Attic Ductwork R Value

It will most likely be a fiberglass batt so multiply the thickness in inches by 3 2 to find out the r value or the r value might be visible on a product label.

Attic ductwork r value.

When determining how much insulation you need don t guesstimate calculate. The effective r value of a buried duct installation depends on the size of the ducts the r value of the duct insulation and the depth of the loose fill insulation. Was your ductboard existing and you added a zoning system. Table 1 shows effective r values for 8 inch round ducts at three attic insulation levels and three duct insulation levels r 4 2 r 6 and r 8.

Or you live in a state that doesn t require r 8 on ducts in attics. Here s how that 3 500 sf house would come out with those. Existing 3 4 inches of insulation. 6 305 btu hour 0 53 ton r 4 2 duct insulation.

Recommended insulation levels for retrofitting existing wood framed buildings. The higher this value is the better you can expect the insulation to perform. There are no r value requirements for ductwork installed in other locations. R values represent the heat resistant properties of an insulating material.

R 6 duct insulation 6 305 btu hour 0 53 ton r 4 2 duct insulation 7 948 btu hour 0 66 ton. It comes down to three options the first of which is to convert his attic into a conditioned space by installing 4 1 2 inches of polyiso insulation above the roof deck and then adding a new standing seam metal roof. Some other factors to consider. 7 948 btu hour 0 66 ton the numbers are even higher for the additional heating load.

I m looking at you mississippi and alabama r 6 and r 4 2 are common r values for ducts. Know exactly how much you need with our project calculators. R value measures how well certain building insulation materials can resist heat. Return ducts ductwork that brings expended air back to the hvac system to be filtered reconditioned and redistributed require insulation with an r value of 3 5 for exterior ducts and ducts in a ventilated attic or unvented attic above an insulated ceiling.

The higher the r value the greater the insulation performance. How often do you think you get the full labeled r value. The duct insulation r values i mentioned above are what s on the product label. Not sure where you are at but here in florida the minimum r value for ducts installed in an attic or any unconditioned space is r 6.

The mass of the insulation consisting of both its density and thickness and the compression ratio at installation which determines the final compressed density and effectiveness of the insulation. Add insulation to attic. If it was you don t have much recourse. If the insulation is a foam board or sprayed on foam use any visible label information or multiply the thickness in inches by 5 to estimate the r value.