acoustic analysis project 1

TABLE OF CONTENT

ABSTRACT

1.0 INTRODUCTION

1.1 Objectives

1.2 Site Study

1.2.1 Introduction

1.2.2 Site Selection Reasons

1.2.3 Measured Drawings

1.3 Methodology

1.3.1 Identification of Existing Conditions

2.0 LITERATURE REVIEW

2.1 Acoustics

2.1.1 Sound

2.1.2 Amplitude, Wavelength & Frequency

2.1.3 Common Sound in Decibels

2.1.4 Acoustics in Architecture

2.1.5 Acoustics Standard ANSI (2008) S12.2-2008

3.0 PRECEDENT STUDY

3.1 Introduction to Building

3.2 Statistical Analysis Method/Questionnaire

3.3 Formula for Acoustic Analysis Calculation

4.0 CASE STUDY

4.1 Site Study and Zoning

4.2 External Noise Source

4.3 Interior Noise Sources

4.3.1 SPACE 1: Gymnasium

4.3.1.1 Existing Equipment

4.3.1.2 Cooling System

4.3.1.3 Human noise

4.3.2 SPACE 2: Physiology Room



4.3.2.3 Human noise

4.4 Tabulation & Interpretation of Data

4.5 Acoustic Fixtures and Specifications

4.6 Gymasium calculation

4.6.1 Calculation of sound intensity of indoor noise source

4.6.2 The calculation of sound level

4.6.3 Analysis & Evaluation

4.6.4 Sound reduction index calculation

4.6.5 Reverberation Time Calculation

4.7 Acoustic Analysis

4.8 PHYSIOTHERAPY CALCULATION


4.8.2 The calculation of sound level


4.8.4 Sound reduction index calculation


4.9 Acoustic Analysis for Physiotherapy

5.0 References

ABSTRACT

This report consists of the study of how acoustics affects the environment and we chose to conduct at SOSCO Rehabilitation Centre, Melacca as our case study. In order to carry out the performance evaluation, we’ve requested the proper floor plans from the facilities management that govern the site buildings, and also produced elevations and sections for the ease of data collection. Collection of acoustics data is carried out at the functioning hour of the building to quantify and qualify the existing condition of the site. All the data and drawings collected were then further used to carry out an analysis to study the performance of the building. A list of figures are used as well and a list of references is provided at the end of the report for the ease of navigation. Additionally, photographs were also taken on site to further identify acoustics sources of the chosen area.

1.0 INTRODUCTION

Acoustics study on buildings and spaces within is crucial as considerations of maintaining and having good quality noise control. Some key spaces that requires critical acoustics control are galleries, concert halls, restaurants and many other spaces.

In short, this project is design to expose and introduce us acoustics requirement in a suggested space. In a group of 7, we have chosen SOSCO Rehabilitation Centre, Melacca, as our site study. We have conducted several site visits to ensure the success of the project outcome. Measurement and calculations of acoustic readings and site measurement are done during the visits and after the visit respectively. Lastly, we concluded the analysis based on the results of our findings and observations.

1.1 Objectives and Aim

1. To observe and understand acoustics and its characteristics.2. To understand acoustic requirement in a suggested place.3. To determine the different types of acoustics throughout this project.4. To determine the characteristics and function of sound within the intended space.5. To critically report and analyze the space and suggest remedies to improve acoustic

qualities within the space.

The primary objective of this project is to impart the understanding of acoustics and characteristic and requirement in a suggested space, thereby determine their functions and various factors affecting it. With the data collected and the relevant knowledge, an analysis is to perform to evaluate the suggested space with a critical mindset. Besides that, understanding the acoustics elements and existing arrangement helps in determining the acoustics characteristics that is reflected in the data collection by using certain methods or calculations. Backed up with precedent studies, drawing comparison with the site study, our precedent studies will aid in achieving all the objectives above.

1.2 Site Study

Case Study: SOCSO Rehabilitation Center, Melacca.

Identification of space: Gymnasium rehabilitation space and physiotherapy room.

Address: Pusat Rehabilitasi Perkeso

Lot PT 7263 [H.S (D) 18923]

Bandar Hijau, Hang Tuah Jaya,

Melaka, 75450, Malaysia.

1.2.1 Introduction

SOCSO Rehabilitation Centre is located at Bandar Hijau, Hang Tuah Jaya, Melacca. It is a rehabilitation centre that consists of an administration block and 5 extended wings. Namely, the Gymnasium, Vocational, Physiotherapy, Hydrotherapy and the Speech and Audio therapy.

Under SOCSO’s "Return to Work" program, disabled patients undergo physical and vocational rehabilitation in order to rejoin the workforce. The architect, Anuar Aziz Architect, called this process the "Journey to Healing," where the patients will heal physically and mentally, and lead a normal working life after the rehabilitation process.

The allied health institute will provide the skilled personnel. This green certified complex was designed with ‘nature’ and ‘spirituality’ integral to the healing process. A universal access-for-all concept and Malaysian Standard for disabled access is applied throughout.

The concept of the building is each building is given a different identity according to functions and ease of way finding. Calming and soft colors are utilized throughout the complex.

1.2.2 Site Selection Reasons

Based on observation, the building provides sufficient functional spaces to conduct out an analysis on acoustics conditions. The gymnasium space and the physiological therapy space with specific function would help us develop an understanding on how noise is controlled to achieve comfort for users based on different programs and functions.

In terms of acoustics properties, the gymnasium space and the physiological therapy space can be categorized into semi enclosed space, though the gymnasium has a higher ceiling

space compared to the other. Numerous noise producing elements are spotted within the spaces ranging from electronic equipments, to human activities.

1.2.3 Measured Drawings

Figure 1 Floor Plan of Physiotherapy Room

Figure 2 Floor plan of Gymnasium Room

2.0 Precedent study

2.1. INTRODUCTION TO BUILDING

Bahcesehir University (BAU) Office, Besiktas Campus

Figure 3.1a: Bahcesehir University Besiktas Campus

Located in Istanbul, Turkey, the Bahcesehir University is a well-known private educational institution with its main campus located at the edge of the Bosporus in Besiktas. The university consists of eight faculties: a school of language, two vocational schools and four institutes that provide post graduate education, with an average of 17,000 registered students studying at the university.

