A refrigeration system comprising: a compressor for compressing a refrigerant; a condenser for cooling the refrigerant; an expansion device for expanding the refrigerant; and an evaporator for heating the refrigerant, wherein at least one of the condenser and the evaporator is a microchannel heat exchanger comprising: a plurality of microchannel tubes including a first set of microchannel tubes and a second set of microchannel tubes; a first circuit including the first set of microchannel tubes, wherein a portion of the refrigerant flows through the first set of microchannel tubes and exchanges heat with air; and a second circuit including the second set of microchannel tubes, wherein a remainder of the refrigerant flows through the second set of microchannel tubes and exchanges heat with the air, wherein the refrigerant make two passes through the plurality of microchannel tubes, wherein the portion of the refrigerant flows through a first group of the first set of microchannel tubes in a first direction and then flows through a second group of the first set of microchannel tubes in an opposing second direction, wherein the remainder of the refrigerant flows through a first group of the second set of microchannel tubes in the first direction and then flows through a second group of the second set of microchannel tubes in the opposing second direction, and wherein the first group of the first set of microchannel tubes and the first group of the second set of microchannel tubes are adjacent, wherein the microchannel heat exchanger further comprises; a distributor for splitting the refrigerant into two paths with the portion of the refrigerant in one path and the remainder of the refrigerant in another path, and in that the refrigerant from the first circuit and the refrigerant from the second circuit combine into a common refrigerant flow. a compressor for compressing a refrigerant; a condenser for cooling the refrigerant; an expansion device for expanding the refrigerant; and an evaporator for heating the refrigerant, wherein at least one of the condenser and the evaporator is a microchannel heat exchanger comprising: a plurality of microchannel tubes including a first set of microchannel tubes and a second set of microchannel tubes; a first circuit including the first set of microchannel tubes, a plurality of microchannel tubes including a first set of microchannel tubes and a second set of microchannel tubes; a first circuit including the first set of microchannel tubes, wherein a portion of the refrigerant flows through the first set of microchannel tubes and exchanges heat with air; and a second circuit including the second set of microchannel tubes, wherein a remainder of the refrigerant flows through the second set of microchannel tubes and exchanges heat with the air, wherein the refrigerant make two passes through the plurality of microchannel tubes, wherein the portion of the refrigerant flows through a first group of the first set of microchannel tubes in a first direction and then flows through a second group of the first set of microchannel tubes in an opposing second direction, wherein the remainder of the refrigerant flows through a first group of the second set of microchannel tubes in the first direction and then flows through a second group of the second set of microchannel tubes in the opposing second direction, and wherein the first group of the first set of microchannel tubes and the first group of the second set of microchannel tubes are adjacent, wherein the microchannel heat exchanger further comprises; a distributor for splitting the refrigerant into two paths with the portion of the refrigerant in one path and the remainder of the refrigerant in another path, and in that the refrigerant from the first circuit and the refrigerant from the second circuit combine into a common refrigerant flow.