Heating ducts are a type of ventilation system used to regulate the temperature of a building. They consist of a VENT, which is an opening in the wall or ceiling that allows air to flow into and out of the building, and a SHAFT, which is a tube or pipe that carries the air from the VENT to the heating system. The combination of the VENT and the SHAFT creates a heating duct, which helps to keep the building at a comfortable temperature.