right now air is sucked through the cabinet and exhausted into the attic. i have tried exhausting it back into the ac venting but it gets to hot in the rooms. i dont think humidity will be a problem as i live in the desert and its really dry here most of the summer, except through our rainy season. i figured what i could do is have it come on a few times during the day (night cycle in the cabinet) just to exhaust and refresh the air instead of running it all 12 hours of dark time. thanks for your input just seeing if anyone else had tried this.