Garage door ventilation systems

A ventilation system for a garage door, the ventilation system comprising:

• a frame, wherein the frame comprises:
• a first side frame and a second side frame spaced apart so as to define an interior space therebetween;
• and
• one or more longitudinal slots provided by a periphery of the frame so that each longitudinal slot communicates with said interior space;
• and
• one or more filters movable between a nested condition and an unnested condition removed from the frame;
• a plurality of grip brackets connected to the frame;
• and
• a plurality of travel bars directly fixed to a lowest section of the garage door, wherein the pluralities of grip brackets and travel bars are configured so that the frame is movable in a vertical direction between a retracted position and an extended position projecting beyond the lowest section of the garage door,
• wherein each travel bar terminates with a foot,
• whereby with the garage door in a partially open position, the frame closes a gap between the lowest section of the garage door and a floor of the garage of the garage door, and wherein the garage door is in a fully closed position, each foot engages the floor of the garage.