The utility model belongs to the field of centrifugal fans, in particular to a low-pressure centrifugal fan. A low-pressure centrifugal fan includes a casing, an impeller, an air inlet ring, a rivet, a wheel hub, a positioning sleeve, a motor, and a disk at the shaft end. An air inlet is arranged outside the impeller, and an air outlet is arranged at the outer edge of the casing. The flow channel of the casing is 10% wider than that of the same type of centrifugal fan, and the flow channel of the impeller is 10% wider than that of the impeller of the centrifugal fan of the same type. Compared with the original 4-72 series fan, the flow passage of impeller and casing is widened, and the volume of fan is reduced. At the same time, the back arc profile of single plate is selected, the blade inlet angle is 30 ° and the blade outlet angle is 36 ° so as to ensure the air pressure and air volume, and achieve the highest total pressure efficiency. The air inlet and outlet are designed to be increased to facilitate the subsequent construction of users. We're well-known as one of the leading low pressure centrifugal fan manufacturers and suppliers in China for our quality products and competitive price. Please feel free to buy bulk low pressure centrifugal fan from our factory.