Bathroom Heaters – Are They Simply an Indulgence?
I’ve recently mentioned in a couple threads that I’ll finally be breaking ground this coming fall for a new home in Maine, which will be relatively small (1,214 sq ft over a basement,) very well insulated and as airtight as possible. I’m not taking it as far as a Passivhaus for a number of reasons, but that’s another thread.
Right now, I’m ironing out the details of the HVAC system. This little home will be primarily heated with an efficient wood pellet stove and require somewhere around 9,100 Btuh in the dead of winter to keep the place at 72F. The pellet stove, located in the living room, will have a 4″ heat duct connected to the bedroom above it, providing whatever heat may be needed upstairs at night. There will also be a single-split cool/heat pump for seasonal A/C as well as functioning as a back up heat source. Finally, I’ll be relying on passive solar heat entering all of the south-facing windows in the winter to warm up soapstone tiles on both floors, much like a simple heat sink.
The two areas of the house where I’ll occasionally want some spot heating are the main bathroom (where a shower will be used instead of a tub) and a basement workshop. The bath will be 42 sq ft and the workshop area will be around 150 sq ft. Putting a small heater in either space likely qualifies as an unnecessary indulgence in an energy efficient home, but I’d still like to weigh my options. In both instances, I’d have the heat source on a timer and be judicious about when it’s used. In the bathroom, I’m envisioning the heater near the floor (either a wall or toe-kick heater most likely, although electric radiant in the floor may be a possibility depending on how quickly it heats up a floor.) In the workshop, I’m open to suggestions. It’s really about coming up with solutions in either case that heat up a space quickly and efficiently.
By the way, in the main bath there will be a Panasonic FV-13VKML3 WhisperGreen-Lite exhaust fan in the ceiling, so possibly the option for space heating could tie into this somehow, even if it’s just at the controls.
What heat source would you recommend for each space? I’d appreciate any thoughts or suggestions.
Litawyn
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Replies
Litawyn,
It sounds like you'll end up with an electric resistance heater -- either a baseboard heater, a kickspace heater, or in-floor resistance wires.
I live in a wood-heated house with no heat in the bathroom. It's possible.
Martin,
If I had to take a guess right now, it would probably be none of those three. I've been leaning toward a Stelpro Wall Fan Heater in each space. I'm just curious whether there are better options I should be considering.
Litawyn
Fastest bath heat is heat lamps in ceiling. Best is floor tile heat. Your wall heater would be nice in workshop or better a pellet stove there.
Thanks for the input, AJ Builder. I've spent all evening looking at options and think I'm going to go with electric radiant heat (as you suggested) beneath the bathroom tile and switch over to a programmable electric wall-mount heater in the basement workshop. I've got to admit---the number of options from which to choose in 2012 is overwhelming.
Thanks again for the feedback.
Litawyn
Some friends just completed a master bath remodel and installed electric under tile heating.
They LOVE it, BUT!!! they found they have to set the timer 45 minutes before they get up so that it is warm when they use the bath. They also stated jokingly that they could have bought another Prius with the increase in their electric bill.
I'm not in the bathroom long enough to spend 45 minutes preheating it. My bath is small enough that my shower heats the room and a bath matt in front of the sink takes care of the cold tile.
I have a heat lamp in the ceiling but have rarely needed it. Colorado Zone 5.
Richard:
That's definitely food for thought. I'll still likely go with electric radiant in the bathroom floor, but I may have to use a timer to get the most out of it and to not have it run any longer than necessary.
I'm curious how much of a difference it takes for a bathroom floor to warm up depending on the flooring material or the spacing of the wires. I'd be going with a 12 watt/sq ft spacing under soapstone tile which absorbs heat and holds it well. What I don't know is whether either of these things would noticeably speed things up.
Thanks for the post.
Litawyn
Litawyn,
A high-mass floor like soapstone will slow things down, not speed things up. If you want fast, responsive heat, in-floor heating cables under soapstone tiles is not the way to go.
