Building science- Lighting and acoustic performance evaluation and design

Building Science Lighting and acoustic performance Evaluation & Design

Lecturer: Mr. Sivaraman Kuppusamy

Members: Alisha Niazali Hirani 0314325 Alvin Mungur 0316886 Melissa Anne Mei Hong Li 0320729 Muhammad Mubarak 0319984 Muhammad Nabeel Ali Joomun 0320583 Saurabha Iyer 0320569

List of Figures Fig 1.0

D’Kaffe location……………………………………………………..…………………...8

Fig 1.1

Interior spaces of………………………………………………….……………………..8

Fig 1.2

Zoning of spaces…………………………………………………………………..….....9

Fig 2.0.

(Left): Floor plan of Towers A and B. (Right): Floor plan of chosen unit in tower A...19

Fig. 2.2. Relationship between %DF and WFR to illumination level of R1-R4………………..21 Fig 2.3

Zoning of spaces​……………………………………………………………...………….21

Fig 2.4

Natural light contour diagram at 4 pm with a clear sky………………………………..25

Fig 2.5

Artificial light contour diagram of D’Kaffe………………………….…………………...28

Fig 2.6

Zone A interior…………………………………………………………………….……..36

Fig 2.7

Outdoor seating area…………………………………………………………....………37

Fig 2.8

Section cut of Zone A during peak and non-peak hours……………………..……….37

Fig 2.9

Artificial light contour diagram for zone A…………………………………...…………39

Fig 2.10

Furniture at Private Lounge……………………………………………....……………40

Fig 2.11

Lounge area………………………………………………………….………………....40

Fig 2.12

Section cut of zone B during non-peak hours………………………………....……...42

Fig 2.13

Artificial light contour diagram for Zone B……………………………………………..42

Fig 2.14

Section cut of zone C…………………………………………………………………..44

Fig 2.15

Artificial light contour diagram for Zone C…………………………………………….44

Fig 2.16

Zone D bar area………………………………………………………………………..45

1

Fig 2.17

Views of the bar area ………………………………………………………….………45

Fig 2.18

Section cut of zone D…………………………………………………………………..47

Fig 2.19

Artificial light contour diagram for Zone D…………………………………………….47

Fig 2.20

Zone E interior…………………………………………………………………………..48

Fig 2.21

Section cut of Zone E…………………………………………………………………..50

Fig 2.22

Artificial light contour diagram for Zone E………………………………………….....50

Fig 2.23

Zone F: Kitchen area…………………………………………………………………...51

Fig 2.24

Section cut of Zone F…………………………………………………………………...53

Fig. 2.25 Artificial light contour diagram for Zone F………………………………………….….53 Fig 3.0.

Boundary noise measurements………………………………………………………..60

Fig. 3.1

Sitemap with outdoor noise sources……………………………………………….….66

Fig. 3.2

Speaker position……………………………………………………………………..…67

Fig 3.3

Coffee machine position………………………………………………………………..68

Fig 3.4 ​

​Dart machine positions………………………………………………………………...69

Fig 3.5

Bar during peak hour…………………………………………………………...……....70

Fig 3.6

Noise sources from human activity…………………………………………………….70

Fig. 3.7

Air conditioners position………………………………………………………………...71

Fig 3.8

Bar counter ……………………………………………………………………………..72

Fig. 3.9

Sound source from bar………………………………………………………………....72

Fig 3.10

Section of zone A……………………………………………………………………….77

2

Fig 3.11

Acoustic ray diagram for outdoor noise………………………………………………..77

Fig 3.12

Acoustic diagram for zone A and B……………………………………………………77

Fig 3.13

Section of zone A……………………………………………………………………….79

Fig 3.14

Acoustic ray diagram for outdoor noise……………………………………………….79

Fig 3.15

Acoustic ray diagram for zone A and B……………………………………………….79

Fig 3.16

Section of zone B……………………………………………………………………….81

Fig 3.17

Acoustic ray diagram for outside noise………………………………………………..81

Fig 3.18

Acoustic ray diagram for zone A and B………………………………………………..81

Fig 3.19

Section of zone B……………………………………………………………………….83

Fig 3.20

Acoustic ray diagram for outside noise……………………………………………......83

Fig 3.21

Acoustic ray diagram for zone A and B………………………………………………..83

Fig 3.22

Section of zone C……………………………………………………………………….85

Fig 3.23

Section of zone C……………………………………………………………………….87

Fig 3.24

Section of zone D……………………………………………………………………….89

Fig 3.25

Section of zone D……………………………………………………………………….91

Fig 3.26

Section of zone E……………………………………………………………………….93

Fig 3.27

Acoustic ray diagram of zone E………………………………………………………..93

Fig 3.28

Section of zone E……………………………………………………………………….95

Fig 3.29

Acoustic ray diagram for zone E……………………………………………………….95

Fig 3.30

Section of zone F……………………………………………………………………….97

3

Fig 3.31

Section of zone F………………………………………………………………………99

4

List of Tables Table 1.0

Material details with absorption coefficients and reflectance values……...10

Table 2.0

Average daylight factor, appearance and energy implications ..................15

Table 2.1 Tower A WFR, %DF and illumination according to the effective floor area..19 Table 2.2

Natural and artificial illumination readings at 4pm………………………….26

Table 2.3

Artificial illumination readings at 9pm………………………………………..26

Table 2.4

Wall mounted LED light specifications………………………………………..31

Table 2.5

Chandelier candle LED light specifications………………………………….32

Table 2.6

LED spotlight specifications…………………………………………………...33

Table 2.7

Fluorescent light tube specifications………………………………………….34

Table 2.8

LED strip light specifications…………………………………………………..35

Table 3.0.

Summary of indoor noise measurement……………………………………..61

Table 3.1.

Summary of measurements of RTs…………………………………………..61

Table 3.2

Speaker specifications…………………………………………………………67

Table 3.3

Coffee machine specifications………………………………………………...68

Table 3.4

Dart machine specifications …………………………………………………..69

Table 3.5

Air conditioner specifications ………………………………………………….71

5

Contents 1.0 Introduction ……………………………………………………………………………07 1.1 Aims and objectives ………………………………………………………….07 1.2 Case Study: D’Kaffé ………………………………………………………….08 1.3 Zoning of the space …………………..………………………………………09 1.4 Materials in the space……………………………………………….………..10 2.0 Lighting ………………………………………………………………………………...12 2.1 Literature review……………………………………………………………….13 2.2 Precedent study (Journal research) …………………………..…………….18 2.3 Methodology for the case study……………………………………………..23 2.4 Data collection and results ……………….………………………………….25 2.5 Calculations …………………………………………………………………….27 2.6 Conclusion …...……………………..….……………………………………...54 3.0 Acoustics ……………………………………………………………………………….55 3.1 Literature review………………………………………………………………...56 3.2 Precedent study (Journal research) ………………………………..………...59 3.3 Methodology for the case study ……………………………………………...65 3.4 Data collection and results ………………………………………………….…67 3.5 Calculations……………………………………………………………………...74 3.6 Conclusion ……………………………………………………………………...111 4.0 References ……………………………………………………………………………...112

6

1.0 Introduction

Lighting at work is an important aspect to keep in mind while designing a building/space.

Lighting affects the health and safety of the people who occupy it. We can avoid major hazards with good lighting. Poor lighting within the building could cause health issues such as migraine, eyestrain and headaches. Suitable lighting is necessary to create the optimum environmental conditions for maximum productivity of the workers.

Acoustics design is another important factor in order to control the levels of noise within spaces.

Requirements for every space may be different based on its use of function. A good acoustic design preserves the desired noise and eliminates the unwanted sound to provide a perfect and comfortable environment for the users.

In a group of six, we choose D’kaffé as our site of study. We visited the café in order to collect all the data, which include measured drawings of the plan, measurement of lighting and acoustics.

1.1 Aims and objectives of the assignment ●

To understand the lighting and acoustic characteristics & requirement in a suggested space.

●

To critically report and analyze the space.

●

Able to produce a complete documentation on analysis of space in relation to lighting requirement eg. Natural and artificial lighting. (Pictures, sketches and drawing) and analysis of factors which effects the lighting design of a space.

●

Explore and apply understanding of building physic eg. Lighting towards building / construction technology and building materials on existing building projects.

●

Basic understanding and analysis of lighting layout and arrangements by using certain methods or calculations eg. Lumen method and PSALI.

