The ornamental design for a windowairconditionerunit, as shown and described.
FIG. 1 is a front and top perspective view of a window air conditioner unit showing our new ornamental design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a right side elevation view thereof;
FIG. 5 is a left side elevation view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines in the figures show portions of the air conditioner and form no part of the claimed design. The dash-dot-dash line defines a boundary of the claimed design and is not an ornamental part of the design itself.