Abstract: An apparatus and process are provided for filling a passage between first and second elements with fiber insulation material. The apparatus comprises a support, an exhaust box rotatably mounted on the support and having an inner cavity and a fixture, a device effecting rotation of the exhaust box, and first and second elements. The first element has an outer surface and the second element has an inner surface. The second element is positioned relative to the first element such that the first and second elements define therebetween the passage which is filled with fiber insulation material. At least one of the first and second elements is perforated. The apparatus further includes at least one filling nozzle adapted to supply fiber insulation material to the passage and a vacuum source adapted to draw a partial vacuum in the exhaust box inner cavity while the fiber insulation material is supplied to the passage.