A 600 will make your problem worse unless you fix the ventilation system.

You need to move air into the op from outside the op airmass and dump the warmed, moist air someplace where it can not be easily re-drawn into the grow.

Your ventilation system, whether an exhaust fan with a passive intake (2x the size of the exhaust duct) or an exhaust fan with a powered intake (a fan about the same size as the exhaust), should be able to move the room's airmass in 3-5 mins. In example, a 1000 cu ft room needs a 200-330cfm exhaust blower. Your mileage may vary depending upon how much light power you're running.

It's been said- got to get the air down to 75-77, 80 on a bad day. Even CO2 rooms only run at 85, 90 intermittent max.

'Good ventilation' does not include leaving a closet door open a couple hours a day.