Rak-43.3415 Building Physics Design 2 ACOUSTICAL DESIGN

Rak-43.3415 Building Physics Design 2ACOUSTICAL DESIGNAutumn 2015LECTURE 1Introduction to Acoustical DesignMatias Remes, M.Sc FISE A acoustics

Course arrangements

Schedule Lectures (6) 8.9-13.10 Tue 16.15-20 in hall R2, mainthemes:––––––8.9 Lecture 1: Introduction, basic concepts of acoustics15.9 Lecture 2: Airborne sound insulation22.9 Lecture 3: Impact sound insulation29.9 Lecture 4: Room acoustics6.10 Lecture 5: HVAC noise control, vibration isolation13.10 Lecture 6: Traffic noise, guidelines and regulations Exercises (5) 14.9-12.10 Mon 16.15-18 in hall R2 Design exercise: notified later Exam: 16.12.2015, (20.10.2015 for students from previousyears)

Execution Compulsory:– Design exercise– Exam Recommended and desirable:– Attending lectures– Solving exercies independently at home Course books:– RIL 243-1-2007 (only available inFinnish)– Master Handbook of Acoustics,Everest&Pohlman (a few sections, to benotified later)

The scope of acoustics

[Lindsay 1964, muutettu][Lindsay s wheel of acoustics,1964, modified / Remes]

Brief history of acoustics.”Acoustics is a science of the last thirty years.”Physicist Dayton Miller 1931

History.Creek. aκουειν ”to hear” 6th century BCPythagoras investigates the relation between the length and pitch ofstrings 325 BCAristotle writes about the production and reception of sound andechoes 27 ADMarcus Vitruvius Pollio: De Architectura, first instructions on theacoustic design of theaters 800s Islamic culture produces new knowledge on sound-related phenomena(e.g. hearing and speech production) 1500sThe effects of Renaissance cathedrals on music

History. Mid 1600sSound reflection and echoes are explained as analog to thereflection of light, R. Boyle ja R. Hooke deduce that sound needs amedium in order to propagate, G. Galilei investigates the vibrationof strings 1670 sFirst purpose-built concert hall is finished in London 1700sCommercialisation of music and theatre industry creates new socialand acoustical framework 1816P. S. Laplace discovers the equation for calculating the speed ofsound (Newton attempted this before but did not get the right result)

History. Beginning of 1800sPractical research on the behaviour of sound in enclosed spaces(background: growing need for auditoria and development of orchestralmusic). C. Bullfinch, R. Mills and J. S. Russell develop methods forimproving speech intelligibility in rooms.1850Joseph Henry discovers the Precedence effect and evaluates that theshape of the room does not explain alone the way it sound, but materialshave to be considered also1860sHermann von Helmholtz investigates speech production, sense of hearingand sound disturbance1876A. G. Bell invents the microphone (however, condensator microphone is notinvented until 1916)1877Lord Rayleigh: The Theory of Sound, the mathematical principles of soundand vibration

History. End of 1800sWallace Clement Sabine hired to improve the acoustics of theFogg Art Museum in Harvard Sabine invents a method for measuring the reverberation timeof a room using an organ pipe and stopwatch Sabine equation for calculating the reverberation time 1895W. C. Sabine as acoustical designer of the Boston Symphony Hall 1920Efirst patented acoustical tile 1927First anechoic chamber built (F. Watson)

History. 1930sFirst sound level meter (P. Sabine) 1930s Suggestions for sound insulation regulations in several countries,measurement of and methods to decrease traffic noise in largecities acoustics becomes a tool for humans to control the environment 1943The Finnish Ääniteknillinen yhditys (now Akustinen Seura /Acoustical Society of Finland) is established the field of acoustical expertise in Finland expands, teachingacoustics begins gradually in the 1950s and 1960s

Acoustics as a field of science andtechnology Old field of science but significant effects not until the 20th century Acoustics has enabled, e.g.––––Telephone, radio, recording and reproduction of sound, talking moviesHearing protection in industrial labourPrivacy in residential buildingsThe building of spaces which work according to desired function Sound plays an important role in how people experience andperceive the surrounding environment–––––HearingSpeech, communicationMusicWarning signalsSound in nature

Acoustical design of buildings” Akustinen suunnittelu on suoritettava samanaikaisestiyleisen suunnittelutyön yhteydessä, jotta saadaanestetyksi sellaiset ratkaisut, jotka estävät optimaalistenakustisten tulosten saavuttamisen.”Tekniikan lisensiaatti Eero Lampio 1962

The ”four-field” of acoustical designBuildingacousticsRoomacousticsAcoustical designof tionisolation

The ”four-field” of acoustical design

Room acoustics ”Good room acousticsmeans that speech andmusic is perceived asbeautiful, natural andclear in every point ofthe room.”Engineer U. Varjo 1938 The reflection,attennuation andpropagation of sound ina space Goal: sound (speech,orchestra etc.) soundsas is required by theuse of space

Building acoustics 1/3 Transition of soundbetween spaces viastructures– Not only through theseparating structure, butalso as flankingtransmission and throughholes etc. 3 parts depending on thenature of the soundsource:– Airborne sound insulation– Impact sound insulation– Structure-borne soundinsulation

