Evaporative cooling unit and data center

A data center comprising:

• an equipment room;
• and
• an evaporative cooling unit;
• wherein the evaporative cooling unit comprise an outdoor channel, an indoor channel, and a heat exchange apparatus, wherein the heat exchange apparatus is configured to exchange heat of air in the outdoor channel with that of air in the indoor channel, the evaporative cooling unit further comprises an air filter and a defrosting apparatus that are disposed in the outdoor channel, wherein the air filter is located between an air intake vent of the outdoor channel and the heat exchange apparatus, and the defrosting apparatus is located on a side that is of the air filter and that is close to the air intake vent of the outdoor channel;
• wherein, the defrosting apparatus comprises a heat exchange film, and the heat exchange film has a first channel and a second channel that are arranged crosswise, wherein the first channel communicates with the air intake vent of the outdoor channel, the second channel communicates with the indoor channel, and the first channel communicates with the second channel, and, the defrosting apparatus further comprises a switch valve, wherein the switch valve is configured to control the second channel to communicate with the indoor channel;
• and
• wherein the indoor channel separately communicates with the equipment room.