Most duct liner specifications require that duct liner be mechanically fastened (pinned) to the sheet
metal duct with weld pins. Pinning, which is in addition to the application of wet-applied or PSA
adhesives to bond the insulation to the inside of the ductwork, fulfills the requirements of SMACNA’s
Duct Construction Standard.
Duct insulation manufacturers typically report “air erosion” testing up to 10,000 fpm and reference
ASTM C1071 and/or UL181. The test method requires subjecting the insulation to air velocities at a
rate 2.5 times the manufacturer’s published maximum fpm. For example, 4,000 fpm continuous x
2.5 = 10,000 fpm test velocity.
When mechanical fastening is not a project requirement, AEROFLEX Breathe-EZ Duct Insulation
with PSA can be installed as a duct liner without pins when expected air velocities will not exceed
4,000 feet per minute (fpm, continuous). The insulation will not break away, crack, peel, flake off, or
show evidence of delamination or continued erosion. At leading edges, a metal nosing shall be
installed per the SMACNA Duct Construction Standard.
In addition to thoroughly cleaning the sheet metal, fabrication and installation of Breathe-EZ PSA
Duct Liner, as detailed in Aeroflex USA’s Installation Guide, must be carefully followed.
Caution: Installing standard AEROFLEX Breathe-EZ (no PSA) without mechanical fasteners is not
an approved installation method.
