... outlet and inlet system1,the YDW series centrifugal fan is of Siemens technology, this fan has low noise, large air volume,low ... energy consumption, etc. air inlet fan modelYDW4.5L;air capacity:14000m3/h;pressure800Pa;velocity:940rpm;power4KW ... ;quatity:2sets.air outlet fan modelYDW5.6M;air capacity:20000m3/h;pressure800Pa;velocity:900rpm; ...