The utility model relates to an evaporation fan, which comprises a volute pedestal, impellers, a motor assembly and a volute upper cover. A centrifugal double-axis fan is fixed in a mounting chamber of an air conditioner (HVAC) assembly in a screw extrusion manner through a wedge nut, a split pin and a screw; the volute pedestal is a basic structure for assembling the fan structure; the motor assembly is fixed in a semi-circular concave base in the middle of the volute pedestal; the first impeller and the second impeller are fixed on two protruding shaft ends of the motor in a interference assembly; a filter is fixed on both sides of the concave base of the volute pedestal through self-tapping screws to surround the other half circumference of the motor; and the volute upper cover is fixedly mounted on the upper end of the impellers through self-tapping screws to form an air channel of the fan together with the volute pedestal. The evaporation fan has the advantages of low noise, convenient installation and maintenance, reduced assembly time and labor intensity and improved fan efficiency.