Internal Insulaiton on solid walls-REVERSE DIFFUSION MEMBRANE Published March 24, 2016 at 3492 × 4945 in Internal Insulaiton on solid walls-REVERSE DIFFUSION MEMBRANE A IWI system using a vapour open insulation material with a reverse diffusion membrane allows vapour to pass inwards through the membrane in a “Reverse Diffusion” phase but does not allow vapour from the inside. ← Previous Next →