Martin:
What's the optimal bathroom flooring to be using over in-floor heating cables? And is there an optimal way to have the system installed if you want things to heat up quickly?
Litawyn
For quick response, choose a kickspace heater or a wall-mounted electric resistance heater with a blower.
Martin:
My question wasn't about the fastest overall solution. I'll still be going with in-floor heating cables in the bath. If soapstone tiles aren't the best thing to be using over electric radiant cables, what do you feel the optimal floor covering would be if one wants a system that produces a warm bathroom floor as quickly as possible?
Your feedback is much appreciated.
Litawyn
Fastest? Probably laminate flooring.
How about the best floor covering that doesn't look like it was destined for a doublewide? How would you rate stone vs wood vs tile? And regarding stone, is there a particular kind that's better than others?
Thanks again for the feedback.
Litawyn
I have two installs right here at my use during the Superbowl. They both are with standard tile, they heat up in just minutes, the whole bathroom warms too if the door is closed, the owners love it, they are both 300 watt floors set for 3 hours use per day and are also able to be turned on manually. They have seen no increase of energy costs like the Prius story above.
Standard thickness tile is fine. Do not use laminate just get something that has less thickness that has the look you are desiring. There should be a tile that fits your needs of the look you want while being quick to warm.
Litawyn, heat will transit faster through a thin tile than a thicker one. Soapstone being thick with a high density will take longer to warm up. Operating cost for a small bathroom should be minimal. At 10W per square ft, a 400W bathroom floor mat running 2 hours a day (morning and night) during 200 heating days @ $0.15/Kwh would cost you $24 per year (0.4 X 2 X 200 X 0.15). Enjoy it and good luck with your project!
Marc & AJ:
That's great news. I'm glad to hear a system like this doesn't take forever to heat up. I'll only actually have 20 sq ft of the main bathroom with radiant heat in the floor. I'll be going with a system that's 12 watts/sq ft, so I'll be looking at 240 watts/hr x 3 hours/day (on a timer) x 200 heating days x $0.15 kWh = $21.60/year. That's nothing. I just need to pick out the stone or tile I want and will make sure to go with one the thinner options available.
Thanks for helping me figure this out.
Litawyn
OK - I can't help but offer an alternative suggestion...especially given the headline...
How about this...instead of spending $500 upfront in order USE ~150kWh/year (electric radiant), put the $500 into your PV system in order to GENERATE ~150kWh/year.
John:
You make a great point.
For me though, it's a balance between efficiency, cost-effectiveness and comfort. Comfort has got to be factored into to the equation. One could take it to an extreme and live in a sterile, minimalist, super-insulated box that costs virtually nothing to heat and takes no effort to maintain. Who'd really enjoy living in such a space though? Shouldn't everyone allow themselves a few indulgences? I think about those people you occasionally see on the news who live the life of an ascetic, but die with a million bucks in the bank, never having allowed themselves any pleasures. What's the point?
By the way, I believe the Solar PV system being put on the roof (16 - 333 watt panels) may already be maximizing what I can expect in the way of electricity from the limited available space. I couldn't see going much larger unless it were with a more powerful panel in the same space.
Thanks for the post.
Litawyn
I was hoping you would post your last post Litawyn. I concur.
You are way ahead of most. A one percenter in the world of green IMO.
AJ:
Thanks for the vote of confidence, man. Much appreciated.
Litawyn
My recommendation is tempered with a bad experience with the electric floor radiant. I have a diligent tile guy, but something happened and it doesn't work. Obviously, most of the time these things work fine.
But it makes you think, "What if there's a problem"? Well, service, repair, or replacement is big trouble.
But let's assume there is never any trouble with electric radiant floor, and talk about wet naked people. To be "comfortable" a wet naked person needs a small room with the air at 80+. Having warm feet doesn't cut it if the air is only 72F. A bath mat does the trick for your feet. Don't you need one for safety anyway?
