Attic Ductwork R Value

Add insulation to attic.

Attic ductwork r value.

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. The higher this value is the better you can expect the insulation to perform. The duct insulation r values i mentioned above are what s on the product label. Ducting values are determined by two factors.

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. I m looking at you mississippi and alabama r 6 and r 4 2 are common r values for ducts. 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. Or you live in a state that doesn t require r 8 on ducts in attics.

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. If it was you don t have much recourse. R values represent the heat resistant properties of an insulating material.

Look at your ductwork. Existing 3 4 inches of insulation. 7 948 btu hour 0 66 ton the numbers are even higher for the additional heating load. 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.

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. 6 305 btu hour 0 53 ton r 4 2 duct insulation. The higher the r value the greater the insulation performance. 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.

Know exactly how much you need with our project calculators. How often do you think you get the full labeled r value. R 6 duct insulation 6 305 btu hour 0 53 ton r 4 2 duct insulation 7 948 btu hour 0 66 ton. Recommended insulation levels for retrofitting existing wood framed buildings.

There are no r value requirements for ductwork installed in other locations. R value measures how well certain building insulation materials can resist heat. Was your ductboard existing and you added a zoning system. 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.