This humidity problem is kicking my ass

Man this humidity problem is kicking my ass. I have tried almost everything. I have plenty of air exchange. The air intake ducting that brings air in from outside the house into the flower room is actually dripping water onto my flower room floor. I had a air filter screen cut to the size of the duct and taped in place to prevent bugs and mold spores from entering. Water just condenses on the screen and dripps intop a puddle on the floor. I live in Portland oregon where it has rained in the last week but its not raining today and hassent rained in a few days. What is causing this? How do I stop it? I have a few plants in flower at week 5 and need this resolved. I have been told by local growers that I shouldnt need a dehumidifier but may be getting one today. Can someone help me resolve this....or can someone recommend a dehumidifier that doesnt take up a huge amount of space or cost a whole lot.

Thanks everyone

Grasshopper

OK lets see

720 cfm hydrafarm fan as passive exhaust with my carbon scrubber is what is exhausting a 8x14x6 feet tall room lit with a 1000 watt aircooled fixture. 420 cfm fan on the cooling the light...but this comes in from outside the room and exits outside the room.

have you measured your relative humidity?

How do you figure relative humidity? I have the electronic humidity hydrometers.


GH

so what is it reading?