How To Insulate Duct In Attic

Look for signs of air leaks at seams or joints such as streams of dust.

How to insulate duct in attic.

The next best option is to encapsulate the ducts. Use a paintbrush to apply duct mastic to the joints where an elbow. Insulation itself keeps warm air in and prevents cold air from infiltrating. If necessary switch the wires to reduce the blower to its lowest.

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. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. The duct work is the backbone of air exchange and ventilation. Insulate and air seal to pull the attic inside the building.

Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. 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. Bury the ducts deeply in 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.

How to insulate your attic duct system step by step with video instructions assess current state of attic insulation. Check the speed of the blower motor on the furnace. Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards. How to insulate your central air heating ducts 1.

Make sure the foil surface of the insulation is free of dust before applying the tape. Measure and cut your duct insulation a little large to allow overlap at every seam both lengthwise and on the ends. Wrap the insulation around the duct allowing the beginning edge to ride up slightly over the previous piece. Inspect the span of ductwork to be insulated.

How to insulate the attic air sealing the attic energy saving attic insulation duration. If using this technique in a humid or marine climate the ducts must be encapsulated with spray foam before installing the blown insulation. That s what happened to the ducts in the lead photo of this article. See recommendations for accomplishing this at the building america solution center.

Sure up leaky duct joints. This isn t equivalent to bringing them into the conditioned space as you ll still have additional duct load but it s a lot better than having them in unconditioned attic space.