The space that we chose to study is the Faculty of Architecture & Design of Bahcesehir University. Position on the side of the shore, the buildings are formed in the shape of long, narrow rectangular prisms sited very close and are interconnected to one another. These buildings face the garden on the shore and sea with one of their narrow sides, and a high traffic artery of the city with the other.

The office occupies half of the 1st floor of Block B and faces sea on the East, and other two neighboring buildings (buildings A and C) on the north and south. There are two different types of office spaces in the faculty. Open-offices with semi-enclosed partitions in the central area and are used by the teaching/research assistants; the closed offices surrounding the central area from three sides, shared by two or three academic staff. Closed offices, with regard to their

orientation as A and B, create 2 subgroups within closed office type.

2.1.2.1 ACOUSTIC COMFORT/NOISE CONTROL

Measurements regarding the environmental noise in the space were taken in the morning (10.00-10.11), noon (13.00-13.12) and afternoon (16.26-16.36) times of a working day, with the windows tightly shut. These periods were decided in reference to the standard working hours of the users. Sound level meter and sound pressure equipment were set in the middle of the office and central area 150cm above the ground level and then used for comparison with the standards IEC 60651 and IEC 60804.

Placement of equipment for acoustic analysis

2.3.1.2 ACOUSTIC COMFORT

Acoustics data of Office A close to neighboring building

Acoustics data of Office A campus side

Acoustics data of Office B

Acoustics data of Office C

2.4 Conclusion

Through the data taken in the precedent study of the Bahcesehir University Besiktas Campus, the result was shown that the environmental noise appeared to influence the perception of environmental quality. Mentioned by the occupants, they show dissatisfaction of acoustic privacy and noise control due to the fact that they are not that well maintained as it is affect by environmental elements.

The findings shown a slightly higher environmental sound intensity compared to optimum human condition, the poor choice of materials for sound buffering is one of the key faults of providing bad acoustic control

3.0 Research Methodology


Sound and Acoustic analysis plays a role in the acoustic design performance, sound and noise level of the noise. The analysis might involve in design fine tuning in order to achieve the standards from ANSI, IEC and ISO. A simple and fairly effective method of diagnostics can be performed with acoustical equipment.

Description of Equipment

(a) Acoustic Measuring Equipment (Digital Sound Level Meter)

Figure 3.2.1.1: Sound Level Meter

GENERAL SPECIFICATIONS

Measurement 30 – 130 dBResolution 0.1 dBMeasured QuantitiesLinearity Characteristics of “A” frequency weighting network meet IEC

61672 class 2.Under 94 dB input signal, the accuracy are:31.5 Hz ± 3.5 dB63 Hz ± 2.5 dB125 Hz ± 2.0 dB250 Hz ± 1.9 dB500 Hz ± 1.9 dB1 K Hz ± 1.4 dB2 K Hz ± 2.6 dB4 K Hz ± 3.6 dB8 K Hz ± 5.6 dB

Power Supply Alkaline or heavy duty DC 1.5V battery (UM3, AA) x 6 PCs. Or equivalent.DC 9V adapter input. (AC/ DC power adapter is optional).

Dimension 245mm x 68mm x 45mmWeight 489g

Table 3.2.1.2: General Specification of Sound Level Meter

(b) Smartphone [OnePlus One]

An additional recording device is used as a result comparison with the digital sound level meter. A median result is then obtained and will be averaged in the recordings table.

(c) Measuring Tape

The tape is used to measure a constant height of the position of the sound meter and the grids established for the area, which is at 1m and 1.5m respectively. The height is taken on one person as reference to obtain an accurate reading.

(d) Camera [a7ii Sony]

The camera is used to record pictures on the source of sound in the cafe and its surrounding.

3.2 Data Collection Method

The sound level meter is placed at the same height of 1m for each point in order to obtain an accurate reading. This is done to ensure the consistency of the measurements taken. The readings were recorded on a plotted plan with 1.5m x 1.5m gridlines. Noises produced by us students are kept to the minimum to obtain the best sound reading result.

Procedure

1. Push the Power Switch to switch on the device.2. Record the dB value by holding the Noise Indicator at 1m height, approximately at

waist height (ear level while sitting).3. Record the data displayed on the device.4. Repeat 2 and 3 until all data are completed.

Figure 3.2.2.1: Position of Noise Indicator at 1 meter

3.3 Formula for Acoustic Analysis Calculation

Calculation for Reverberation Time:

Reverberation time (RT) is a measure of the amount of reverberation in a space and equal to the time required for the level of a steady sound to decay by 60dB after the sound has stopped. The decay rate depends on the amount of sound absorption in a room, the room geometry, and the frequency of the sound.

Reverberation Time Formula: RT = (0.16 x V) divide by A

Where,

V = Volume of space

A = Total absorption (Material Covering Area x Absorption Coefficient)

4.0 CASE STUDY

4.1 Site Study and Zoning

4.2 External Noise Source

Located in a fairly remote part of Bemban, Malacca, the SOCSO Rehabilitation Centre is located between Jalan Kolej Yayasan Saad and Lebuhraya Utara-Selatan. Since Kolej Yayasan Saad is located before SOCSO Rehabilitation Centre, vehicle circulation in front of our site is quite minimal as the other end only consists of a solar farm and an undeveloped road end. Contrastingly, the back of SOCSO Rehabilitation Centre is the North-South highway where many high-speed vehicles pass by the site.

But through our observation, SOCSO Rehabilitation Centre is surrounded by lush and thick greeneries, thus constant audible sound ranges just around 50 to 55 dB, an optimum sound range for the disables to concentrate on their trainings without any unnecessary disturbances.

