[Exeric]

I have had a further thought that may or may not pan out. These are just pipe (duct?) dreams so far. I will have to monitor temperatures as you suggested after sealing off the ridge vents and installing the sealed radiant barrier. If it does become an overly efficient heat collector, big if, then I could use that big 8" ducted fan to blow the hot air anywhere. It could even be even be to an air/water heat exchanger located elsewhere.

I have never liked the idea of having those solar collectors in the attic or on the roof, or on the side of the house if the south side of the house is viewable to the street. In the first case you would have accessibility problems once the attic is insulated and also the leakage problem. In the second case you would be using up prime space for solar cells. Third case, well, they're ugly. You could locate the heat exchanger anywhere, including a completely out of the way shaded area.

One more big advantage of doing it this way. You can't really store the heat energy in air efficiently over long periods of time. So when it gets cold at night in winter the blown hot air is gone. On the other hand if you have more heat collected from the attic during the day than you need then you one could store that heat in the water tank and release it at night. This really would only work though if you can collect more BTUs during the day than you require. Same big "if".