Cyclones are the most commonly used air pollution abatement device for separating particulate matter (PM) from air streams in agricultural processing such as cotton ginning. The performance of cyclones is a function of the geometry of the cyclone, air density, inlet velocity, and the particle size distribution (PSD) of the entrained PM. Multiple models have been proposed to predict the performance of cyclones given different geometric proportions, but many of these models do not quantify changes in performance with increasing cyclone diameter given fixed geometric proportions. This paper empirically explores the change in performance of 1D3D and 2D2D cyclones as cyclone diameter is varied from six to 36 inches.