A refrigeration system including a refrigeration circuit that has an evaporator, a compressor, a condenser, and a heat exchanger. The evaporator, compressor, and condenser are fluidly connected and arranged in series with each other. A liquid line fluidly connects the evaporator to the condenser and a suction line fluidly connects the compressor to the evaporator. The heat exchanger includes a plurality of first refrigerant flow tubes that is in fluid communication with one of the suction line and the liquid line, and a second refrigerant flow tube that is in fluid communication with the other of the suction line and the liquid line. Each of the first refrigerant flow tubes and the second refrigerant flow tube have microchannels, and the second refrigerant flow tube positioned between and cooperates with the first refrigerant flow tubes to heat vapor refrigerant flowing in the suction line.