An embodiment make-up air system includes a switch assembly including a housing configured to be mounted to an exhaust air duct, a rod pivotally mounted to the housing, the rod having a paddle mounted on a first rod end disposed outside the housing, the paddle including an angled portion, and a switch disposed in the housing, the switch actuated by the rod when the paddle experiences a predetermined flow of air through the exhaust duct, and a fresh air intake assembly operably coupled to the switch assembly, the fresh air intake assembly configured to open a damper disposed in a fresh air intake duct to initiate a flow of fresh air when the switch in the switch assembly has been actuated.