Temps can run a little higher with LEDs because the heat intensity is lower than HPS. I'm kicking myself for not book marking it but someone posted a very informative video a couple months back done by one of the LED manufacturers. They found that a temp of 85 and RH of 40% under LEDs provided the optimum transpiration rate. At that combo the plant transpires at a rate that optimizes nutrient uptake. I've since dialed up the temp in my outdoor grow box and even though I have no humidity control, I've not experienced any ill effects. This was good news to me as I normally have shut down my box from the beginning of June till mid-late Sept. because of high heat. Outdoor temps have been high here this week, and temps inside the box are hitting close to 90 but still within their suggested range. So far, so good. This should also allow me to start back up in the beginning of Sept., so I'm picking up a month on each end, enough time for an extra grow every year.