●

Basic understanding and analysis of acoustic design layout and arrangements by using certain methods or calculations eg. Reverberation time and sound transmission coefficient.

7

1.2 Case Study: D’Kaffé Located in the commercial part of dk senza condominium D’Kaffé is a bar and café which caters to mostly students and young adults. On many occasions it has karaoke nights and open mic events. Besides that, one of the reasons of selecting this place was to notice the things wrong or right with the sound and acoustics with a place we regularly visit. It is a place all our group member regularly go for food but still ignore the basic things like sound and lighting of the place.

The café does not have a lot of openings and has a clearly visible lighting problem which we could prove with our findings and research. One more reason is the various materials used in the café. The variety of lights used.

Fig 1.0 D’Kaffe location

Fig 1.1 Interior spaces of D’kaffe

8

1.3 Zoning of the Space

Fig 1.2 Zoning of spaces

Zone A- Entrance and stage Zone B- Lounge Zone C- Lounge Zone D- Bar Zone E- Dining and games Zone F- Kitchen

9

1.4 Materials in the space

MATERIAL​​

DETAILS​​

ABSORPTION COEFFICIENT (500Hz)​​

REFLECTANCE VALUE​​

​0.03

20-30%​

​0.05

20-30%​

​0.1

20-40%​

​ Clay brick

Color: Red​ ​

Texture: Matte​

​ Concrete finish​​

Color: Grey​ ​

Texture: Semi glossy​ Rough​

Faux stone brick​ ​

Color: Grey​ Texture: ​ Matte​ Rough​ ​

​

10

MATERIAL​​

DETAILS​​

ABSORPTION COEFFICIENT (500 Hz)​​

REFLECTANCE VALUE​​

​0.03

20-40%​

​0.05

40%​

​0.06

70%​

​ Silica brick​

Color: White​ ​

Texture: Matte​

Concrete floor​

Color: Grey​ ​

Texture: Semi glossy​ Rough​

​ False ceiling​ ​

Color: Light grey​ Texture: ​ Matte​ Rough​ ​

​

Table 1.0 Material details with absorption coefficients and reflectance values

11

2.0 LIGHTING

12

2.1 Lighting Literature Review

Electromagnetic ​radiation occurs over an extremely wide range of ​wavelengths​, from ​gamma rays with wavelengths less than about 1 × 10​−11 metre to ​radio waves measured in metres.

Within that broad ​spectrum the wavelengths visible to humans occupy a very narrow band, from about 700 nanometres (nm; billionths of a metre) for ​red light down to about 400 nm for violet light. (Stark, 2016)

2.1.1 Light in architecture Light is the most important factor in the appreciation and understanding of Architecture. The relationship between light and architecture is grounded in the principles of physics; it is about energy and matter but in this particular case it also implies an emotional effect on people. The quality of lighting in a space defines its character and creates impressions. The human eye perceives its form through the incidence and reflection of light and in that way acquires information about the ambiance in a given place. Visual impressions are interpreted in our brains and put in context to create emotions that move us to take particular actions. (Palacio, 2015)

2.1.1.1 Lumen Lumen (lm) is the ​SI derived unit of ​luminous flux​, a measure of the total quantity of visible light emitted by a source. Luminous flux is ​weighted according to a model of the human eye​'s sensitivity to various ​wavelengths​. Lumens are related to ​lux in that one lux is one lumen per square meter.​ Brighter lights have a higher lumen value than dim lights.

2.1.1.2 Illuminance Illuminance describes the measurement of the amount of light falling onto (illuminating) and spreading over a given surface area. Illuminance also correlates with how humans perceive the brightness of an illuminated area. Illuminance refers to a specific kind of light measurement. The SI unit for illuminance is lux (lx). (Konica Minolta, 2016)

13

2.1.2 Artificial lighting Artificial light sources are categorized by the technology used to produce the light. It converts electrical energy to produce light and heat (N/A, 2013). Artificial lighting can create different experience and ambience to a space. There's dozens of sources, with a few common in household applications and others more suitable for industrial uses. The five most common light sources are as follows: 1. Incandescent lamp.

2. Compact fluorescent lamp.

3. Fluorescent tube.

4. Discharge lamps.

5. Light Emitting Diode (LED).

2.1.3 Natural daylighting Daylighting is any light that the sun produces and that strikes the earth both directly or indirectly. It is a controlled admission of natural light into a building. Daylighting helps create a visually stimulating and productive environment while reducing buildings’ energy costs. A Daylighting system consists of daylight-responsive lighting controlled systems as well as apertures such as windows and skylights. ( Ander, 2014)

2.1.4 Daylight Factors and Distribution The daylight factor (DF) is commonly used to determine the ratio of internal light level to external light level. The following expression is used: DF =

Ei E0

x 100%

Where: DF = Daylight Factor

Ei = illuminance due to daylight at a point on the indoor working plane E0 = Simultaneous outdoor illuminance on a horizontal plane from an unobstructed hemisphere of overcast sky

14

Average DF

Appearance

Energy Implications

< 2%

room looks gloomy

Electric lighting needed most of the day

2% to 5%

Predominantly daylit appearance, but supplementary artificial lighting is needed.

Good balance between lighting and thermal aspects

> 5%

Room appears strongly day lit

Daytime electric lighting rarely needed, but potential for thermal problems due to overheating in summer and heat losses in winter

Table 2.0 Average daylight factor, appearance and energy implications (Comfortable Low Energy Architecture , N/D)

15

2.1.5 Lumen Method Lumen Method is a simplified method to calculate the light level in a room. The method is a series of calculations that uses horizontal illuminance critâ&#x20AC;&#x2039;eria to establish a uniform luminaire laâ&#x20AC;&#x2039;yout in a space. Lumen Method is a calculation used to identify the number of luminaires or light fixtures required to achieve a given average illuminance level of space (McKeegan, 2013). It is expressed: N=

ExA F x UF x MF

Where: N = Number of lamps required E = Illuminance level required (lux) A = Area at working plane height (m2) F = Average luminous flux from each lamp (lm) UF = Utilization factor, an allowance for the light distribution of the luminaire and the room surfaces MF: Maintenance factor, an allowance for reduced light output because of deterioration.

2.1.6 Room Index Room Index (RI) is a ration of room plan area to half the wall area between the working and luminaire planes. It is expressed: RI =

LxW Hm x (L + W)

Where: L = length of Room W = Width of Room Hm = Mounting Height (i.e the vertical distance between the working plan and the luminaire)

16

2.1.7 Maintenance Factor The â&#x20AC;&#x2039;maintenance factor is defined as the ratio of illuminance produced by a lighting system after a certain period of time to the illuminance produced by the system when new.

MF= LLMF x LSF x LMF x RSMF

Where: LLMF= Light Lumen Maintenance Factor LSF = Lamp Survival Factor LMF = Luminaire Maintenance Factor RSMF = Room Surface Maintenance Factor Note: When MF cannot be found the value 0.8 is used.

17

2.2 Precedent Study (Journal Research)

Relationship between Window to Floor Area Ratio and Single Point Daylight Factor in Varied Residential Rooms in Malaysia

2.2.1 Introduction An effective use of daylight within a building enables its occupants to enjoy an indoor environment that is aesthetically pleasing while also reducing the energy required for artificial lighting systems and therefore leads to a more sustainable building design. A naturally illuminated indoor environment is influenced by many design aspects; one of which is window design. Window design depends on the optimization of the ‘glazed area’ for visual comfort without glare while window positioning also plays an important role in the distribution of daylight levels. (Nedhal, Syed, & Adel, 2016) The Malaysian Uniform Building By-Law #39 (1) states that, ‘Every room designed, adapted or used for residential, business or other purposes shall be provided with natural lighting and natural ventilation by means of one or more windows having a total area of not less than 10% of the clear floor area.’ This requirement is depicted by the window-to-floor-area ratio (WFR).

Furthermore, the by-law mentioned is investigated by determining the relationship between WFR and daylight levels in terms of the percentage of Daylight Factor (%DF). The minimum WFR as stated in the by-law is assessed by: 1. Determining whether a WFR less than 10% is indeed adequate for lighting purposes.

