The ornamental design for the misting fan, as shown and described.
FIG. 1 is a rear view of the misting fan showing our new design;
FIG. 2 is a first perspective view thereof;
FIG. 3 is a second perspective view thereof;
FIG. 4 is a third perspective view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a left side view thereof;
FIG. 7 is a front view thereof;
FIG. 8 is a top view thereof;
FIG. 9 is a bottom view thereof; and,
FIG. 10 is a fourth perspective view thereof.
The dash-dot-dash broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines are directed to portions of the misting fan. The broken lines form no part of the claimed design.