Heat exchanger and heat exchange method

A heat exchange method of carrying out heat exchange in a plurality of surfaces, the heat exchange method comprising:

• preparing an upper header pipe, a lower header pipe, and a plurality of heat exchange pipes provided between a pair of the upper header pipe and the lower header pipe in each of a plurality of heat exchange function surface units;
• connecting the plurality of heat exchange function surface units in parallel, and connecting a plurality of the lower header pipes to a lower collection pipe through a branch current adjusting section;
• and
• branching, by the branch current adjusting section, refrigerant inside the lower collection pipe in parallel to the plurality of heat exchange function surface units, subjecting the refrigerant to the heat exchange in the each of the plurality of heat exchange function surface units, and causing the refrigerant to flow out from a plurality of the upper header pipes so as to be joined together to an upper side collection pipe.