A 2D2D type cyclone inlet was substituted for the tall, narrow inlet of the standard 1D3D cyclone in an attempt to overcome choking problems when using the standard flat-top inlet transition, or performance problems when using an inverted transition. This inlet modification lowered the modified cyclone's emissions by 8 to 9%, and slightly reduced its static pressure requirements. The 1D3D cyclone equipped with a 2D2D inlet operated satisfactorily with either the standard 1D3D type air outlet duct, or the shorter 2D2D type outlet. The size of the cyclone's trash exit significantly affected PM10 emissions. A larger (D/3) size exit produced PM10 emissions that were about 8% lower than those resulting from use of the standard, small-diameter (D/4) exit.