An energy efficient refrigeration system having a valve in series with a fixed flow restrictor between the condenser and evaporator of the system. The valve is controlled to permit fluid flow whenever the compressor is running, and when the compressor is not running, only in the event the pressure at the outlet of the compressor is above a preselected pressure. The preselected pressure is a high pressure, such as would prevent starting of the compressor, which, in the illustrated embodiment, is a rotary compressor. The pressure sensing structure, in the illustrated embodiment, utilizes an analog of the pressure of the liquid refrigerant within the condenser and, more specifically, utilizes a temperature condition which corresponds to the liquid pressure therein. Alternatively, the temperature sensing may be of the condenser or of the ambient space in which the condenser is housed. The control valve and associated control circuit are arranged to provide a fail-safe function and assure that the valve is open whenever the compressor is operating.