well in veg humidity is fine you don't need to bring it down until the end of the flower cycle.

You don't bring in fresh air from the outside and run an exhause if you are using co². I may have read it wrong but it sounded like that is what you were doing. The idea if enhanced CO² it to reach X level and hold it there for hours. Exhausting the air in the room only once every 3-4 hours then starting all over again. A sealed room uses AC to cool the room down. The fan running is fine to more the gas around.

You are not using the exhaust while you are using CO² at the same time are you?
Zandor Reviewed by Zandor on . CO2 /Temps/Humidity Question!!! Small Grow Room Split Veg/Flower (currently vegging in Flower side to start perpetual grow). BTW, CO2 is the bomb... clones have taken off and doubled in size in 4 days, and just keep growing!!! Situation: I'm running co2 off a Telair 8001 in veg side that is demanding a boost every 6 minutes, drawdown is about 1-1.5 ppm / second between 1600 to 1400 ppm. So I end up getting a demand off the Telair for CO2 to bring it back up. Seems dialed in. BUT temps are staying at about 78-79 with Rating: 5