Annotated plan to indicate noise sources

4.3 Interior Noise Sources

4.3.1 SPACE 1: Gymnasium

Inside the SOCSO Rehabilitation Centre’s gymnasium space, we noticed some of the key activities of patients exercising and trainings with their nurses’ guidance.

From our observation, we noted that the music produced by the speakers have quite a high sound intensity level in our chosen analysis space, whereas the sound from the gym equipment and air diffusers are moderate, but noticeable.

Sound produced by human activities are considered low as patients tend to train individually and independently according to their own pace, thus there was not much human interaction in the area unless by-standing nurses come to aid.


Some of the most significant noise produced are the electronic equipment present in our chosen gymnasium area. The one component that constantly produces noise are the speakers located on corner walls of the room, blasting catchy beats to motivate the patients. Occasional rings from the phone can be heard as well for the nurses to communicate any reports of situations. Lastly, electronic gym equipment such as the treadmills can be quite noticeable when used by patients during operating hours of the day, whereas other equipment such as the bicycle and lifting training produces little to none noises.


Though moderate, yet noticeable, the noise generated through air diffusers are located at higher walls can be heard constantly. Noise produce from the air diffusers are related by the velocity settings of the AHU panels, and for the gymnasium, it was considered set slightly above average due to the fact that users will experience body heat during a workout. Thus the higher velocity of conditioned air caused a slightly higher intensity of sound level, yet it is still not till extend which will distract the users.

4.3.1.3 Human noise

Human interactions are considered low in the gymnasium due to the fact that most users attended as independent individuals, and not as groups. As so, human communications such as chats and discussions are very faint, thus overall human noises are low. Only a few grudges sounds can be heard during their activities.

4.3.2 SPACE 2: Physiology Room

The other chosen area of SOCSO Rehabilitation Centre’s is the Physiology room, located a block away from the gymnasium. Comparison wise, the sound intensity level of the Physiology room is slightly higher than the gymnasium, but with dissimilar factors.

From our observation, we noticed that the room ceiling is much lower than the gymnasium, thus noise reflection is closer and more obvious. The most significant noises are produced by human noises due to the fact that this particular room consists of many patients interacting with their nurses. The sound from electronic equipment and air diffusers are too moderate yet noticeable as well.


Unlike the gymnasium, the physiology room consists of numerous of specialized equipment that measures and records the patients’ performance, although those are seldom used and only used on critical phases only, thus they do not contribute much to the noise level of the area. Other electronic equipment are the phones and computers which occasionally rings when used by nurses to communicate with other departments.


The ceiling fixed air diffusers present in the physiology room has the similar moderate yet noticeable noise produced, but not till extend which will distract and affect the patients and nurses who are using the facilities as communication is still clearly hearable. Additionally, we observed that the velocity is not as powerful as the gymnasium as not much vigorous activities present in this block. Thus, a fainter noise is produced in this area.

4.3.2.3 Human noise

For this room, human noise level is considerably higher than the gymnasium due to the higher amount of patient and nurse interactions. Usually new patients are introduced to this area first to familiarize themselves to their trainings, thus many nurses are present to guide and motivate them to push through their limits, and therefore occasional loud grudges sound may occur in this area of space.

4.4 Tabulation & Interpretation of Data

The colors present in the table represent the respective zones in the colored plan. The reading were taken at the level of 1m

4.5 Acoustic Fixtures and Specifications

Item Type TreadmillProduct Name Biodex RTM600Weight 179kgSound Pressure Level 70 – 76 dB

Dimension 218cm x 69cm x 137cmPlacement Floor

Item Type TelephoneProduct Name Panasonic KX-550BWeight 495gSound Pressure Level 80dBDimension 9.6cm x 15cm x 20cmPlacement Table

Item Type SpeakerProduct Name JBL CSS-1S/TWeight 2000gSound Pressure Level 96 – 106 dBDimension 29cm x 15.9cm x 14.3cmPlacement Wall

–

Product Name Air DiffusersSound Pressure Level 40 – 50 dBPlacement Wall

Item Type BasinSound Pressure Level 40 dBDimension 47cm x 55 cmPlacement Wall

Item Type Computer Monitor

Product Name HP V241p LED MonitorWeight 3, 855gSound Pressure Level 35 dBDimension 55cm x 40cm x 5cmPlacement Table

Item Type Printer

Product Name HP Deskjet 1000 seriesWeight 3,600gSound Pressure Level 50 dBDimension 42.7cm x 30cm x 15.5cmPlacement Table

Item Type PrinterProduct Name HP Officejet 4000 seriesWeight 6,000gSound Pressure Level 55 dBDimension 44.5cm x 33cm x 17cmPlacement Wall

4.6 GYMNASIUM CALCULATION


To obtain the intensity of the sound of each noise source in order

By using formula, SIL = 10 log ( I Io )

Where I = the intensity of sound being measured, (W/m2 )

Io = the intensity of the threshold of hearing, taken as 10-12 W/m2

Air diffuser

The maximum sound power level of the air diffuser is 50dB.

SIL = 10 log (IacIo

)

50 = 10 log (IacIo

)

5.0 = log ( Iac / 1 x 10 -12)

105 = ( Iac / 1 x 10 -12)

Iac = 1 x 10 -12 x 105

Iac = 1 x 10 -7

The air diffuser sound intensity is 1 x 10 -7 W/m2

Treadmill Biodex RTM 600

The maximum sound power level of the treadmill is 76dB.

SIL = 10 log (ItmIo

)

76 = 10 log (ItmIo

)

7.6 = log ( Itm / 1 x 10 -12)

107.6 = ( Itm / 1 x 10 -12)

Itm = 1 x 10-12 x 107.6

Itm = 1 x 10-4.4

The treadmill sound intensity is 1 x 10-4.4 W/m2

Telephone Panasonic KX-550B

The maximum sound power level of the telephone is 80 dB.

