The ornamental design for an aircurtainguide for a refrigerator, as shown and described.
FIG. 1 is a front view of an air curtain guide for a refrigerator showing my new design;
FIG. 2 is a left side view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a bottom view thereof;
FIG. 6 is a perspective view thereof, shown in use condition; and,
FIG. 7 is a perspective view thereof, shown in another use condition.
The broken lines shown in drawings show portions of the air curtain guide for a refrigerator and in FIGS. 6 & 7 show environment and neither form parts of the claimed design.