The hall of residential building has a large population mobility, and the crowds are dense during the peak travel hours. It is necessary to strengthen ventilation, speed up air flow and reduce the risk of disease transmission.

When the electric fan is working (assuming that there is no heat transfer between indoor and outdoor), the indoor temperature will not decrease, but will increase. Let's analyze the reasons for the temperature rise. When the electric fan is working, because there is current passing through the coil of the electric fan and the wires are resistive, it will inevitably generate heat and heat, and the temperature will naturally rise. But why do people feel cold? Because there is a lot of sweat on the surface of human body, the indoor air will flow when the electric fan works, so it can promote the rapid evaporation of sweat, and people will feel cool in combination with the need to absorb a lot of heat.