SIL = 10 log ( ¿Io

)

80 = 10 log ( ¿Io

)

8.0 = log ( It / 1 x 10 -12)

108.0 = ( It / 1 x 10 -12)

It = 1 x 10-12 x 108.0

It = 1 x 10-4

The telephone sound intensity is 1 x 10-4 W/m2

Speaker JBL CSS-1S/T

The maximum sound power level of the speaker is 106dB

SIL = 10 log (IsIo

)

106 = 10 log (IsIo

)

10.6 = log ( Is / 1 x 10 -12)

1010.6 = ( Is / 1 x 10 -12)

Is = 1 x 10-12 x 1010.6

Is = 1 x 10-1.4

The speaker sound intensity is 1 x 10-1.4 W/m2

Basin

The maximum sound power level of the basin is 40 dB

SIL = 10 log (IbIo

)

40 = 10 log (IbIo

)

4.0 = log ( Ib / 1 x 10 -12)

104 = ( Ib / 1 x 10 -12)

Ib = 1 x 10-12 x 104

Ib = 1 x 10-8

The basin sound intensity is 1 x 10-8 W/m2

Human Activities

The maximum sound power level of the human activities is around 60 dB.

SIL = 10 log (IrIo

)

60 = 10 log (IrIo

)

6.0 = log ( Ir / 1 x 10 -12)

106.0 = ( Ir / 1 x 10 -12)

Ir = 1 x 10-12 x 106.0

Ir = 1 x 10-6

The human activities sound intensity is 1 x 10-6 W/m2

4.6.2 THE CALCULATION OF SOUND LEVEL

Air diffuser 1 x 10-7 W/m2 Telephone Panasonic KX-550B 1 x 10-4 W/m2

Basin 1 x 10-8 W/m2

Speaker JBL CSS-1S/T 1 x 10-1.4 W/m2

Treadmill Biodex RTM 600 1 x 10-4.4 W/m2 Human Activities 1 x 10-6 W/m2

The sound intensity of all indoor noise sources is calculated beforehand. The sound level of different zones can be calculated using data shown in table above and these formula,

I = I1 + I2 + I3 +…+ In and SIL = 10 log ( I Io ).



Zone 01: Rowling machine zone

Total intensity = 2 x air duct + 1 telephone + 2 human activities

= 2 x ( 1 x 10 -7) + 1 x 10-4 + 2 x (1 x 10-6 )= 1.022 x 10 -4 W/m2

SIL = 10 log (IIo

)

SIL = 10 log ( 1.022 X 10-4 / 1 x 10-12)

SIL = 80.10 dB

Zone 02: Bike riding area

Total intensity = 3 x air duct + 1 basin + 1 speaker + 2 human activities

= 3 x ( 1 x 10 -7) + 1 x 10-8 + 1 x 10-8 + 2 x (1 x 10-6 )

= 2.320 x 10 -6

SIL = 10 log (IIo

)

SIL = 10 log ( 2.320x10-6 / 1 x 10-12)

SIL = 63.65 dB

Zone 03: Multipurpose machine zone

Total intensity = 1 speaker + 2 human activities

= 1 x 10-8 + 2 x (1 x 10-6 )= 2.010 x 10-6 W/m2

SIL = 10 log (IIo

)

SIL = 10 log (2.01 x 10-6/ 1 x 10-12)

SIL = 63.03 dB

Zone 04: Treadmill area

Total intensity = 3 treadmill + 2 air duct + 1 speaker

= 3 x ( 1 x 10-4.4) + 2 x ( 1 x 10 -7) + 1 x 10-8

= 1.196 x 10-4 W/m2

SIL = 10 log (IIo

)

SIL = 10 log (1.196 x 10-4 / 1 x 10-12)

SIL = 80.78 dB

4.6.3 ANALYSIS AND EVALUATION

Zone 1: Rowling machine zone

Highest reading: 74dB

SIL = 10 log (I 1Io

)

74 = 10 log (I1 / 1 x 10-12)

7.4 = log (I1 / 1 x 10-12)

107.4 = (I1 / 1 x 10-12)

I1 = 1 x 10-12 x 107.4

I1 = 1 x 10-4.6 W/m2

Lowest reading: 58dB

SIL = 10 log (I 2Io

)

58 = 10 log (I2 / 1 x 10-12)

5.8 = 10 log (I2 / 1 x 10-12)

105.8 = (I2 / 1 x 10-12)

I2 = 1 x 10-12 x 105.8

I2 = 1 x 10-6.2 W/m2

Total intensity, I = 1 x 10-4.6 + 1 x 10-6.2 = 2.57 x 10 -5

SIL = 10 log (IIo

)

SIL = 10 log (2.57 x 10 -5/ 1 x 10-12)

SIL = 74.10 dB

The sound intensity level at Zone 1 is 74.10 dB.

Zone 2: Bike riding area

Highest reading: 77 dB

SIL = 10 log (I 1Io

)

77 = 10 log (I1 / 1 x 10-12)

7.7 = log (I1 / 1 x 10-12)

107.7 = (I1 / 1 x 10-12)

I1 = 1 x 10-12 x 107.7

I1 = 1 x 10-4.3 W/m2

Lowest reading: 63 dB

SIL = 10 log (I 2Io

)

63 = 10 log (I2 / 1 x 10-12)

6.3 = 10 log (I2 / 1 x 10-12)

106.3 = (I2 / 1 x 10-12)

I2 = 1 x 10-12 x 106.3

I2 = 1 x 10-5.7 W/m2


SIL = 10 log (IIo

)

SIL = 10 log (5.21 x 10 -5/ 1 x 10-12)

SIL = 77.17 dB


Zone 3: Multipurpose machine zone


SIL = 10 log (I 1Io

)

71 = 10 log (I1 / 1 x 10-12)

7.1 = log (I1 / 1 x 10-12)

107.1 = (I1 / 1 x 10-12)

I1 = 1 x 10-12 x 107.1

I1 = 1 x 10-4.9 W/m2


SIL = 10 log (I 2Io

)

54 = 10 log (I2 / 1 x 10-12)

5.4 = 10 log (I2 / 1 x 10-12)

105.4 = (I2 / 1 x 10-12)

