How To Insulate Heating Ducts In Attic

Use a paintbrush to apply duct mastic to the joints where an elbow connects to a duct.

How to insulate heating ducts in attic.

Energy saver dealers 204 202 views. 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. Install loose fill insulation to cover the ducts and the attic floor to meet or exceed the code required r value for attic insulation. Inspect the span of ductwork to be insulated.

For an added layer of protection you can apply duct mastic to the tape and duct. 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. To install sleeves you must either disassemble the ductwork and slide it on before reassembling the ducts or as many homeowners find themselves doing slit it and wrap it around like the blanket style material. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place.

Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards. The rigid insulation was saturated from condensation. 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. Bury the ducts deeply in insulation.

Check the speed of the blower motor on the furnace. That s what happened to the ducts in the lead photo of this article. Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. How to insulate the attic air sealing the attic energy saving attic insulation duration.

Come in pre measured lengths. Look for signs of air leaks at seams or joints such as streams of dust. Obtain foil face fiberglass insulation based on the sizes. Don t use standard cloth duct tape on hvac ductwork since the adhesive won t hold up to extreme temperatures.

If using this technique in a humid or marine climate the ducts must be encapsulated with spray foam before installing the blown insulation. Measure the size of all square rectangular or circular ducts. How to insulate your central air heating ducts 1. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value.

If necessary switch the wires to reduce the blower to its lowest speed. 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. They may have an adhesive strip to make the installation a little easier.