Abstract: A dual ventilation system is provided for a structure. The system has a suction tube assembly with an exhaust outlet in an upper end thereof and an exhaust fan therein. An intake vent or other intake means is in a lower portion of the structure in flow communication with the suction tube assembly. At least one channel is proximate a lower portion of the structure in flow communication with at least one lower interior portion of an exterior wall of the structure and in flow communication with the suction tube. In structures having a sump pump, the sump pump liner is in flow communication with the channel.