Exemplary semiconductor processing chambers may include a chamber body including sidewalls and a base. The chambers may include a substrate support extending through the base of the chamber body. The substrate support may include a support platen configured to support a semiconductor substrate. The substrate support may include a shaft coupled with the support platen. The chambers may include a foreline conduit offset from a center of the base for exhausting a gas from the chamber body, and an exhaust volume coupled to the foreline conduit. The chambers may include a pumping plate comprising a central aperture through which the shaft extends, and further comprising exit apertures for directing at least a portion of the gas from the chamber body to the exhaust volume. The exit apertures may be disposed at locations opposite the foreline conduit so as to reduce nonuniformity in gas flow.