Window fan

A window fan comprising:

• a housing having at least one air flow opening adapted to communicate with the space inside of a window, at least one air flow opening adapted to communicate with the space outside of a window, and an adjustably extendable side extension, said adjustably extendable side extension comprising a first outer guide and a second outer guide, said first outer guide having formed on its inner surface at least one row of projections, and a plurality of telescoping panels, said telescoping panels being disposed between said pair of outer guides on opposite sides of said at least one row of projections;
• b) a locking assembly mounted on said housing, said locking assembly having means for engaging the projections on said first outer guide and being movable between a first position in which said engaging means engages the projections in a ratchet-type fashion, permitting movement of the outer guide upon the application thereto of a substantial force, and a second position in which said engaging means engages the projections in a locking fashion, preventing movement of the outer guide;
• and
• c) at least one fan unit mounted inside said housing.

A window fan comprising:

• a. a housing having a pair of air flow openings adapted to communicate with the space inside of a window, at least one air flow opening adapted to communicate with the space outside of a window, and an adjustably extendable side extension, said adjustably extendable side extension comprising a first outer guide and a second outer guide, said first outer guide having formed on its inner surface at least one row of projections, and a plurality of telescoping panels, said telescoping panels being disposed between said pair of outer guides on opposite sides of said at least one row of projections;
• b. a locking assembly mounted on said housing, said locking assembly including means for engaging the projections on said first outer guide in a ratchet-type fashion, permitting movement thereof upon the application thereto of a substantial force;
• and
• c. a pair of fan units mounted inside said housing, one of said fan units being used to move air through one of said air flow openings adapted to communicate with the space inside of a window, the other of said fan units being used to move air through the other of said air flow openings adapted to communicate with the space inside of a window, each of said pair of fan units comprising an electrically reversible fan motor and a set of an blades rotatably mounted on said electrically reversible fan motor;
• d. a single power switch movable between an open position in which neither of said fan units receives electricity from a power source and one or more closed positions in which both of said fan units receive electricity from a power source;
• and
• e. a pair of intake/exhaust switches, one of said pair of intake/exhaust switches controlling the direction of rotation of one of said pair of electrically reversible fan motors, the other of said pair of intake/exhaust switches independently controlling the direction of rotation of the other of said pair of electrically reversible fan motors.