Ventilation Systems for Tunneling Work

We provide contra fans (high-pressure axial flow fans) used for road/railroad tunneling work and construction of underground power stations and underground storage centers, etc., and the MDEX series of large dust collectors for capturing dust generated by construction work.

Tunneling Work Ventilation System Line-up


Contra-fans for tunneling work are generally used for feeding fresh air to the working face. An air duct is attached to the discharge side of the fan.
An air duct may extend to over 2,000m in the case of a large-scale project. So, unlike general-purpose axial flow fans, contra fans are high-pressure fans with total pressure capacity of 5kPa (500kg/m2).
“CONTRA” means contrary.

Model Airflow rate
Total pressure
kPa (mmAq)
kW x 2
Standard weight
Total length
Airflow rate control method
MFA90P2-SC33L 750 3.92 (400) 37 3,430 8,102  
MFA90P2-SC4L 1,000 3.43 (350) 37 3,430 8,102  
MFA110P2-SC31-VPS 1,200 3.92 (400) 55 6,800 9,656 Variable pitch blade control
MFA110P2-SC3-VPS 1,500 4.9 (500) 80 6,800 9,656 Variable pitch blade control
MFA125P2-SC5-VPS 2,000 4.9 (500) 110 8,000 9,703 Variable pitch blade control
MFA160P2-SC3-VPS 3,000 4.9 (500) 160 15,700 14,888 Variable pitch blade control


The MDEX series of large-scale bug-filter-type dust collectors are used for tunneling work. The standard MDEX series offers airflow capacity of 1,800-3,000m3/min.
Equipped with an innovative automatic filter cleaning system, stable dust collection performance is achieved for a long time, contributing to maintenance of a good working environment. An air curtain to prevent the passage of dust is included as standard equipment.