horn-cone fans 1.air flow 49530m3/h . 2.cone ... fan can save 20% of energy than the simple fan. 3.Galvanized frame, Fiber glass horn ... -cone fans1. Reasonable cone designing, low noise, big air flow, strong ventilation, ... bearing, high-strength, low noise, durable3. Using air downstream principle, pvc shutter or aluminum shutter, antioxidant, ...