R-value of air space. - Alan(CaliforniaRadiant)Forbes

Alan(CaliforniaRadiant)Forbes

This has probably been discussed before, but I can't remember the outcome.

One of our contractors is building a room that will be a dance floor; it has to be springy like some basketball courts I've seen. The floor construction will be: concrete slab-flat 2x4 sleepers-hardwood. This means that there will be 1-1/2" of air between the hardwood and the concrete.

I need an R-value for that space so I can plug it into my heat calc's. Any ideas.

Alan

<A HREF="http://www.heatinghelp.com/getListed.cfm?id=53&Step=30">To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"</A>

Mike T., Swampeast MO

Hard to find and inexact

r-value of 1/2" - 4" of air: APPROX 1.0

BUT, I don't believe this is "all of the story." You also need to add "air film" resistance values for both the top of the subfloor and underneath of the finish floor. Approx r .6 each? Total now about r-2.2. Since 1 1/2" softwood has 1.88 you should be safe using the r 2.2 number.



http://coloradoenergy.org/procorner/stuff/r-values.htm

j_4

r value for air space

straight out of ASHRAE..let me know if you can read off the 1.5" column....if not, i'll e mail you a .pdf...i'd say it's approx 0.8