yea well we seems to share the same problem .. as Im sure many share with us .. heat .. high temps around this time a year ..atlest in my part of the world (Denmark)
I had 90ish in my room when I just build it ..
when I got my ventilator (125mm/285M3/hr) it make it drop to 85F or so ..
running it at night made it drop a few more so I had 80-82F
but then summer hit us ..
and I was up on 85F agin ..
so I made a tube from my passiv intake over my window and to my grow room .. also provide fresh air/co2 ..
so now I can keep it around 82F .. maybe 78-80 fist hour then 82F untill last few hrs when if can go up to 84- 86F
but plants dont seems to mind and now I have it more or less in place and know what to expect .. I bet 8 months a year I can keep 78F ..
winther I might have to cut the tube to the outdoor ..
summer I have to plan .. so I veg with T5HO ..
but I will actualy .. next month is usealy the hottest and most humid so it will be perfect for my small seedlings Im about to start ..
just hope them last 3 weeks of flowering wont get any hotter now ..
next weeks actualy look nice .. lol .. did`t expect myself to sais so .. they prommise cold wether and rain