Building acoustics 2/3 Sound insulation4540353025201510Kipsilevy 2 x 13 mm (18 kg/m2)Puu 50 mm (25 kg/m2)5Kevytbetoni 68 mm (27 kg/m2)Taajuus [Hz]31502000125080050031520012580050 Choosing theconstruction type isalso acoustic design50R ' [dB]– Between spaces(airborne and impact)– From inside tooutside and viceversa– Equipment noise– VibrationRakenteidenilmaääneneristävyyksiä

Building acoustics 3/3 Airborne sound (ilmaääni) is soundproduced in and propagated in air,whereas structure-borne sound(runkoääni) propagates instructures Speech is airborne sound Sounds caused by walking ordropping objects on the floor areimpact sound (askelääni) Piano produces airborne sound andstructure-borne sound through itsfeet which are in contact with thefloor structure All technical equipment produce bothairborne and structure-borne sound

Noise control 1/2 Outdoor noise sources:road, railway andairplane traffic Indoor noise sources:machinery and serviceequipment (talotekniikka) Goal: to diminish theproduction andpropagation of noiseKuva: Salter 1999

Noise control 2/2 HVAC equipment– outdoors– indoors Traffic noise– Road traffic– Railway traffic– Airplane traffic Machinery, industry Measurement of noiseemission Noise modelling

Vibration isolation 1/2”Älköön kukaan pitäkövarastoa, tai käyttäkökiinteistöä niin, ettänaapuri taikka muu kärsii siitä pysyväistäkohtuutonta rasitusta,kuten kipinöiden,tuhkan, noen, savun,lämmön, löyhkän,kaasujen, höyryn,tärinän, jyskeen taikkamuun sellaisen kautta.”Laki eräistä naapuruussuhteista1920

Vibration isolation 2/2 All machinery incontact with thebuilding frame vibrateand produce sound Goal: to diminish thepropagation of thevibration energy byisolating the machinefrom the buildingframe using elasticbuilding elementsSähköjohto vapaasti riippuvana lenkkinäPallotasainPallotasainBetonilaatta 250 mmTärinäneristimetBetonimassa

Goals os acoustical design Suitability to intended use– Suitability to speech / music– Appropriate sound insulationbetween spaces Healthiness– Hearing loss– Acoustic ergonomy Comfort– Living spaces in noisy areas– Connection between acoustics andaesthetics (”wow-factor”)– Concert halls etc.Kuokkala church 2010Lassila Hirvilammi Arkkitehdit,Helimäki Acoustics

Significance of acoustical design 1/3 The starting points of acoustic design:1. Healthiness2. Comfort3. Use of space Achieving good acoustical conditions in a buildingrequires that all the points are taken into consideration! The need of acoustical design is not limited todemanding spaces such as concert halls, but acousticaldesign is needed in everyday buildings as well (when,e.g., choosing the construction type of a soundinsulating structure in a school or residential building)

Significance of acoustical design 2/3 Sound constitutes a significant part of the humansensory environmentNoise (”unwanted sound”) has significant physiologicalanf psychological effects on humans–Research has been extensive from the beginning if the 20thcentury–The effects of noise are not limited to loud noise (hearingdamage risk), but also a quiet sound can be perceived as noiseif it, for example, hinders concentrationBad acoustics also has economic consequences.Akustiikka 10/11

Significance of acoustical design 3/3Investing in acoustics is worth it A space which does not function acoustically as required byits use is a stranded investment, i.e. bad business! Improving the acoustical conditions in a finished building isalways k of expertsWork spent by the user to solve the problemLarger design costsLarger building costs Savings earned during the use of the building– The effects of acoustics on working conditions– There is no need to do changes to a space which works asintended!

Regulations and instruction in acoustics The National Building Code of Finland, Section C1-1998 The National Building Code of Finland, Section D2-2010 Asumisterveysohje (2003) by the Ministry of Social Affairsand Health Government Decision on the Noise Level Guide Values(993/1992) Acoustic Clasification of Spaces in Buildings, standard SFS5907

Acoustics in the building projectAcoustics should be considered in the building project as soonas possible – the sooner, the more demanding the project is!

Acoustics in the building projectProject planning phase (hankesuunnittelu) Sound insulation– Appropriate level of sound insulation according to use of spaces– Space program (tilaohjelma): positioning of noisy / quiet spaces Room acoustics– Use of space surface area, volume, shape, room acousticalmaterials Control of HVAC noise– Determine the permitted noise levels– Space needs required by noise control measures (silencers etc.),positioning of engine rooms and noisy machinery Control of traffic noise– Noise surveys ( recommendations, e.g., for positioning ofbuildings, estimate of the need for facade sound insulation(ulkovaipan ääneneristys, UÄE)– Vibration surveys

Acoustics in the building projectPreliminary design phase (luonnossuunnittelu) Sound insulation– Definition of sound insulation target values– Construction types of separating and flanking structures, sound insulationrequirements of doors, floor coverings Room acoustics– Basic shape of speech and performance spaces, room acoustical requirementsas technical values (e.g., reverberation time)– Amounts and types of room acoustical materials, furnishings and decoration Control of HVAC noise– Permitted HVAC noise levels according to the uses of spaces and principles ofhow the target values can be fulfilled, selection of sewer system Control of traffic noise– More accurate noise survey (requirements for facade sound insulation, balconyglazings, noise barriers), effects of vibration surveys– Determination of construction types: exterior wall (US), roof (YP) (sufficientsound insulation for a given use)– Facade sound insulation survey (ulkovaipan ääneneristys, UÄE) Cost for the project