I am curious what the relationship is between cavity depth, rated insulation, and effective insulation in framed walls. I am referencing the ASHRAE 90.1 doc because it is really the only one I have on this subject. I have charted Table A9.2B and a logarithmic trendline appears to be a good fit for extrapolating. If anyone in academia, industry, or the societies has more information on this subject I would certainly be grateful to receive a good lead. Thank you.

Kevin Kyte, LEED (r) AP