Ventilation and air movement equipment, namely, air impellers for ventilation; electric motor-driven fans, ventilating fans for industrial use, and blowing machines in the nature of electric fans for ventilation and air moving systems; integral component parts for the aforesaid goods, in particular ventilating fan wheels, ventilating fan blades, fan wheels, fan blades, blowing machine wheels, housings for blowing machines in the nature of electric fans, inflow nozzles, outflow nozzles, diffus...