Solar Hot Air Collector (Aluminum Downspout) First Test!

First attempt at building an aluminum downspout solar hot air collector. Dimensions are 4' x 8' x 6". The input uses a 6" x 4" reducer with a temporary fan setup using old ducting I had laying around. The fan is AC, taken out of an old under mount microwave oven and runs at 2700 RPM. I don't have a way to test the exact output however. There is no glazing yet but the entire box is sealed using high temp silicone and the downspout is painted with stove paint, also high heat. Insulated with 1/2" silver-board and sealed all around. Thanks for visiting.