Hi buddy, let the air coming into the fan to pass trough a container filled with salt. If the filtered inlet is airtight you'll collect a lot of humidity in this salt container. This will have to go down trough some drain hole.
have you checked your Hygrometer in a sealed sandwich bag with a small pot of wet salt ? after a few hours it should read 75% an less you grow massive buds and your in the last 2 weeks in flower, humidity below 70 is fine and will give you healthy happy plants all the Way through flower
2 inch usb a 7"oscillating fan and 4" extractor fan with filter Cheers buzzer been a really cheap set up but she's working for me
I would rather have high humidity over those temps... I flower in 60-70% humidity just fine and my plants look perfectly healthy all the way to harvest with no mold issues whatsoever... I have a lot of airflow too which is important.. but those temps won't be good in flower much worse than the high humidity imo.