Do you know the Chimney Effect of elevators?

What is the “Chimney Effect”?
The chimney effect means that when the indoor temperature is higher than the outdoor temperature, the hot indoor air with low density will rise along the channel and seep out from the upper floors through the gaps. The cold outdoor air with high density will penetrate from the lower floors to supplement the indoor temperature.

Why is the “Chimney Effect” likely to cause elevator failure?
The elevator is equivalent to a huge chimney. When the weather is cold, the temperature of the air outside the shaft is low and the inside of the shaft is relatively closed. At this time, the air will flow upward along the space in the shaft and enter through the building doors and windows and the elevator landing door. The elevator shaft forms convection with the air in the shaft, causing air pressure differences. These air pressure differences may have a certain impact on the elevator.

What impact does air pressure difference have on elevator operation?
·Obstruct the elevator from closing the door. The elevator door motor and power match the weight of the car door and landing door. Under normal circumstances, it can drive the car door and landing door. However, due to air convection, cold air will enter through entrances and exits such as corridors, garages, and basements. In the elevator shaft, the wind generates pressure on the gap between the landing door leaves, resulting in high door closing resistance. The originally set motor closing torque cannot completely close the elevator landing doors on some floors. The elevator control system detects that the elevator door is not closed normally, so The elevator is not running. And because the air pressure at the bottom is high, the air comes in, and the air pressure at the top is low, so the air is more obvious the higher the floor. This failure phenomenon mainly occurs on the bottom and high floors.

·You will hear “abnormal noise” during operation. The air convection inside and outside the elevator shaft causes vibration and abnormal noise when it passes through the gap in the landing door. When we ride the elevator up and down, the air in the elevator shaft also recirculates and convection. At this time, we may hear the sound of air flow. However, this is not a fault of the elevator itself and does not affect the normal operation of the elevator.

·It will cause the car to shake. When the high-speed airflow and the elevator move in opposite directions, serious turbulence can be generated up and down the elevator car. Affected by these turbulences, the elevator car will shake significantly when running.

How to reduce the impact of “Chimney Effect” on elevators?
·Close the unit door in time to reduce the impact of strong wind on the elevator hall door.

·The maintenance unit can adjust the hall door self-closing device according to the actual situation to increase the self-closing force of the door closing, or reset the door machine parameters to increase the closing torque, thereby reducing the impact of strong wind on the elevator closing the door.

·Reduce the impact of wind on the elevator door closing by reducing or closing the vents at the top of the elevator shaft.