Exhaust fans are used to remove smoke from the fire, so that people will not be suffocated by smoke. Exhaust fans are usually used to replace air and keep it fresh. Generally, the exhaust fan has low rotating speed and high requirements for noise control, and is equipped with a muffler. The exhaust fan has a high speed and needs low noise control, but its entrance is equipped with a fire damper. When the exhaust temperature is higher than 280℃, the fire damper will be automatically closed, and the exhaust fan will be stopped for combined transportation. In case of fire, the combined transport should turn off the exhaust fan.
The exhaust air requires temperature resistance, and the cable requires NH type, and dual power supply can be used.
At present, the design of two-speed smoke exhaust fan is generally adopted.