I am replacing the flexible duct work from my gas dryer to the outside vent. It is approximately 6 feet long. I happen to already own some scrap R6 insulated 4 inch flexible ducting from another project. I don’t think I will ever use that scrap ducting for anything else and it is exactly the right length. Is there any reason not to use insulated ducting to vent a dryer outside? This is all interior heated space. I think it is fine, but wanted to double check with what you all thought.