An energy-efficient refrigerator includes a refrigerator control system for generating refrigerator control signals responsive to cooling demands of respective refrigerator compartments; a refrigeration apparatus coupled to the control system; and a multiplex damper system disposed to selectively direct the cooling-air from the refrigeration apparatus to compartments in response to the refrigerator control signals. The multiplex damper system comprises a single movable control damper disposed to direct cooling-air flow to a single or multiple compartments. The evaporator and its associated fan and a variable speed compressor are independently controlled by the refrigerator control system. The variable speed compressor typically comprises a continuously variable speed motor such as an electronically commutated motor. The refrigeration control system is coupled to sensors, such as compartment temperature sensors, ambient condition sensors, and compartment access door sensors, so as to determine the cooling demands of respective refrigerator compartments, and generates control signals for the refrigeration apparatus, including, for example, compressor motor speed, evaporator and condenser fan operation, and other control functions.