Solar Collector Design And Material

[Pepe_Silvia]

First of all, it seems like "collector" is used to mean a couple different things around here.  Some use it to refer to the 'window' that the sunlight passes through, while the Virginia Tech design refers to it as a painted piece of material that the sun hits after passing through the 'window', as seen here:



 


For my kiln I thought to slightly modify their design.  The idea is that the angle will be more incident to the sunlight and provide better absorption.

Are there any flaws in this concept?  I've drawn it out below.





I also cannot find much reading on what material is best for the collector.  I plan on painting it with the same roofing sealer I used on the walls.  Is there any material choice that would be better than another, or is having a surface there all that matters?

[Southside]

@GeneWengert-WoodDoc 

[Planman1954]

That is very similar to the Pineywoods and my solar dry kiln air flow, except it flows the opposite direction. Also the backup facing metal is screwed under the rafters with clear glazing on the top. This provides a heat producing plenum for the air to heat and recirculate. Check out "solar dry kiln construction."

[Pepe_Silvia]

I like that design, thanks for sharing.