Abstract: An air vent for a dryer or the like in which the air vent is located outside of the building and has a light weight valve member which rests upon the end of a pipe leading to the blower outlet. Normally this light weight closure is effective to close off the end of the pipe and prevent the entrance of cold air into the pipe. When the blower is turned on, the light weight valve member floats upwardly and permits air to pass out through various openings. The vent includes a housing which encloses the light weight valve member and the upper portion of the pipe against which the valve member seats. The valve member may be of spherical form. The housing has a cover which may be either spaced from the housing to permit air to pass out between the cover and the housing, or fitted tightly to the top of the housing so that all of the air leaving the blower has to pass downwardly between the pipe and the housing.