Bakersfield: Thanks for your advice. With the 3 exhaust fans I have running, its at 1500 cfm. Air intake is really through the cracks in the building. All dehuey's are exhausted also. I can't run the exhaust fans 24/7 because it drives the temp down below 65 once the lights are out. We are not running CO2 since we are exhausting everything. With 1500 CFM, it takes 7 minutes to exchange the air in here. But its just getting replaced by colder/wet air from outside (50 degrees and 90% humidity). Wish someone could turn the rain off.
If your not running lights 24/7 there's no need to ventilate too long after lights out.
I have a few additional questions:
How do you heat the structure?
Have you checked your hygrometer out to see if it works correctly and or move it around in the room to check for inconsistencies in the readings?
Do you have a leaking roof with moldy wet walls or huge puddles of water on the floor from drainage or hydro unit?
Remember that warm indoor air can hold a bunch more moisture than cold wet air. So as your 45f outdoor air may be 80% rh, as it is warmed to to 80f it will drop to under 20% as shown in the graph below.
Depending on how tight the trailer is, I'd say you need an active air intake.
