I tested an evacuated solar thermal tube in January in Idaho. The tube heated from 55 degrees to 120 degrees in 10 minutes. The temperature went to 350 degrees in 30 minutes. The tube reached 395 degrees in 60 minutes.
I completed the same test in September of 2011. For this test I used 2 tubes one with a reflector one with out. The tube without the reflector achieved very similar results to the January test. The tube with the reflector was 40 degrees warmer in 10 minutes. 6o degrees warmer in 30 minutes and 220 degrees hotter in 60 minutes.
I was impressed with the gain using the reflector. There is a tremenduous amount of energy available for us to
use from the sun. The other interesting item was the energy gain from the tube in January vs. September was very similar.
Carl S.
