The rain bird does water the back yard but I have quite a few big oak trees that use it and grass does not grow that well under them . It is turned on right now , hot as the hinges of hell today but not 100 yet !
I also use the aluminet but it is on the roof outside.
Thanks Deb. I grew up in Iowa, and the humidity was a big problem there also. Great for growing grass, corn and mosquitoes, bad for comfort.
I hope you found a solution to the heat build-up problem. It seems like putting the shade cloth on top of the greenhouse will block some heat from making it inside, plus a high exhaust fan to remove the hottest air would be most affordable.