Well, radiant heat is wonderful, if you are doing a new build; yes it will heat the house. If you have baseboard hydronic heat now, radiant floor heat doesn't hook into that well, as the temperature is different (my understanding), and you would need a separate circuit/zone for that in any event.

lots of folks love the radiant heat electric floor mats to warm the floors, especially in colder climates, so I am sure people will chime in with the love fest soon! it would certainly add to the temperature of the room, but not likely enough to heat it entirely.

If you just want to warm the floor, electric. If you want to heat the room, hydronic. It's that cut and dry.

Electric heat is quiet, clean and efficient - so is Radiant Hot Water heat.

To add a heated floor to your bathroom with hot water you need a boiler and a system as well. If you have this in your home it is as simple as opening up drywall everywhere, running new lines, patching dry wall, covering pipe with 1 1/2" of cement and going from there.

Cost wise this is a two day discussion with hundreds of variables if we need to compare apples to oranges.

I'm installing some "Old School" Cast Iron Column Radiators and Cast Iron baseboards in my home and am installing a little electric heat as well in the way of forced air wall mount radiators, baseboard electric fin and electric cable heat. I have 17 water feed radiators and baseboards in total so the cost of my boiler and piping is share by the lot - averaged out.

The hook up a boiler to one zone would be crazy talk and not very efficent.

The heat generated by these various systems varies greatly with things like room shape, size, location, wall thickness etc all factored in to give you a required BTU number that the room needs to stay warm.

This information can be found online for free, can be done easier with paid software or can be done by a plumbing wholesalers staff engineer. This report is of not much cost $75.00 here in Vancouver and can be credited back if you purchase their product.

Once you know the heat needed (BTU's) you can start the process.

A typical renovation for me is this - Bathroom has one exterior wall, is above a heated space and I did all the insulating and vapour barrier. In these renovations I use only cable heat to heat these rooms. The heating cable I use generates roughly 34 BTU's per square foot and in a 40 square foot bathroom 600 - 900 BTU's is normally enough (with large tubs and vanities the floor footprint drops and in doing so those drops the total BTU's you can generate in this reduced square footage). If we fall short of the required amount we install a kick space electric heater under the vanity or an in wall vanity.

Luxury items like towel warmers will all add a little more warmth.

I was drawn to the "Old School" Column radiators as they only require 160 degree water temperature to operate and that after the water stops circulating they can stay warm for 6 hours. The cost of these was 4 times what I could have done with a cheaper copper fin system but will add the character I'm looking for.

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I am looking for a way to heat the entire room as an alternative to our baseboard hot water heat, so I guess electric is out. We kicked around the idea of a toe kick heater, but I would also like a furniture-style vanity, so no toe kick. Does hydronic radiant heat work well (as well as baseboard hot water heat)? Our plumber mentioned it may take a while for the room to heat up. Any other alternatives? I would like something sort of hidden and out of the way. The room is approximately 90 square feet.

Hydronic radiant heat is probably one of the most efficient and best ways to heat any space. The point that John made, is a good one, though, and that is that the cost might not be conducive to getting this done, especially just for the bathroom. Radiant heat isn't cheap to install to start out with, and it's even more expensive when installed after the fact, and if you're only doing one room, you might even have a hard time finding a heating company to do the job for you. But if cost isn't a problem, and you CAN get someone to do it, you can't beat it.

In case you are interested, we had a space problem with running our baseboard- not much space left over in the new bathroom. This plagued me for a while during the design/research/demo phase.

The solution we used was a hydronic radiator towel bar by Runtal. Let me tell you, that thing heats not just the bathroom, but my whole bedroom! I suppose with the reno, and the added insulation in the bathroom, the heat loss is so much less that the one I picked is essentially over sized. The upside is it works wonderfully, and makes my towel absolutely deliciously warm in the morning.

It is run through the baseboard, with the rest of the heating, no separate zone, so only comes on with the rest of the house heat- so I can't "plan" to have it on when I shower, but I shower in the morning when the heat starts running anyway, so it is always nice and toasty. There is no extra cost, no added electric bill, it's just a great way to heat the room, with the added benefit of the use and look of a heated towel bar.

It was economical, practical and did the job as needed, and then some.

You can just see it in the top left of this photo...

