Insulate Heat Ducts In Attic

Looking at the cooling side only the additional load would be.

Insulate heat ducts in attic.

Hvac ductwork is typically visible in your attic especially flexible ductwork. Today s flexible ductwork is covered with a shiny metallic cover this is its vapor barrier. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. All the ducts are in the attic.

Inspect the span of ductwork to be insulated. To insulate the exterior you have a choice between sleeve style insulation and blanket wraps which literally wrap around the ductwork. R 8 duct insulation 5 227 btu hour. Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct.

Make sure the foil surface of the insulation is free of dust before applying the tape. Check the speed of the blower motor on 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. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place.

How to insulate your central air heating ducts 1. Because the simplest and cheapest way to insulate an attic is to add material to the floor. When hvac ducts are installed in a vented attic in a dry climate bury the ducts in attic insulation to protect them from temperature extremes in the unconditioned attic space. Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards.

Plan to pull up the flooring and layer new insulation on top of the old. 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. The rigid insulation was saturated from condensation. According to rightsuite the software we use the supply ducts have about 560 square feet of surface area and the return ducts 101 square feet.

The shiny vapor barrier will protect the ductwork from sweating as long as it s exposed to the surrounding air. She asked me to go into the attic to find the roof leaks or where the snow is blowing in through the soffits. 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 a paintbrush to apply duct mastic to the joints where an elbow. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value.