Radiant Heat
Greetings All
I'm a couple of days away from laying a 6" slab w/ radiant heat in my new detached garage.
Industry radiant heat practice is 2" from top, based on my limited research.
here a couple of good sites that I read
http://www.inspect-ny.com/heat/Radiant-Slab-Heat-Mistakes.htm
http://findarticles.com/p/articles/mi_m0BPR/is_6_20/ai_102862289/
current issue is that contractor wanted to install heating tubes on mesh and then install 1" high x 5 ' long spacers/chairs on the 2" insulation foam while the concrete is being poured.
I resolved issue, I think, by having him install 3" high chairs under the mesh and tubes. Tubes should be 1/2" dia ID.
So.. 3" + 3/4" OD tubes
6" - 3 3/4" = 2 1/4" below slab surface [2" below is industry practice]
I can't find a chart or an educated opinion on what % difference in heating costs between 2 1/4" below and 5" below surface. From the above sites it seems like it would be substantinal? I roughly figure 2-3x more at 5" below that 2 1/4' below based on reading those sites. It's just my wild guess.
This is more than just searching for abstract thought. I have a relationship with the contractor "off work site". We didn't know each other very well before this garage came on steam. I gave him a heads up and history of my act so he had some idea of the kind of guy he was dealing with. "some idea" = warning
needless to say his 5" from slab surface and my 2 1/4" from surface caused some friction etc
so now that we're friends again [old build history is again again again etc] and tubes will be placed contrary to his routine I'm looking for hard info on this. My heating costs 2 1/4" vs 5" below?
I can't find anything on google
If you can offer an educated opinion or a lead that would be great
thx