That technology has been around for quite awhile-but I like the fact that this individual had the capital to make it a business.
I built one similar to that unit two years ago(soup cans as I don't drink soda, plywood box with a reclaimed window for the face, wrapped PVC pipe through a SIP window block and a leather 'hinge' for a one-way valve) and I have never regretted the $5 worth of high-temp gasket sealer nor the $10 block of SIP...paid for itself in savings in one month. In the summer, I run the heat feed into an all-purpose curing/dehydrating cabinet, and cure wood for walking sticks or make jerky-works a treat on bamboo fishing poles too!
Frankly,it astounds me that A) there is enough of a demand now that this innovator was able to start a business building these units, and B) that the people wise enough to buy these units aren't wise enough to manufacture their own for the cost of spare parts and elbow grease...the manufacture of Solar Thermal isn't exactly a Trade Secret, after all...
