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hVac systEm quality installation ratEr chEcklist duct quality installation hVac in ExtErior Walls must haVE continuous r-6 insulation
hVac ducts, cavities used as ducts, and combustion inlets and outlets may pass perpendicularly through exterior walls but shall not be run within exterior walls unless at least r-6 continuous insulation is provided on exterior side of the cavity, along with an interior and exterior air barrier where required by the thermal Enclosure system rater checklist A. Install insulation without misalignments, compressions, gaps, or voids in all building cavities with ducts or cavities used as ducts. B. If non-rigid insulation is used, install a rigid air barrier or other supporting material to hold insulation in place. C. Seal all seams, gaps, and holes of the air barrier with caulk or foam.
duct installation tiPs • •
EPA requires that all ducts in exterior walls must be within the air barrier as well as the thermal boundary. It is important for the framer and HVAC contractor to coordinate on the location of a return duct. This allows for proper spacing of the floor or roof structure for installation of the return.
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If installing supply ducts within the walls, verify that the duct is capable of outputting the necessary air flow. Typically, only double-wall assemblies will have enough depth to allow for proper insulation and duct size.
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If installing return ducts using the floor or ceiling structure, EPA recommends to seal both the exterior and the interior of all return boxes to prevent air leakage.
tradEs hVac
Last Updated: 10/28/11
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