Post-combustion conditioning systems are described that include a flue gas conditioning device configured to condition an exhaust stream to produce a conditioned stream. First and second outlet ducts can be fluidly coupled to, and substantially supported by, the flue gas conditioning device. This advantageously can eliminate costly ductwork, reduce the space required, and reduce the pressure drop of the system. The first outlet duct can fluidly couple the flue gas conditioning device to an exhaust duct, such that the conditioned stream can flow from the first conditioning device via the first outlet duct.