Spread of household air conditioning system is continued to be increased. Along with the spread, the acknowledgement on product quality by the customer is increasing. Therefore, not only basic performances like cooling and power consumption but also design and noise level of in-house and external unit become the important factors. Axial fan in the external unit of air conditioning system is for ventilation and air supplying unit, and the related products have been widely adopted as household electronics, automobile engine, big sized blower in factory, tunnel, and subway. In this study, commercial 3-winged propeller fan from S company is modified to 2-winged fan for the cost reduction. Using 3D modelling, the fan shape is modified, and analysis flow is adopted to provide the way to reduce cost while maintaining the same wind capacity.