abs_coef_table - SOUND ABSORPTION DATA FOR COMMON BUILDING...

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Unformatted text preview: SOUND ABSORPTION DATA FOR COMMON BUILDING MATERIALS AND FURNISHINGS M NRC Material 125R: 250R: 50011: 1000112 2000Hz 4000Hz Numher‘ waist ta. 0. m Sotmd‘Raflectlng: 1. Brick. unglaaed 0,02 0.02 0.03 0.04 0.05 0.0? 0.05 2. Brick. unglazed and painted 0.01 0.01 0.02 0.02 0.02 0.03 0.00 3. Concrete. rough 0.01 0.02 0.04 0.06 0.09 0.10 0.05 4. Concrete block. painted 0.10 0.05 0.06 0.07 0.09 0.08 0.05 5. Glass. heavy {large panes}I 0.18 0.06 0.04 0.03 0.02 0.02 0.05 5. Glass. ordinary window 0.35 0.25 0.18 0.12 0.0? 0.04 0.15 ?. Gypsum board. 1.12 in thick [nailed to 2 X 43. 16 in 0.29 0.10 0.05 0.04 0.0? 0.09 0.05 061 9. Gypsum board. 1 layer. 5.18 in thick [screwed to 1 )t' 0.55 0.14 0.08 0.04 0.12 0.11 0.10 33. 16 in or: with airspaces filled with fibrous insulation} 9. Construction no. 8 with 2 layers of SIB—in-thick 0.28 0.12 0.10 0.0? 0.13 0.09 0.10 gypsum board 10. Marble 0r glazed tile 0.01 0.01 0.01 0.01 0.02 0.02 0.00 11. Plaster on brick 0.01 0.02 0.02 0.03 0.04 0.05 0.05 12. Plaster on concrete block tor 1 in thick on lath) 0.12 0.09 0.0? 0.05 0.05 0.04 0.05 13. Plaster on lath 0.14 0.10 0.06 0.05 0.04 0.03 0.05 14. Plywood. 3f8-in paneing 0.28 0.22 0.1? 0.09 0.10 0.11 0.15 15. Steel 0.05 0.10 0.10 0.10 0.0? 0.02 0.10 16. Venetian blinds. metal 0.06 0.05 0.0? 0.15 0.13 0.1? 0.10 1?. Wood. H4-in paneling. with airspace behind 0.42 0.21 0. to 0.08 0.06 0.06 0. to 18. Wood. 1~in paneling with airspace behind 0.19 0.14 0.09 0.06 0.06 0.05 0.10 Sound-Absorbing: 19. Caterem block. coarse 0.36 0.44 0.31 0.29 0.39 0.25 0.35 20. Lightweight drapery, 10 ozlydz. flat on wall (More: 003 0.04 0.1 1 0.17 0.24 0.35 0.15 Sound-reflecting at most frequencies.) 21. Mediunweight drapery. 14 ozi‘yd’. draped to halt area 0.0? 0.31 0.49 0.?5 0.?0 0.60 0.55 lie, 2 ft of drapery to 1 ft of wall] 22. Heavyweight drapery. 18 ozfyda. draped to halfarea 0.14 0.35 0.55 0.72 0.?0 0.65 0 60 23. riwgessiabricmnah.eilzozzyd=.¢apeamhan 0.09 0.32 0.50 0.83 0.39 0.25 055 area (Note: The deeper the airspace behind the drapery (up to 12 in). the greater the low—frequency absorption} 24. Shredded-wood fiberboard. 2 in thick on concrete 0.15 0.26 0.62 0.94 0.64 0.92 0.60 ' (mtg. 4) 25. Thick. fibrous material behind open facing 0.60 0.75 0.82 0.30 0.60 0.38 0.75 26. Carpet. heavy. on SIB-in perforated mineral fiberboard 0.3? 0.41 0.63 0.85 0.96 0.92 0.?0 with airspace behind 2?. Wood. 1.!2—in paneling. perforated 3;16-in-diameter 04-0 0.90 0.00 0.50 0.40 0.30 0.65 hates, it '31; open area. with 2 LIZ-in glass fiber in airspace behind min. In Sound-Reflecting: 28. Concrete or terrazzo 0.01 0.01 0.02 0.02 0.02 0.02 0.00 29. Linoleum. rubber, or asphalt tile on concrete 0.02 0.03 0.03 0.03 0.03 0.02 0.05 30. Marble or glazed tile 0.01 0.01 0.01 0.01 0.02 0.02 0.00 31. Wood 0.15 0.11 0.10 0.0? 0.06 0.0? 0.10 32. Wood parquet on concrete 0.04 0.04 0.0? 0.06 0.06 0.0? 0.05 Sound-Absorbing: 33. Carpet. heavy. on cOrICrete 0.02 0.06 0.14 0.3? 0.60 0.65 0.30 34. Carpet. heavy. on loam rubber 0.08 0.24 0.5? 0.69 0.?1 0.73 0.55 35. Carpet. heavy. with Impermeable latex backing on foam 0.08 0.2? 0.39 0.34 0.48 0.63 0.35 rubber 36. bidder-outdoor carpet 0.01 0.05 0.10 0.20 0.45 0.65 0.20 Mimsto. I—lfllf Sound-Reflecting: 3?. Concrete 0.01 0.01 0.02 0.02 0.02 0.02 0.00 38. Gypsum board. 1 .12 in thick 0.29 0.10 0.05 0.04 0.07 0.09 0.05 39. Gypsum board. 122 in thick. in suspension system 0.15 0.10 0.05 0.04 0.0? 0.09 0.05 40. Plaster on lath 0.14 0. 10 0.06 0.05 0.04 0.03 0.05 41. Plywood. 318 in thick 0.23 0.22 0.1? 0.09 0.10 0.11 0.15 Sound-Mpg: 42. Acoustical board. 314 in thick. in suspension system 0.?6 0.93 0.83 0.99 0.99 0.94 0.95 lmtg. El 43. Shredded-de fiberboard. 2 in thick on lay-ingrid 0.59 0.51 0.53 0.?3 0.6-8 0.?4 0.65 tmtg. El =9 Dru nu" a nBAM‘rmu Sound Absorption NRC material 125 Hz 250 Hz 500 Hz 1000 Hz 2000 Hz 4000 Hz Numb-er‘t 4-4. Thin. porous sound-absorbing material. 0.10 0.60 0.80 0.82 0.?8 0.60 0.?5 3.14 in thick lmtg. B) 45. Thick. porous sound—absorbing material. 