"Of course, Richard tested the AP and not the MVTR and perhaps 5 years ago an AP of 0,17 CFM was deemed good to very good (as nearly all WPB-materials had a cfm of 0)."
I'm a bit confused, since Richard said this earlier.
"The executive summary is that my lab tests show air permeability is poor (on par with low cost micro-porous PU coatings averaging .17 CFM) versus 3 layer eVent (averaging .53 CFM for UL 3 layer jackets)."
My confusion stems from this--my understanding is that low cost micro porous PU coatings have been around for awhile, and have been considered "poor" in the breath-ability/air permeability department for awhile.
Then, comparing that to average 3 layer UL eVent material, by the numbers it seems that these are roughly 3 times more air permeable than the cuben-eVent and the PU stuff, which in my mind is a considerable difference.
Or isn't it?