The best replacement for round duct is square.

The best alternatives to round duct are rated as following:
★★★★★  square
★★★★  square duct
★★★  rectangular

Your alternative for round duct is not listed? Suggest!


No companions for round duct have been suggested so far.
You have in mind a companion for round duct and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of round duct in all years. Click on graph for more.
round duct
square
square duct