Ducts In Attic Insulation

Wrap the insulation around the duct and then pinch the seam closed.

Ducts in attic insulation.

Figure 1 shows a duct that is encapsulated in spray foam and then partially fully or deeply buried in blown attic insulation. 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. Solutions to the attic duct problem. When these ducts are exposed to exterior air the plastic jacket never gets cold enough to permit condensation because the hot attic air keeps the plastic jacket warm.

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. If the ducts in your home are in unconditioned space seal and insulate them. Since burying ducts is simply one of several ways to address the energy waste associated. The insulation levels should meet or exceed the code required r value for attic insulation.

To install preformed duct insulation start by disconnecting an elbow to expose the end of the duct. The duct insulation should include a vapor barrier cover. If you re building a new house place ducts in the conditioned space to avoid the energy losses associated with most duct systems. They found r 8 duct insulation was sufficient to prevent.

Repeat to insulate the remaining ducts. Add additional sealant if necessary. In a vented attic this can happen when the duct is in close proximity to conditioned space i e the ceiling and also thermally isolated from the hot attic beneath the ceiling 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. In last week s blog i discussed the practice of burying attic ducts in deep insulation. 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. Test total duct leakage.

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. Install loose fill insulation to cover the ducts and the attic floor to meet or exceed the code required r value for attic insulation. Apply a long strip of foil tape along the seam in the insulation. But in my last article i also showed you some preliminary results from a research study on buried ducts in a hot humid climate.

Other times insulation may be on the outside. If your attic has enough insulation and proper air sealing and your home still feels drafty and cold in the.