Discharge Calculations per AHRI 885-08

Project / Zone: Zone ID Octave Band 2 3 4 5 6 7Input Parameters: Type Mid Frequency, Hz 125 250 500 1000 2000 4000

Duct Width, in. 8 Input Pwl 65 63 66 66 66 64Duct Height, in. 8 Lining Reduction 2 6 12 25 29 18

Lining Thickness, in. 1 Elbow reduction* 0 0 0 0 0 0Length Lined duct,Ft 5 Tee Reduction* 0 0 0 0 0 0Number of Elbows* 0 Power splits 0 0 0 0 0 0

Type 1 1, Lined Rectangular End Reflection 10 5 2 1 0 0Number of Tees* 0 Flex Duct Reduction 5 10 18 19 21 12Type 1 1, Lined Rectangular Other (Custom) Number of Zones fed 1 Environmental Adjustment Factor 2 1 0 0 0 0End Reflection, Eq Dia., in. 8 Room Attenuation 5 6 7 8 9 10Flex Length, ft. 5 Total Attenuation 24 28 39 53 59 40Diameter, in. 8 Output Spl 41 35 27 13 7 24Room Volume, CuFt 2400 Output NC 27

Distance, ft. 5 Output RC 16

Note: the results agree with Standard 885 within 1 dB and the differences are due to rounding.

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Input Pwl Output Spl

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Discharge Calculations per AHRI 885-08

0 1 2 3 4 5 6 7 8

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Discharge Calculations per AHRI 885-08

Radiated Calculations per AHRI 885-08

Project / Zone: Zone IDInput Parameters:

ARI 885-08 TypeCeiling Type 1 1, Mineral Fiber User inputs only in unshaded areas.

For no ceiling, use discharge calculations Octave Band 2 3 4 5 6 7 Mid Frequency, Hz 125 250 500 1000 2000 4000Input Pwl 56 57 58 60 63 55 User input, Sound Power rating, From catalog or softwareCeiling Plenum / Room Attenuation 16 18 20 26 31 36 From AHRI 885-08Other (Custom) 0 0 0 0 0 0 User InputEnvironmental Adjustment Factor 2 1 0 0 0 0 From AHRI 885-08Total Attenuation 18 19 20 26 31 36 Arithmetic Sum of Attenuation factorsOutput Spl, AHRI 885-08 38 38 38 34 32 19 Predicted Room RadiatedSound Pressure level Output NC 33 Predicted Radiated NC Output RC 35 Predicted Radiated RC

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Input Pwl Output Spl, AHRI 885-08 NC Lines

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Radiated Calculations per AHRI 885-08

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Input Pwl Output Spl, AHRI 885-08 RC Lines

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Radiated Calculations per AHRI 885-08

Room Sound CalculationsThis page adds the sound from the VAV box in the previous examples to the sound from a selected diffuser

Project Zone IDOctave Band 2 3 4 5 6 7Mid Frequency, Hz 125 250 500 1000 2000 4000VAV Box Discharge Sound Pressure 41 35 27 13 7 24 Copied from Discharge TabVAV Box Radiated Sound Pressure 38 38 38 34 32 19 Copied from Radiated Tab

Diffuser Sound Power 44 45 44 46 44 27 Input this from diffuser manufacturer raw (uncorrected) sound power data# of Diffusers 1 Input number of diffuser near observer (within 15 ft.) *Room Attenuation 5 6 7 8 9 10 From Discharge SheetOther (Custom) 0 0 0 0 0 0 User defined attenuationEnvironmental Adjustment Factor 2 1 0 0 0 0 From AHRI 885-08

Diffuser Sound Pressure 37 38 37 38 35 17 Resultant room sound pressure from diffuser(s)

Total Room Sound Pressure 44 42 41 40 37 26 Log sum of Discharge, Radiated and diffuser sound pressure levels.

Output NC 38 Predicted Room NC R? H?

Output RC, Letters 39 N N Predicted Room RCDbA 44 Predicted Room dBA

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Room Sound Cal-culations

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Room Sound Calcula-tions

Linear, dBA, and dBC Calculations:June 15, 1995 Version Input O.B. Data Given

Data Linear dBA dBC No. Under Linear ColumnFreq., Hz. Input Calc. Calc. Freq., Hz.

