A rooftop spinner, also known as a turbine or whirlybird vent, is a type of roof vent that relies on wind to spin a turbine and draw air from inside the property up through the vent. They are typically round and protrude from residential rooftops, and are attached directly to attic spaces to siphon away hot, humid air and prevent mold, rot, or other moisture problems. Turbine vents are a flexible solution for attic ventilation when there is no more room for ridge vents, and they do not require an energy source to run. However, their effectiveness depends on the amount of wind present, and they require periodic maintenance. In addition to residential use, rooftop spinners are also used on van roofs to ventilate the vehicle.