This has been a gratifying addition to the estate. When the garden works, sometimes it REALLY works. Of course neighbors get some overflow, but their gardens tend to be working too. Nothing would go to waste if we did not harvest, of course, but all kinds of dried stuff is nice to have: tomatoes, herbs, banana slices, mango slices, kale leaves - those are our top uses.
This is a simple design inspired by inheriting two suitable glass panes. It is a simple box with 1x6 plank sides (to make total "depth" of 11 inches (28cm). The "bottom" is a thin sheet of galvanized steel. Interior is painted flat black and it gets quite warm in there - I should measure some time.
Just be be clear, is that a vent on top? I'm surprised I've never thought of this, it's basically a little greenhouse. I can only imagine all the sun dried tomato!
yes, a vent stack; it helps air flow. There are three two-inch (5cm) holes at the bottom end to admit air. An earlier iteration of this design had screens over the holes to keep critters out, but it turned out to not be an issue so we have not screened the holes on this unit.
We saw a design for a solar dryer popular with Peace Corps volunteers - a heat-collector box with a small dryer compartment on top and three little trays in a stack. But I thought, why not put the dryer trays right inside the heat collector? I just checked the temperature and with partly-cloudy skies, it is 50C in the box.