The ornamental design for an airfiltrationsystem, as shown and described.
FIG. 1 is a perspective view of an air filtration system showing our new design;
FIG. 2 is a front view of the air filtration system;
FIG. 3 is a rear view of the air filtration system;
FIG. 4 is a right side view of the air filtration system;
FIG. 5 is a left side view of the air filtration system;
FIG. 6 is a top view of the air filtration system;
FIG. 7 is a bottom view of the air filtration system; and,
FIG. 8 is a perspective view of the air filtration system with a remote control separated from the system.
The broken lines showing in the figures are included for the purpose of illustrating portions of the air filtration device that form no part of the claimed design.