Can a Window Fan be mounted vertically?

A window fan by design is to be mounted horizontally. The reason for this is from a basic fit perspective, the fan is typically designed to be mounted to the window frame which makes the mounting capability very difficult since it will not be properly mounted to the frame of the window.

In addition, mounting the fan on the vertical can put undue pressure on the motor itself which can lead to premature product failure. Therefore it is strongly suggested that the window fan be mounted horizontally.