"Walter Cohen" wrote in message

If you are saying I could make any size opening (i.e. 2" - 3") then maybe
I'll look for a reducing coupling at my local HD to attach to the 4" vent
flexible tubing.

No, you NEVER reduce the dryer vent size. A 4" round vent covers 12.5 sq.
in. You can use a 3" x 4" square to get the same results. Or 2 x 6 1/2.

Be sure the vent will not be blocked by snow either.