Electric pedal-operated fan, pay attention to keeping the fan level during installation; the weight of the return air duct and valve should not be placed on the housing. Selection of the fan type should

Based on the air volume and pressure loss of the air intake system, determine the calculation of air volume and pressure loss, and separately calculate the fresh air volume during clean ventilation and the air purification ventilation.

Fresh air volume and the corresponding pressure loss at that air volume. If clean ventilation and filter-toxin ventilation share a single fan, the fan should be sized based on the combined air volumes and their pressure requirements.

Select a fan for power loss; if clean ventilation and filter ventilation are separately set with intake fans, the intake fans should be adjusted according to the fresh air volume of clean ventilation and its pressure loss, as well as the filter ventilation.

Venti fans, separately selected for air volume and pressure loss.