The wind blown down by industrial ceiling fans is hot and cannot achieve cooling effect. Is this correct?

Some people say that the wind blown down by a 7-meter-3 fan is hot, is that right? Firstly, let's take a look at the motion diagram of the airflow after turning on the fan. The airflow is indeed a continuous supply of air from the roof to the ground. Common sense tells us that hot air has a low density and accumulates on the roof, which is why some people say that what comes down from a large fan is the hot air from the roof. But this statement is both correct and incorrect. Why? The fan is turned on, and the air from the roof is constantly being sent to the ground. Is the roof in a negative pressure state, and the air next to it will quickly replenish and flow to the roof, forming such a circulation of air flow. So what blows down is not always the air from the roof, but an air circulation.

简单来说就是当大风扇转动时，扇叶带动气流，气流沿着扇叶角度向下移动，当向下移动的气流遇到地面后向外折射移动，这种向外折射移动的气流称为水平喷射，相对于风扇的直径，在持续源源不断的气流向外推下，形成一个大面积的圆柱形立体风。当持续喷射压力流达到其潜力，它就会向外移动，直到遇到侧壁或其他垂直表面，所以柱形立体风往往大于风扇直径的数倍以上。这种立体移动气流会破坏身体周围的水分饱和边界层，并加速蒸发，从而产生冷却效果。