The ornamental design for a body for a portablefan, as shown and described.
FIG. 1 is a right side front perspective view of a body for a portable fan showing my new design;
FIG. 2 is a left side rear perspective view thereof;
FIG. 3 is a front 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 rear elevation view thereof; and,
FIG. 7 is a top plan view thereof.
The broken lines showing of front grills, rear grills, and support base represent portions of the body for a portable fan that form no part of the claimed design.