2. Whether a maximum WFR should be imposed to avoid over-lit spaces.

2.2.2 Case Study and Data Collection The View Condominium also known as the Penang Twin Towers was selected as the case study for this journal. The condominium located in the Batu Uban area in Penang, Malaysia, was chosen for its unique design, variety of room configurations/layouts, different window

18

shapes and glass areas which give a wide range of WFR values. The residential scheme consists of 2 towers A and B oriented Southeast and Northeast respectively and are connected via a skybridge on the 14​th floor. There is a total of 164 units with each floor consisting of 3 residential units. One Unit in Tower A was chosen for the study; the rooms in the unit are labeled R1, R2, R3 and R4 as shown in Figure 2.0

Fig 2.0. (Left): Floor plan of Towers A and B. (Right): Floor plan of chosen unit in tower A.

Data collection was conducted using Babuc/A data logger connected to an indoor lux meter probe (E​i​) placed at the center of each room (R1-R4) at 1m above floor level and an outdoor lux meter probe (E​o​). Readings were continuously collected at set time intervals from the months of April till July. Direct sunlight penetration was countered by considering data collected only at high sun altitude which was observed to be from 10.30am – 3.30pm. It is also important to mention that in this case, all rooms were emptied of any furniture and curtains/blinds to avoid internal reflective components. The reflectance factors of walls, floors and ceilings were kept as originally specified.

In this case, only one data point for %DF was measured per room due to limitations in available equipment. Also, due to the irregularly shaped rooms, correction factors were required when determining the WFR values. Window and floor areas needed to be the ‘effective WFR’ influenced by the single %DF point in the middle and not the overall WFR of the entire room because not all light from the window is reflected onto the single-point %DF in the center of the

19

room. Table 2.1 shows the effective floor areas and WFR values of R1 to R4 along with their respective minimum, maximum and average %DF as well as illumination levels in lux.

Table 2.1. Tower A WFR, %DF and illumination according to the effective floor area.

(Nedhal, Syed, & Adel, 2016)

20

2.2.3 Analysis and discussion Figure 2.1 below ranks the rooms according to their effective WFR. From this, all rooms satisfy UBBL #39 (1) because all of them have WFR values greater than 10%. Also, WFR significantly influences the single point %DF and illumination levels – The higher the WFR, the higher the single point average %DF.

Fig 2.1 Tower A Rooms ranking according to WFR (Nedhal, Syed, & Adel, 2016)

To further determine the relationship between %DF to WFR and natural illumination levels (E​i​) to WFR, regression studies were conducted according to the following condition: %DF=SC+IRC

Fig. 2.2. Relationship between %DF and WFR to illumination level of R1-R4 (Nedhal, Syed, & Adel, 2016)

21

In Figure 2.2, the blue lines pertain to units at the topmost floors of the tower where SC values are high. In terms of absolute natural illuminance levels in lux, were found to be over-lit due to the presence large areas of glass and hence high WFR values. Therefore, designers of high rise buildings with daylighting situations where SC values are high, should be cautious of having excessively high WFR percentages, which lead to over-lit spaces that cause glare and heat gain.

But it is important to note that these readings were obtained in the absence of furniture and curtains across the windows. So, if these variables were to be factored in, the values are most definitely expected to decrease. However, based on illumination standards for typical rooms, a WFR of 5% was shown to be sufficient when values of 500 lux were predicted from the graph.

Another important observation from the graph is that the dotted line does not converge at zero.

Logically, when WFR approaches zero, the resulting %DF should also reach zero implying that the room has no window area at all. But this is not the case in the graph as a 2%DF is obtained with a WFR of zero which indicates that: ·

Rooms R1-R4 are not in isolation-they are linked via doors to adjacent spaces.

·

Leakage of light from linked spaces occurs through voids. (eg: via opened doors, gaps

beneath doors etc.)

Therefore, limiting the passage of light only to window area as calculated in WFR is impossible, especially in a building with connected spaces.

2.2.4 Conclusion By analyzing the results obtained in the project, the following conclusions were derived: ●

%DF is a valid and reliable assessment of daylight in spaces, but is limited to sky illuminance conditions in Malaysia.

●

In cases where %DF is mostly determined by SC and IRC, an average %DF of 1%-2% can be considered sufficient.

●

Connection of spaces via linked passageways/corridors is an important design consideration as they do have an important effect on indoor illumination.

●

A WFR of 25% is suggested as the upper limit to avoid over-lit spaces.

22

2.3

Methodology for the Case Study

2.3.1 Preparation 1. Preliminary study and identification of the type of spaces were studied to choose the suitable case study.

2. Precedent studies were done to have a better understanding on how light functions or affect in a certain space.

3. In obtaining the permission to use the site as case study, visitations, calls and emails were made to different chosen places.

4. Digital lux meter was supplied by the tutor and the equipment was tested before visiting the site.

5. The place was measured in order to draw the plan.

6. The spaces were determined.

7. Grid lines with the distance of 2 meters was plotted on the plan for recording purposes.

8. A basic standard and regulations such as CIBSE, ASHARE and MS1525 were also studied beforehand to analyze and compare the readings later on.

2.3.2 Equipments used a. Digital lux meter

23

b. Camera

c. Measuring tape

2.3.3 Data Collection Data were collected at non-peak hour between 4 pm to 5 pm and peak hour between 9 pm to 11 pm. The first set of readings was taken using a combination of both natural and artificial light and the second set was taken using only the artificial light within the room. The readings were taken 1 meter and 1.5 meter above the ground level at each corresponding time with both day lighting and artificial lighting. Materials used in the space were studied and recorded to indicate the coefficient value and reflectance value towards the lighting. Finally, all the data were analyzed to develop a conclusion and to suggest several possible improvements to the design of the room to enhance the design concept.

24

2.4

Data Collection and Results

2.4.1 Data collection

Fig 2.3 Zoning of spaces

25

2.4.2 Light data records

A. Natural and artificial illumination at 4pm

Natural and Artificial illumination (Reading at 1m, Reading at 1.5m) 1

2

3

4

5

6

7

8

9

10

11

A

27,36

46,54

98,101

NA

NA

NA

NA

88,186

23,17

27,24

26,38

B

9,4

9,4

21,9

NA

NA

NA

NA

100,200

4,12

7,4

14,14

C

8,6

7,4

9,4

7,4

6,5

48,93

51,65

50,64

11,15

10,5

13,9

D

16,20

16,24

10,15

13,15

13,18

13,10

75,100

160,87

173,104

180,111

170,99

E

18,24

17,21

13,34

11,15

10,27

11,15

NA

162,88

190,120

198,122

191,119

Table 2.2 Natural and artificial illumination readings at 4pm

B. Artificial illumination at 9pm

Artificial illumination ( Reading at 1m, Reading at 1.5m) 1

2

3

4

5

6

7

8

9

10

11

A

7,21

27,29

27,30

NA

NA

NA

NA

25,58

6,7

10,12

10,13

B

2,6

1,3

18,28

NA

NA

NA

NA

0,1

0,0

1,0

1,0

C

70,80

2,8

0,2

0,1

10,2

0,1

0,0

0,0

0,0

1,3

3,5

D

6,9

2,4

0,1

1,1

4,3

1,1

0,0

160,87

173,104

180,111

170,99

E

3,11

6,4

3,11

2,2

2,7

2,2

NA

162,88

190,120

198,122

191,119

Table 2.3 Artificial illumination readings at 9pm

26

2.5 Calculations 2.5.1 Daylight factor analysis: The daylight factor of a café should be between 1-3%. The calculation below is the daylight factor calculations for D café.

Daylight facto​r = E​i​ /E​o x​ 100 Where ​E​O is outdoor illuminance on a horizontal plane and E​I is illuminance due to ​ ​ daylight.

E​i for zone A ​= 64 lux ​ E​i ​for zone D​ = 26.33 lux E​o ​for the café is​ = 18000 lux Hence by formula:

Daylight factor for zone A​ = 64/18000 X 100 = 0.3%

Daylight factor for zone E​ = 26.33/18000 X 100 = 0.14%

Conclusion Both the zones, zone A and Zone B have a poor daylight factor.

27

Natural light contour diagram

Fig 2.4 Natural light contour diagram at 4 pm with a clear sky

28

2.5.2 Observations and discussions

Observation 1 Light data collected during the peak hour are lower compared to the data collected during non-peak hour.

Discussion 1 The reason is because the peak hour occur during night time, therefore there is no daylight contributing to the light readings. The high number people during the peak hour result in more shadow which diffuse the general light levels.

Observation 2 Light data collected at height 1.5m above the ground is higher than the reading taken at 1m above the ground level.

Discussion 2 At 1.5m level, the lux meter is closer to the artificial light source, therefore reading is higher.

