not sure what the problem is for y'all with rusting, can't imagine any of you have a more humid area than the "wet coast" here on Vancouver Island and the only problem I have with things rusting is when they're left out in the rain - under cover, heated or not, things stay for years the way they were when I put them there .... maybe you guys have metal clad buildings? condensation dripping from the metal might be the problem, insulation would be the solution
OTOH, we have pretty steady air movement here, from a slight breeze to howling winds and that probably keeps condensation at bay when inside temps are about the same as outside - right now it's 92% humidity, this time of year it's rarely less than 80%
Bill