Hydrophilic aluminum foil is generally used on the evaporator of air conditioners, and its surface is highly hydrophilic. Its main function is to make the moisture in the hot air easily spread and spread down the sheet when it condenses into water droplets on the heat exchange sheet. In this way, the ventilation effect of the heat exchange can be prevented from being affected by the “bridge” of water drops between the heat exchange fins, thereby improving the heat exchange rate of the air conditioner and saving electricity under the same cooling capacity.