Nevertheless, the large difference in reading only happens in the grid points which have artificial electric lighting Observation 3 Sequence of light density collected during daytime at different area.

DENSITY OF LIGHT

AREA

High

Area near the entrance (Zone A and E)

Medium

Bar area (Zone D)

Low

Lounge area (Zone B and C)

29

Discussion 3

Area

Reason

Entrance (Zone A and E)

Material used at the entrance is glass doors and windows, penetration of exterior day light increases the density of light at area near to the entrance.

Bar (Zone D)

The area is near the entrance therefore the light density of the area is also affected by daylight penetration.

Lounge (Zone B and C)

The area is situated the furthermost from the entrance hence has little/no daylight penetration.

30

2.5.3 Artificial lighting specifications:

Table 2.4 Wall mounted LED light specifications

31

Table 2.5 Chandelier candle LED light specifications

32

Table 2.6 LED spotlight specifications

33

Table 2.7 Fluorescent light tube specifications

34

Table 2.8 LED strip light specifications

35

2.5.4 Lighting Analysis and Lumen Method Calculations

Fig 2.5 Artificial light contour diagram of Dâ&#x20AC;&#x2122;Kaffe

36

2.5.4.1 Zone A: Entrance

Fig 2.6 Zone A interior

It can be concluded based on daylight factor analysis that zone A has insufficient natural day lighting. The cafe is not well exposed to the daylight as it can be seen from the picture below, only the outdoor seating area receives good amount of daylight.

Lack of proper opening and use of darker materials causes the cafe to be darker than usual. Also the due to the angle of penetration of light from the outdoors into the cafe, not all of the light is able to enter the cafe. This causes the space to be darker than it should be.

Fig 2.7 Outdoor seating area

37

2.5.4.2 Lumen method calculation for zone A:

Conclusion Hence the remaining 20 lux would need: Considering the ceiling lights alone.

N = E (required lux) x Area / lumen (ceiling light) x UF x MF = 20 x 58.58/ 300 x 0.53 x 0.8 = 9.2 = 10 lights.

The total no. of additional lights are 10 more ceiling lights.

38

Sections and contours

Fig 2.8 Section cut of Zone A during peak and non-peak hours

Fig 2.9 Artificial light contour diagram for zone A

39

2.5.4.3 Zone B and C: Private Lounge

Fig 2.10 Furniture at Private Lounge

According to the daylight factor analysis zone B has the least amount of daylight penetration but has more number of artificial light per meter square compared to other area, as it is situated furthermost from entrance/openings. Hence it can be said that the area is designed to create a warmer and more intimate space.

Fig 2.11 Lounge area

40

2.5.4.4 Lumen method calculation for zone B

Conclusion Hence the remaining 19.26 lux would need: Considering the ceiling lights alone N = E(required lux) x Area/ lumen(ceiling light) x UF x MF = 19.26 x 22.62/ 300 x 0.43 x 0.8 = 4.22= 5 lights.

The total no. of additional lights are 5 more ceiling lights.

41

Sections and contours

Fig 2.12 Section cut of zone B during non-peak hours

Fig 2.13 Artificial light contour diagram for Zone B

42

2.5.4.5 Lumen method calculation for zone C

Conclusion Hence the remaining 31.40 lux would need: Considering the ceiling lights alone N = E(required lux) x Area/ lumen(ceiling light) x UF x MF = 31.40 x 12.76/ 300 x 0.36 x 0.8 = 4.63= 5 lights.

The total no. of additional lights are 5 more ceiling lights.

43

Sections and contours

Fig 2.14 Section cut of zone C

Fig 2.15 Artificial light contour diagram for Zone C

44

2.5.4.6 Zone D: Bar Area

Fig 2.16 Zone D bar area

According the daylight factor analysis this area is less dimmer during the day compared to zone B but requires more number of artificial light during peak hour. There are many obstruction in this area. The daylight penetrates through the large opening, however it is blocked by the shelf as seen in the picture above.

The shadows from the high cabinet in the bar work place makes the area darker and prone to accidents due to less artificial lighting.

Fig 2.17 Views of the bar area

45

2.5.4.7 Lumen method calculation for zone D

Conclusion Hence the remaining 47.88 lux would need: Considering the ceiling lights alone N = E(required lux) x Area/ lumen(ceiling light) x UF x MF = 47.88 x 27.72/ 300 x 0.43 x 0.8 = 12.86= 13 lights.

The total no. of additional lights are 13 more ceiling lights.

46

Sections and contours

Fig 2.18 Section cut of zone D

Fig 2.19 Artificial light contour diagram for Zone D

47

2.5.4.8 Zone E: Secondary entrance

Fig 2.20 Zone E interior

Zone E like zone A is closer to the openings so it has more amount daylight penetration. The amount of daylight penetration at zone E is less compared to zone A as the openings are smaller and there are obstructions which blocks the daylight and causing shadows. During the peak hour zone E is darker compared to the rest of the zones. The artificial lighting in the zone E is the least compared to all the other zones.

Nearer to the window it might seem there is a lot of light, however at a point slightly further away from the window there are shadows created by the objects and the illumination reading shows low measurements.

48

2.5.4.9 Lumen method calculation for zone E:

Conclusion Hence the remaining 55.19lux would need: Considering the ceiling lights alone N = E(required lux) x Area/ lumen(ceiling light) x UF x MF = 55.19 x 54.94/ 300 x 0.57 x 0.8 = 22.16= 23 lights.

The total no. of additional lights are 23 more ceiling lights.

49

Sections and contours

Fig 2.21 Section cut of Zone E

Fig 2.22 Artificial light contour diagram for Zone E

50

2.5.4.10 Zone F: Kitchen

Fig 2.23 Zone F: Kitchen area

(The management did not permit permission for pictures to be taken in this zone which is the kitchen)

51

2.5.4.11 Lumen method calculation for zone F:

Conclusion Hence the remaining 46.1 lux would need: Considering the ceiling lights alone N = E (required lux) x Area/ lumen (ceiling light) x UF x MF = 46.1x 30.4/ 3350 x 0.48 x 0.8 = 1 = 1 light.

The total no. of additional lights required is 1 more light.

52

Sections and contours

Fig 2.24 Section cut of Zone F

Fig. 2.25 Artificial light contour diagram for Zone F

53

2.6 Conclusion: Based on our data collections, it can be conclude that D Kaffe bistro has a dim environment that lacks of artificial lighting. The use of dim light bulbs however has become a trend in many café’s and provides a very calm ambience for the customers. During day time, the cafe receives insufficient day lighting focuses except on certain areas with the aid of openings at the entrance and the side of the café. As for the night lightings, we found that D Kaffe bistro are primarily using atmospheric overhead lighting, and the lux meter reading shows that the café lacks lighting giving a general dim environment as this might be the general idea of the café owner.

In order to create a pleasing working environment, D Kaffe bistro should have additional lightings to put on. The artificial lighting installed all of the spaces studied is not acceptable and does not meet the MS1525 standards. after all the lumen calculation has been done in this analysis, the result shows that there are still number of lights that needs to be installed in each of the spaces. Without calculation it is also quite obvious that the spaces does not have enough lighting. Bulb with higher power or more number of bulbs can be added to solve the issue and and create more productive environment, preventing from any accidents.

Overall, considerations has to be taken not only to illuminate the space but at the same time create a pleasant environment and take care of the well being of users in the space.

54

3.0 ACOUSTICS

55

3.1 Acoustics literature review In design and construction acoustic comfort is an important consideration. The acoustical environment in and around buildings is influenced by numerous interrelated and interdependent factors associated with the building planning-design construction process.

The extent of

acoustical problems involved is influences from the very onset of building development from the selection of the site to the arrangement of the spaces within the building. Construction elements and materials of the finished spaces determine how well sound is transmitted to adjacent spaces and how well sound is perceived.

In design and construction acoustic comfort is an important consideration. Post occupancy of acoustic performance is often necessary in order to ensure design features are effective.

Acoustic performance will affect inhabitants not only physiologically but also psychologically and sociologically.

3.1.1 Decibel Scale Generally sound pressure level expressed in μPa or Pa is used to assess sound exposure to humans. Human ear’ audible sound pressure levels range from 20 μPa (hearing threshold) till 20 Pa (pain threshold), resulting in the scale 1:10,000,000. Since using such a large scale is not practical, a logarithmic scale in decibels (dB) was introduced which is also in agreement with physiological and psychological hearing sensations.

