Section 233319 - Sound Attenuators

This master should be used by designers working on Port of Portland construction projects and by designers working for PDX tenants (“Tenants”). Usage notes highlight a few specific editing choices, however the entire section should be evaluated and edited to fit specific project needs.

SECTION 233319 - SOUND ATTENUATORS

PART 1 - GENERAL

0.1 DESCRIPTION

A. This section describes sound attenuators.

0.2 REFERENCES

A. ASTM: American Society for Testing and Materials 1. ASTM E477: Standard Test Method for Measuring Acoustical and Airflow Performance of Duct Liner Materials and Prefabricated Silencers

0.3 SUBMITTALS

A. For products specified herein, submit product/material data, shop drawings, and as-constructed drawings.

B. Product Data: Include attenuation and regeneration ratings, pressure drops, and capacity data.

PART 2 - PRODUCTS

0.1 RECTANGULAR DUCT SILENCERS

A. Acceptable Manufacturers: Industrial Acoustics Company; Semco; Krueger; American Air Filter; Titus; or equal.

B. Description: 1. Galvanized sheet steel construction of not less than 22 gauge for outer casing and internal perforated sheet metal liner. 2. Pressure rated airtight at 6-inch W.G. differential between inside and outside of silencer. 3. Straight-through air passage to minimize noise regeneration due to turbulence. 4. Acoustical Fill Material: Inorganic glass fiber not less than 4 pcf density, at not less than 5 percent compression, eliminating voids caused by settling.

C. Performance: 1. Ratings determined in duct to reverberant room test facility in accordance with ASTM E477. 2. Static pressure losses as indicated on drawings. 3. Dynamic insertion loss based on forward flow at 2000 fpm not less than the following:

4/27/2018 SOUND ATTENUATORS D:\Docs\2018-04-04\0c37f35d3fa3ede91e019d8e7fc9687c.doc 233319-1 Octave Band Center Frequency (HZ) Type 63 125 250 500 1000 2000 4000 8000 3S 6 10 15 25 34 35 28 17 5S 7 16 22 38 45 46 41 26 7S 9 17 34 44 49 49 45 35 3MS 4 7 12 19 23 23 18 11 5MS 6 10 18 30 42 34 23 14 7MS 10 14 24 36 48 44 31 18 3L 4 5 9 14 23 24 14 10 5L 6 7 13 21 29 39 20 14 7L 8 13 18 28 40 47 26 18 3LFS 8 12 21 25 25 21 17 14 5LFS 10 18 28 33 36 29 21 16 7LFS 11 21 38 46 49 39 29 19 7LFM 13 15 29 39 38 22 17 14 3ES 3 7 13 23 32 34 24 18 5ES 7 12 19 33 48 49 36 25 7ES 7 16 32 46 54 51 48 34 3ML 2 5 10 17 17 13 10 8 5ML 3 8 15 28 30 21 14 10 7ML 4 12 20 36 38 28 18 12 3LFL 4 7 12 15 15 10 9 8 5LFL 6 10 16 24 25 14 11 11 7LFL 9 13 22 36 31 17 13 13

PART 3 - EXECUTION

0.1 INSTALLATION

A. Install in ducts in accordance with the manufacturer’s recommendations.

B. Seal space between each module with nosing strips and duct sealer to prevent air from passing between modules.

C. Where attenuators are installed directly on concrete, provide 30-pound roofing felt or 1-inch roofing insulation under attenuators (not required when attenuators do not come in contact with concrete).

END OF SECTION 233319

SOUND ATTENUATORS 4/27/2018 233319-2 D:\Docs\2018-04-04\0c37f35d3fa3ede91e019d8e7fc9687c.doc