How To Insulate Heating Ducts In Attic

When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value.

How to insulate heating ducts in attic.

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. Inspect the span of ductwork to be insulated. Measure the size of all square rectangular or circular ducts.

Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards. Bury the ducts deeply in insulation. If necessary switch the wires to reduce the blower to its lowest speed. 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.

Measure each run of exposed duct in an attic basement or under a subfloor. Energy saver dealers 204 202 views. Use a paintbrush to apply duct mastic to the joints where an elbow connects to a duct. If using this technique in a humid or marine climate the ducts must be encapsulated with spray foam before installing the blown insulation.

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. Check the speed of the blower motor on the furnace. The rigid insulation was saturated from condensation. Install loose fill insulation to cover the ducts and the attic floor to meet or exceed the code required r value for attic insulation.

They may have an adhesive strip to make the installation a little easier. 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. Come in pre measured lengths. For an added layer of protection you can apply duct mastic to the tape and duct.

In the end it s probably best to buy the blanket insulation. Look for signs of air leaks at seams or joints such as streams of dust. She asked me to go into the attic to find the roof leaks or where the snow is blowing in through the soffits. Don t use standard cloth duct tape on hvac ductwork since the adhesive won t hold up to extreme temperatures.

That s what happened to the ducts in the lead photo of this article. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. 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.