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Community and Q&A

Bathroom electrical radiant floor vs. heat lamp

Rian Bart | Posted in Green Products and Materials on

My contractor recommended installing electrical radiant heat mat in the bathroom floor. He put his bathroom radiant floor on a timer 1 hour before he gets up to ensure the bathroom floor is warm in the morning.

I found an alternative – Panasonic Exhaust Fans WhisperWarmâ„¢ 110 CFM Ceiling Mounted Bathroom Fan/Heat/Light Combination)? The Panasonic spec says it takes “Heating Element Watts 1400” which also uses a lot of energy.

Has anyone compared the on-going energy consumption and comfort level of these 2 options?

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Replies

  1. Riversong | | #1

    If the bath mat doesn't electrocute you when you get out of the shower, it will offer more comfort per watt than an overhead heater, since people prefer warm toes and cool heads.

  2. Andy Ault, CLC | | #2

    We've done both over they years, and our clients have far-and-away preferred the heated floor option. We haven't tracked the actual energy comparison, but the clients with the heated floors have said they would do it again, and the ones with the heat lamps / fans have said they really didn't use them that often.

    I've noticed that that the heated floors seem to feel "dryer" and more comfortable, where lamps/fans seem to feel more like a sauna and less even. The fans / lamps also directly fight the exhaust fan which is trying to get the hot, humid air OUT of the bathroom, rather than just adding radiant heat from below. The cost of the radiant floor will be more, but I think your contractor is giving you the correct advice.

  3. carol | | #3

    I had a radiant heat mat installed under the floor tiles about a year ago during a bathroom renovation, and I absolutely love it! Since I keep the central heating quite low, I run the bathroom heat most of the time (in our area electric is still much cheaper than the oil guzzled by the boiler heating system). It's a small bathroom (5'x7') and during last winter's blizzards, it was the one room in the house that remained toasty and warm. The increase in my electric bill was hardly noticeable, and was actually offset by a decrease in oil consumption.

    The contractor built in redundancy by including a second sensor in the floor, because he said that's what typically breaks down with these types of systems. Rather than ripping up tiles to replace a broken sensor, I can simply switch wires at the thermostat. Other parts of the system can be replaced or repaired more easily.

    All the best, and enjoy!
    c

  4. J Chesnut | | #4

    If you are trying to determine the energy consumption you need to know the watt rating of the product and then you need to make assumptions about the amount of time it will be running.
    Electric radiant in-floor matts come in different sizes and therefore different watt ratings. In-floor matts as you pointed out are often run on a timer to come on in the morning and at night so the floor is heated before you enter the bathroom. Over head lamps are typically turned on when one enters the bath. I think it is possible that the lamps use less energy because they will be on less often.
    Most homes have neither. You will save the most energy by not installing one.

  5. David Meiland | | #5

    I'm not sure how you'd compare the energy use of two electrical resistance heaters. They both use the same fuel with the same efficiency. As others have said, the floor heating is going to provide a higher level of perceived comfort, and I'd go so far as to worry that the overhead heat lamp will be uncomfortable enough so as to go largely unused. You would presumably have some level of "jacket loss" with a heat lamp in a ceiling enclosure, especially if you have an attic directly above, and you would no doubt lose some heat from a floor mat into the slab or crawl space, but other than that, a watt in is a watt out. I would install the floor mat and hope that it's only used lightly, not as a primary source of heat. FWIW, I have seen quite a few of these over the years that were broken. I think there are probably much-improved models on the market these days, but they require careful installation.

  6. Amy | | #6

    I found some interesting info from Suntouch:

    If you are concerned about EMF - "With fully armored and grounded power leads and twin wire design, SunTouch’s electric floor heating system is the only electric floor warming product manufactured in America that is designed to cancel EMF (electromagnetic fields)."

    Cost estimate - http://www.sun-touch.com/project-estimator . You enter your sf and KWH rate, it tells you the cost to operate per day.

  7. markobmf | | #7

    electric radiant is inexpensive and effective. Suntouch is the highest quality offering. Of all the things clients refer to in a long completed bath remodel, first that comes to mind is the warm floors. It has quite an impact.

  8. Michael Chandler | | #8

    Just to add a third option we have occasionally laid a short loop of 3/8" PEX on TOP of the sub-floor in bathrooms and then filled between with wonder board and tiled right on over with thin set (a crack membrane would be nice but we've done fine without one) then we connect it to the demand recirculation system so when the client calls for hot water it brings it to the fixtures first and then through the floor and back to the tempering tank. Kills two birds with one stone.

  9. Riversong | | #9

    Kills two birds with one stone.

    Feeds two birds with one scone.

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