What is Spiracoustic?
- Spiracoustic comes in sheets of insulation—one side is a foil backing, the other is a black coated grooved surface for the airstream
Spiracoustic is a Johns Manville engineered interior liner for spiral ductwork that is positioned as an alternative to the Double Wall method of Perforated and Unfaced Liner by providing a lighter, easier to install product. Providing the same acoustic (noise reduction) and thermal values as double wall but with a 50% weight reduction, drastically reducing installation costs.
If it’s so appealing , why isn’t everyone using it?
A few reasons…
Changing habits—most duct fab shops have been making double wall for so long using the method of perf and unfaced.
Price of the product—though it doesn’t look like anything more than Sheets of Ductboard with grooves, it’s expensive; contractors often can’t look past that initial cost to see the savings they would make up in installation costs.
Contacting Engineer—Double Wall using perf inner wall, unfaced liner and mylar wrap is a SMACNA standard and although JM’s track record is near perfect when reaching out to engineers and getting Spiracoustic approved, some contractors prefer not contacting the Engineer.
- JM’s answer for double wall
- Pieces of Spiracoustic cut out for use inside Fittings like Laterals and Wyes in Double Wall. Contractor in Atlanta started using the JM Spiracoustic when they worked on the Mercedes Benz stadium. Since then they have pretty much gone exclusively with it whenever Double Wall is specified
Fits tight and secure regardless of diameter unless it’s under 8″. Simply cut the factory grooved board to the diameter you need and slide it in. factory coated to prevent any fibers in the airstream, but use of JM SuperSeal Coating to recoat any fabrication cuts or installation damage will help to ensure an ideal system installation. The airstream surface and transverse edges are protected with JM’s factory-applied proprietary black Permacote® acrylic coating.
Airstream and section ends are coated with an EPA registered anti-microbial agent
Spiracoustic Liner Installation
- Measure to a length that’s 1/2″ to 3/4″ less than the circumference of the duct diameter. Circumference = π (3.14) * diameter
- Cut with a Duct Knife such as DuroDyne’s SK6
- Roll and tape over the cut seam
- Collapse into a heart shape
- Insert and product will automatically expand into place
Photos from the field
- JM Spiracoustic Liner inside large diameter Spiral pipe Reducer
- Weld pins are only required on duct that has a diameter of 60″ or greater such as this 96” Spiral Pipe section. RF Knox Company, Smyrna Ga
- Resembles ductboard but with grooves to fold round inside the duct. On extra large diameter duct, weld pins added to secure.
- Curved surface comes together closing gaps of the grooves
NOTE: it is worth mentioning that with a name like “Plus” one might think that there is also regular version. There is not. Spiracoustic Plus is the only Spiracoustic product that Johns Manville sells.
