TheCommish
Registered User
Working out of the 2012 IECC residential climate zone 5.
Prescriptively floor insulation over unconditioned space must be R-30, exterior walls R-20 and attics R48/38, typical here may area the duct is installed in the bay of the floor joists (no longer panning the bay), a 6 inch duct with R-6 insulation wrap fills most of the bay precluding the installation of R-30 in that bay, is this allowed?
Should the ducts not be allowed in the bay so that R-30 is installed meeting the requirements of Table R402.1.1?
Further what about the obstructing of a bay, wall or floor of size such as waste or vent piping that significantly reducing the ability to get the required R-values in the bay?
On the performance side, HERS raters who I have talked/listened to have to take into account the quality of insulation installed have said they put in their calculations the reduced R-value for the square footage of the diminished insulation.
Prescriptively floor insulation over unconditioned space must be R-30, exterior walls R-20 and attics R48/38, typical here may area the duct is installed in the bay of the floor joists (no longer panning the bay), a 6 inch duct with R-6 insulation wrap fills most of the bay precluding the installation of R-30 in that bay, is this allowed?
Should the ducts not be allowed in the bay so that R-30 is installed meeting the requirements of Table R402.1.1?
Further what about the obstructing of a bay, wall or floor of size such as waste or vent piping that significantly reducing the ability to get the required R-values in the bay?
On the performance side, HERS raters who I have talked/listened to have to take into account the quality of insulation installed have said they put in their calculations the reduced R-value for the square footage of the diminished insulation.
