Ive noticed my growroom was hot. I got a guage and realised with the door closed the temp is over 100 degrees in the hottest part of the day. With a fan and the door open the temperature is what you see.
Im running a cheap 400watt hps and have 2 bogus 1000w LED growlights are pretty bright but are no more than 200w I'm sure. doubt it equals 1000w.
I have no real ducting. Just a fan
Remember It is turning cold.