For sound pressure level measurements a reference value of 0.00002 newtons/square meter ( 2 x 10−5 N/ m2 ) is used. This is the threshold of hearing for a typical healthy person. The sound pressure level is given the following expression.

Lp = 20 log

p p0

Where:

Lp = sound level in decibels (dB) p = measured sound pressure of concern

56

p0 = preference sound pressure, usually taken to be 2 x 10−5 N/ m2

3.1.2 Sound Intensity Level Sound intensity is defined as the sound per unit area. The usual content is the measurement of sound intensity in the air at a listener’s location. The basic units are watts/ m2 or watts/ cm2 .

Many sound intensity measurements are made relative to a standard threshold of hearing intensity I 0 SIL = 10 log

I I0

Where ​I​ = sound intensity and ​Io​​ = reference intensity

3.1.3 Reverberation Reverberation time (RT) or ( T 60 ) is defined as the length of time taken for sound to decay from its initial level. It can be described as the persistence or lingering of sound one hears within a room as the sound is continuously reflected by the room’e boundaries and gradually dies away.

The reverberation period (time in seconds for the source is turned off) is directly proportional to the cubic volume of the space and inversely proportional to the total sound absorption present.

T = 0.05

V A

(English units), or

T = 0.06

V A

(Metric)

Where: T = reverberation time in seconds V = volume in cubic feet (or cubic meters) A = total absorption in square feet ( or square meters) (sum of roof surfaces times their sound absorption coefficients plus the sound absorption provided by furnishing or audience, etc)

57

3.1.4 Sound Reduction Index Is used to measure the level of Sound Insulation building elements or structures have to reduce sound transmission.

SRI = 10 log

1 T

Where: SRI = Sound reduction index T = Transmission of sound frequency

58

3.2 Precedent Study A Total Building Performance Approach to Evaluating Building Acoustics Performance

3.2.1 Introduction Acoustic comfort is important in the design and construction of buildings. Since acoustic performance of a building affects its users, post occupancy evaluations of acoustic performance are required to be conducted to ensure that the building’s acoustic design features are effective.

Acoustic quality is affected by the building’s interior, structural, envelope and mechanical systems. This article presents a detailed acoustic evaluation of an office building by adapting a total building performance (TBP) approach. TBP is a holistic approach that evaluates a building through a series of detailed analysis of a building’s systems and subsystems. It is also used to suggest strategies to integrate various building performance mandates to deliver specific performance requirements through objective and subjective methods. (Mahbub, Kua, & Lee, 2011)

3.2.2 Building description and project background This detailed acoustic evaluation was conducted on the main office building of a multinational company located in Singapore. The building is 3 storeyed with 2 mezzanine floors. All floors in the warehouse area are built as flat floors for truck movements within the storage facility. The building is constructed with post-tension reinforced concrete slabs (thickness of 310mm) at the first and second storeys and metal truss roofing at the third storey. The floor to floor height is 4.4m. The office space is designed so that the executive rooms are on the periphery and the work stations and amenities are located in the interior areas. False ceilings are used in the office space; normal gypsum boards are used. Also, full height gypsum board partitions with rock wool infill are used. The main doors are glazed, all cabin doors are partly glazed and the rest are opaque and solid doors. The building uses a variable refrigerant volume system for air conditioning with outdoor units located on the roof; the end units are Fan Coil Units in the offices. The evaluation of total acoustical performance of the building was carried out in 4 stages:

59

1.

Plan/archive analysis

2.

Expert walkthrough

3.

Objective measurement

4.

Subjective study

(Mahbub, Kua, & Lee, 2011) *Note: Of the 4 stages, only Objective measurement and evaluation are covered in this summary of the journal article.

3.2.3 Methodology and objective evaluation The instruments used were an integrating real time sound analyzer, an acoustical calibrator and a four-channel real time acoustic analyzer with omni-directional microphones. A boundary noise measurement was carried out when the factory was in full operating condition. Measurements were taken between 3-5m apart along the boundary. Noise mapping by a grid method was carried out at a height of 1.2m. (Mahbub, Kua, & Lee, 2011) The highest measured noise levels during the boundary noise measurements are shown in Figure 3.0. All these values were found to be within the specified limit of 75dBA according to given guidelines.

60

Fig 3.0. Boundary noise measurements

The indoor noise map for the 2 mezzanine floors 1M and 2M respectively and the second floor warehouse showed that all values were within the maximum permissible level of 85dBA. Therefore, the overall noise level was generally considered steady. Apart from this, spot measurements were later taken at several locations to create a noise map for different office spaces. The results are summarized in Table 3.0.

Location

Measurements and Observations

1M

Noise levels were found to be within the requirements of the Green Mark Scheme (45dBA-55dBA) Overall noise levels of the office, executive room and meeting room exceeded the CP 13 standards (Private executive office: 40dBA, general office: 45dBA, conference room: 40dBA) by 1dBA, 7dBA and 5dBA respectively.

Second Floor

Noise levels were within the Green Mark Scheme requirements. The overall background noise level of the office space, executive offices and meeting rooms exceeded the CP 13 standards by 2dBA and 7-11dBA respectively.

61

2M

Overall background noise level in the training room, executive offices and meeting room exceeded the CP 13 standard by 1-3dBA.

*Note: Singapore Standard CP 13 â&#x20AC;&#x201C; Code of Practice for Mechanical Ventilation and Air Conditioning in Buildings Table 3.0. Summary of indoor noise measurement

Reverberation Time (RT) measurements were carried out in training rooms, conference rooms and the reception area. The evaluation criteria of RT for general office areas were considered between 0.4s-0.6s and private offices, 0.6s-0.8s. The measured RT values are shown in Table 3.1.

Location

Measurements and Observations

1M

The measured RT values (avg. 0.5s) in the meeting room were in an acceptable range.

Second Office

2M

Floor

-

RT values in the training room were in the higher range: 250Hz-2kHz (>1s) â&#x20AC;&#x201C; This could contribute to poor speech intelligibility.

RT values at the lift lobby was also high: 250Hz-4kHz (1.3s). Due to high reflectivity of the marble walls, floor and hard ceiling.

RT values in the reception area were within the guidelines.

RT values in the training room was high: 125Hz-2kHz (<1s) RT values in the conference room and meeting room were in within the guidelines.

Table 3.1. Summary of measurements of RTs

62

3.2.4 Integrated acoustic solutions 1.

Improvements to the envelope system

Through analysis, it was observed that outdoor noise levels affected the readings taken resulting in them exceeding the given guidelines. Such insufficient noise isolation can be effectively addressed by improving the envelope and interior systems. Presently, the use of a single glazing window only provides a moderate range of sound insulation (approx. 10dBA).

Re-application of some of the window seals around the windows is recommended.

The company is considering double glazing windows. They have an air gap in between that provides better control of outdoor, low frequency traffic noise and have a minimum sound reduction of 25dB-30dB. 2.

Improvements to the structural system

The 1M and 2M offices are separated from the second and third floor warehouses by thick concrete ceilings; also, note that the structure needed to facilitate truck movement to and from the warehouses. Noise readings taken from these offices were observed to exceed the levels stated in the guidelines. This showed that even though a thicker ceiling was provided, vehicular movement still caused higher noise levels. Another problem encountered in the workstations â&#x20AC;&#x201C; partial height partitions between workstations were not effective in providing proper speech privacy as the noise levels measured were high. RT values in the training rooms too were higher than recommended. This increase in reverberance was due to the use of reflective finishes in the structure.

Understanding how the structural system affected the acoustics allowed for recommendations to be made. Firstly, higher workstation partitions (approx. 1.7m) to replace those existing were recommended. Floor to floor partitions - though more effective, were not used as air circulation and light penetration would be hindered. Secondly, the use of an acoustical ceiling and absorptive wall surfaces were suggested to provide improved speech intelligibility and control of echo in the office spaces.

3.

Improvements to interior and mechanical systems

Another reason for high background noise in the office spaces is due certain frequencies of the obtained readings corresponding to ranges of most HVAC equipment. Specifically, the noise level recorded, was in the frequency range of 250Hz-350Hz which was deduced to be the

63

noises caused by the FCU mounted to the ceiling. Another noise level at 4000Hz corresponded to the frequency radiated by the diffuser where the fresh air supply was directly connected to the FCU. A few considerations were made to the company. Firstly, the noises caused by the diffuser could be controlled through the use of a low noise fan and by controlling the flow of fresh air.

