Inline fan and new air

Bring in new air from passive air vents at the bottom of the tent, ensure they have a dust filter on them. I have the same system as you, inline fan and carbon filter inside the tent at verry top and its sucking the air from inside the tent and pushing it out its exhaust. Do not push the air it is sucking out of the tent back into it, it will be hot and not as fresh, want new air with fresh CO2 and less heat and humidity. My system vents into the room it pulls from, but the room it pulls from is quite large and its vents to a area that not close to its intake vents. so it works out fine, Ideally I would vent directly outside but don't have the setup for that yet. Good Luck!

Air in and air out will help keep your room cool and can help reduce rh or increase, depending on the air outside the tent. But you want a little more air out than in.

The most important one is the one throwing air out because air will always be sucked in from the tent. You can do another one sucking air in but the one throwing aur out should be stronger to create negative pressure Good luck with the rest of your grow.