The prediction of emission concentrations from cyclone collectors is integral to the permitting of agricultural facilities including cotton gins. One method for predicting emission concentrations utilizes fractional efficiency curves. Fractional efficiency curves (FEC's) were developed for 1D2D, 1D3D, and 2D2D cyclone designs. The procedure used to develop these new FEC's incorporated log-normalized distributions and results of particle sizing using the Coulter Counter. Another method that has been used by many air pollution regulators is the Classical Cyclone Design process (CCD). These new FECs were used to compare performances of three cyclone designs currently being used by cotton gins to abate PM₁₀. The two methods were compared and the use of the FEC method was far superior to the CCD process. The results indicate that properly designed and operated cyclones are high efficiency collectors and can be used as a final abatement device for agricultural processing facilities.