A fan tube ventilation system is a type of mechanical ventilation system that uses a fan to draw air from the outside into a building or other enclosed space. The fan is typically mounted in a tube or duct that runs from the outside of the building to the inside. The fan is used to create a positive pressure in the tube, which forces the air from the outside to enter the building. This type of ventilation system is often used in commercial and industrial buildings, as well as in homes, to provide fresh air and reduce the amount of pollutants in the air. It is also used to reduce the amount of energy needed to heat and cool the building, as the fan can be used to draw in cooler air from outside in the summer and warmer air in the winter. Fan tube ventilation systems are typically more efficient than other types of ventilation systems, as they can move large amounts of air with minimal energy consumption.