Precautions when using air filter cotton

　　When replacing the product, first remove the air inlet, ceiling and filter screen, carefully clean the ventilation ducts, corners and places that are easy to accumulate dust, then close the door, open the fan for about 1 hour, clean it, then install the filter. cotton. When installing the filter cotton, there should be no gap between the filter material and the frame and the circumference. First install the ceiling and air inlet filter cotton, open the fan for about 4 hours, and then clean the work, then install the cotton. Can be used.