So I recommend an electric kickspace heater for $153, which actually can get the room to 80F during the shower. The electric radiant mat can't quite get the job done because it first has to heat up all that tile. Placed correctly, the heater will hit your feet directly.
And the average handyman can easily service, repair, or replace a kickspace heater.
Your neighbors and guests will be much more impressed with the floor heat, though, because you almost never see it in a doublewide :)
Kevin,
Right. The problem with choosing finishes like those you can see in your neighbor's double-wide is that someone might mistake you for a low-income American. You know, the type of person who buys a double-wide.
Kevin has a good point. We've had a couple of clients install these and see them fail within ten years. Personally I like materials that are intrinsically warmer than tile underfoot in the bathroom such as cork or wood, plus of course a nice thick absorbent bath mat.
AJ,
It's fine to choose soapstone tile. It's a great flooring.
I'm just smiling about the reasons behind the choice, that's all. Choose it because you like it...
There are several ways to heat or not heat a bathroom. In the end it us just a PERSONAL choice. The overall specs if this home seem right in the PGH (see pretty good house blog).
Heat lamps, wall heaters are fine too... and having assembled a few double wides years ago... I think I better say nuttin.
You guys are too funny. This person desires a choice just a bit different than you'd choose and you hog pile them for it. LOL
It's not being put in your home and you don't even have to live with it next door. Three silly posts deserve a fourth.
AJ,
Where I live, only upper-income families can afford to live in a double-wide. Most of my neighbors have single-wides.
Kevin:
A kickspace heater would be another worthwhile option to consider if the room were being configured for a lower cabinet of some sort. Since I'm going with a pedestal sink instead, I also considered a basic electric wall heater as an alternative that would've pretty much worked the same way. However, I've heard so many people as of late rave about having electric radiant heat in their bathroom floors that I've decided to go with the silent and less obtrusive option.
Litawyn
I have to agree with Kevin, bathroom heat is about more than "warm feet", its about wet, naked bodies. Cold feet can be solved by a bath mat. It would seem that 10w/sf might heat up the tile fairly quickly but would take along while to heat the room. I prefer a softer, warmer bath floor than tile and have used both cork and linoleum.
And I am NOT trying to convince the original poster that MY preferences are better for them.
At some point these discussion go beyond the OP question and become a discussion of a general topic. I personally like to hear all the options AND the reasoning behind them. Also, double wides and tract homes usually have found the most cost effective option out there and can be used as a starting point in any decision processs.
Richard:
You make good sense. At some point though, the decision boils down to personal taste. And that's completely subjective.
Litawyn
Martin:
I don't believe I shared with you all of "the reasons behind the choice." You simply assumed you had them all.
Yes, I like soapstone. But my primary reason for going with it in the main bath is because I'll be using it in the dining room and laundry as well, both of which face solar south and are basically all glass on the south side. I'm hoping the soapstone tile in these rooms will function as a heat sink of sorts on a sunny winter day, absorbing and retaining a lot of passive solar heat. These rooms also will require 10x the amount of soapstone as the bath, so I considered allowing the needs of these to dictate the flooring in the bathroom.
True, I did make the assumption that there was more of a benefit to heating up soapstone tile from below than it appears there is, but my choice for the soapstone was primarily driven by my usage of it in these other two rooms and the fact that I like the overall look of the stuff. Its potential ability in the bathroom to heat up quickly would've simply been a bonus. Further, if I'm going to pay to have 210 sq ft of tile shipped in for the dining room and laundry, it becomes effortless and quite cost effective to just add another 20 sq ft of the stuff for the bath.
Litawyn
P.S. Laminate Flooring? What do you think I'm building? A tract home in Armenia?
