Abstract: A ventilator for a cooking unit located in a counter has a housing suitable for mounting beneath the counter. A vent member moves in a generally vertical direction with respect to the housing between a retracted position in which said vent member is flush with the counter and an extended position in which the vent extends above the counter adjacent to the cooking unit. The vent member is in fluid communication with said housing. A blower is coupled to said housing for drawing cooking effluents produced at the cooking unit into said vent member, downwardly through said vent member into said housing, and discharging same from said ventilator. A motor is mounted on the housing for moving a roller in an arcuate path. The roller engages a follower surface mounted on the vent such that travel of the roller along the follower surface drives the vent to the extended position.