1. A drainage outlet should be reserved at the upper opening of the fan, with a position of approximately 15 to 20 centimeters. The lower end of the peak opening should be properly plugged. The lower peak does not need to leave a drainage outlet, but it needs to be tightly attached to the base.
2. There should be a flashing plate around the base of the centrifugal fan, and the flashing plate can be fixed with rivets. The diameter of the rivet is chosen to be 5mm, and the density is around 10cm. When using rivets for fixation, they must be firmly fixed and not loose. The perimeter of the flashing board should be flat, without any warping or collapse. The flashing board around should be higher than the outer part near the base edge to prevent water accumulation in the fan in the future.
3. There should be no large areas of rust spots around the fan base.
