I use a product called DAMP CHECK, it's a container, a crystal holder, and a bag of crystal. Put the crystal holder inside the container, and pour in the crystals. The crystals draw moisture out of the covered area and the container collects and holds the liquid. I use four in my 26' and good for all winter, nice fresh smell when you uncover, and never a hint of a problem. Got mine off the net, refills of crystal are available in four packs.