Radiant Floor Heat???

[Capt J-rod]

I am thinking about putting electric radiant floor heat in my 21RBS... My original idea is to buy the 1/4" foil faced insulation that goes under vinyl siding and lay it over the aluminum, then the heating mat, then a vinyl snap lock floor. It is 120V and has it's own thermostat. No more cold floor, and possibly no more space heater in the fall or spring! Thoughts?

https://www.warmlyyours.com/en-US/products/line/floor-heating-environ-flex-roll

[Merlin]

Well, here's a few thoughts for starters......

Is the foil faced insulation meant to be walked on, even under the tile and mat? If not, what will that do to the integrity of the mat?

RVs get a lot of sand, moisture, etc on the floors and would the tile keep that from the mat. If not, what will that do to the integrity of the mat?

Life on the road is hard on a camper. If the mat has integrity problems in an aluminum trailer, can you be sure there won't be a leakage to the trailer structure?

The 1/4" insulation is a SUPER thin layer to expect any real effect. Will that mean a huge heat loss under the trailer?

Thermostatic control, but of how much power in total? How many mats and how long will you need, since they are only 18" wide? Will the RV electrical system handle those and, if so, will you be able to use other 120VAC electrical devices while it's heating?

RVs are not well insulated beasts; will the mat heating element be enough to heat the whole thing? If not, is there enough electrical capacity to be able to use a space heater in addition to the heating mat?

So, safety, longevity, heat loss, and electrical capacity seem to me the big 4. If those are all a "go", try it out?

[Capt J-rod]

Wattage, 12watts per square foot so 4'x16' = 768 watts divided by 120 = 6.4 amps. The underlayment that they use is actually like cork which is probably a smarter product. Heat rises so heat loss through the floor is minimal. The vinyl snap lock is pretty moisture resistant so I don't think moisture going down is a concern, however I remember some posts of water coming through the aluminum floor which might be a concern. I don't expect it to "heat" the camper when it is 35 degrees out but it would definitely help. I currently have the rubber work out mats that are like a jig saw puzzle. My buddy just did three rooms in his house and it is pretty nice on the feet. I would probably only do in front of the couch and sink over to the bed. I think the bathroom is begging for trouble. The floor being aluminum or rubber currently just leaves the trailer with an un-finished look. I appreciate the insight... I'm still on the fence. If it worked and held up I thing it would be an awesome addition. I adde another link, they make a 3'x10' mat that would probably be a good start and it is 360 watts, so 3 amps... So the draw isn't a big deal. I'll put a call into the mfg tomorrow and see if they freak out.

[DavidM]

"Heat rises so heat loss through the floor is minimal"  Yes, for convection, no for conduction.

Follow this geeky stuff from a retired chemical engineer for the conduction losses:

That hot pad will be at least 90 degrees when sandwiched between the foil faced pad on the bottom and the vinyl on top. The 1/4" pad will have an R value of no better than 2 and the aluminum below that almost nil. Let's say you have an outside temp of 40 degrees and a square footage of 64.

So the heat loss wil be (90-40)*64/2= 1,600 btu per hour or about 470 watts. So most of your heat will go out the bottom of the floor.

Also I agree with eveythng Merlin said above.

David

[Railsnstiles]

Taking the conduction loss into account, it might still be nice if your feet hit a warm floor rather than a cold one.  There are products that are built to go uner a rug that might fill the bill.  Such as this:  https://www.floormat.com/heated/rugbuddy-systems/.  I would not expect it to heat the trailer, but it doesnt pull a big load, and seems to be resistant to water.

[Merlin]

For my floor, I have 1/2" thick interlocking foam squares (the kind used for exercise mats) on top of the aluminum and then several soft area rugs on top of those. The result is a warm, soft, quiet, insulated floor that has been durable, doesn't appreciably reduce headroom, and is easy to care for.

https://www.amazon.com/IncStores-Interlocking-Excellent-conventions-exercises/dp/B00DGCDYR0/ref=sr_1_3?rps=1&ie=UTF8&qid=1505301800&sr=8-3&keywords=Oak+interlocking+foam+tiles.&refinements=p_85%3A2470955011

[Capt J-rod]

Thats what I've got too Merlin. I'll probably give up the dream and just wear better socks lol!