I was last year same problemwith my New grow room and where i grow in. I put styrofoam on walls. Before i have 95%humi,all my humi measure items broke when over nights. Now i have mid 40.
And wery good air dryer is space heaters 1000/2000 w 10 bucks. First year i dry air with that. Not directly on grow room because things heat up fast, but this was best air drier what i found. But its heats up things