Insulating Air Conditioning Ducts In Attic

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

Insulating air conditioning ducts in attic.

Insulating hvac ductwork when insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. The attic duct is cold because cold air is flowing through it. R 8 duct insulation 5 227 btu hour. So logically the ducts deserve more not less insulation.

This old paper faced insulation on hvac ductwork needs updating. Here is a description of the phenomenon. Fresh air ducts will focus on the fresh air in your air conditioning system. When the attic is 20 f that insulation is addressing a delta t of 50 f.

Sometimes the insulation is inside the ductwork. I was wondering is there any figures on the expected energy temp lose. Flexible ductwork comes with different insulation r values. Put it in an attic full of blown insulation and you re forcing.

Make sure the foil surface of the insulation is free of dust before applying the tape. But the air in the ducts is facing a delta t of maybe 100 f or 120 f a greater delta t. I live in montreal and had a lennox air conditioner and ducts installed in the attic. A round duct is the most effective.

The condenser in your air conditioner works hard to get rid of heat and pressurize refrigerant for the return trip through your house. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. 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. You will need less material than you would for a rectangular or a square duct.

Other times insulation may be on the outside. After all most new homes have r 49 insulation on the attic floor holladay continues. Imperial 6 in x 300 in insulated polyester flexible duct. 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.

The metal duct boot the fitting that holds the register or diffuser that is visible on your ceiling is also cold. 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. 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. Attic insulation keeps summer heat waiting proper attic insulation prevents summer s hot air from entering the house.

For pricing and availability. Imperial 4 in x 60 in galvanized steel round duct pipe. All the ducts are in the attic.