Big fan of fans. good way to control the environment. I opt for a steady flow from an input Fan/filter and an out also fan/filter combination. not too much unless the humidity gets high then full on. using leds it's not so much about heat for me as humidity. my Intake sits in a constant cool of 69 or so right now, flowing at a low setting and just enough out to have a neg feel to the tent. just a smidge. Been working so far, need to add humidity right now we are a dry 40's, been boosting it to 60's with a cool sonic fog setup. ( sounds better than plastic qt container with pond fogger)

Inside I like the standard cheap tent fan from HD, the black one you can zip tie the f r anywhere also have a 6" clip fan for cross breeze, not too strong.