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Here is a link that might be useful: Runtal Towel rediators

The easiest and by far the least expensive way to add a single hydronic zone would be to buy a small stand-alone water heater and set up an independent zone just for the bathroom. Set the temp to roughly 120 degrees, pretty much all you'd need is a pump to circulate the water and a t-stat to turn on the pump.

Thanks for all of your comments. They have been very helpful. Has anyone else switched from baseboard hot water heat to radiant heat as the main heating source for your bathroom? Are you happy you did? (Maybe I should start a separate thread about this.)

We have done this 4 times in the past 5 years with great success. We have simply removed the zone or bypassed the bathroom and installed our cable electric heat.

The clients love their warm tiles and the rooms have been nicely heated. I will say this that your pets will thank you the most!

Thanks for responding, John. Was the cable electric heat in your bathroom the only source of heat? If so, how long does it take to heat the room? What does it look like?

The heat in most rooms was only the cable heat. it looks like nothing because it's buried under the floor tile.

We used small electric forced air heaters for make up heat on really cold days but most rooms where heated only with the cable.

We do an excellent job insulating and removing drafts and use spray foam insulation as well. These are pricey options that deliver high end results.

We've had discussions about this over in John Bridge's forum. While some systems might be able to heat the room slightly, most electric radiant heat manufacturers will tell you that to try and use their system as a primary source of heat will put a strain on the system that it's not meant to take, and will shorten the life of the system considerably, and as a result, they will not warranty a system that's used as the only source of heat in the room.

Homeowners who want a different perspective might find it in some HVAC forums. Not tile forums. Heat is a question of power. Heat is not a tile-laying question.

That, I'll agree with. That said though, before anyone purchases a electric radiant heating product, regardless of how well you intend to insulate, you might want to give the manufacturer a call and see if they'll stand behind their product as a primary heat source.

I'm just sayin.

Once again Bill you point out solid advice. I went back and read the warranty on the cable heat I use and looked for the sole heat clause. I was relieved that I did not find one. It has been years since I read it and I'm upset that I have not made a point to re check in such a long time.

Like you suggested Bill I contacted Michael Galante (Vice President Sales and MarketingEASYHEAT USA Headquarters www.easyheat.com) by email this morning and will hopefully have an answer for all by the end of the day.

You can contact Easy Heat direct here;
2 Connecticut South Drive
East Granby , CT 06026
Tel (877) 656-6331
Fax (888) 600-6692
www.easyheat.com
Michael Galante
Vice President Sales and Marketing
(860) 653-1618

I only use this cable system. I only use 240 volt not 120 volt. I hate the matts and refuse to use them. I have had city inspectors through jobs where we have done this and nothing has been said - this does not mean it's right only that it might be OK or didn't get noticed.

Bill makes an excellent point that "heat is a question of power" and electricity and your homes safety are too important to leave to chance. I have been pulling wire and doing this type of work since I was 18 (currently 41). I wired my first home at 19 (Basement only - tiny house) and have been working with electricians all my life. I have a very good understanding of our Vancouver electrical code and have just finished wiring my complete home (not so tiny 3100 square feet).

We often work on old homes in upscale neighborhoods of Vancouver and the North Shore. Many of these homes have old Knob and Tube wiring. We have not as yet nor ever will hook up a heating system to wire that we have not pulled ourselves back to the main panel. Too many DIY'ers and Handy Men are out there and you don't know for sure for sure unless it's all your work. Just watch a episode or two of "Holmes on Homes" to see the scary electrical work out there.

We pull new wire, tone for shorts install and test our GFI's and breakers. All ship shape and we can sleep at night knowing that we did everything in our power to keep the family safe and sound.

I have mentioned this time and time again online - check with your local building department and like Bill mentioned check with the supplier as well.

My opinion is that of a bathroom renovator not as an HVAC ticketed installer and my opinions and my installations are designed from my collective experience of building bathrooms and kitchens over the past 20 years. No ones opinion should be taken as fact and always search for others that agree or disagree.

We build dream bathrooms and we do it from the studs and joist up. We remove every trace of the old bathroom and often our renovations involve exterior repairs or framing changes. Most times there is a HVAC forced air duct in our bathrooms and we like to roll them into a side wall so the floor does not need to have a duct grill in it. Often we roll these lines under the vanity so the air blows across the tile floor and hits the tub. This warms the floors with no cable heat installed.