Secondly, a suggestion was made for the application of an absorptive lining in the ductwork.

3.2.5 Conclusion This article demonstrates how a comprehensive TBP process has been applied to assess the acoustic performance through a series of detailed stages. The Objective measurements show the degree to which the chosen buildingâ&#x20AC;&#x2122;s working environmental conditions satisfy the evaluation criteria. Though this summary only provides insight into the stage of objective measurements and evaluation, it must be made clear that the rest of the stages ie: plan/archive analysis, expert walkthrough and subjective measurements are an integral part of the TBP process in assessing the buildingâ&#x20AC;&#x2122;s acoustic performance.

Sound insulation was found to be one of the greater challenges to overcome especially as this was an office building that was located next to warehouses. The offices at the periphery were found to be affected by traffic noise. Some of the interior designs of the office spaces resulted in poor RT values, low speech intelligibility and privacy. The choice of partial height partitions though insulated, also contributed to negative acoustic performance within the office spaces.

Finally, instead of only suggesting solutions focusing on the interior aspects of the building, the TBP process was used as a guideline to prescribe a range of solutions in all the building systems. Through the TBP process, various information collection methodologies are used together to improve the overall acoustic quality of the building.

64

3.3 Methodology for the case study 3.3.1 Preparation ●

Preliminary study and identification of the type of space were studied to choose the suitable case study.

●

Precedent studies were done to have a better understanding of how acoustics functions and affecting the surrounding in a certain space.

●

In obtaining approval to use site as case study we visited them for permissions.

●

We measured the site and took notes.

●

Spaces were determined

●

Grid lines with distance 2m was plotted on the plan for recording purpose.

●

Sound meter was gathered with the light meter from the school.

●

A basic standard and regulations were studied beforehand so as to help us analyze our readings.

3.3.2 Devices used 1.

Sound meter

2.

Camera

65

3.3.3 Data collection Data were collected at non peak hours and peak hours. The acoustic readings were taken according to the intersection of the grid lines at 1m above ground. It was ensured that the sound level meter stabilizers with the surrounding noise before the readings were taken. The noise source, furniture and materials used in the space were analyzed and recorded as these may affect the sound level recorded.

66

3.4 Data Collection and Results 3.4.1 Outdoor noise source

Vehicle noise Construction site noise

â&#x20AC;&#x2039;Fig. 3.1 Sitemap with outdoor noise sources The site is surrounded by the highway which is the main source of outdoor noise. It is caused by the vehicles that goes through this road day and night.

Another noise source, which is temporary, is the construction site next to the site. Noise is mostly produced during the day, when construction processes are carried out.

67

3.4.2 Indoor noise sources 3.4.2.1 Speakers Music is constantly being played inside. As from 9 p.m., peak hour, they do performance like singing. The music playing is quite loud which makes it the main source of sound in the bar.

Product Name

S-DJ50XS Pioneer Speakers

Weight

6.5 kg per Speaker

Colour

Black

Sound Pressure Level

75 dB

Dimensions

197 x 301 x 262 mm

Placement

Wall Mounted Speakers

Table 3.2 Speaker specifications

Fig. 3.2 Speakers position

68

3.4.2.2 Coffee machine The coffee machine is usually used and it makes a loud noise while preparing the coffee Product Name

Illy Coffee Machine

Weight

3 kg

Colour

Grey

Sound Pressure Level

40 - 50 dB

Dimensions

300 x 300 x 250 mm

Placement

Coffee Bar

Table 3.3 Coffee machine specifications

Fig 3.3 Coffee machine position

69

3.4.2.3 Dart machine The machine is mostly used during peak hours. It has sound effects and some music, when being played. When not in use, it still do some short random sound effects.

Product Name

Phoenix Dart Machine

Weight

50 kg

Colour

Black

Sound Pressure Level

75-85 dB

Dimensions

600 x 800 x 2400 mm

Placement

Dart Area

Table 3.4 Dart machine specifications

Fig 3.4 â&#x20AC;&#x2039;Dart machine positions

70

3.4.2.4 Human activity The bar is a place that is mostly used for socialization. People come to have a drink or eat together. People talking, walking, ordering are sources of noise in the bar which is quite loud during peak hours.

Fig 3.5 Bar during peak hour

Fig 3.6 Noise sources from human activity

71

3.4.2.5 Air conditioners The fan of the indoor unit of the air conditioner constantly produces a low noise when it is being used.

Product Name

York Ceiling Air-Conditioner

Weight

25 kg

Colour

White

Sound Pressure Level

50 â&#x20AC;&#x201C; 55 dB

Dimensions

275 x 570 x 570 mm

Placement

Ceiling

Table 3.5 Air conditioner specifications

Fig. 3.7 Air conditioners position

72

3.4.2.6 Bar At the bar counter, the glasses and bottles are constantly being moved which creates sudden loud noise.

â&#x20AC;&#x2039; Fig 3.8 Bar counter

Fig. 3.9 Sound source from bar

73

3.5 CALCULATIONS 3.5.1 Calculation of Sound Intensity of Indoor Noise Source Intensity of the sound of each internal noise sources are calculated based on the formula: SWL = 10 log (đ?&#x2018;&#x2013;

đ?&#x2018;&#x2013;

đ?&#x2018;&#x;đ?&#x2018;&#x2019;đ?&#x2018;&#x201C;

)

Air Conditioner Max sound power level: 55 dB 55

=

5.5

=

đ??ź

=

đ??ź ) 1 Ă&#x2014; 10â&#x2C6;&#x2019;12 đ??ź đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D;10 ( ) 1 Ă&#x2014; 10â&#x2C6;&#x2019;12 10 đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D;10 (

3.16 x 10â&#x2C6;&#x2019;7

Sound Intensity of air conditioner = 3.16 x 10â&#x2C6;&#x2019;7 W/m2

Coffee Machine Max sound power level: 50 dB 50

=

5

=

đ??ź

=

đ??ź ) 1 Ă&#x2014; 10â&#x2C6;&#x2019;12 đ??ź đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D;10 ( ) 1 Ă&#x2014; 10â&#x2C6;&#x2019;12 10 đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D;10 (

1.0 x 10â&#x2C6;&#x2019;7

Sound Intensity of coffee machine = 1.0 x 10â&#x2C6;&#x2019;7 W/m2

74

Phoenix Dart Machine Max sound power level: 85 dB 85

=

8.5

=

đ??ź

=

đ??ź ) 1 Ă&#x2014; 10â&#x2C6;&#x2019;12 đ??ź đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D;10 ( ) 1 Ă&#x2014; 10â&#x2C6;&#x2019;12 10 đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D;10 (

3.16 x 10â&#x2C6;&#x2019;4

Sound Intensity of phoenix dart machine = 3.16 x 10â&#x2C6;&#x2019;4 W/m2

Speaker Max sound power level: 75 dB 75

=

7.5

=

đ??ź

=

đ??ź ) 1 Ă&#x2014; 10â&#x2C6;&#x2019;12 đ??ź đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D;10 ( ) 1 Ă&#x2014; 10â&#x2C6;&#x2019;12 10 đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D;10 (

3.16 x 10â&#x2C6;&#x2019;5

Sound Intensity of air conditioner = 3.16 x 10â&#x2C6;&#x2019;5 W/m2

Overall SWL of Internal Noise Source Indoor Noise Source Air conditioner

Sound Intensity (W/m2) 3.16 x 10â&#x2C6;&#x2019;7

Coffee Machine

1.0 x 10â&#x2C6;&#x2019;7

Dart Game Machine Speaker

3.16 x 10â&#x2C6;&#x2019;4

Total Intensity

3.48 x 10â&#x2C6;&#x2019;4

3.16 x 10â&#x2C6;&#x2019;5

Overall SWL

= =

10 đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D;10 (

3.48 x 10â&#x2C6;&#x2019;4 ) 1 Ă&#x2014; 10â&#x2C6;&#x2019;12

85 dB

75

3.5.2 Calculation of Sound Intensity Level ZONE A NON-PEAK HOUR Highest reading: 77 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

77

=

10 𝑙𝑜𝑔10 (

7.7

=

𝑙𝑜𝑔10 (

107.7

=

𝐼 1 × 10−12

𝐼

=

5.012 x 10-5

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

Lowest reading: 58 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

58

=

10 𝑙𝑜𝑔10 (

5.8

=

𝑙𝑜𝑔10 (

105.8

=

𝐼 1× 10−12

𝐼

=

6.310 x 10-7

Total intensity

Total SWL

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

=

5.012 x 10-5 + 6.310 x 10-7

=

5.075 x 10-5

=

10 𝑙𝑜𝑔10 (

=

77 dB

5.075×10−5 ) 1 × 10−12

76

Fig 3.10 Section of zone A

Fig 3.11 Acoustic ray diagram for outdoor noise

Fig 3.12 Acoustic diagram for zone A and B Hence the SWL in zone A for non-peak time is 77 dB. This value lies within the range for a standard restaurant since at off peak times, the restaurant does not perform live sessions, hence the use of speakers is reduced and this produces a lower SWL value.

