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Panl-Flow® HVAC Silencers & Duct Silencers

Standard Duct Sizes • High Insertion Loss • Low Pressure Drop • Low Break-Out Noise

Industrial Noise Control Panl-Flow HVAC silencers are used to attenuate airborne noise through commercial HVAC ductwork systems, building openings, sound enclosures, ventilating fans, and plenum equipment.

HVAC Silencer Benefits:

Panl-Flow HVAC silencers are an excellent choice for applications requiring maximum insertion loss (noise reduction), low static pressure drop, low maintenance, and quick delivery. Use a Panl-Flow silencer wherever you need to reduce airborne noise while allowing air movement:

  • Air flow in and out of a noisy area or building
  • Fan and blower intake or discharge
  • Air Handling Plenums
  • Equipment Enclosures

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HVAC Silencer & HVAC Duct Silencers

HVAC Silencers with square-to-round transitions

HVAC Silencers

A Typical Bank of HVAC Silencers

HVAC Silencer Applications

  • HVAC Ductwork
  • Turbines
  • Fans
  • Material Handling & Conveying Equipment
  • Engine Intakes & Discharge
  • Blowers
  • Air Handlers
  • Radiators
  • Plenums
  • Cooling Towers
  • Building Vent Walls
  • Acoustic Enclosures
  • Genset Housings
  • Compressor Enclosures
  • Electric Motor Enclosures
  • Dynamometer Test Cells
  • and many others

HVAC Silencer Design & Construction

HVAC Silencer Internal Construction

INC Panl-Flow silencers are of an absorptive design, manufactured in square and rectangular sizes with round transitions to match common ductwork and equipment dimensions. The length of the silencer combined with the volume and velocity of the air moving through it determines the insertion loss or sound attenuation characteristics of the unit. Our silencers are constructed of an exterior sealed shell with sound absorbing baffles or “bullets” running lengthwise through the silencer. Panl-Flow construction features:

  • Rigid assembly with all exterior joints and seams lock-formed to be air and water-tight.
  • Standard 26 gauge solid exterior with 22 gauge interior perforated interior bullets designed and sized for maximum performance.
  • Heavy 18 gauge exterior casings available for low “break-out” noise.
  • Solid rounded aerodynamic bullet ends for minimum pressure drop and smooth air flow.
  • Absorptive fill is inert, and meets ASTM E-84 Class I fire rating.
  • Custom designs available for a wide range of CFM, pressure drop and insertion loss requirements.
  • Standard materials include G90 galvanized, electro-galvanized, aluminum and stainless steel.

HVAC Silencer - Accessories & Options

  • Silencers can stacked in banks for large openings applications.
  • All silencers can be fitted with mounting flanges, bird screens, and weather caps.
  • Compatible elbows and other ducting transition shapes available.
  • Cross-talk designs available.

HVAC Silencer Elbow Fitting

Typical Elbow Fitting

HVAC Duct Silencer Bird Screens

Silencers Fitted with
Bird Screens & Fittings

Bank of Stacked HVAC Silencers

Bank of Stacked Silencers

Custom Mounting Flanges for HVAC Silencer

Custom Mounting Flanges

Discharge Silencer  With Transition

Discharge Silencer
With Transition

Square to Round Transition for HVAC Silencer

Square to Round Transition

HVAC Silencers & HVAC Duct Silencers Acoustical Test Data

The following is a sampling of acoustical characteristics of our standard silencer lengths. Certified test reports are available from an independent acoustical testing lab.

Standard Panl-Flow HVAC Silencers - Acoustical Data (Insertion Loss)

Silencer Length / Style CFM SP Min SP Max Net Insertion Loss by Frequency (Hz)
63 125 250 500 1000 2000 4000 8000
Low Pressure Drop (LP)
36SP 82500 .05 1.4 3 3 7 11 16 17 10 7
60SP 82500 .05 1.6 5 6 12 18 27 27 15 10
84SP 82500 .06 1.8 6 7 13 25 37 35 19 13
Standard Pressure Drop (SP)
36LP 28320 .05 1.5 6 7 16 28 35 41 32 25
60LP 28320 .05 1.6 7 16 25 41 49 46 41 29
84LP 28320 .06 1.7 10 15 33 42 48 45 44 32
Data shown is based on a face velocity of 0 fpm. For a complete list of detailed aerodynamic and acoustical data by silencer size download a copy of our Panl-Flow Selection Guide.

download Panl-Flow HVAC Silencer Brochure and Selection Charts


Other Products:

Sorba-Glas Noise Absorbing Wall Blankets
Panl-Sorb Acoustical Metal Panels
Bafl-Sorb Sound Absorbing Ceiling Baffles
Fabri-Sorb Decorative Acoustical Panels
Portable Acoustic Panels
Noise Control Adhesives & Accessories


Questions? Your INC Sales Engineer is ready to provide answers, planning help, application tips — whatever you need! Call us at 1-800-954-1998, send Email, or fill out a Request For Quotation — whatever is easiest for you.

Contact Us about HVAC Silencers

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