According to certain embodiments, a device for conditioning a flow of air includes a casing with an inlet and an outlet. The device has a flow conditioner disposed within the casing and concentrically aligned with the casing. The flow conditioner has a cylindrical portion and a domed end portion capping the cylindrical portion. The flow conditioner forms an annulus region between the flow conditioner and the casing. The flow conditioner also forms a mixing chamber interior to the flow conditioner. The flow conditioner also has a plurality of holes throughout the flow conditioner that are configured to permit air to pass from the inlet of the casing and the annulus into the mixing chamber. The device also has a flow straightener located at the outlet of the casing configured to straighten the airflow as it flows from the mixing chamber out of the device.