Definition: ventilation - A means of removing body moisture to prevent condensation buildup inside your tent. As you sleep your body gives off moisture through perspiration and breathing. This moisture condenses on the inside of the tent walls, inside and on top of your sleeping bag, and on the tent floor. It's no fun waking up wet. Most tents provide a roof vent and doors or windows with screens. To avoid the buildup of condensation simply open your roof vent and zip a door or window partially open.