grow room ventilation

hi there, about to move my plants into the grow room. ( they are 2“ - 3“ tall). Do i need to run the exhaust fan, the oscillating fan or both?; just figured that, because they are so small I could save myself a few pennies by not running the fans for a week or two... RW :peace:

I'm trying to find a (somewhat) definitive answer about the air pathways when an air-cooled hood and a carbon filter are both used. I thought, blow the fan over the light, connect the carbon air filter on the exhaust. But if I'm bringing air in from outside the room to cool the lights, it...