What R-value should duct insulation be?

What R-value should duct insulation be?

R-value of 3.5 is required for buried ductwork and ducts installed in an unvented attic with roof insulation or in an unconditioned space (including both ventilated and unventilated crawlspaces). There are no R-value requirements for ductwork installed in an indirectly conditioned space.

What is plenum insulation?

Plenum wrap is a blanket insulation that has a robust fire rating and is commonly used in plenum spaces. It is made from inorganic fibers that are encased in a scrim-reinforced foil, and it can withstand exposure to flames for 1-2 hours.

What is R 4.2 insulation?

Reflectix® Duct Insulation is an alternative to other types of fibrous insulation products. Ease of handling and quick installation make Reflectix® the first choice when selecting insulation for round or rectangular ductwork in HVAC systems. The product provides an R-4.2 when installed directly to the duct.

Should plenum be insulated?

simple answer…all supply plenums and ductwork, fittings, etc. is required to be insulated, and only after sealing all joints/connections with either approved foil tape or mastic material.

What is R-8 insulation used for?

EcoFoil R-8 HVAC Duct Wrap Insulation is specifically designed to reduce radiant heat gain/loss in residential and commercial duct applications. The insulation also helps control condensation by providing an airtight thermal break around the HVAC ducting.

What R-value is flex duct?

For example, a six-inch diameter, nominal R-8 flex duct has an actual R-value of only 5.62 not counting surface films. With the film resistances the total R-value of 6.45 is 19% less than the nominal value. For R-11 ducts (six-inch diameter) the R-value with films is only 7.81, 29% less than the nominal value.

Does the plenum need to be insulated?

What is plenum box in HVAC?

Plenum boxes are usually situated on either side of the fan or heat exchanger and have the important function of bringing in, distributing, and removing air. They are the air’s first stop after being heated or cooled and its last stop before going back into your AC, heat pump, or furnace.

What is the R value of flex duct?

How thick is r12 duct?

It delivers R-12 insulating performance in just 2 inches, making it an ideal material for rooftop duct applications. The lightweight material has a foil facer on both sides and is easy to fabricate on the jobsite.

How are Plenum boxes insulated with duct liner?

Plenum Boxes insulated with Duct Liner for Residential In residential new construction, contractors fit a Plenum box over the inside unit (either vertical or horizontal) — A&P Sheet Metal, Memphis TN A plenum box fits over the inside unit and is the first stage of the air supply. Holes, usually 2, are cut out of the box.

What is the R-value of duct insulation?

Duct insulation must conform to requirements for R-value. The R-value of insulation is a rating of effectiveness. It indicates how well the insulation resists the flow of heat from a warm area to a cooler area.

What is a plenum box on a furnace?

A plenum box fits over the inside unit and is the first stage of the air supply. Holes, usually 2, are cut out of the box. These holes, typically 12” or 14” diameter round are cut out by the HVAC contractor during the install. A round Airtite takeoff is typically used over the hole; either Snaplock pipe or Flex Duct attaches to the Airtite takeoff.

What kind of insulation do you use to insulate ductwork?

Insulation USed to Externally Insulate HVAC Ducts. Sheet metal ducts must first be tightly sealed Resilient fibrous glass insulation, thicknesses from 11/ 2 to 4 in. (38 to 102mm) Insulation Boards Fibrous glass insulation boards are also available for application to the outside of sealed sheet metal ducts, housings, and plenums.