Trane TRG-TRC007-EN manual Setting a Design Goal

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period three

Acoustical Analysis

notes

Setting a Design Goal

room type

RC(N) criteria

 

hotels/motels

25 to 35

 

guest rooms

 

banquet rooms

25 to 35

 

libraries

30 to 40

 

office buildings

30 to 40

 

open plan offices

 

public lobbies

40 to 45

 

performing arts

25 max

 

theaters

 

practice rooms

35 max

 

schools

40 max

 

small classrooms

 

large classrooms

35 max

Figure 34

Setting a Design Goal

The first step of an acoustical design is to quantify the goal. Period Two introduced several single-number descriptors that designers commonly use to define the acoustical design goal for a space. Each descriptor has its advantages its and drawbacks.

In general, when defining the acoustical design goal for an interior space, either an NC value or an RC value is used. To aid HVAC system designers, the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) recommends target RC ratings for various types of spaces, and encourages the use of the RC rating method whenever the space requires a neutral, unobtrusive background sound. Figure 34 includes an excerpt from the ASHRAE Handbook—Applications(Table 43 in Chapter 46 of the 1999 edition).

As mentioned earlier, A-weighting is also used in many hearing-protection safety standards for industrial environments. These standards generally take the form of a maximum A-weighted sound-pressure level at a specified distance from the piece of machinery.

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Contents Air Conditioning Clinic Fundamentals of Hvac Acoustics Business Reply Mail One of the Fundamental Series Comment CardFundamentals of Hvac Acoustics Fundamentals of Hvac Acoustics PrefaceContents TRG-TRC007-EN Fundamentals of Sound Fundamentals of SoundWhat is Sound? What is Sound?Sound Wave and Frequency Wavelength Broadband Sound and Tones Broadband SoundOctave Bands Octave BandsLogarithmic sums One-Third Octave Bands Sound Power and Sound Pressure Sound Power and Sound PressureAn Analogy Decibel DB = 10 log10 ´ log Logarithmic ScaleEquation for Sound Pressure Equation for Sound Power50 dB + 44 dB = 51 dB Logarithmic Addition of DecibelsHuman Ear Sound Perception Rating MethodsHuman Ear Response Loudness Contours Single-Number Rating Methods Response to TonesSingle-Number Rating Methods Sound Perception and Rating Methods C WeightingWeighting Example Weighting Noise Criteria NC Curves NC-39 Room Criteria RC Curves MPa DB ref Pressure Sound Perception and Rating Methods RC-31 R Phon and Sone Octave-Band Rating Method Octave-Band Rating MethodAcoustical Analysis Acoustical AnalysisSetting a Design Goal Setting a Design GoalAcoustical Analysis Source-Path-Receiver Analysis Acoustical AnalysisSource-Path-Receiver Model Airborne Typical Sound PathsExample of Multiple Sound Paths Examples of a Single Sound PathIdentifying Sound Sources and Paths Sound-Path Modeling Modeling Sound PathsSupply Algorithms for Sound-Path Modeling Computerized Analysis Tools Terms Used in Sound-Path Modeling Attenuation and RegenerationSound Transmission Insertion loss IL Noise reduction NR Transmission loss TL Absorption Reflected Sound Receiver Sound Correction Equipment Sound Rating Equipment Sound RatingFields of Measurement Free FieldDistance Correction in a Free Field = L p1 20 logLot Near Field Reverberant Field Semireverberant Field Hvac Equipment Sound Rating Rating Hvac EquipmentReverberant-Room Method Free-Field Method Industry Standards Ducted Air-Handling Equipment Air Handler Test Configurations Former Methods of Sound Testing ARI Standard Sound Power by Octave Band Review-Period One ReviewNoise criteria NC Room criteria RC Review-Period TwoReview-Period Three Review-Period Four Review Questions for Period QuizOctave-band frequency, Hz Answers Glossary Glossary Room effect See receiver room correction Glossary Trane