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Old 01-10-15, 06:51 AM   #32
AC_Hacker
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Quote:
Originally Posted by bennelson View Post
This image is very interesting because it really helps to visualize why radiant floor heating is so comfortable. Most people relax by sitting down or reclining on a couch, which puts them in the colder part of the room. If this image was of a room with a radiant floor, the greatest warmth would be closer to the area where people tend to relax.

In other words, the thermograph would be reversed, top to bottom.


Quote:
Originally Posted by bennelson View Post
The stud area clearly illustrates the rule of thumb that because of thermal bridging, a normal stud wall reduces the nominal insulation value, and yields an effective total insulation value that is 18% lower than the rated value of insulation. So if you built a normal stud wall and filled the cavities with mineral wool, a 6" cavity (5.5") would have an R-value of R23. So applying the 18% thermal bridge penalty would give you an effective R-value of R19 for the wall. This is assuming standard stud spacings. That's a big loss.

When you said, "the wood stove may heat the surface of the wall, but not the studs", I think you are incorrect. The wood stove is actually heating the sheet rock (R-0.9 per inch), which is a pretty good thermal conductor, and the sheet rock is conducting the heat through the stud (R-1 per inch) and out of the house. Look how clearly defined the stove and pipe are, and how 'vague' the stud area is.The blue 'stud shadow' is wider than the width of a stud because the heat in the sheetrock in the area of the stud is being drawn toward the stud and out into the cold.

A 1/2" layer of Poly-Iso foam over the studs before the sheetrock would certainly help reduce (but not eliminate) the thermal bridging. A better strategy would be to build the wall, using staggered studs, or some similar strategy, like perhaps a Mooney Wall.

By the way, if you present the Mooney Wall on your personal blog, don't forget to cite Build It Solar, they certainly deserve the credit, in the same way as you should cite other sources of information and ideas that you might elaborate on.

It will enhance your credibility.

-AC
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Last edited by AC_Hacker; 01-10-15 at 11:15 AM..
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