I found the zimpure design ineffective at shifting the volume of air expelled by the robox.
50% would leak out the sides of the robox due to back pressure on the small output.
I made this version to attach an hold hoover/vacuum hose to (35mm).
Plug the lead in.. and hang the other end out the window!
For best use.. possibly consider putting another fan somewhere near the window on an adapter/unit to 'pull' the air down the pipe. The robox fan is good.. but every bit helps!