radiant heating - Page 3

JeepinAudiophile · 02-27-2005, 05:25 PM

I am planning on installing radiant heating in my 68' tradewind. I agree with over 59 that the thought of giving water access to my newly replaced floor kinda scares me. I have found an electric elements that can be laid under the flooring tiles. Of course this means you have to be plugged in to use the radiant heat. I can't remember the company that makes it, but i will rummage through my files and find the company. It would be nice to be able to use the radiant heat when not plugged in- but for me, the possibility of water damage outweighs the niceities of having radiant heating when boon-docking. --Chad--

malconium · 02-28-2005, 06:20 PM

The concern relative to water damage and the floor is, of course, a valid one. That is a primary reason I installed a Polyboard subfloor. I have been intending to install hot water radiant heat right along so the decision to use Polyboard (which is completly waterproof and rot proof) was part of that larger plan.

Electric radiant heaing solutions are available from a number of sources. I do not know for sure if there would be any issues relative to the total current required when plugged in, though. What are you anticipating your total wattage to be for your electric floor heating system?
Malcolm

markdoane · 02-28-2005, 07:22 PM

Quote:

Originally Posted by JeepinAudiophile

. . . I have found an electric elements that can be laid under the flooring tiles. Of course this means you have to be plugged in to use the radiant heat. . . . but for me, the possibility of water damage outweighs the niceities of having radiant heating when boon-docking. --Chad--

I don't think you could get enough heat flux to do more than take the chill off. In wood (non-masonry) floors, the electric heat cable is limited to 10w/sq ft. So for a 88 sf ft area, you could only get about 880 watts (3000 btu/hr), less than a hair dryer.

Would be really nice for those cool (but not freezing) mornings, though.

pamelake · 02-28-2005, 07:25 PM

There are several companies (Warmquest is one) that make very thin electric coils or mesh to install under wood or tile flooring. This is what I would like to do in my '74 Tradewind. Nice, quiet, even heat when you are plugged in seems nice (and not too expensive). I wonder what the problems would be? I would love to hear from someone who has done this. Thanks, Pam

markdoane · 02-28-2005, 07:47 PM

Pam,

I did this in my 'indoor' bathroom. It was tile on backerboard with the wire set in thinset. It's a lot of work if done in thinset. I don't even know if thinset would work in an airstream.

If you install under a wood floor, you need to 'superinsulate' the floor, or else you lose too much heat to the belly. If you install it above the subfloor, it would need to be in grooves or between firring strips.

I used wire from http://www.warmlyyours.com/
There prices were half of what it costs at Home Depot.

malconium · 02-28-2005, 10:31 PM

Here are several sites that supply electric radiant heating materials.

This one has a product that can be installed under laminate flooring without any thin set:

http://www.warmlyyours.com/

This site offers, among other things, a low voltage system:

http://www.warmzone.com/RadiantHeat/RadiantHeat.asp

These guys were the choice of "Ask This Old House" and etc.:

http://www.nuheat.com/homeowners/experts.cfm

This company offers a lot of different sizes of standard mats:

http://www.suntouch.net/

I think in general that radiant floor heating systems require less energy than forced air systems because of the radiant heat delivery mechanism. One of the sites mentions 41 watts per square foot as being enough to keep the floor at 80+ degrees. I suggest checking the vendor claims closely before concluding that these systems are only capable of keep the chill off.

Malcolm

markdoane · 03-01-2005, 07:31 AM

Quote:

Originally Posted by malconium

. . . One of the sites mentions 41 watts per square foot as being enough to keep the floor at 80+ degrees. I suggest checking the vendor claims closely before concluding that these systems are only capable of keep the chill off.

