Mike Jay wrote:Thanks Hans, the video was good and it was fun to read through the comments that people put on there. It seems like it would make more sense to use outside air to reduce the chances of condensation between the layers. I also don't know why he has an outlet. That would get at Mike P's concerns about pushing lots of air through the air gap and eliminating the static air against the film (which is where you get most of your R value).
I guess I don't see the insulation value of the blower as compared to using spacers to keep the two layers apart (and no blower). I do see the advantage to the blower for film longevity and wind resistance.
I did see a plan to put a blower on a check valve so that once the layers are inflated, the fan turns off. When the air leaks enough to drop the pressure, the fan kicks back on. I wonder if there are other simple ways to create 1psi of pressure without a fan? Simple windmill that pumps air?
Todd Parr wrote:I spent a couple days reading everything I could find regarding the blower/insulation thing. Without fail, people say it increases the R-value, and without fail, they don't give any real evidence of that. I'm going to keep looking
Mike Phillipps wrote:I'm reading this book at the moment: