I'm trying to get more heat and cooling to the second floor in our
house.

We have a few sections of flexible, metalized (but not metal) ribbed
tubing in the basement that connect the furnace to the ducts going
upstairs. This is probably slowing down a lot of the airflow. I'm
guessing they used it where they had to go up and around beams and
tight corners.

Should I:
- leave it
- replace it with same sized galvanized ducting (5" I think) It would
be a slightly longer distance because of the limitations of the
pieces.
- find a flexible ducting material that's smooth on the inside to
reduce friction

Thanks in Advance