We needed a fan that would pull enough pressure from a large room to create a testing chamber for storm simulations. This blower fan created WAY more pressure than we anticipated! We were able to simulate hurricane force pressure on the window wall while evacuating the air from the room. Best fan we've ever used! High and low speed settings, heavy duty ducting, heavy duty, top notch quality and durability (we keep the fan running for hours at a time). Strongly recommend!