I2 = 1 x 10-12 x 105.4

I2 = 1 x 10-6.6 W/m2


SIL = 10 log (IIo

)

SIL = 10 log (1.28 x 10 -5/ 1 x 10-12)

SIL = 71.07 dB


Zone 4: Treadmill area


SIL = 10 log (I 1Io

)

77 = 10 log (I1 / 1 x 10-12)

7.7 = log (I1 / 1 x 10-12)

107.7 = (I1 / 1 x 10-12)

I1 = 1 x 10-12 x 107.7

I1 = 1 x 10-4.3 W/m2


SIL = 10 log (I 2Io

)

62 = 10 log (I2 / 1 x 10-12)

6.2 = 10 log (I2 / 1 x 10-12)

106.2 = (I2 / 1 x 10-12)

I2 = 1 x 10-12 x 106.2

I2 = 1 x 10-5.8 W/m2


SIL = 10 log (IIo

)

SIL = 10 log (5.17 x 10 -5/ 1 x 10-12)

SIL = 77.13 dB


4.6.4 SOUND REDUCTION INDEX CALCULATION

Wall 1

Component Material Colour Finish Surface Area, m2

Sound Reduction

Index (500Hz)

Transmission Coefficient,

T = 1

log−1( R10

)

Wall Concrete White Smooth 15 50 1 x 10-5

Mirror Glass Transparent

Reflective 37.5 26 2.51 x 10-3

Sound Reduction index for each material of wall 1

T0=(T 1x A 1 )+ (T 2xA 2 )

A 1+A 2

T0= (1 x 10-5 x 15.0) + (2.51 x 10-3 x 37.5) / 15.0+37.5

T0= 1.80 x 10-3

R= 10 log (1T 0

)

R= 10 log (1

1.80x 10−3)

R= 10 log 555.56

R= 27.45 dB

The overall SRI for wall 1 is 27.45 dB

Sound Reduction Index: Wall 2


Sound Reduction

Index (500Hz)


T = 1

log−1( R10

)

Wall Concrete White Smooth 33.3 50 1 x 10-5

Door Glass Transparent Reflective 3.0 31 7.94 x 10-4

Window Glass Transparent Reflective 1.2 26 2.51 x 10-3

Sound Reduction index for each material on wall 2

T0=(T 1x A 1 )+ (T 2xA 2 )+(T 3 x A3 )

A1+A2+A 3

T0= (1 x 10-5 x 33.3) + (7.94 x 10-4 x 3.0) + (2.51 x 10-3 x 1.2) / 33.3+3.0+1.2

T0= 1.53x10-4

R= 10 log (1T 0

)

R= 10 log (1

1.53x 10−4)

R= 10 log 6535.95

R= 38.15 dB




Sound Reduction

Index (500Hz)


T = 1

log−1( R10

)


Door Glass Transparent

Reflective 3.0 31 7.94 x 10-4

Window Glass Transparent

Reflective 1.8 26 2.51 x 10-3


T0=(T 1x A 1 )+ (T 2xA 2 )+(T 3 x A3 )

A1+A2+A 3

T0= (1 x 10-5 x 47.7) + (7.94 x 10-4 x 3.0) + (2.51 x 10-3 x 1.8) / 47.7+3.0+1.8

T0= 1.41x10-4

R= 10 log (1T 0

)

R= 10 log (1

1.41x 10−4)

R= 10 log 7092.20

R= 38.51 dB



Sound Reduction

Index (500Hz)


T = 1

log−1( R10

)


Door Timber Brown Veneer 3.0 24 3.98 x 10-3


T0=(T 1x A 1 )+ (T 2xA 2 )

A 1+A 2

T0= (1 x 10-5 x 19.5) + (3.98 x 10-3x 3.0) / 19.5+3.0

T0= 5.40x10-4

R= 10 log (1T 0

)

R= 10 log (1

5.40x 10−4)

R= 10 log 1851.85

R= 32.68 dB



Gymnasium

Component

Material

Colour

Finish

Surface

Area, m2

Absorption

Coefficient

(500Hz)

Sound Absorption 500Hz

(m2

sabin)

Absorption

Coefficient

(2000Hz)

Sound Absorption 2000Hz

(m2

sabin)Wall Concret

eWhit

eSmo- oth

115.50

0.05 5.78 0.05 5.78

Ceiling Plaster Ceiling

White

Dott-ed

110.25

0.02 2.21 0.04 4.41

Floor Ceramic Tiles

Blue Smo-oth

110.25

0.01 1.10 0.02 1.10

Door Timber Light Brow

n

Vene-er

3.0 0.06 0.18 0.10 0.30

Door Glass Trans-

parent

Refle- fec-tive

6.0 0.06 0.36 0.03 0.18

Window Glass Trans-

parent

Refle- fec-tive

3.0 0.18 0.54 0.07 0.21

Mirror Glass Trans-

parent

Refle- fec-tive

37.5 0.06 2.25 0.03 1.13

People - - - 7 0.46 3.22 0.51 3.57Total Absorption(A) 15.64 16.68

Sound Absorption of different materials in gymnasium

Reverberation Time when absorption coefficient at 500Hz,

Room volume of Gymnasium, V = 10.5x10.5x5

= 551.25m3

Reverberation Time = (0.16 x V) / A

= (0.16 x 551.25) / 15.64

= 5.64s


Room volume of Gymnasium, V = 10.5x10.5x5

= 551.25m3


= (0.16 x 551.25) / 16.68

= 5.29s


Type of Occupancy & activities

Recommended Design Sound Level (dB)

Recommended Reverberation Time (s)

Gymnasium 35 1.00

In referring to AS/ZS 2107:2000 standard for sound levels and reverberation times for building interiors. We found out that the recommended design sound level should be average 35 dB. The recommended reverberation time is 1.00s.