Malcolm

Yeah, I'm all for that! Where did you get that number? I would believe 41 Btu/sqft, but not 41 w/sqft. I think that would curl your flooring and fry your toes.

malconium · 03-02-2005, 07:55 PM

Don,

You are right - it would appear that I got watts and BTUs mixed up. The following is a quote from the site listed below:

"Nuheat produces 12 watts per square foot or 41 BTU at full power producing a floor temperature of 88 - 92 degrees Fahrenheit"

The site with the above quote is:

http://www.nuheat.com/homeowners/features.cfm

Malcolm

jerri · 03-20-2005, 11:00 PM

I am new to this, or would that be rivetless.
Radiant Flooring is going great. 1/2 In pex roughed in. 300 feet in all which gives you about 3 gallons of liquid. One RV 500 modified at the factory to specs (exspensive).Rayon cutting boards milled and machined to mount the pipes into between the chassis members ( exspensive) I will do my best to get photos for you. Bubble wrap insulation with foil sides (expensive again). Work in progress.Threading 300 feet of pipe in the chassis PRICELESS!!!!!!!!!!!!!!!

malconium · 03-22-2005, 01:07 AM

Jerri,

Sounds interesting and I will be looking forward to your photos.

Malcolm

FranyPul · 04-10-2005, 10:01 PM

I may be coming in a little late on this, but I'm happy to see that others have considered radiant heat and that I'm not entirely out of my mind. Have you all hear of Warmboards? They are supposed to go in like a regular base floor, have grooves cut out for piping, and all lined with, I think, aluminum. Any floor type can go on top of it. Because I have to replace my floor anyway, I was hoping to go with the Warmboards and put bamboo on top.

(no I can't afford this)

Kim

malconium · 04-11-2005, 03:16 PM

Originally I was thinking of using aluminum fins that would snap around the radiant heating tubes to help distribute the heat. Lately I have been thinking of taking another approach. I have not been able to work on my AS for a while because of other things but that doesn't stop me from thinking about various aspects of the pending remodel. At anyrate I asked a local company that supplies radiant heating things for DIY installations what they would think about just having the tubing fastened to the floor and no aluminum fins. They told me that actually the air around the tubing would work OK to get the heat distributed - it just might take a little longer.

I had originally been thinking of stapeling radiant foil insulation on top of my Polyboard floor, then putting 1x2 strips on top at about 6" on center. I was going to center the plastic tubing in between the 1x2 in aluminum fins that would span from 1x2 to 1x2. The 1x2 was going to support the final flooring. I was thinking about using some form of floating floor that could span 5" gaps. Maybe laminate, bamboo or cork. As an alternative I could envision using something like 1/4" underlayment plywood on top of the 1x2's with the finish floor on top of that (if the floor was flexible).

I was thinking about the support issue recently and it occurred to me to wonder if I really needed the 1x2 to support a floating floor if I was not going to use the aluminum fins. I went and looked at some of the PEX tubing at Home Depot and I find that it is actually very stiff. So I am wondering what would happen if I fastened down my PEX tubing at about 6" on center and just set my floating floor directly on top of it. What I do not know is how flexible the tubing would get when it warms up. It does seem like having it full of water would also help improve its crush resistance.

So my current thinking is this:

1.) Add a layer of reflective foil insulation on top of the Polyboard subfloor.

2.) Lay out my PEX tubing at about 6" on center and staple it down to the Polyboard.

3.) Install a floating floor directly on top of the PEX tubing. I might pick a variety of floating floor that has a foam or cork backer layer that could deform where the staples are that hold down the PEX tubing.

I would appreciate any feedback that anyone would have on this bare bones approach. Especially if anyone knows what the crush strength of the PEX tubing would be at temperature.

Thanks,

Malcolm

stinkytwinky · 05-03-2005, 10:34 AM

Are you suggesting that one would use this in conjunction with the hot water heater?

herbigrf · 06-30-2005, 04:15 PM

We have radiant heating in our ceiling of our house which is lousy. This winter I was on the internet and found two types of radiant heating that you can put in the floor. One of them was a rug with built in heating that you could plug into a regular outlet. Would be great for a trailer if you had good power access.