Abstract: A cover for preventing water and other damage to an external air conditioner compressor/condenser unit is formed as a rectangular housing having vertical sidewalls and a top ceiling portion. An open bottom end of the housing is dimensioned for insertion over an air conditioner compressor unit. The housing has three sidewalls and an open side for abutment against an exterior wall of a house or mobile home. A plurality of rows of pivotal shutters cover each of the sidewalls and top ceiling of the housing and are selectively moveable between open and closed positions. When the air conditioner is not in use, the shutters are closed to protect the unit from the environment. When the air conditioner compressor unit is in use, the shutters are moved to an open position to allow air flow to the unit, while still providing shade to enhance the operating efficiency of the system.