Zones Sound Pressure Level (dB)

Reverberation Time(s) 500Hz

Reverberation Time(s) 2000Hz

Zone 1:Rowling machine zone

74.105.64 5.29

Zone 2:Bike riding area

77.17

Zone 3:Multipurpose machine zone

71.07

Zone 4:Treadmill area 77.13

From the table above, conclusion had been made. All the 4 zones in the gymnasium do not meet the minimum requirement of the acoustic standard. From the table above, Zone 2 has the highest sound pressure level due to the amount of furniture, human activities and external noise source from outdoor. However, Zone 3 has lowest sound pressure level due to lacking of human activities and there is no air diffuser locate on the top of the zone.

Recommended reverberation time for gymnasium (<750m3) is 1.00s. However, the reverberation time in this gymnasium is around 5.00s which does not meet the minimum requirement. This is due to the materials cannot absorb sounds efficiently or this space is too large with too less sound absorption materials.

In conclusion, the gymnasium area in this building is huge leap the acoustic standard. Some improvement should be taken to lower down the sound pressure level in this gymnasium.

4.8 PHYSIOTHERAPY CALCULATION


To obtain the intensity of the sound of each noise source in order

By using formula, SIL = 10 log ( I Io )



BASIN

The maximum sound power level of the basin is 40 dB

SIL = 10 log (IbIo

)

40 = 10 log (IbIo

)

4.0 = log ( Ib / 1 x 10 -12)

104 = ( Ib / 1 x 10 -12)

Ib = 1 x 10-12 x 104

Ib = 1 x 10-8

The basin sound intensity is 1 x 10-8 W/m2

AIR SUPPLY DIFFUSER

The maximum sound power level of the diffuser is 50dB.

SIL = 10 log (IacIo

)

50 = 10 log (IacIo

)

5.0 = log ( Iac / 1 x 10 -12)

105 = ( Iac / 1 x 10 -12)

Iac = 1 x 10 -12 x 105

Iac = 1 x 10 -7

The air duct sound intensity is 1 x 10 -7 W/m2

TELEPHONE

The maximum sound power level of the telephone is 80 dB.

SIL = 10 log ( ¿Io

)

80 = 10 log ( ¿Io

)

8.0 = log ( It / 1 x 10 -12)

108.0 = ( It / 1 x 10 -12)

It = 1 x 10-12 x 108.0

It = 1 x 10-4

The telephone sound intensity is 1 x 10-4 W/m2

COMPUTER

The maximum sound power level of the computer is 35 dB.

SIL = 10 log (IcIo

)

35 = 10 log (IcIo

)

3.5 = log ( Ic / 1 x 10 -12)

103.5 = ( Ic / 1 x 10 -12)

Ic = 1 x 10-12 x 103.5

Ic = 1 x 10-8.5

The computer sound intensity is 1 x 10-8.5 W/m2

HP DESKJET PRINTER

The maximum sound power level of the deskjet printer is 50 dB.

SIL = 10 log (IpIo

)

50 = 10 log (IpIo

)

5.0 = log ( Ip / 1 x 10 -12)

105.0 = ( Ip / 1 x 10 -12)

Idp = 1 x 10-12 x 105.0

Idp = 1 x 10-7

The deskjet printer sound intensity is 1 x 10-7 W/m2

HP OFFICEJET PRINTER

The maximum sound power level of the officejet printer is 55 dB.

SIL = 10 log (IpIo

)

55 = 10 log (IpIo

)

5.5 = log ( Ip / 1 x 10 -12)

105.5 = ( Ip / 1 x 10 -12)

Iop = 1 x 10-12 x 105.5

Iop = 1 x 10-6.5

The officejet printer sound intensity is 1 x 10-6.5 W/m2

Human Activity

The maximum sound power level of the human activity is 50 dB.

SIL = 10 log (IhaIo

)

60 = 10 log (IhaIo

)

6.0 = log ( Iha / 1 x 10 -12)

106.0 = ( Iha / 1 x 10 -12)

Idp = 1 x 10-12 x 106.0

Idp = 1 x 10-6

The human activity sound intensity is 1 x 10-6 W/m2

4.8.2 CALCULATION OF SOUND LEVEL

Calculate to obtain the sound level in different zones to compare with the collected data.

Indoor Noise Sources Sound Intensity (w/m2)Basin, Ib 1 x 10-8 W/m2

Air Supply Diffuser, Iac 1 x 10 -7 W/m2

Telephone, It 1 x 10 -4 W/m2

Computer, Ic 1 x 10 -8.5 W/m2

HP Deskjet Printer, Idp 1 x 10 -7 W/m2

HP Officejet Printer, Iop 1 x 10 -6.5 W/m2

Human Activity, Iha 1 x 10 -6 W/m2

The sound intensity of all indoor noise sources is calculated beforehand. The sound level of different zones can be calculated using data shown in table above and these formulas,

I = I1+I2+I3+…+In and SIL = 10 log (110

)

Where I = the intensity of sound being measured, (W/m2)

Io = the intensity of threshold of hearing, taken as 10-12 W/m2

Zone 1 : Robotic Gait Area (Worst case scenario)

(1 x Basin) + (10 x Air Diffuser) + (2 x Telephone) + (1 x Computer) + (1 x Officejet Printer) + (4 x Human Activity)

Total intensity, I = (1 x Ib) + (10 x Iac) + (2 x It) + (1 x Ic) + (1 x Iop) + (4 x Iha)

= (1 x 1 x 10-8) + (10 x 1 x 10 -7) + (2 x 1 x 10 -4) + (1 x 1 x 10 -8.5) +

(1 x 1 x 10 -6.5) + (4 x 1 x 10 -6)

= 2.05 x 10-4 W/m2

SIL = 10 log (IIo

)

= 10 log (2.05 x 10-4 / 1 x 10-12)

= 83.12 dB

Hence, the sound intensity level in this area is 83.12 dB.

