Patent attributes
A sheathing layer spans a supporting surface from which moisture is to be removed. In one exemplary system, ventilation channels extend between opposed ends of the substrate layer, communicating with an outlet opening at one end and with a duct at the opposing end which in turn communicates with an inlet opening at the same end of the substrate layer as the outlet opening. A fan is arranged to circulate air through channels from the inlet opening to the outlet opening to replace humid air in the channels with drier replacement air. In another example, a substrate layer includes ventilation channels communicating only between the supporting surface and an outlet opening. The outlet opening connects to a fan which maintains the channels at a vacuum pressure to withdraw moisture therefrom.