31.5 79.0 39.6 76.0 31.5 Excluded, DIH 10/15/0363 74.0 47.8 73.2 63

125 43.6 27.5 43.4 125250 41.9 33.3 41.9 250500 40.6 37.4 40.6 500

1000 39.7 39.7 39.7 10002000 36.6 37.8 36.4 20004000 26.1 27.1 25.3 40008000 36.0 34.9 33.0 8000 Excluded, DIH 10/15/03

16000 -6.6 -8.5 16000Linear 80.2 - - LineardBA - 43.8 - dBAdBC - - 77.8 dBC

A-wgt Linear dBA dBC C-wgt-39.4 79.0 39.6 76.0 -3 Excluded, DIH 10/15/03-26.2 74.0 47.8 73.2 -0.8-16.1 43.6 27.5 43.4 -0.2-8.6 41.9 33.3 41.9 0-3.2 40.6 37.4 40.6 0

0 39.7 39.7 39.7 01.2 36.6 37.8 36.4 -0.21 26.1 27.1 25.3 -0.8

-1.1 36.0 34.9 33.0 -3 Excluded, DIH 10/15/03-6.6 0.0 -6.6 -8.5 -8.5

Overall 80.2 43.8 77.8 OverallValue Linear dBA dBC Value

Sound Constants - AHRI 885-08

Band Constants

Octave Band 2 3 4 5 6Mid Frequency, Hz 125 250 500 1000 2000

NC DriversIntcpt -31.6 -18.9 -8.5 -2.2 1

M1 1.28 1.18 1.09 1.02 1.00

Lined DuctConstants 125 250 500 1000 2000

C1 -0.865 -0.582 -0.0121 0.298 0.089

C2 0.723 0.826 0.487 0.513 0.862

C3 0.375 0.975 0.868 0.317 0

Flex DuctConstants 125 250 500 1000 2000

C1 2.601 -2.023119 1.533116 23.452 26.15493C2 -0.1250605 1.276239 1.407587 -2.844882 -2.885191C3 -0.0063392 -0.0821164 -0.0831661 0.08517541 0.08842091C4 0.4852413 -0.6914328 1.948206 0.8380425 1.702466C5 0.07757873 0.4378392 0.06271727 0.3254958 0.1615714C6 -0.0052214 -0.020816 -0.0050562 -0.0146852 -0.0099562

Elbows, 11-20 " Wide (use Avg = 15")Elbow Type 125 250 500 1000 2000kHz* avg. width 2 3.8 7.5 15 301, Lined Rectangular 1 6 6 11 102, Lined rect, Turning Vanes 1 4 4 7 73, Unlined Rectangular 1 5 5 8 44, Unlined Round 1 2 2 3 3

Basis of table Type 1 Type 2 Type 3

Hz Loss fw Loss fw Loss125 1 1.9-3.8 1 1.9-3.8 1250 6 3.8-7.5 4 3.8-7.5 5500 11 7.5 - 15 7 >15 8

1000 10 >15 42000 3

Tees, 11-20 " WideElbow Type 125 250 500 1000 20001, Lined Rectangular 4 9 9 14 132, Lined rect, Turning Vanes 4 7 7 10 103, Unlined Rectangular 4 8 8 11 74, Unlined Round 4 5 5 6 6

End Reflection

1127 Speed of sound , f/second

Pi 3.14159 Pi

0.7

2

AHRI 885-08 / Radiated, combined ceiling plenum/space effectCeiling/Plenum Effect Attenuation Values, Radiated soundTile Type 125 250 500 1000 20001, Mineral Fiber 16 18 20 26 312, Mineral Fiber 15 17 19 25 303, Glass Fiber 16 15 17 17 184, Glass Fiber 17 18 21 25 295, Glass Fiber, TL Backed 17 18 22 27 326, Gypsym Board Tiles 16 18 18 21 227, Solid Gypsum Board 21 25 25 27 278, Solid Gypsum Board 23 27 27 29 299, Double Gypsum Board 27 31 31 33 3310, Double Gypsum Board 29 33 33 35 3511, Concealed Spline 23 24 24 29 33

Space Effect, Point Source Log Distance, ft. 10

Log Room Volume, CuFt 5

Log Frequency, Hz 3

Constant 25

Environmental Adjustment Factor

C0

a1 a1, flush - Terminated duct, Pink Noise, full octave

a2 a2, flush - Terminated duct, Pink Noise, full octave, rounded

Standard referenced 125 250 500 1000 2000

ARI 885-90 3 2 1 1 1

AHRI 885-08 2 1 0 0 0

Equation

74000

NC= M1*Band Spl+ Intcpt

3.10.98

4000 dB/ft = 10^C1 * p/a^C2 * t^C30.0649 where :0.629 p/a = 2*(Width+Height)/(Width*Height)*12, in inches

0 t = lining thickness, in.

