FIG. 1 is a bottom perspective view of an air conditioner showing my new design;
FIG. 2 is a bottom plan view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a front elevational view thereof, the rear being identical in appearance;
FIG. 5 is a right side elevational view thereof, the left side identical in appearance; and,
FIG. 6 is a vertical cross-sectional view thereof taken along line 6-6 in FIG. 2, with the broken-line disclosure understood to be part of the article in which the claimed design is embodied, but which forms no part of the claimed design.