77

ZONE A PEAK HOUR Highest reading: 98 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

98

=

10 𝑙𝑜𝑔10 (

9.8

=

𝑙𝑜𝑔10 (

109.8

=

𝐼 1 × 10−12

𝐼

=

6.310 x 10-3

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

Lowest reading: 74 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

74

=

10 𝑙𝑜𝑔10 (

7.4

=

𝑙𝑜𝑔10 (

107.4

=

𝐼 1× 10−12

𝐼

=

2.512 x 10-5

Total intensity

Total SWL

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

=

6.310 x 10-3

=

6.335 x 10-3

=

10 𝑙𝑜𝑔10 (

=

98 dB

+ 2.512 x 10-5

6.335×10−3 ) 1 × 10−12

78

Fig 3.13 Section of zone A

Fig 3.14 Acoustic ray diagram for outdoor noise

Fig 3.15 Acoustic ray diagram for zone A and B Hence the SWL in zone A for peak time is 98 dB. This zone records a high value compared to a maximum standard of 80 dB for restaurants because of the speakers located on stage within that zone.

79

ZONE B NON-PEAK HOUR Highest reading: 60 dB 𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

60

=

10 𝑙𝑜𝑔10 (

6

=

𝑙𝑜𝑔10 (

106

=

𝐼

=

𝐼 𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 1 × 10−12 1 x 10-6

Lowest reading: 53 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

53

=

10 𝑙𝑜𝑔10 (

5.3

=

𝑙𝑜𝑔10 (

105.3

=

𝐼 1× 10−12

𝐼

=

1.995 x 10-7

Total intensity

Total SWL

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

=

1 x 10-6 + 1.995 x 10-7

=

1.200 x 10-6

=

10 𝑙𝑜𝑔10 (

=

61 dB

1.200×10−6 ) 1 × 10−12

80

Fig 3.16 Section of zone B

Fig 3.17 Acoustic ray diagram for outside noise

Figure 3.18 Acoustic ray diagram for zone A and B Hence the SWL in zone B for non-peak time is 61 dB. This value lies within the range for a standard restaurant. Moreover, in zone B, the presence of fabric materials reduces the SWL in that zone.

81

ZONE B PEAK HOUR Highest reading: 93 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

93

=

10 𝑙𝑜𝑔10 (

9.3

=

𝑙𝑜𝑔10 (

109.3

=

𝐼 1 × 10−12

𝐼

=

1.995 x 10-3

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

Lowest reading: 74 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

76

=

10 𝑙𝑜𝑔10 (

7.6

=

𝑙𝑜𝑔10 (

107.6

=

𝐼 1× 10−12

𝐼

=

3.981 x 10-5

Total intensity

Total SWL

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

=

1.995 x 10-3

=

2.035 x 10-3

=

10 𝑙𝑜𝑔10 (

=

93 dB

+ 3.981 x 10-5

2.035×10−3 ) 1 × 10−12

82

Fig 3.19 Section of zone B

Fig 3.20 Acoustic ray diagram for outside noise

Fig 3.21 Acoustic ray diagram for zone A and B

Hence the SWL in zone B for peak time is 93 dB. This zone records a high value because of its proximity to the stage where the speakers are located and fully operational during peak time.

83

ZONE C NON-PEAK HOUR Highest reading: 64 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

64

=

10 𝑙𝑜𝑔10 (

6.4

=

𝑙𝑜𝑔10 (

106.4

=

𝐼 1 × 10−12

𝐼

=

2.512 x 10-6

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

Lowest reading: 55 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

55

=

10 𝑙𝑜𝑔10 (

5.5

=

𝑙𝑜𝑔10 (

105.5

=

𝐼 1× 10−12

𝐼

=

3.162 x 10-7

Total intensity

Total SWL

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

=

2.512 x 10-6 + 3.162 x 10-7

=

2.828 x 10-6

=

10 𝑙𝑜𝑔10 (

=

65 dB

2.828×10−6 ) 1 × 10−12

84

Fig 3.22 Section of zone C

Hence the SWL in zone C for non-peak time is 65 dB. This value lies within the range for a standard restaurant. Moreover, in zone C, the presence of fabric materials reduces the total SWL in that zone.

85

ZONE C PEAK HOUR Highest reading: 78 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

78

=

10 𝑙𝑜𝑔10 (

7.8

=

𝑙𝑜𝑔10 (

107.8

=

𝐼 1 × 10−12

𝐼

=

6.310 x 10-5

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

Lowest reading: 64 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

64

=

10 𝑙𝑜𝑔10 (

6.4

=

𝑙𝑜𝑔10 (

106.4

=

𝐼 1× 10−12

𝐼

=

2.512 x 10-6

Total intensity

Total SWL

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

=

6.310 x 10-5

=

6.561 x 10-5

=

10 𝑙𝑜𝑔10 (

=

78 dB

+ 2.512 x 10-6

6.561×10−5 ) 1 × 10−12

86

Fig 3.23 Section of zone C

Hence the SWL in zone C for peak time is 78 dB. This zone records fair value compared to the maximum standard of 80 dB for a restaurant.

87

ZONE D NON-PEAK HOUR Highest Reading: 68 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

68

=

10 𝑙𝑜𝑔10 (

6.8

=

𝑙𝑜𝑔10 (

106.8

=

𝐼 1 × 10−12

𝐼

=

6.310 x 10-6

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

Lowest reading: 61 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

61

=

10 𝑙𝑜𝑔10 (

6.1

=

𝑙𝑜𝑔10 (

106.1

=

𝐼 1× 10−12

𝐼

=

1.259 x 10-6

Total intensity

Total SWL

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

=

6.310 x 10-6 + 1.259 x 10-6

=

7.569 x 10-6

=

10 𝑙𝑜𝑔10 (

=

69 dB

7.569×10−6 ) 1 × 10−12

88

Figure 3.24 Section of zone D

Hence the SWL in zone D for non-peak time is 69 dB. This value lies within the range for a standard restaurant due to the inactivity during off-peak times.

89

ZONE D PEAK HOUR Highest reading: 90 dB 𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

90

=

10 𝑙𝑜𝑔10 (

9

=

𝑙𝑜𝑔10 (

109

=

𝐼

=

𝐼 𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 1 × 10−12 1 x 10-3

Lowest reading: 64 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

64

=

10 𝑙𝑜𝑔10 (

6.4

=

𝑙𝑜𝑔10 (

106.4

=

𝐼 1× 10−12

𝐼

=

2.512 x 10-6

Total intensity

Total SWL

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

=

1 x 10-3

=

1.003 x 10-3

=

10 𝑙𝑜𝑔10 (

=

90 dB

+ 2.512 x 10-6

1.003×10−3 ) 1 × 10−12

90

Fig 3.25 Section of zone D

Hence the SWL in zone D for peak time is 90 dB. This zone records a high value because of its proximity to the open bar where the coffee machine and other appliances are located.

91

ZONE E NON-PEAK HOUR Highest reading: 69 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

69

=

10 𝑙𝑜𝑔10 (

6.9

=

𝑙𝑜𝑔10 (

106.9

=

𝐼 1 × 10−12

𝐼

=

7.943 x 10-6

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

Lowest reading: 59 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

59

=

10 𝑙𝑜𝑔10 (

5.9

=

𝑙𝑜𝑔10 (

105.9

=

𝐼 1× 10−12

𝐼

=

7.943 x 10-7

Total intensity

Total SWL

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

=

7.943 x 10-6 + 7.943 x 10-7

=

8.737 x 10-6

=

10 𝑙𝑜𝑔10 (

=

69 dB

8.737×10−6 ) 1 × 10−12

92

Fig 3.26 Section of zone E

Fig 3.27 Acoustic ray diagram of zone E

Hence the SWL in zone E for non-peak time is 69 dB. This value lies within the range for a standard restaurant and the main noise source comes from the animation from the dart machines when users are not playing.

