Abstract: An air blower installed on a barbeque smoker, including: (a) a rotary air blowing fan having an air outlet, (b) an air blower body having a first end and a second end with an air passage inside the air blower body between the first end and the second end, (c) a front installation panel, (d) a torsion spring having two arms with a round ring on each of the two arms, (e) a torsion spring retention pin, and (f) a shutter. When the rotary air blowing fan is turned on, the rotary air blowing fan blows air into the air blower body, through the shutter. When the rotary air blowing fan is turned off, the shutter close the air passage by its gravity. The torsion spring can be in the shape of a “V” or a “V” with two arms bent inward so they are approximately parallel.