"Exhaust Fan" different different specifications ventilation effect, the amount of this type fan ventilation mesh on the market generally 32000m / h ~ 45000m / h between . Ventilation up to 98%. The main circulation exhaust type fan form factor, there are three, namely 1380 * 1380 * 400mm1.5 kW, 1220 * 1220 * 400mm1.0 kW, 1060 * 1060 * 400mm0.75 kW three specifications. "Exhaust Fan" rotating belt can be divided into direct type rotating motor to rotate two kinds. Belt-type fan rotation speed is generally 400 to 450 rev / min, with low noise characteristics. Direct motor rotational fan speed is high, 440 to 720 rev / min. "Exhaust Fan" from the blade structure is divided, there are five leaves, six leaves, Paris three structures.