The last link above is still a bit of a puzzle to me -- if anyone has any ideas, I'm all ears.
This screen collector is very cheap and very easy to build -- it will be interesting to see if its as efficient as the downspout collector when run side by side.
Hi Gary,
Bernoulli's Principle?
The blow duct is so close to the center downspot tubes, the velocity is considerably higher the rest of the downspout tubes.
The blow is sort of focused, and a higher velocity.
The suck duct is so close to the center downspot tubes, it is almost like a weak direct connection.
The suck is not focused, more even, and lower velocity.
I know that is not a great explanation...
Sit 5' in front of a box. Lots of wind.
Sit 5' behind a 20" box fan. Not much wind to feel.
Same volvume of air. One is focused, one is not.
Need to keep the velocity more even near the tube ends.
1st thing that comes to mind is fiber furnace air filter material. Might try a piece from the glass at the end of the collector, to the back of the collector at the bottom of the tubes.
Speaking of fiber furnace air filter material, it would be interesting to see the window screen solar air heater compared to one with 3 layers of fiber furnace air filter material spray painted flat black.
A college student (in India?) ran some similar tests, and he came up with 3 layers of spray painted flat black furnace filters was quite effective. It is what I used in the last version of my solar water disstiller, and it worked better than anything else I tried (never did get the heater core and cooler thing built).
G-