Heat Pump

FIG. 1 is a top, front and right side perspective view of a heat pump, showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a top, front and left side perspective view thereof; and,

FIG. 4 is a left side view thereof, with the right side view being identical.

The rear and bottom views are not shown and form no part of the claimed design. The interior features of FIGS. 1 and 2 shown in broken lines and the features in FIGS. 2 and 4 that are surrounded by broken lines depict portions of the heat pump that form no part of the claimed design.