Insulating Air Conditioning Ducts In Attic
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.
Insulating air conditioning ducts in attic. How to insulate hvac ductwork today s homeowner. Sometimes the insulation is inside the ductwork. 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. The metal duct boot the fitting that holds the register or diffuser that is visible on your ceiling is also cold.
Fresh air ducts will focus on the fresh air in your air conditioning system. I was wondering is there any figures on the expected energy temp lose. Insulating hvac ductwork when insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. After all most new homes have r 49 insulation on the attic floor holladay continues.
Here is a description of the phenomenon. Find hvac duct fittings at lowe s today. Looking at the cooling side only the additional load would be. The attic duct is cold because cold air is flowing through it.
For pricing and availability. 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. R 8 duct insulation 5 227 btu hour. Put it in an attic full of blown insulation and you re forcing.
When the attic is 20 f that insulation is addressing a delta t of 50 f. I live in montreal and had a lennox air conditioner and ducts installed in the attic. 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. The condenser in your air conditioner works hard to get rid of heat and pressurize refrigerant for the return trip through your house.
You will need less material than you would for a rectangular or a square duct. Attic insulation keeps summer heat waiting proper attic insulation prevents summer s hot air from entering the house. Other times insulation may be on the outside. So logically the ducts deserve more not less insulation.
Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. Make sure the foil surface of the insulation is free of dust before applying the tape. This old paper faced insulation on hvac ductwork needs updating. All the ducts are in the attic.
But the air in the ducts is facing a delta t of maybe 100 f or 120 f a greater delta t. Flexible ductwork comes with different insulation r values. The air in your vented attic is hot and humid just like all outdoor air in florida.