to be extremely convenient, accessible, and easy to set and to change. I use the one that came with the electric floor set up.
posted by gingerbeer at 11:20 AM on January 22, 2018

Ah, sorry. Controlling the temperature of a radiant floor in a bathroom by sensing the air temperature of the bathroom (a thermostat on the wall) is an inferior solution.
posted by the Real Dan at 10:42 PM on January 26, 2018

Got it. Agreed. The distinction isn't the location of the thermostat, but what it is measuring - air temperature vs floor temperature. Thanks for clarifying.
posted by gingerbeer at 9:13 AM on January 27, 2018

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