I have a small 6 X10 lean to greenhouse in Sonora, MX and heat control i stay main problem. I have auto vent openers in the roof, a auto vent fan and screen window in the door. Also have installed a misting system on an hourly timer to spray the gravel floor, a circulating fan and an evaporative cooler. I added 60% black shad cloth to the top and 50% on the side facing west on a shade house frame about a foot away from the greenhouse walls. Despite all of this and extra spraying, the heat climbs above 90F in the afternoon. So next I bought a 60% aluminum net shade cloth and placed it in the greenhouse just below the double polycarb walls, but it doesn't seem to be helping a whole lot. it has been a few degrees warmer lately but the inside temps will not stay below 90 in the pm (upper half of GH). Would it be better to place it on the shade house frame to deflect the radiation before it actually enters the greenhouse? Not sure what else I can do to defeat the heat until the humidity jumps up later in the summer. Hopefully I can get an affordable solution, other than building an air conditioned dome over my back yard (just kidding).