According to the theory of indirect evaporative cooler, heat can be taken away through water evaporation by wrapping water absorbent film on the cooling surface of air conditioner condenser.
应用间接蒸发散热的原理，在空调冷凝器表面包覆吸水膜，利用水蒸发带走热量。
2
On the contrary, in the nighttime, the air near the surface is cooler and sound waves are refracted to the earth surface (Fig. 2).