4000 IL, by Band = (C1+C2*Dia+C3*Dia^2) + ((C4+C5*Dia+C6*Dia^2)*Length) 25.06003 Diameter in inches, Length in feet-4.0431 Edited 11/19/2008 to make totals the same as the -98 version. DIH

0.16269050.22396860.344374-0.020039

40006010 Excerpted from tables D11,12, AHRI 885-087 Using tables below, and freq (in Khz) * Width, the followong tables apply33

Type 4 Hz at 15" width (mean)

fw Loss fw Loss from AHRI 885-08

1.9-3.8 1 1.9-3.83.8-7.5 2 3.8-7.57.5 - 15 3 >7.515-30>30

Same as above, plus 3db for I split4000

131066

Where F = octave band frequency.

D in inches

788.9

Table from ARI standard 327.2494000 2.410703

36 5.81148833 6.81148819 0.83324235 8.3324239222830343634

Shultz equationRoom SPL = Sound Power less (10 * Log(Distance) + 5 * Log(Volume)+ 3 * Log(Freq[I]) - 25)

ERL (From ASHRAE RP 1314) ERL = 10*Log(1+(a1*c/Pi*f*(D/12))^a2)

, flush - Terminated duct, Pink Noise, full octave

, flush - Terminated duct, Pink Noise, full octave, rounded

4000

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Application Reductions0 0

IL, by Band = (C1+C2*Dia+C3*Dia^2) + ((C4+C5*Dia+C6*Dia^2)*Length)

Room SPL = Sound Power less (10 * Log(Distance) + 5 * Log(Volume)+ 3 * Log(Freq[I]) - 25)

ERL (From ASHRAE RP 1314) ERL = 10*Log(1+(a1*c/Pi*f*(D/12))^a2)

Application Reductions0 0 0 0

WRITTEN BY: TARSHA L. SIMON DATE: Jan 17, 1991MODIFIED BY: D Int-Hout, 2/95 NCPLOT RC Data

-2 50-1 45

32 0 0 40NC15 63 1 47 1 35

125 2 36 2 30250 3 29 3 25500 4 22 4 20

1000 5 17 5 152000 6 14 6 104000 7 12 7 5

8 0

-1 5032 0 45

NC20 63 1 51 40125 2 40 35250 3 33 30500 4 26 25

1000 5 22 202000 6 19 154000 7 17 10

8 5

-1 5532 0 50

NC25 63 1 54 45125 2 44 40250 3 37 35500 4 31 30

1000 5 27 252000 6 24 204000 7 22 15

8 10

-1 600 55

NC30 63 1 57 50125 2 48 45250 3 41 40500 4 35 35

1000 5 31 302000 6 29 254000 7 28 20

8 15

-1 650 60

NC35 63 1 60 55125 2 52 50250 3 45 45

500 4 40 401000 5 36 352000 6 34 304000 7 33 25

8 20

-1 700 65

NC40 63 1 64 60125 2 56 55250 3 50 50500 4 45 45

1000 5 41 402000 6 39 354000 7 38 30

8 25

-1 750 70

NC45 63 1 67 65125 2 60 60250 3 54 55500 4 49 50

1000 5 46 452000 6 44 404000 7 43 35

8 30

-1 800 75

NC50 63 1 71 70125 2 64 65250 3 58 60500 4 54 55

1000 5 51 502000 6 49 454000 7 48 40

8 35

-1 850 80

NC55 63 1 74 75125 2 67 70250 3 62 65500 4 58 60

1000 5 56 552000 6 54 504000 7 53 45

8 40

-1 900 85

NC60 63 1 77 80125 2 71 75

250 3 67 70500 4 63 65

1000 5 61 602000 6 59 554000 7 58 50

8 45

-1 950 90

NC65 63 1 80 85125 2 75 80250 3 71 75500 4 68 70

1000 5 66 652000 6 64 604000 7 63 55

8 50

-1 78 780 58 58

HEARING THRESHO 1 36 362 22 223 13 134 8 15678