I have a 6'x7' wet bathroom incorporating an open shower. I keep the adjoining hallway chilly. The bathroom uses in floor cable radiant electric heat throughout, Nuheat's 110V, 426W kit. During heating seasons, I keep the floor at 86 to 88ºF with a night time setback . Floor heat alone is inadequate for the other user, an elderly stroke victim, during and after showers. The solution was a bathroom exhaust fan with an integrated 1500W heater/exhaust fan by Broan, model QTX100HL. The ceiling heater has worked extremely well for us over the past four years. Floor heat alone is generally warm enough for me, but when it's not, I really appreciate that 1500W in the ceiling. I'm still a little embarrassed for poo-pooing it as an inelegant solution when the contractor suggested it. I did try one 250W IR bulb to get a feel for how well it would work and still decided to with the combo heater/exhaust fan.
Stewart:
I was glad to read your post. Originally, I was planning to rely solely on SunTouch WarmWire electric radiant heat in the main bath (42 ft² x 15 watt/ft² or 2,150 Btu/h) but I've gone ahead and switched from the basic Panasonic exhaust fan I originally mentioned to the Broan QTX110HFLT model with the heater, ventilation and low-energy fluorescents. It'll be nice to have two options for heating the bathroom, even though that's clearly an indulgence.
I appreciate the suggestion.
Litawyn
We've had a Broan heater/ventilator installed in our house 17 years ago. It's still working in our shower/toilet room and heats up the space very quickly when we take a shower. I was considering in floor heat in our new energy efficient home but I think I will stick with the heat fan.
Overall solution: Broan heater/ventilator; that unit will be the main source of rapid heat and the radiant floor is just for foot comfort while drying off and using the mirror. Even though the area is relatively small (6X7) make the heated area even smaller, say 3X5 and put in 20 watt/sq ft electrical elements. Have the tile guy cut the thickness of the soapstone in half. Also, behind the "working area" of the vanity mirror, put 4 sq ft of switched electric element to keep it condensation-free year-round. Happy shaving.
Hello Litawyn,
Not sure what will be under the tile but when I spoke to a person in a tile store about how to quickly heat up a tile floor, he recommended to go with foam-based backer boards. I forget the brand name but from top and bottom they look like regular concrete backer boards but the cross-section shows that the core is of some blue closed cell foam. They felt pretty rigid and come in 1/4 and 1/2. The insulation below the floor heating will reduce energy "loss" into the subfloor and maximize heat transfer into the tiles above.
Christoph
Sometimes there is so much misinformation here.
Soapstone works great over electric radiant. We have it in our kitchen over Ditra (and the heat cables under the Ditra) and see no problems with responsiveness.
Soapstone is great in a bathroom because it is not slippery when wet - unlike humans!
Modern floor heat thermostats remove the guesswork. You program the time and temp and after a few cycles they figure out what time to turn on to get the floor to the proper temperature by the time you set.
The temperature sensors are more likely to fail than the heat cables, so put two temperature sensors under your tile and pull both sets of wires to your thermostat. If one fails you can easily connect the second temperature sensor.
One of the most important things to remember is that underfloor electric heat does not generate much heat sideways in the tile. This means you had better be sure to run the cables under your cabinet toekick and near the toilet where your feet will rest when you're reading -- but do keep the wires away from the wax ring on the toilet and anywhere that nails can cause havoc.
Billy
Great comments. I have a similar sized (1200 sq ft) cottage in Maine - SIPs over post & beam. I can't use wood heat as I'm not there all the time, so I went with propane and a vented Hot Dawg downstairs (work area) for the major heat source and a gas fireplace/stove upstairs. That needs no electricity to run, so protects against freezing.
The bathroom is similar (3' shower, no bath) but I went with a simple short baseboard electric heater (almost never used) and a ceiling heatlamp on a rotary timer. I have carpet over the wood floor and find that plenty comfy.
I have used underfloor heating, both under slate (a better choice than soapstone, I would think, as it is harder) and ceramic tile. The ceramic tile heats much more quickly and I would think is more suitable for a bathroom. You can get UFH thermostats that read the existing floor temp and then calculate when to come on to reach a set temp at a target time. (Aube - now Honeywell, I think).
In the future, I will add PV solar as backup (I am on-grid) and an air-to-air heat pump.
