Ventalation may not be best idea.
We have a two story steel shop building with windows at the ends.
All of the heat moves upstairs, so we leave the windows open, some cross flow helps.
Went up first winter to get something and it was raining inside due to condensaton on the steel.
It is insulated!
Issue is cold damp air moving through shop condensed on the structural steel when it was cold, closing windows in winter solved problem.
So keep it closed up to keep additional moisture out, then use crystals or small dehumidifier to dry it out
Tony & Lori
1989 Country Coach Savannah SE