Zone 2 : Open Therapy Area (Worst case scenario)

(2 x Basin) + (5 x Air Diffuser) + (1 x Computer) + (1 x Deskjet Printer) + (4 x Human Activity)

Total intensity, I = (2 x Ib) + (5 x Iac) + (1 x Ic) + (1 x Idp) + (4 x Iha)

= (2 x 1 x 10-8) + (5 x 1 x 10 -7) + (1 x 1 x 10 -8.5) +(1 x 1 x 10 -7) + (4 x 1 x 10 -6)

= 4.62 x 10-6 W/m2

SIL = 10 log (IIo

)

= 10 log (4.62 x 10-6 / 1 x 10-12)

= 66.65 dB


Zone 3 : Staff Base Area (Worst case scenario)

(1 x Basin) + (2 x Air Diffuser) + (2 x Telephone) + (3 x Computer) + (1 x Human Activity)

Total intensity, I = (1 x Ib) + (2 x Iac) + (2 x It) + (3 x Ic) + (1 x Iha)

= (1 x 1 x 10-8) + (2 x 1 x 10 -7) + (2 x 1 x 10 -4) + (3 x 1 x 10 -8.5) + (1 x 1 x 10 -6)

= 2.01x10-4 W/m2

SIL = 10 log (IIo

)

= 10 log (2.01 x 10-4 / 1 x 10-12)

= 83.03 dB


Zone 4 : Neuro Assessment Area (Worst case scenario)

(1 x Air Diffuser) + (1x Computer) + (1 x Human Activity)

Total intensity, I = (1 x Iac) + (1 x Ic) + (1 x Iha)

= (1 x 1 x 10 -7) + (1 x 1 x 10 -8.5) + (1 x 1 x 10 -6)

= 1.01x10-6 W/m2

SIL = 10 log (IIo

)

= 10 log (1.01x10-6 / 1 x 10-12)

= 60.04 dB



Zone 1 : Robotic Gait Area

Highest Reading : 68 dB

SIL = 10 log (I 1Io

)

68 = 10 log (I1 / 1 x 10-12)

106.8 = (I1 / 1 x 10-12)

I1 = 106.8 x 1 x 10-12

I1 = 6.31 x 10-6 W/m2

Lowest Reading : 51

SIL = 10 log (I 1Io

)

51 = 10 log (I1 / 1 x 10-12)

105.1 = (I1 / 1 x 10-12)

I1 = 105.1 x 1 x 10-12

I1 = 1.26 x 10-7 W/m2

Total Intensity,

I = (6.31 x 10-6) + (1.26 x 10-7)

= 6.44 x 10-6 W/m2

SIL = 10 log (IIo

)

= 10 log (6.44 x 10-6 / 1 x 10-12)

= 68.09 dB

The sound intensity level at Robotic Gait Area (Zone 1) is 68.09 dB.

Zone 2 : Open Therapy Area


SIL = 10 log (I 1Io

)

68 = 10 log (I1 / 1 x 10-12)

106.8 = (I1 / 1 x 10-12)

I1 = 106.8 x 1 x 10-12

I1 = 6.31 x 10-6 W/m2

Lowest Reading : 52

SIL = 10 log (I 1Io

)

52 = 10 log (I1 / 1 x 10-12)

105.2 = (I1 / 1 x 10-12)

I1 = 105.2 x 1 x 10-12

I1 = 1.59 x 10-7 W/m2

Total Intensity,

I = (6.31 x 10-6) + (1.59 x 10-7)

= 6.47 x 10-6 W/m2

SIL = 10 log (IIo

)

= 10 log (6.47 x 10-6 / 1 x 10-12)

= 68.11 dB

The sound intensity level at Open Therapy Area (Zone 2) is 68.11 dB.

Zone 3 : Staff Base Area


SIL = 10 log (I 1Io

)

63 = 10 log (I1 / 1 x 10-12)

106.3 = (I1 / 1 x 10-12)

I1 = 106.3 x 1 x 10-12

I1 = 2.00 x 10-6 W/m2

Lowest Reading : 51

SIL = 10 log (I 1Io

)

51 = 10 log (I1 / 1 x 10-12)

105.1 = (I1 / 1 x 10-12)

I1 = 105.1 x 1 x 10-12

I1 = 1.26 x 10-7 W/m2

Total Intensity,

I = (2.00 x 10-6) + (1.26 x 10-7)

= 2.13 x 10-6 W/m2

SIL = 10 log (IIo

)

= 10 log (2.13 x 10-6 / 1 x 10-12)

= 63.28 dB

The sound intensity level at Staff Base Area (Zone 3) is 63.28 dB.

Zone 4 : Neuro Assessment Area


SIL = 10 log (I 1Io

)

68 = 10 log (I1 / 1 x 10-12)

106.8 = (I1 / 1 x 10-12)

I1 = 106.8 x 1 x 10-12

I1 = 6.31 x 10-6 W/m2

Lowest Reading : 56

SIL = 10 log (I 1Io

)

56 = 10 log (I1 / 1 x 10-12)

105.6 = (I1 / 1 x 10-12)

I1 = 105.6 x 1 x 10-12

I1 = 3.98 x 10-7 W/m2

Total Intensity,

I = (6.31 x 10-6) + (3.98 x 10-7)

= 6.71 x 10-6 W/m2

SIL = 10 log (IIo

)

= 10 log (6.71 x 10-6 / 1 x 10-12)

= 68.27 dB

The sound intensity level at Neuro Assessment Area (Zone 4) is 68.27 dB.

4.8.4 SOUND REDUCTION INDEX CALCULATION

Wall 1

Component Material Color Finish Surface Area,m2

Sound ReductionIndex(500Hz)

Transmission Coefficient, T

T=1

log−1( R10

)

Wall Concrete Light blue Smooth 54.36 50 1.00 x 10-5



T0 = (T 1x A 1 )+(T 2 x A2)

A1+A2

T0 = (1.00 x 10-5 x 54.36) + (2.51 x 10-3 x 1.44) / 54.36 + 1.44

= 4.16 x 10-3 / 55.8

= 7.46 x 10-5

SRI = 10 log (1T 0 )

= 10 log (1 / 7.46 x 10-5)

= 41.27 dB

Hence, the overall SRI is 41.27 dB.

