I have a sump pump room in the basement with metal door, lock and no windows. The room is not wet, no mildew or anything, but you can smell the presence of water there. I just measured humidity there - 61% now, but it's a rainy day today so it's even 64% in the rest of the basement and the same 61% upstairs. I haven't lived in the house during winter and spring time yet (just moved in) so I have no idea how it's going to change. Do you think this room is suitable for ammo storage?