Technical Specifications

Speech Guard System                        Technical Data Sheet

Speech Guard G2 Plenum Return Silencer               Sheet ID – 1133.3538.2019                   

 Speech Guard is installed within the ceiling plenum, as open return grills provide a significant pathway for speech to escape from private offices and meeting rooms to be heard in neighboring spaces. This installation additionally reduces any noise from the plenum entering the office via this pathway.


Benefits: This product is part of the Speech Guard System that blocks the audibility of crosstalk that normally happens with drop tile ceiling systems. This system eliminates sounds associated with distraction and reduced productivity. Durable toughness provides increased resistance to damage that can occur from shipping, handling, installation and servicing. If cleaning is necessary, the surface may be cleaned using standard industry-recognized dry methods. 


Composition and Materials: The Plenum Silencer has a Mat-Faced Finish, produced with a core of strong glass fibers and bonded with a thermosetting resin. The air stream side of the air flow duct features a black fiber glass mat, with a fire-resistant foil scrim on the exterior, extending the full width of the chute.


Application Examples: Speech Privacy and Noise Reduction in office buildings, conference rooms, HR departments, Legal departments and medical facilities.



Speech Guard G2 Plenum Return Silencer

Sizes available for the following standard ceilings:

2×2 or 2×4 ceiling grid systems


Product Description:

Color – Black

Hood Size – 31”w x 9”h x 1”t

Chute Size – 18” high oa, trimmed – 14” oa

Mat Size – 24”w x 24”w x ½”t 


Fire Classification: Class A, Testing Method

Mat-Faced air flow meets the Surface Burning Characteristics and Limited Combustibility of the following standards:

ASTM E84 (UL 723), NFPA 90A and 90B, Canada: CAN/ULC S102-M88

Maximum Flame Spread Index: 25

Maximum Smoke Development: 50


General Properties:

Operating Temperature (max.) – ASTM C411          250° (121° C)

Air velocity (max.) – ASTM C1071                          5000 fpm (25.4 m/sec)

Internal Pressure (max.) – UL 181                             2° w.c. (498 Pa)                                         

Fungi resistance – ASTM C1338                               Does not breed or promote

Fungi resistance – ASTM G21                                   No growth

Bacteria resistance – ASTM G22                               No growth

Water vapor transmission – ASTM E96                    < 0.02 Perms

Water vapor solutions – ASTM C1104                      < %5 by weight