Wall 2




T=1

log−1( R10

)

Wall Concrete White Smooth 38.25 50 1.00 x 10-5

Door Glass Transparent Reflective 3.6 31 7.94 x 10-4


T0 = (T 1x A 1 )+(T 2 x A2)

A1+A2

T0 = (1.00 x 10-5 x 38.25) + (7.94 x 10-4 x 3.6) / 38.25 + 3.6

= 3.24 x 10-3 / 41.85

= 7.74 x 10-5

SRI = 10 log (1T 0 )

= 10 log (1 / 7.74 x 10-5)

= 41.11 dB


Wall 3




T=1

log−1( R10

)

Wall Concrete White Smooth 45 50 1.00 x 10-5



T0 = (T 1x A 1 )+(T 2 x A2)

A1+A2

T0 = (1.00 x 10-5 x 45) + (2.51 x 10-3 x 10.8) / 45 + 10.8

= 0.028 / 55.8

= 5.02 x 10-4

SRI = 10 log (1T 0 )

= 10 log (1 / 5.02 x 10-4)

= 32.99 dB


Wall 4




T=1

log−1( R10

)

Wall Concrete White Smooth 7.5 50 1.00 x 10-5

Door Timber Light Brown Smooth 1.8 24 3.98 x 10-3


T0 = (T 1x A 1 )+(T 2 x A2)

A1+A2

T0 = (1.00 x 10-5 x 7.5) + (3.98 x 10-3 x 1.8) / 7.5 + 1.8

= 7.24 x 10-3 / 9.3

= 7.79 x 10-4

SRI = 10 log (1T 0 )

= 10 log (1 / 7.79 x 10-4)

= 31.09 dB


Component

Material Color Finish Surface Area, m2

Absorption Coefficient(500Hz)

Sound Absorption(500Hz) (m2 sabin)

Absorption Coefficient(2000Hz)

Sound Absorption(200Hz) (m2 sabin)

Wall Concrete

White, Light Blue

Smooth 145.11 0.05 7.26 0.05 7.26

Ceiling Plaster Ceiling

White Dotted 243 0.02 4.86 0.04 9.72

Floor Ceramic Tiles

Blue Veneer 243 0.01 2.43 0.02 4.86

Door Timber Light Brown

Veneer 1.8 0.06 0.11 0.10 0.18

Door Glass Transparent

Reflective

3.6 0.06 0.22 0.03 0.11

Window Glass Transparent

Reflective

12.24 0.18 2.2 0.07 0.86

People - - - 10 0.46 4.6 0.51 5.1Total Absorption (A) 21.68 28.09

4.8.5 REVERBERATION TIME CALCULATION


Room volume of Gymnasium, V = 13.5x18x3.1

= 753.3m3


= (0.16 x 753.3) / 21.68

= 5.56s


Room volume of Gymnasium, V = 13.5x18x3.1

= 753.3m3


= (0.16 x 753.3) / 28.09

= 4.29s

4.9 Acoustic Analysis for Physiotherapy

Type of Occupancy & activities

Recommended Design Sound Level (dB)

Recommended Reverberation Time (s)

Physiotherapy 30 1.00 - 1.25

Table 4.2.6l: AS/NZS 2107:2000

In referring to AS/NZS 2107:2000 standard for sound levels and reverberation times for building interiors. We found out that the recommended design sound level should be 40-45dB range. As for the recommended reverberation time is 0.4 to 0.6s.

Zones Sound Pressure Level (dB)

Reverberation Time 500Hz (S)

Reverberation Time 2000Hz (S)

1 : Robotic Gait Area 68.09

5.56 4.29

2 : Open Therapy Area

68.11

3 : Staff Base Area 63.284 : Neuro Assessment Area

68.27

From the summary table above, we can conclude that all the 4 zones in the Physiotherapy Room exceeds and even doubled up the minimum requirement of the acoustic standard.

From the table, the Neuro Assessment Area is the one with the highest sound pressure level. This is because there are 3 sides of walls covering it, where other spaces only covered by 2 sides of walls. This cause the area become more enclosed and thus with higher Sound Pressure. Besides, the Staff Base Area is the one having the lowest sound pressure level. This is due to the fact that they are open space instead of enclosed space like the zone 4, Neuro Assessment Area.

As a conclusion, the Physiotherapy Room is designed in an open plan manners, all the zones are connected and function as multipurpose. From the table we can understand that, the sound pressure level in this room is actually greatly higher than the recommended standard. In a nutshell, improvement such as acoustic ceiling and wall panel can be installed to better improve the acoustic environment of the office.

5.0 ReferenceZ. Maekawa, & P. Lord. (1994). Environmental and Architectural Acoustics. London: E &FN Spon.

Salvan, G. S. (1999). Architectural Utilies 3. Quezon City: JMC Press.

Sound Is A Pressure Wave. (2015). Retrieved from The Physics Classroom:http://www.physicsclassroom.com/class/sound/Lesson-1/Sound-is-a-PressureWave

Physics Communication Using Waves. (2014). Retrieved from BBC:http://www.bbc.co.uk/bitesize/standard/physics/telecommunications/communication_using_waves/revision/5/

M. B. (2010). Acoustics and Architectural Design. Taylor & Francis e-Library: New York

L. M. (2014). Architectural Acoustics. USA: Elsevier Inc.

Brooks, C. N. (2003). Architectural Acoustics. US: McFarland Company, Inc.

Absorption Coefficient Chart - Soundproof Your Home. (n.d.). Retrieved May 31, 2016, from http://soundproofyourhome.com/absorption-coefficient-chart/

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http://l.facebook.com/l.php?u=http%3A%2F%2Fwww.bbc.co.uk%2Fbitesize%2Fstandard%2Fphysics%2Ftelecommunications%2Fcommuni&h=RAQGXe6C8

http://l.facebook.com/l.php?u=http%3A%2F%2Fwww.physicsclassroom.com%2Fclass%2Fsound%2FLesson-1%2FSound-is-a-PressureWave&h=RAQGXe6C8

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acoustic analysis project 1

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