I have an 80 year old house on So. Cal. We've decided to redo our hvac system and got bids to remove the asbestos wrapped ducts throughout and replace with new ducts.
My question is that one contractor said that he would use mylar flex duct throughout even in the ducts in the walls. That seemed kinda odd to me, when I questioned him about it he said that that is the way all new construction is done nowadays and it works better with todays more efficient systems.
Can anyone shed some light on this for me? it seems to me that metal ducting would actually be less restrictive and more efficient or is that just an old school thinking? I guess I'm also thinking that if I'm going to be opening the walls, is it ok to put flex ducting back?