For this test I wanted to compare how a metal pipe heats up using solar energy with and without stale air insulation. For the solar thermal bike the pipe will be over 150c. The pipe must be insulated with something that lets the light energy in but insulated the hot pipe from heat loss from conduction, convection and radiation. Professionals use a glass vacuum tube. Because of the cost and possibility of loosing the vacuum in the vacuum tube I wanted to test how well just stale air would insulate. Cool
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