Existing 3 4 inches of insulation.
Attic duct insulation r value.
R 10 at 2 ft.
R 8 inside thermal envelope.
The duct insulation r values i mentioned above are what s on the product label.
For most applications a rating of r 6 or better will provide the best efficiency and long term cost effectiveness.
Some other factors to consider.
Value r 10 continuous or r 13 cavity r15 continuous or r 19 cavity slab r value and depth ft r 10 at 2 ft.
R 8 inside thermal envelope.
R value of r 6 is required for exterior ductwork or ducts installed in a ventilated attic or an unvented attic above a vented ceiling.
If you install 2 layers of a reflective insulation does the r value double.
If the product is simply doubled with no air space between the layers a very minimal benefit is obtained r 1 1 per layer for the reflective double bubble.
With multiple layers of product and airspaces between each layer enhanced performance will be gained.
6 305 btu hour 0 53 ton r 4 2 duct insulation.
Purchasing the ducting and the insulation separately is often more cost effective and has a greater variety of options when it comes time to choose the r value of your insulation.
Crawl space wall r value r 10 continuous or r 13 cavity 15 continuous or r 19 cavity duct r value supply in attic.
For contractors looking for r 12 duct warp microlite fsk formaldehyde free duct wrap is the only duct wrap on the market with an installed r value of r 12 in a single layer.
When determining how much insulation you need don t guesstimate calculate.
7 948 btu hour 0 66 ton the numbers are even higher for the additional heating load.
N a all other ducts.
R 6 and r 4 2 are common r values for ducts.
Here s how that 3 500 sf house would come out with those.
R 6 supply in attic.
Microlite fsk duct wrap comes with an fsk foil scrim kraft facing designed to help ensure a closed system that prevents moisture drive and offers condensation control.
R 6 duct insulation 6 305 btu hour 0 53 ton r 4 2 duct insulation 7 948 btu hour 0 66 ton the numbers are even higher for the additional heating load.
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.
How often do you think you get the full labeled r value.
R value measures how well certain building insulation materials can resist heat.
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.
Recommended insulation levels for retrofitting existing wood framed buildings.
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.
