02-22-2007, 10:00 PM
What is the minimum R-value for sheetmetal duct insulation (duct wrap)installed in uncondition space (attic) within building envelope, according to 2003 International Energy Conservation code. I have been given conflicting answers from local code officials- supply/ret duct R-5, supply duct R-8/ ret duct R-4 etc. Job is located in zone 4 (Philadelphia suburbs). Appreciate your input.