A heat exchanger system is disclosed by embodiments of the present invention. The heat exchanger system comprises an upper manifold, a middle manifold and a lower manifold arranged successively from top to bottom, wherein a first heat-exchanging tube is arranged between the upper manifold and the middle manifold, and a second heat-exchanging tube is arranged between the middle manifold and the lower manifold. The middle manifold has a first chamber and a second chamber separated from each other. During circulation of refrigerant, the refrigerant in the upper manifold flows through the first heat-exchanging tube down to the first chamber, and flows via a first communicating part into the chamber of the lower manifold, and subsequently the refrigerant flows through the second heat-exchanging tube up into the second chamber and then returns via a second communicating part to the upper manifold.