[Jim W]

Our camper is stored all winter in a storage lot, in farm country. The wife insist on the camper being closed up tight to keep the fine silt from farming that will enter through open windows and roof vents.

So I use a product called Damp Rid, this is a moisture absorber. Can be bought in any grocery store or home goods store. Works well, we have never had any mold or mildew in the camper from storing it this way. I pour this in a container that allows the moisture to be absorbed and the water is then trapped below it.

I empty the container about once a month when the camper is being stored in the winter. Will also replace the Damp Rid as required.
Jim W.