Abstract: Fan noise is the main noise source of range hood, vacuum cleaner, hair dryer and other household appliances. Noise management is the key to the development of such products. In order to shorten development cycle of the products, noise prediction should be carried out in the design stage. The traditional method is to model the fan and the system as a whole, and use the computational fluid dynamics-computational aeroacoustics (CFD-CAA) method to calculate aerodynamic noise. However, this method couples the acoustic source to the sound propagation process. Whenever there is a modification in the design, the whole system needs to be calculated, so the development efficiency is low. Therefore, an acoustic source modeling method which can decouple the acoustic source characteristics from the sound propagation process in the system is proposed. By analyzing the characteristics of the fan aerodynamic noise, the fan equivalent source model is established. To quickly predict the noises of different systems in different working conditions, the tuyere noise of the fan is tested and the equivalent source strength is extracted. This model is applied to the noise analysis of two types of range hoods. The results show that the prediction error of system noise is about 3 dB for different air-duct structures.