Abstract: A sensor assembly includes a housing and a sensor unit attached to the housing. The sensor unit includes a cylindrical shell defining a vertical axis and rotatable around the axis relative to the housing. The cylindrical shell extends upward along the axis from a lower edge. The sensor unit includes a first frustoconical panel fixed to the cylindrical shell, centered on the axis, and extending downward and radially outward from the lower edge. The housing includes a second frustoconical panel centered on the axis, defining a gap with the first frustoconical panel, and defining an airflow outlet from the housing radially inside the second frustoconical panel relative to the axis. The sensor unit defines an airflow inlet radially inside the lower edge relative to the axis and positioned to receive airflow from the airflow outlet. At least one of the frustoconical panels includes a ridge extending into the gap.

Abstract: A panel and defrost plenum includes a manifold section, an air feed section and a branch section. The manifold section includes a first air distribution door, a second air distribution door and an optional third air distribution door. The manifold section also includes at least one actuator to displace the first air distribution door, the second air distribution door and the optional third air distribution door if present, between multiple operating positions. The air feed section is located upstream of the manifold section and functions to deliver an airstream past a package restriction to the manifold section. The branch section is downstream from the manifold section. A related method of routing an airstream past a package restriction is also disclosed.