Turbine ventilators utilize natural wind and the thermal convection caused by the temperature difference between indoors and outdoors to drive a turbine, thereby using centrifugal force and negative pressure to expel stale, hot indoor air.
The term "non-powered" for ventilation hoods doesn't mean they require no power at all, but rather that they don't need additional electrical energy to operate; they rely solely on natural wind. Their working principle is similar to that of range hoods and chimneys, essentially using the pressure difference between indoor and outdoor air to achieve air exchange. When natural wind blows from outside, the airflow drives the turbine blades of the hood to rotate. The rotating blades generate centrifugal force, lowering the air pressure in the central area and creating a negative pressure zone. Because the air pressure inside the hood is lower than the indoor air pressure, the indoor air is drawn upwards and expelled outdoors through the hood. When the indoor temperature is higher than the outdoor temperature, the hot indoor air, due to its lower density, rises naturally, driving the turbine blades to rotate. This rotation also generates centrifugal force, creating negative pressure inside the hood. This negative pressure further accelerates the rise and expulsion of hot air, achieving ventilation without relying on external wind.
