In a heat exchanger that includes heat-absorbing fins and heat-absorbing tubes, each of which pierces through a corresponding through hole formed by a burring process, when a brazing material held by each of brazing material holding portions is positioned above a corresponding missing portion, formed by removing a part of a burring wall of each of the through holes, melts and penetrates between each of the burring walls and the corresponding heat-absorbing tube, each of the brazing material holding portions is extended above the corresponding missing portion at a predetermined distance. A notched portion concaved downward is positioned on each side of the respective brazing material holding portions.

An inward gas/liquid distribution structure used in microchannel heat exchangers is disclosed. The inward gas/liquid distribution structure can help optimizing refrigerant distribution for a microchannel heat exchanger with long distribution pipe or a microchannel heat exchanger having significant wind field differences. The inward gas/liquid distribution structure includes an inlet header component. The inlet header component has n inlets that are configured to allow gas/liquid to enter the inlet header component, and n is an integer that is greater than or equal to 2. The inward gas/liquid distribution structure also includes m distribution components. The m distribution components are located in the inlet header component and connected to the n inlets, respectively. In an example, the number m equals to the number n.

A heat exchanging element. The heat exchanging element is comprised of a plurality of spaced-apart through a common barrier, plates. The plates are capable of transmitting heat from a first end of said plates in contact with a heat source on one side of the common barrier, directly to a second end of the plates that are in contact with a heat sink on the opposite side of the common barrier.