This document describes a mobile cleaning robot including a chassis having a forward portion and an aft portion; a blower affixed to the chassis; a bin supported by the chassis and configured to receive airflow from the blower, the chassis enabling evacuation of the bin through a bottom of the robot. The bin includes a top, a bottom, a sidewall, and an internal barrier. The bin includes a first volume and a second volume separated by the internal barrier and a filter unit supported by the internal barrier and removably disposed in an airflow path between the first volume that includes an intake port in the bin and the second volume that includes an exhaust port in the bin.