There are so many factors involved in making the right choice. Discuss these with your contractor and make sure you get the right system for your home.

Here is a link that might be useful: Easy Heat Warranty

It's all about the BTUs.

A good installer will run a heat loss calc of some sort to see how many BTUs the room needs in winter. Then choose a heat source that can provide those BTUs.

When your old home requires 30btu/sqft and an electric resistance heat cable or mat system supplies a maximum of 15, you could be in for a chilly winter.

So run the numbers and know things will work before work begins rather than just hoping things will work after construction is complete.

As has been mentioned, good insulation (foam or dense-packed cellulose) and proper detailing of the envelope could allow an electric resistance system to be the sole heat source, but the house/room has to be very well detailed to achieve that performance in a northern climate.

No reply yesterday. I'll wait another day and then call them direct.

Busy day today - plumbing inspector is coming out to check my flooded drain and vent lines and my pressurized water lines (water lines under 200 psi test ).

This is my reply in regards to my question about heating a room;

"our systems are engineered and designed to provide personal comfort
warmth when installed under tile marble, other stone or floating wood
floors.

The systems, (installation instructions) are not designed to provide
direction for installations as a primary heat source. We know our
systems provide some supplemental heat to a room but there are so many
variables to consider and we have no data to provide on this. "

Like Bill mentioned above.

That said it may be necessary to re-evaulate my install practice. The email seems open to the chance that it might work and if they had all the variables maybe.....

I know I have working examples, I built them. I know the heat doesn't stay on all the time and the rooms are comfortable in the winter.

All said there is too much "Gray Area" to just leave it. Planning a mini kick heater is easy to add to the system and can be feed from the same 240 volt line if planned correctly.

Thanks Bill. You can't believe everything you read on the internet. Here I go talking about my installs and the specs say it is not a primary heat source. I have worked out the math and have two more rooms planned for this type of heating (my shower and my daughters). To be safe I'm going to redesign my heat load so if I need to add a 300 watt kick heater into one or both of these bathrooms it will be easy and safe.

Always read your instructions! Call the manufacture as well! Check and Double check....

Convert Watts to BTU's and draw conclusions yourself.
When you know how many watts you need, you don't have to run around in circles asking all the wrong parties for information or implicit warrantees they may be reluctant to give you.
Know what you need and know what the manufacturer won't guarantee.
Check and Double check.
Yes. Read your instructions. Call the manufacturer. But don't ask a vague question that they won't warranty the answer to.

johnfrwhipple, have you found mongo's numbers to be correct? 15Btu, 30Btu, etc.

I can't confirm Mongo's numbers as I only work with one type of cable. I have done the math on every job and have heated rooms with just this type of heat source.

It does say not a primary heat source as mentioned above.

Heat loss calculations are easy to preform. Converting Watts to Amps, Amps to watts, Watts to BTU's are basic math calculations with many online calculators.

Vancouver is a mild climate with some cold cold days.

I have three more rooms getting ready for cable heat as we speak. I'll post all my information so everyone can draw their own conclusions to the ability of this type of install.

For the record this is my home that I'm renovating. We added a new floor and I have pulled all the electrical permits myself. All work has been checked by the City inspectors and we are ready for insulation.

My spray foamers are coming Friday to spray the underside of my Kitchen floor, Ensuite shower floor, some of my old 2"x4" stud walls and my south dormer in my bedroom.

The warmth you get from just 2" of 2lb spray foam is insane. Build up to 3 1/4" and you have R20 and no airflow which means no air leakage.

Stand by for updates.

I found someone like you saying that a heat cable gives WAY more than 15 BTU/hour. Link below.

I like to work with Watts as my units.

One thing I enjoy is to adjust the space between the parallel lines in the cable on the floor, to suit the spot. One can spread the 3" spacing out, or move the wires closer in. This depends on what that spot needs. With the world's best insulation, heat is still sent to the outdoors. Insulation slows down that heat transfer, so you can manage better to adjust your comfort levels. In those floor areas that are most going to lose heat to the outdoors, I compress the spacing. In other areas I increase the spacing so the floor is less heated there. Around the thermostat's probe I don't do any adjusting, so the thermostat has the same local environment as it was programmed for. Making the floor-wall junction be extra heated is a great way to ensure your floor appears evenly heated. Even in a Vancouver mild climate, and in a well-insulated building, it will improve "performance", the user's subjective experience.

