They found r 8 duct insulation was sufficient to prevent.
Ducts in attic insulation.
Mechanically fasten and mastic seal all duct connections.
If you re building a new house place ducts in the conditioned space to avoid the energy losses associated with most duct systems.
Wrap the insulation around the duct and then pinch the seam closed.
Because the moving air is in the ductwork for only a short period of time it does not need the insulation r value the attic floor requires.
In this case the temperature gradient between supply air and the ceiling can be such that the duct surface could be cooler than the local dew point.
Test total duct leakage.
Other times insulation may be on the outside.
Add additional sealant if necessary.
In last week s blog i discussed the practice of burying attic ducts in deep insulation.
To install preformed duct insulation start by disconnecting an elbow to expose the end of the duct.
Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards that specify an r value of 8 for attic ducts and 6 for ducts located anywhere else.
But in my last article i also showed you some preliminary results from a research study on buried ducts in a hot humid climate.
If your attic has enough insulation and proper air sealing and your home still feels drafty and cold in the.
Apply a long strip of foil tape along the seam in the insulation.
If the ducts in your home are in unconditioned space seal and insulate them.
Secure the insulation with short strips of foil tape.
Repeat to insulate the remaining ducts.
Since burying ducts is simply one of several ways to address the energy waste associated.
The duct insulation should include a vapor barrier cover.
Yes when you bury ducts in attic insulation in a humid climate you increase the risk of water vapor condensation on the jacket of the duct insulation.
Install loose fill insulation to cover the ducts and the attic floor to meet or exceed the code required r value for attic insulation.
The insulation levels should meet or exceed the code required r value for attic insulation.
Most attic ducts are insulated flex ducts that is flex ducts with r 6 or r 8 fiberglass insulation along with an exterior polyethylene jacket.
Sometimes the insulation is inside the ductwork.
Solutions to the attic duct problem.
Flexible ductwork comes with different insulation r values.