Help with decisions installing Radiant heat floor mats under laminate (insulation, crawl space)
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THat;s a great question....unfortunately I am guessing the manufacturer is out of business and I think they are being sold by a third party. Like I tried to imply, I understand the purchase is a risk. Since I am not sure about the results of the entire project...and my attempts to start it in a "removable manor," will help me decide whether I should purchase the same product (at less than $1.50 per sf including thermostat). YES, in retrospect, I realize my purchase has left me without some tech support (which I RARELY use in any purchase)...but in this purchase may be a mistake on my part.
Long said short: I;ve made the purchase and I want to give it a try and see what we have for results.
I have asked for input because I wanted to know if anyone had used a sandwich technique (for lack of a better term since it has developed throughout this post) and possible considerations and.or concerns with this technique.
I have received a lot of good information. BUt am always open to more....especially someone with experience with radiant heat (floor installation) and mat....and perhaps under laminate (or surface other than tile).
THat;s a great question....unfortunately I am guessing the manufacturer is out of business and I think they are being sold by a third party. Like I tried to imply, I understand the purchase is a risk. Since I am not sure about the results of the entire project...and my attempts to start it in a "removable manor," will help me decide whether I should purchase the same product (at less than $1.50 per sf including thermostat). YES, in retrospect, I realize my purchase has left me without some tech support (which I RARELY use in any purchase)...but in this purchase may be a mistake on my part.
Long said short: I;ve made the purchase and I want to give it a try and see what we have for results.
Why not at least TRY to contact the manufacturer? If the stuff you bought has a UL listing on it (and I would NEVER install /use any kind of electrical heating device without UL listing -- Appliances and HVAC/R ) the firms MUST have set of standards!
Really, I have lived in old homes too. I know that sometimes it means "opening up a can of worms" but if you want something that is SAFE you really should get a handle on how to DO THIS RIGHT...
You’re asking about heating loads, specifically, about which heat transfer multiplier (HTM) is the lowest for your floor component alternatives.
To solve in the basic sense, use the following:
HTM = U x (TD+25)
U = the reciprocal of the added/combined r values of the floor components.
TD = the temperature difference between indoor and outdoor temps.
Thermal mass is a different kettle of fish. TM adds time to the process offering comfort and stability. Time + poor insulation = greater inefficiency.
“Downward losses” can be noteworthy as heat travels in all directions thru conductive and radiant transfer. Conductive transfer is the most efficient means of heat transfer across structural components and all are proportional to TD. Proportionally compare an 85° floor to a 65° room and an uninsulated 0° crawl space and you can pretty easily imagine where the most heat will go. From a convective standpoint, gravity makes heavy cold AIR sink and displace warm AIR.
For the casual reader, Chet summed up the problem, symptom and solution in post #4 logically. Solve insulation problems with insulation solutions FIRST. Adding heat is simply asking the utility company to finance an improper work around.
Do you not think adding an inch of insulation on top of the existing tile floor solves the insulation problem? [Perhaps combined with a layer of foil faced bubble wrap.] I guess my question is: what difference does it make where the insulation goes?
Thanks again for your VALUABLE input.
I do understand your comment on thermal mass, but if I am adding a radiant floor mat (electrical) shouldnt there be some thermal mass to help hold the heat (so it shouldnt need to kick on and off as often). If my top layer is laminate.....I am questioning whether it is sufficient mass.......I would rather not tile (for numerous reasons).
If you do nothing, your floor values of .05 for the tile + the floor structure average 1.2 R = 1.25
If you add R4.2 astrofoil + 1” styrene you’ve added about 9 to the 1.7 for 11ish
If you add 8” of glass for a conventional insulator instead of the astro foil and styrene you would have about R33
Let’s say you’re in Lincoln which has a design heating temp of 0° and an indoor of 70
Do nothing and you’d have an HTM of 76
Your plan gives you an HTM of 9.5
Conventional insulation would provide an HTM of less than 3
HTM X Sq/Ft = total btu transfer (+/-) from inside to outside (of just the surface in question).
The astro foil doubles as a vapor barrier and would be next to the wood structure in an ideal world, otherwise I’d get it as low as possible to avoid a squishy floor.
TM is for comfort and usually a part of a well designed radiant floor. It’s a buffer to make the surface temp consistent across the floor and make the temp changes gradual. Both are ideal. It conflicts with efficiency when a surface is poorly insulated because it makes the heat loss constantly available…it’s a siphon.
I plan to put about 1 inch of either blue insulation board (or even foil covered insulation board DOWN on the tile first...then I would like to put the foil bubble wrap on top, then the radiant floor mesh and finally the laminate.
You should research the melting point and combustible temp of the material. Not sure if the material can handle the temps from the wire. A fire would be unfortunate.
Does the blocked off room crawlspace open up into the cellar? If you hired a company to use a gas powered concrete saw (1 hour) to cut a hole big enough to access the other room, the heat from the basement would also go into the crawlspace and the room above would feel instantly warmer. You could also spray-foam the ceilings and walls while your in there.
By doing this, you may not need to add any additional heat to the room.
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