UNDERGROUND HEAT EXCHANGER AND AIR CONDITIONING SYSTEM INCLUDING THE SAME

摘要

A heat-transfer pipe (12) is formed so as to extend from a top portion of an outer pipe (11) and to be bent at a bottom portion of the outer pipe (11) to return to the top portion, and is arranged such that at least a portion thereof contacts an inner circumferential surface of the outer pipe (11). The heat-transfer pipe (12) is configured to allow fluid to be heat-exchanged to flow thereinside in opposite directions in heating operation and cooling operation.