Through a thermal-state model experiment, the effects of air channels in five layout patterns on heat transfer and ventilation characteristics of the wet cooling tower were investigated under different crosswind velocities and circulating water flowrates in this paper. The dimensions and operating conditions of the model tower were obtained by scaling down those of the prototype according to similarity principles. Experimental results manifest that all patterns of air channels can not only enhance the heat transfer and ventilation performance but also decrease the variation amplitudes of performance parameters versus crosswind velocity. Under most crosswind velocities, the positive effects of air channels are more remarkable under 0.000065 m3/s than those under 0.0001 m3/s. Compared with the original tower performance, the effect of the P4 and P5 pattern is superior to that of the P2 and P1 pattern. Besides, the P3 pattern of air channels with a length of 0.27 times the tower bottom diameter and a number of 8 can provide an optimal tower performance, which is recommended in engineering applications.