Insulating Air Conditioning Ducts In Attic

Flexible ductwork comes with different insulation r values.

Insulating air conditioning ducts in attic.

After all most new homes have r 49 insulation on the attic floor holladay continues. When the attic is 20 f that insulation is addressing a delta t of 50 f. Hot air tends to rise and an attic is the best place for hot summer air to creep inside your home and destabilize the efforts of your hvac in maintaining a cool temperature. 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.

I live in montreal and had a lennox air conditioner and ducts installed in the attic. Here is a description of the phenomenon. Fresh air ducts will focus on the fresh air in your air conditioning system. The air in your vented attic is hot and humid just like all outdoor air in florida.

Sometimes the insulation is inside the ductwork. The metal duct boot the fitting that holds the register or diffuser that is visible on your ceiling is also cold. Put it in an attic full of blown insulation and you re forcing. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place.

Find hvac duct fittings at lowe s today. This old paper faced insulation on hvac ductwork needs updating. I was wondering is there any figures on the expected energy temp lose. Imperial 4 in x 60 in galvanized steel round duct pipe.

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. So logically the ducts deserve more not less insulation. What i ve observed attic temp 50c vent temp 21c attic temp 37c vent temp 18c attic temp 25c vent temp 13c not sure what the r value off flexible duct or main metal duct is. How to insulate hvac ductwork today s homeowner.

Imperial 6 in x 300 in insulated polyester flexible duct. Insulating hvac ductwork when insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. Attic insulation keeps summer heat waiting proper attic insulation prevents summer s hot air from entering the house. The attic duct is cold because cold air is flowing through it.

Make sure the foil surface of the insulation is free of dust before applying the tape. A round duct is the most effective. But the air in the ducts is facing a delta t of maybe 100 f or 120 f a greater delta t. All the ducts are in the attic.

Looking at the cooling side only the additional load would be. For pricing and availability. R 8 duct insulation 5 227 btu hour.