A crystal puller for growing a crystal ingot includes a housing, insulation, a crucible assembly, a heat shield, and a dust barrier. The housing encloses a growth chamber, and has an upper wall with an inner surface and an aperture. The insulation separates an inside of the housing into an upper area and a lower area, and has a central opening. The crucible assembly is within the lower area to contain the melt. The heat shield is adjacent the central opening of the insulation, and forms a labyrinth gas path with the crucible assembly. The dust barrier extends from the inner surface of the upper wall to one of the insulation and the heat shield, and forms a seal with the upper wall around the aperture to inhibit particles from entering the growth chamber through the upper area of the housing.