Why is it called ping pong?
For something this inexpensive, we're surprised there isn't a better name for it. If you've ever tried to get a good picture on a table tennis table, you know that the ball doesn't always hit the paddle. Instead, it often bounces around the table and lands in places you wouldn't expect. This is exactly what's going on here - instead of bouncing on a flat surface, the ball hits a curved surface on the roof. That causes a bit of a rebounding action that results in the ball being forced to follow a parabolic path - hence "ping pong". It's hard to imagine how this concept would work on a smaller scale, but we were pleasantly surprised to see it work on such a large scale. We tested this idea on a large roof (~100 square feet) with a large open area at the base of the structure. We ran our pool heater through a test using this method to ensure that it would have the same effect as we saw in our large tests. In every test run, we used a 2'x4' ...