There are three main ways of tunnel ventilation:
1. Longitudinal ventilation. The fresh air sent out (ie, pressed in) by the ventilator enters the lane from the air passage at one end of the tunnel, pushing and diluting the dirty air to flow longitudinally along the lane, and discharging it to the other end.
2. Horizontal ventilation. The fresh air sent by the ventilator enters the lane horizontally through the intake air passage on the air intake opening on the floor (or side wall) of the driveway, diluting the dirty air and then passing through the lane laterally through the row on the top plate (or the other side wall) The air inlet enters the exhaust air duct (inhaled by the fan) and is discharged outside the hole.
3. Semi-lateral ventilation. There is only one air duct in the tunnel, which is generally used for air intake. Fresh air enters the lane horizontally, and the dirty air flows out along the longitudinal direction of the lane.