This problem should be divided into 2 parts: First, heat for feet, and second, heat for room. It is possible to have cold feet in a heated room (we have marble tile). Also your feet can be warm and the rest of you chilled if you are on a rug and the room is cold. So we use a floor rug and a cottom mat on top. Once dry we put on socks or slippers before stepping off the mat onto the marble floor. For the room we use a heat lamp on a timer. This coupled with the heat from the shower spray makes the room comfortable. If it's really cold outside we turn the heat lamp on a few minutes early. We live in Bloomington, IL. I hope this helps
While the question was about electric resistance heat, I'd like to suggest some "out of the box" solutions. a) What about having that 4" duct from the pellet stove also ducted to the bath, where the exhaust fan might pull warm air from that source - minimizing use of the resistance heat. As one who lives where electrcity is now running 20 cts/kw and headed higher w. the price of oil, resistance heating is more than a 'nice' option. Also, some in our area find that excess/unused P/Voltaic capacity can be used to heat water and stored. In a small way could this be used (even thermosiphon) for floor heating of bath? No mention was made for provision of domestic hot water needs- can this be tied to need for air/floor heat of bath and intermittent heating of shop?
I have lived with many different heating systems and arrangements during my 62-years. The best I have found are in-floor heating systems; further, Hydronic In-floor Heating Systems followed closely by Electric Grid In-floor Heating Systems. I have built both systems into my own bathroom: Electric Grid under floor tile on the dry-side (toilet and sink area) and Hydronic embedded in concrete slab under floor tile on the wet-side (shower and drying area). The Hydronically heated floor is more robust than the Electrically heated floor.
I despise Broan products. The only thing louder is a jet taking off.
Sorry no Broan for me, and no soup for you if you like Broan!
I am building a passive house and we have also been considering a heat source for each the two baths. After considering elec. Res. mat under tile, electric baseboard, or heat lamp we are leaning toward electric radiant heat ceiling mounted panels. Has anyone investigated this option?
I know someone who's quite familiar with the pros and cons of ceiling-mounted radiant panels. His name is Rob Brown and he's the owner of Northeast Radiant Technology here in Maine. He's also a regular contributor to the Radiant Forum on GreenBuildingTalk and has likely addressed many questions about this exact topic. He posts as "NRT.Rob" in that Forum and can probably answer any question you might have. He's a good guy, too.
Litawyn
AJ is apparently the Broan Nazi. Who knew?
Litawyn
I am not married to Broan, they are noisy but so is running water when you take a shower. Is there another heat fan lamp alternative I should consider?
Elizabeth,
Panasonic WhisperWarm:
http://www.panasonic.com/business/building-products/ventilation-systems/products/whisper-warm.asp
I'm a little late into this discussion, but I read some years ago (before the electric heating in the floor rage started), about a fellow who installed the hot water copper pipe supply to his shower in the floor (in parallel runs, back-filled with thinset under the tile). His comment was, " When I finish showering, the floor is warm & toasty !". Seems to me the same system would be even easier to install with today's pex piping. The pex probably wouldn't conduct heat as well as the copper pipe though. He said, The only down-fall is it takes a little longer for the water to arrive hot at the shower head". Maybe he had the right idea !
With electric costing around .18 / Kwh here in Maine, I wouldn't try to heat a space with it. I installed electric radiant under a tile floor in our kitchen years ago. We use it to take the chill off the floor and that causes a big jump in our electric bill each winter. We keep the floor set at 72F .
Ken,
You're completely right about heating with electric, in a large area. I'm in Nova Scotia,Canada, and electric in-floor can get expensive. I think the warm feet thing is nice but I would use another main source for large areas. We have hot-water baseboard as main heat.
OK, yaa all keep tryin to fit square pegs in round holes. Best bathroom set up is... drum roll, heated tile, no noise, infrared lamps overhead if more heat desired though not needed for normal homosapiens, as the floor can do the job perfectly, NO BROAN, noisy, go with Panasonic or a remote located vent fan, put electronic switch on fan so it runs after the shower is over....