2 in thick 0.39 0.60 0.?8 0.90 0.?9 0.?0 0.?5 (mtg. Bl . or thin material with airspace behind (mtg. Di 46. Sprayed ceilulose fibers. 1 in thick on concrete (mtg. 0.06 0.29 0.?5 0.93 0.93 0.?6 0.?5 A} 4?. Glass-fiber root fabric. 12 02,1de ' 0.65 0.?1 0.82 0.86 0. ?6 0.62 0.90 43. GlassAfiber roof fabric. 3? 1,12 ozfycl2 (Note: Sound— 0.38 0.23 0.1? 0.15 0.09 0.06 0.15 reflecting at most frequencies.) 49. Polyurethane foam. 1 in thick. open cell. reticulated 0.0? 0.11 0.20 0.32 0.60 0.95 0.30 50. Parallel glass-fiberboard panels, 1 in thick by 18 in 0.0? 0.20 0.40 0.52 0.60 0.6? 0.45 deep. spaced 1B in apart. suspended 12 in below cemng 51. Parallel glass—fiberboard panels, 1 in thick by 19 in 0.10 0.29 0.62 1.12 1.33 1.38 0.55 deep. spaced 6 112 in apart. suspended 12 in below ceiling Seats and Audience“- 5 1 91¢ 52. Fabric wall—upholstered seats. with perforated seat 0.19 0.3? 0.56 0.6? 0.61 0.59 pans. unoccupied 53. Leathercovered upholstered seats. unoccupied‘ 0.44 0.54 0.60 0.62 0.53 0.50 54. Audience. seated in uphoisterecl seats' 0.39 0.5? 0.30 0.94 0.92 0.8? 55. Congregation. seated in wooden pews 0.5? 0.61 0.?5 0.86 0.91 0.86 56. Chair. metal or wood seat, unoccupied 0.15 0. 19 0.22 0.39 0.38 0.30 51'. Students. informally dressed, seated in tabieterm chairs 0.30 0.41 0.49 0.84 0.8? 0.84 Wingsrsi! 58. Deep balcony. with upholstered Seats 0. 50—1 .00 59. Diffusers or grilles. mechanical system 0.15—0.50 60. Stage 0.25—0.?5 Misceilanemsil 9- “l 51. Gravel. loose and moist. 4 in thick 0.25 0.60 0.65 0.?0 0.?5 0.80 0.?0 62. Grass. marion bluegrass. 2 in high 0.11 0.26 0.60 0.69 0.92 0.99 0.60 63. Snow. freshly fallen. 4 in thick 0.45 0.?5 0.90 0.95 0.95 0.95 0.90 64. Soil. rough 0.15 0.25 0.40 0.55 0.60 0.60 0.45 65. Trees. balsam firs. 20 ft2 ground area per tree. 6 ft high 0.03 0.06 0.1 1 0.1? 0.2? 0.31 0.15 65. Water surface {swimming pool] 0.01 0.01 0.01 0.02 0.02 0.03 0.00 ' NRC {noiSe reduction coefficient) is a single-number ratin of the sound absorption coefficients of a material. It is an average that only includes the coefficients in the 250 to 2 Hz frequency range and therefore should be used with caution. See page 50 for a discussion of the NRC rating method. 1Flefer to manufacturer's catalogs for absorption data which should be from up—to—date tests by independent acoustical laboratories according to current ASTM procedures. $Coefficients are per square foot of seating floor area or per unit. Where the audience is randomly spaced [e.g.. courtroom. cafeteria). mid—frequency absorption can be estimated at about 5 sabins per person. To be precise. ooefficients per person must be stated in relation to spacing pattern. §The floor area occupied by the audience must be calculated to include an edge effect at aisles. For an aisle bounded on both sides by audience. include a strip 3 ft wide; for an aisle bounded on only one side by audience, include a strip 1 1‘2 ft wide. No edge effect is used when the seating abuts walls or balcony fronts (because the edge is shielded}. e coefficients are also valid for orchestra and choral areas at 5 to B it2 per person. Orchestra areas include people. instruments. music racks. etc. No edge effects are used around musicians. flcoefficients for openings depend on absorption and cubic volume of opposite side. Test Reference “Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberation Room Method.” ASTM C 423. Available from American Society for Testing and Materiets iASTM}. 1916 Ftace Street. Philadelphia. PA 19103, Sources 1. L. L. Beranek. "Audience and Chair Absorption in Large Halls." Journal of the Acoustical Society of America. January 1969. 2. A. N. Burd at a!.. "Data for the Acoustic Design of Studios.” British Broadcasting Corporation, BBC Engineering Monograph no. 64, November 1966. 3. E. J. Evans and E. N. Bazley. "Sound Absorbing Materials.” H. M. Stationery Office. London. 1964. ...
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abs_coef_table - SOUND ABSORPTION DATA FOR COMMON BUILDING...

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