A self-contained refrigeration unit wherein two evaporators and fans associated therewith are mounted in a refrigeration space, the first evaporator operating at one evaporating temperature and the second evaporator operating at a lower evaporating temperature. The fans circulate air successively over the first and second evaporators, through a storage area input port, within the storage area of the refrigerator unit and to a storage area output port from which it is returned to the first evaporator. Deflector vanes are provided at the air input port to disperse the incoming air thereby preventing turbulence and to reduce the quantity of ambient air which enters the output port which is located at the side of the storage area opposite the side where the input port is located.