And as to energy, not a problem in a normal size bathroom, as to heating the floor for after the shower, no way!, the bathroom is a great place to get away, for peace and quiet, gather one's thoughts for the day, contemplate green building and posting here, and vacations in Costa Rica surfing for a month each winter....
Bathrooms are great places if warm, and quiet upon entering and for the length of the stay!
No soup.... for the rest of you if you differ from this.
Other than.... my wonderful opinions... have a nice day.
;)
1. 9200 BTUh, seriously? If you put 500 watts in the floor you have the first 1700 BTUh. Obviously, you are keeping them in pretty well so there is only some marginal cost difference between the cost of these BTUs and other sources.
2. Those thick tiles require longer to heat up due to the thermal mass, same reason they work in the sunny room. They will take longer to cool so once you get them warm they will stay warm. All you need to do is shift the start stop time earlier. The amount of energy should be about the same.
3. I am not a fan of electric bathroom floor radiant heat but if the heat is adding to the total house heat requirement, what the hay. It sure is not as wasteful as 5 shower heads blowing hot water and steam. The controls will be in the wall and the most likely part to fail.
4. The Panasonic fans are good. If they have the night light, (mine do) it uses more power than the fan! Put an LED can above the shower though since the Panasonic fans sometimes shut off the light if they are insulated above even though they are IC fans.
5. Don't denigrate laminate flooring. I was convinced that strand bamboo was better but I would give it away if it weren't nailed down and install a high quality laminate in a minute. Not in a bathroom though unless it were cork and top coated.
6. The only thing I can think of that would change this formula is if the floor you intend to install is on a slab or if you intend to use it in the cooling season and throw the heat away. Even an insulated slab will sink off a lot of heat.
Yes. 9,200 Btu/h would be the max I'd likely need, even in the dead of winter, assuming a door or window wasn't foolishly left open. I'm not worried about having sufficient BTU's; I'm more concerned about being able to manage the heat in a small, air-tight house. Yes, having a small woodstove (burning a small amount of compressed wood) is probably not the most practical or reasonable solution, but I'm doing so to have a worry-free heat source in case of a bad winter storm, and because I really enjoy watching a fire burning in a woodstove on a bitter winter day. Even if my electricity goes and the back-up generator runs out of fuel, I'll still have heat from a renewable source of fuel.
When the little wood stove isn't going, the house would be automatically heated by a Mitsubishi Mr. Slim heat pump (23 SEER), by electric radiant flooring in two rooms of the house, by passive solar heat stored in South-facing soapstone flooring, by a (Panasonic!) bathroom ventilator/heater, by a small spot heater in the basement workshop, and by the heat of two warm bodies. An efficient Zehnder ERV would keep the air well-circulated and the temps balanced as much as possible.
I'm glad to hear it. Thanks for further clarifying the soapstone situation.
The electric radiant in the floor is an indulgence, just as is the horribly wasteful shower you reference. Fortunately, the water for this shower all comes from our own well (20 gpm) and will eventually return to it. So even with the shameless gluttony of an occasional hedonistic shower, I'll still be able to sleep at night and not be riddled with guilt. :)
I've heard enough Broan/NuTone bashing in these threads (based upon their noise) that I will ultimately go with a Panasonic model after all.
I recently received some pretty impressive samples of laminate flooring (or High-Performance Vinyl Planks as they're stamped on the back.) In particular, the Vesdura planks from the Zermatt Collection were quite nice. They run around $4/sq ft so it's certainly a less expensive option that soapstone. The stuff now appears to be on clearance though, which isn't a good sign.
I plan to rely on occasional A/C from the super-efficient Mitsubishi Mr. Slim heat/cool pump I previously mentioned. I won't need to use it with much frequency, but it will be nice to have it on our few hot days in July & August.
Litawyn
Build Build build... Litawyn.... breaking ground date... champaign toast completion party date?