John, after a bit more time you will get the hang of being more precise in what you write. As it stands now, every time you write stuff it is vulnerable to a lot of correcting. Imprecise terms and language is what will get you flunked out of engineering school. However, I see you are diligent about researching and finding things out; so I'm positive, and I'd give you a B+ or an A- on this project. You got past the obstacles and you got to the bottom of it all.

hth
-d

Here is a link that might be useful: 30 to 34 BTU/hr for a 230V electric heat cable

Thanks David.

Being precise and listing every point and sub point is tricky. English was my worst subject in school, I'm better at building bathrooms than building paragraphs.

I work harder posting more information but like you mentioned everyone needs to dig deeper, find all the questions that need answering and then go about finding the correct answers and then confirming the source of the answer.

I have spoken with my supplier and received info back from them direct, I then worked out my own math to confirm and then double check the Heat Loss table.

We adjust the cable spacing only a little to try and fudge out dips and valleys. And never bring the cable in closer than spec'd.

Again, I'll post my math and equations with as much detail as I can provide so people can understand the process I use to work out these calculations.

I build stuff every day, I read and hone my skills everyday and I work with pros everyday. I have learned a lot and which each new project there is always the "X" factor. Your gut can tell you when something just doesn't look right and inspectors should be shown what your doing and not left out of the loop.

We have a great group of men and women checking our projects here in Vancouver, get to know your local inspectors - it's worth it.

My building inspector left my home raving about it yesterday - he went on to say it should be entered in a contest and hopes he gets to come back for the final so he can see my home completed. These are not monsters or people to avoid- they are your last double check on your project and honestly speaking you should be the last check on any project.

It's your project - don't trust anyones opinion as fact. Work it out yourself or spend your time finding the right contractor. There are many guys out there who know what their doing, take out permits and do the job right. That said they seem to be the minority...

Just for clarification...the "15" and "30" numbers I used were examples, not specifics. I hope you guys didn't think I ran actual heat loss or supply calcs for his installation. How could I without any data?

"If the envelope (airtight) and insulation are built to high standards, you _ CAN _ indeed use hydronic or electric floor heating to heat the entire space. This is common, not unusual."

davidro, radiant hydronic is quite common, it's how I've heated pretty much every house I've built since the mid-90s.

Radiant electric? Do you know of any code-approved products that are rated as "primary heat sources" for residential? I'd definitely be interested.

Thanks!

mongoct, please let me know what you find out when you go see the web site(s) of electric cable manufacturers.

Let's be aware that electric heat cables can melt snow and ice outdoors. Installed under paving stones and asphalt, which is an uninsulated environment that therefore requires the cable to carry a lot of power (which makes heat). There is no question about the ability of electricity to make heat, enough to do that.

2.
code-approved?
rated?
http://en.wikipedia.org/wiki/Electrical_codes
http://en.wikipedia.org/wiki/National_Electrical_Code
I'm eager to learn more about the electric code.
Whoever knows this code is welcome to post here.
The "authority having jurisdiction" inspects for compliance with these minimum standards set out in "The Code".

Oops. My misunderstanding. I took your previous post to mean that you knew of electrical resistance cables that were approved as sole-source heat for in-house residential.

In my area electrical in-floor can only be used as supplemental heat. In-wall and in-ceiling cable installations are both prohibited.

Part of that is based on the manufacturers that I'm aware of specifying their products as supplemental use only. The other part of that is our AHJ recognizes that an in-floor, under-tile, cable material failure will not be an easy repair, so failure might require a lengthy repair time. Not a good thing in a freezing environment.

Thanks for the reply though.

The search continues...

Actually, I do need to modify my previous post. There are some resistance cables that the manufacturer says they can be used as sole-source heat if the thermal envelope of the house/room can justify it BTU-wise.

I guess in my area it's a moot issue for me, as I usually do full-house hydronic radiant, and my local code only allows electric radiant as a secondary source.

I think that UL restricts the output of electric radiant to 10, 12, and 15 watts/sqft for electric underfloor subfloor, electric mesh mat cable, and electric spool cable, respectively. Not sure though. Those numbers are rattling around in my head though.