If the duct is in a conditioned space then normally we don't insulate. But if you are going to insulate then insulate seperatly. You don't want the duct work to become a form of a heat exchanger and also the duct could condensate
John Wayne once said "Life is tough and it is even tougher if you are stupid"
Tempstar and Trane Dealer
The Following User Says Thank You to Plumber101 For This Useful Post:
I have a retaining wall in front of my house that I'm redoing with the blocks I have. The problem I'm having is I need to transition from a larger block that is 1in taller than the smaller block. Can...