Help with ducting mod idea

I was thinking of using a clear plastic 3" mailing tube to make a straight duct to my hsf. Any ideas on how to attach/seal it to the case and/or the HSF. I thought maybe of using a fan reducer 92-80mm and gluing the tube in to it and bolting the reducer to the case (after making a hole of course)

Any ideas would be appreciated, no matter how unorthodox.
thanks in advance.

Is this gonna be a permanent solution for your case? Or is it just a test run. If your just testing you could use some duct tape.

Check into some plumming supplies. You may find something you can use. I've seen some stuff that might be of use, but I don't know what's availible in your area, or if it'll be the right size, but you may wanna take a look anyways.

Hot glue. Maybe.

Yeah, it's going to be permanent. The trick is have it attach to the side of the case and seal the HSF, and still be able to take the side panel off.

edit: any ideas how to make it seal the HSF?

Well you would need it to definitely still be functional. You should try it as a temporary setup and see what kind of effect it will have. Normally ducting projects take care of just the intake of fresh air. If you close it off completely you risk the chance of possibly not giving your HSF enough breathing room to output the old air. But for your permanent mod you could get the adhesive meant for plexy goes on clear and stays clear. Then you could use a piece of acrylic or plexy to use as asupport for the side door. (Kind of confuisng there).
Anyway we need a few more details about the case. Is the side made of acrylix or plexy?? window??? stuff like that.