radiant barriers and load cal.

[aj1213]

do radiant barriers affect the results of a load cal. i've been told that the programs for load cals don't factor them in.

[cem-bsee]

probably because nobody is sure how to include that as a factor. I have no idea of the formula for the affects of radiant barriers. It would depend upon how & where the barriers are placed. It would depend upon the emissivity of the barrier, of the materials over the ceiling, that of the ceiling, etc. It would depend upon the roofing materials & the amount of sunshine striking the roof, the configuration of the roof, ...

this is being discussed in a thread concerning attic ventilation.

[hvacfella]

There is something called Radiant Barrier Ceramic Paint which is supposed to really reflect sunlight and substantially cut down on heat gain. See : http://www.koolcoat.com Im going to try some on my RV's roof very soon.