Axial roof fans primarily exhibit the following differences:
1. From the perspective of air pressure, the front propeller is larger, the radial propeller is smaller, and the rear propeller is the smallest.
2. From the perspective of efficiency, the rear propeller is more efficient, with the propeller positioned centrally, while the front propeller's efficiency decreases.
3. From the perspective of structural dimensions, under specified airflow and velocity conditions, to achieve equivalent static pressure: the forward impeller has the smallest diameter, the radial impeller has the second smallest diameter, and the rear impeller has the largest diameter.
4. From the perspective of axial roof fan noise, forward-curved impellers produce the highest noise, free-slip impellers produce moderate noise, and backward-curved impellers produce the lowest noise.
