The first thing you want to do is take either air duct sealant or mastic and spread it around the take off.
How to insulate flex ductwork in attic.
Avoid compressing the insulation.
The flex ducts were literally filled shut with ice in the low spots compressing the scant insulation layer beneath them.
That s what happened to the ducts in the lead photo of this article.
Invest in duct insulation today to safeguard your family s health and your pocketbook.
Applying spray foam insulation to the outside of the duct.
If it s uninsulated you should insulated it to at least r 4 to r 8 for dfw.
You re throwing money out the window.
Tape any punctures in the insulation s vapor barrier to prevent leaks.
Mechanically fasten and mastic seal all duct connections.
Start saving money today.
The foam provides a vapor barrier so the ductwork.
Wrapping the duct in a foil faced blanket.
The duct insulation should include a vapor barrier cover.
Spread it around with either your fingers or a disposable chip brush or disposable paint brush.
Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords.
The rigid insulation was saturated from condensation.
Bury the ducts deeply in insulation.
Consider adding more insulation as ductwork is farther from the furnace.
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.
Mastic comes in a bucket air duct sealant comes in a tube they re basically the same thing.
Stop wasting money and energy with a leaking duct system.
How to insulate the attic air sealing the attic energy saving attic insulation duration.
Use a pressure sensitive vapor retarder tape designed for ductwork.
I found instead a vintage 3 ton ac unit with 1 rigid insulation taped all over it and insulated flex duct snaking all over the poorly insulated attic.
If your rigid metal ductwork has any insulation it may already have enough.
By spraying closed cell foam on the ducts before burying them in attic insulation you prevent the condensation problem.
If you want to cover metal ductwork with blown in insulation t hese steps must be followed in this order.
Use metal flex or fiber board ducts that are insulated to code.
Most insulation relies upon the air space between its fibers to deliver the r value promised.
Heaping insulation over the ducts is fine in dry climates but can cause condensation on the duct insulation jacket in humid climates.
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.
The doe s building america program recommends beds buried encapsulated ducts.
Energy saver dealers 204 202 views.
The cost and effort to add more insulation is minimal.
Cover the metal ductwork with closed cell spray foam.
