R-value of 3.5 is required for buried ductwork and ducts installed in an unvented attic with roof insulation or in an unconditioned space (including both ventilated and unventilated crawlspaces). There are no R-value requirements for ductwork installed in an indirectly conditioned space.
What insulation is best for ductwork?
fiberglass
How do you calculate duct insulation?
Measure the diameter of the duct then divide it by 2 to get the radius. Square the radius then multiply the radius by Pi, or 3.14. This will give you square inches of the duct. Divide that total by 144 to get square feet of the actual duct.
The most common material used for insulating heating and cooling ducts is fiberglass. Fiberglass duct insulation is available in various thicknesses and R-values and in either a flexible or rigid form.
What is duct insulation?
Any heating or cooling air ducts located in unconditioned areas should be insulated. Insulating your ducts will reduce energy bills and improve comfort. Also, insulating ducts can help to eliminate condensation problems in damp areas.
What is the minimum R-value for ductwork?
“Supply and return air ducts and plenums shall be insulated with a minimum of R-6 insulation where located in unconditioned spaces and where located outside the building with a minimum of R-8 insulation in climate zones 1-4 and a minimum of R-12 insulation in climate zones 5-8.11 jul 2018
What is the R-value of 1 inch duct board?
The 1-inch fibrous glass duct board has an R-value at 75°F of 4.3 h•ft2•°F/Btu. The 1½-inch board has an R-value of 6.5. The 2-inch board has an R-value of 8.7.
Should ductwork in attic be insulated?
When HVAC ducts are installed in a vented attic in a dry climate, bury the ducts in attic insulation to protect them from temperature extremes in the unconditioned attic space. ... The duct insulation should include a vapor barrier cover. Mechanically fasten and mastic-seal all duct connections.5 abr 2018
Should I insulate ductwork in unfinished basement?
Remember that insulating ducts in the basement will make the basement colder. ... Water pipes and drains in unconditioned spaces could freeze and burst if the heat ducts are fully insulated be-cause there would be no heat source to prevent the space from freezing in cold weather.
What is the R-value of 1 duct board?
2.1. The 1-inch fibrous glass duct board has an R-value at 75°F of 4.3 h•ft2•°F/Btu. The 1½-inch board has an R-value of 6.5.