Insulate Heating Ducts In Attic

In this video this old house plumbing and heating expert richard trethewey helps a homeowner insulate his ductwork.

Insulate heating ducts in attic.

The existing metal ductwork in an older home may or may not have insulation. R 8 duct insulation 5 227 btu hour. All the ducts are in the attic. Insulation typically works by preventing conductive heat flow and r value measures how effective it is at this.

Looking at the cooling side only the additional load would be. Sometimes the insulation is inside the ductwork. The r actually stands for resistance of heat flow that is. Plan to pull up the flooring and layer new insulation on top of the old.

For an added layer of protection you can apply duct mastic to the tape and duct. Duct board much like the duct liner is also a fiberglass product. Other times insulation may be on the outside. If necessary switch the wires to reduce the blower to its lowest speed.

Use metal flex or fiber board ducts that are insulated to code. Let s look for constantly improving methods through sharing. R value is a rating system used for insulation that measures its degree of insulating power. Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards that specify an r value of 8 for attic ducts and 6 for ducts located anywhere else.

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. Don t use standard cloth duct tape on hvac ductwork since the adhesive won t hold up to extreme temperatures. Because the moving air is in the ductwork for only a short period of time it does not need the insulation r value the attic floor requires. Check the speed of the blower motor on the furnace.

Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. The duct insulation should include a vapor barrier cover. What is an attic insulation s r value. Hvac ducts should be buried under insulation hard covered too.

When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. Duct liner isn t generally a diy installation and if your ducts already have liner you don t need to insulate the exterior. Putting a furnace in an attic is not ideal but will happen. But if the floor is covered in plywood you can t stuff enough insulation beneath it to do the job sufficiently not even in warm climates.

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. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords.