Frequently Asked Questions

Frequently Asked Questions

What is the life expectancy of flexible air ducts?

When properly installed per the Air Duct Council (ADC) installation instructions (furnished in each package), flexible air ducts should last for the life of the dwelling.

Why are JPL pressure ratings different than some other flex ducts?

JPL tests and publishes positive pressures based on results of the ADC FD 72-R1 test method. This method requires a 90-degree elbow of the duct and temperatures up to 180 F.   Many of our competitors with higher pressures test the ducts with no bends and at room temperatures.


How do I know if a flex duct thermal rating (R-Value) is true and accurate?

“Look for the ADC Performance mark on the vapor-barrier”. CLICK HERE FOR ADC THERMAL PERFORMANCE

Are there any flex duct installation precautions with UVC?

Yes, the inner core of most flex ducts is susceptible to ultraviolet light and may become brittle if exposed for long periods of time.  JPL suggests one foot distance from the UV source on foil back MNI25, 2 feet on all polyester inner cores and five feet on AMBlue II & AMF/AMR installations.

Is JPL Flexible Ducting Plenum Rated?

Per UL, “U.S. building codes require that certain materials installed in a plenum or air-handling space have a flame spread index of 0-25 and a smoke developed index of 0-50 (25/50 FHC rating) when tested in accordance with ASTM E84.”  All JPL air ducts are certified Class 1 – meaning that they have a Fire Hazard Classification (FHC) rating of (25/50), and should therefore satisfy the plenum rated requirements. In all cases, local authority and jurisdiction has the final say on all code and code interpretations.

What type of product warranty does JPL have?

JPL is one of the few flex duct manufacturers to offer a 10-year limited warranty.


What is the friction loss for JPL flexible ductwork?

Where can I find installation instructions for JPL flexible ductwork?


Further information about proper installation of flexible duct may be found in the Air Duct Council’s Flexible Duct Performance and Installation Standards also known as the “Green Book”

Is your product formaldehyde free?

Based on supplier certifications, no formaldehyde is used in the construction of JPL products which have “Formaldehyde Free” listed on their data sheets. All JPL insulated ducts use formaldehyde free insulation. Plus, all JPL UL-181 Flexible Ducts are GREENGUARD Gold Certified.


What is the approximate outside diameter (OD) of your insulated flexible ductwork?

Because flexible duct is flexible some builders rely on their HVAC contractor to figure out a way to properly install flexible duct from point A to point B in attics, crawl spaces, walls & utility rooms. Knowing a ducts outside diameter (OD) should assist the builder & contractor in designing adequate clearance which will provide higher performance of the air distribution system.

For R4.2 add 2.25” to the duct diameter

For R6    add 3.50” to the duct diameter

For R8    add 4.50” to the duct diameter

Example:  10” R6 Duct has an OD of 13.50”

Do you have a Material Safety Data Sheet on your products?

JPL does not publish a Material Safety Data Sheet (MSDS) on our flexible ductwork products.  An MSDS is generally applicable to chemicals and products that may release toxic materials. To our knowledge there are no hazardous or toxic substances which would be harmful to individuals in the handling of our product nor the end use of conveying conditioned air throughout a dwelling.


What is the proper method of correctly measuring the length of flex duct?

Preferably 2 people extend the duct to its full length. The duct measurement will be made applying approximately 25lbs of tension to the insulation, core and outer-jacket. The shortest component (Insulation, core or jacket) would be considered the measured duct length. Pre-measured marks on the ground are best but a tape measure will also suffice.

Where can I buy your Product??

JPL sells exclusively through HVAC wholesalers. We presently have distribution in 46 of the 50 states. Please email your name, address,  phone number  and a brief explanation of your interest or question about JPL. A Company representative will respond to your inquiry within 5-Days.

Can I store JPL flexible ductwork outdoors?

JPL strongly recommends storing flexible ductwork indoors.  However, unopened/unused JPL flexible ductwork packaged in a bag may be stored outdoors for up to 30-days without package deterioration.  Flexible ductwork packaged in a carton should only be stored indoors.

Why are JPL Insulated Flexible Ductwork Packages longer than some of the competitor’s packages?

Fiberglass insulation has a recovery limit.  Compress beyond this limit and the ability of the fiberglass to recover to its stated R-Value disappears.  Owens Corning, leading FDM fiberglass manufacturer, recommends the length of the longitudinal compression not be less than a 12:1 ratio to meet the thermal properties listed on the duct.  A 25’ section of insulated flexible duct manufactured with OC FDM insulation should not be packaged in a container less than 25” tall.


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