Attic Ductwork R Value

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.

Attic ductwork r value.

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. Add insulation to attic. There are no r value requirements for ductwork installed in other locations. 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.

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. R value measures how well certain building insulation materials can resist heat. Ducting values are determined by two factors. Existing 3 4 inches of insulation.

Look at your ductwork. 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. Recommended insulation levels for retrofitting existing wood framed buildings. 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.

Some other factors to consider. When determining how much insulation you need don t guesstimate calculate. I m looking at you mississippi and alabama r 6 and r 4 2 are common r values for ducts. The duct insulation r values i mentioned above are what s on the product label.

R values represent the heat resistant properties of an insulating material. How often do you think you get the full labeled r value. Here s how that 3 500 sf house would come out with those. Know exactly how much you need with our project calculators.

If it was you don t have much recourse. Or you live in a state that doesn t require r 8 on ducts in attics. R 6 duct insulation 6 305 btu hour 0 53 ton r 4 2 duct insulation 7 948 btu hour 0 66 ton. The higher the r value the greater the insulation performance.

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. 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. 7 948 btu hour 0 66 ton the numbers are even higher for the additional heating load. He d add open cell foam below the roof deck to give the assembly the required r value but the bids range from 40 000 to 60 000.