[Greenbuilding] [BULK] Simpler solar attics

[Nick Pine]

Lawrence Lile writes:

> Have you seen a system that uses soap foam?

Yes.

>How would the soap foam system operate?  How efficient would it be?

A shop vac bubbles air through a pipe full of holes in a 10% SLS detergent 
solution to make bubbles with 1000X the solution volume at night. When the 
foam reaches an air return at the top of the glazing cavity, the bubbles 
push on a window screen which pushes on a microswitch which turns off the 
vac for about an hour. When the foam collapses, it turns on for a few 
seconds. Tiny cold bubbles have about the same insulation value as 
fiberglass insulation, about US R3 per inch.

Nick