A cooling air system is provided for a patty-forming apparatus having a machine base that includes an enclosing wall and contains equipment within the machine base that generates heat, such as electric motors, electrical and control equipment. The machine base includes an air inlet opening and an air outlet opening through the enclosing wall. At least one air fan is arranged to move outside air from the air inlet opening to the air outlet opening. A first air damper is arranged to close the air inlet opening. A second air damper is arranged to close the air outlet opening. The first and second air dampers are configured to automatically close if power is interrupted to the apparatus. The dampers each includes a cover or plate and at least one inlet pneumatic cylinder that elevates the cover above the inlet or outlet opening when energized, allowing outside air to pass through the machine base. Springs are arranged such that when the pneumatic cylinders are de-energized, the springs urge the covers onto the openings to close up the machine base.