What R-value do I need for ductwork?
What R-value do I need for ductwork?
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 the minimum R-value for ductwork?
“Supply and return air ducts and plenums shall be insulated with a minimum of R-6 insulation where located in unconditioned spaces and where located outside the building with a minimum of R-8 insulation in climate zones 1-4 and a minimum of R-12 insulation in climate zones 5-8.
What is the R-value of 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.
Is duct board heat resistant?
Owens Corning QuietR™ Duct Board is a rigid, resin bonded fibrous glass board with a tough, damage-resistant, flame retardant, reinforced aluminum foil (FRK) facing. More precisely, fire rated ventilation ducts can avoid fire and heat spread between two compartments. …
What is the best duct insulation?
Duct Insulation
| Duct Insulation – Recommended R-values by Climate and Duct Location | ||
|---|---|---|
| Climate | Attic | Unheated Basement or Crawlspace |
| Warm – cooling and minimal heating | R-4 to R-8 | R-2 to R-4 |
| Mixed – moderate heating and cooling | R-4 to R-8 | R-2 to R-8 |
| Cold | R-6 to R-11 | R-2 to R-11 |
What’s the best insulation for ductwork?
The fiberglass duct board is by far the most effective. You can find formaldehyde-free insulation that also has an acrylic coating. This coating will help to keep the glass fibers from your airstream and excess noise from your home. You will also be able to enjoy a higher air quality.
What is the minimum level of insulation required on ducts running through an unconditioned basement?
Supply and return ducts located in any other unconditioned space, such as a basement or crawlspace outside the building thermal envelope or a garage, need a minimum of R-6 insulation if they are at least 3 inches in diameter, and R-4.2 if they are smaller than that.
Can duct board be cleaned?
Although fiber board and duct board products are designed to withstand cleaning, only an experienced duct cleaner should be trusted. They are made of fiberglass and small particles become airborne during the cleaning process. Sanitizer can be used to inhibit or kill microbial growth which is common on insulated ducts.
What is HVAC duct board?
Duct board is a semi-rigid fiberglass insulation material often used for residential or light commercial heating and cooling applications in lieu of metal duct. Black, fiberglass mat facing. Antimicrobial coating.
Should you insulate return ducts?
Return air ducts only need to be insulated if they pass through environments that adversely affect the return air temperature. Exhaust air ducts normally do not need insulation. Insulation prevents condensation and dripping from ducts.
What are the R-values for duct insulation?
R-6 and R-4.2 are common R-values for ducts. Here’s how that 3,500 sf house would come out with those: R-6 duct insulation ==> 6,305 BTU/hour (0.53 ton) R-4.2 duct insulation ==> 7,948 BTU/hour (0.66 ton) The numbers are even higher for the additional heating load.
How is the value of a duct determined?
The higher this value is, the better you can expect the insulation to perform. Ducting values are determined by two factors: the mass of the insulation, consisting of both its density and thickness, and the compression ratio at installation, which determines the final compressed density and effectiveness of the insulation.
How big is a sheet of duct board?
R-Value R-Value (SI) 1″ (25 mm) 4.3 .76 1 1 / 2″ (38 mm) 6.5 1.14 2″ (51 mm) 8.7 1.53
How much is a ton of duct insulation?
R-6 and R-4.2 are common R-values for ducts. Here’s how that 3,500 square foot house would come out with those: R-6 duct insulation: 6,305 BTU/hour (0.53 ton) R-4.2 duct insulation: 7,948 BTU/hour (0.66 ton)
R-Value R-Value (SI) 1″ (25 mm) 4.3 .76 1 1 / 2″ (38 mm) 6.5 1.14 2″ (51 mm) 8.7 1.53
What does the are value of insulation mean?
“R” means resistance to heat flow. The higher the R-value, the greater the insulating power. Compare insulation R-values before you buy. There are other factors to consider. The amount of insulation you need depends mainly on the climate you live in.
The higher this value is, the better you can expect the insulation to perform. Ducting values are determined by two factors: the mass of the insulation, consisting of both its density and thickness, and the compression ratio at installation, which determines the final compressed density and effectiveness of the insulation.
Who are the manufacturers of duct board insulation?
The primary manufacturers of fiberglass duct board insulation include: 1 Certainteed 2 Johns Manville 3 Knauf Insulation 4 Manson Insulation 5 Owens Corning