The ornamental design for a filtercase for airpurifier with humidifier, as shown and described.
1. Filter case for air purifier with humidifier
1.1 is a front and right side perspective view.
1.2 is a front elevation view.
1.3 is a rear elevation view.
1.4 is a left side elevation view.
1.5 is a right side elevation view.
1.6 is a top plan view.
1.7 is a bottom plan view.
The broken lines shown in Figures 1.3 and 1.7 are for the purpose of illustrating portions of the filter case for air purifier with humidifier that form no part of the claimed design.