93

ZONE E PEAK HOUR Highest reading: 86 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

86

=

10 𝑙𝑜𝑔10 (

8.6

=

𝑙𝑜𝑔10 (

108.6

=

𝐼 1 × 10−12

𝐼

=

3.981 x 10-4

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

Lowest reading: 60 dB 𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

60

=

10 𝑙𝑜𝑔10 (

6

=

𝑙𝑜𝑔10 (

106

=

𝐼

=

Total intensity

Total SWL

𝐼 𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 1× 10−12 1 x 10-6

=

3.981 x 10-4

=

3.991 x 10-4

=

10 𝑙𝑜𝑔10 (

=

86 dB

+ 1 x 10-6

1.003×10−3 ) 1 × 10−12

94

Fig 3.28 Section of zone E

Fig 3.29 Acoustic ray diagram for zone E

Hence the SWL in zone E for peak time is 86 dB. This zone records a high value specially because of the dart machine animation at all times and when users are playing it.

95

ZONE F NON-PEAK HOUR Highest reading: 62 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

62

=

10 𝑙𝑜𝑔10 (

6.2

=

𝑙𝑜𝑔10 (

106.2

=

𝐼 1 × 10−12

𝐼

=

1.585 x 10-6

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

Lowest reading: 52 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

52

=

10 𝑙𝑜𝑔10 (

5.2

=

𝑙𝑜𝑔10 (

105.2

=

𝐼 1× 10−12

𝐼

=

1.585 x 10-7

Total intensity

Total SWL

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

=

1.585 x 10-6 + 1.585 x 10-7

=

1.744 x 10-6

=

10 𝑙𝑜𝑔10 (

=

62 dB

1.744×10−6 ) 1 × 10−12

96

Fig 3.30 Section of zone F

Hence the SWL in zone F for non-peak time is 52 dB. This zone records a good value due to the inactivity in the kitchen during off peak times.

97

ZONE F PEAK HOUR Highest reading: 73 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

73

=

10 𝑙𝑜𝑔10 (

7.3

=

𝑙𝑜𝑔10 (

107.3

=

𝐼 1 × 10−12

𝐼

=

1.995 x 10-5

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

Lowest reading: 58 dB 𝐼

𝑆𝐼𝐿

=

10 𝑙𝑜𝑔10 (

58

=

10 𝑙𝑜𝑔10 (

5.8

=

𝑙𝑜𝑔10 (

105.8

=

𝐼 1× 10−12

𝐼

=

6.310 x 10-7

Total intensity

Total SWL

𝐼𝑟𝑒𝑓

) , 𝐼𝑟𝑒𝑓 = 1 × 10−12

𝐼 ) 1 × 10−12

𝐼 ) 1 × 10−12

=

1.995 x 10-5

=

2.058 x 10-5

=

10 𝑙𝑜𝑔10 (

=

73 dB

+ 6.310 x 10-7

2.058×10−5 ) 1 × 10−12

98

Fig 3.31 Section of zone F

Hence the SWL in zone F for peak time is 73 dB. This zone records a fair value for a kitchen. The main noise source comes from the electrical appliances as well as staff interacting with each other at all times.

99

3.5.3 REVERBERATION TIME REVERBERATION TIME ( Zone A, Zone B, Zone C, Zone D, Zone E ) Floor Area = 177.5 m2 Total Volume = 177.5 x 4.0 ( Floor to Ceiling Height ) = 710 m3 Material absorption coefficient at 500 Hz for peak hour with 20 people occupying the space Component Column Wall Wall Counter Wall Wall Window Counter Top Table Sofa Door 20 People

Material Plywood with Concrete Finish Rough Concrete Clay Brick Silica Brick Polished Concrete Faux Stone Glass Timber Timber Cotton Timber

Reverberation Time

= = =

Absorption Coefficient (500Hz), S 0.17

Area (m2), A 22.1

Sound Absorption (SA) 3.757

0.05 0.03 0.03 0.05

127.3 97.6 19.4 47.3

6.365 2.928 0.582 2.365

0.1 0.18 0.25

13.1 15.5 4.8

1.31 2.79 1.2

0.25 1.23 0.15 0.46 per person

11.6 48 5.46

2.9 59.04 0.819 9.2 Total Absorption 93.256

0.16 đ?&#x2018;&#x2030; đ??´ 0.16Ă&#x2014;710 93.256 1.22 s

100

REVERBERATION TIME ( Zone A, Zone B, Zone C, Zone D, Zone E ) Floor Area = 177.5 m2 Total Volume = 177.5 x 4.0 ( Floor to Ceiling Height ) = 710 m3 Material absorption coefficient at 2000 Hz for peak hour with 20 people occupying the space Component Column

Wall Wall Counter Wall Wall Window Counter Top Table Sofa Door 20 People

Material Plywood with Concrete Finish Rough Concrete Clay Brick Silica Brick Polished Concrete Faux Stone Glass Timber Timber Cotton Timber

Reverberation Time

= = =

Absorption Coefficient (2000Hz), S 0.10

Area (m2), A 22.1

Sound Absorption (SA) 2.21

0.05

127.3

6.365

0.04 0.04 0.05

97.6 19.4 47.3

3.904 0.776 2.365

0.04 0.07 0.37

13.1 15.5 4.8

0.524 1.085 1.776

0.37 1.00 0.15 0.51 per person

11.6 48 5.46

4.292 48 0.819 10.2 Total Absorption 82.316

0.16 đ?&#x2018;&#x2030; đ??´ 0.16Ă&#x2014;710 82.316 1.38 s

101

REVERBERATION TIME ( Zone A, Zone B, Zone C, Zone D, Zone E ) Floor Area = 177.5 m2 Total Volume = 177.5 x 4.0 ( Floor to Ceiling Height ) = 710 m3 Material absorption coefficient at 500 Hz for non-peak hour with 8 people occupying the space Component Column

Wall Wall Counter Wall Wall Window Counter Top Table Sofa Door 8 People

Material Plywood with Concrete Finish Rough Concrete Clay Brick Silica Brick Polished Concrete Faux Stone Glass Timber Timber Cotton Timber

Reverberation Time

= = =

Absorption Coefficient (500Hz), S 0.17

Area (m2), A 22.1

Sound Absorption (SA) 3.757

0.05

127.3

6.365

0.03 0.03 0.05

97.6 19.4 47.3

2.928 0.582 2.365

0.1 0.18 0.25

13.1 15.5 4.8

1.31 2.79 1.2

0.25 1.23 0.15 0.46 per person

11.6 48 5.46

2.9 59.04 0.819 3.68 Total Absorption 87.736

0.16 đ?&#x2018;&#x2030; đ??´ 0.16Ă&#x2014;710 87.736 1.29 s

102

REVERBERATION TIME ( Zone A, Zone B, Zone C, Zone D, Zone E ) Floor Area = 177.5 m2 Total Volume = 177.5 x 4.0 ( Floor to Ceiling Height ) = 710 m3 Material absorption coefficient at 2000 Hz for non-peak hour with 8 people occupying the space Component Column

Wall Wall Counter Wall Wall Window Counter Top Table Sofa Door 8 People

Material Plywood with Concrete Finish Rough Concrete Clay Brick Silica Brick Polished Concrete Faux Stone Glass Timber Timber Cotton Timber

Reverberation Time

= = =

Absorption Coefficient (2000Hz), S 0.10

Area (m2), A 22.1

Sound Absorption (SA) 2.21

0.05

127.3

6.365

0.04 0.04 0.05

97.6 19.4 47.3

3.904 0.776 2.365

0.04 0.07 0.37

13.1 15.5 4.8

0.524 1.085 1.776

0.37 1.00 0.15 0.51 per person

11.6 48 5.46

4.292 48 0.819 4.08 Total Absorption 76.196

0.16 đ?&#x2018;&#x2030; đ??´ 0.16Ă&#x2014;710 76.196 1.49 s

103

REVERBERATION TIME ( Zone F ) Floor Area = 31.2 m2 Total Volume = 31.2 x 4.0 ( Floor to Ceiling Height ) = 124.8 m3 Material absorption coefficient at 500 Hz for peak hour with 3 people occupying the space Component Wall Kitchen Counter Door 3 People

Material Concrete Stainless Steel Timber

Reverberation Time

= = =

Absorption Coefficient (500Hz), S 0.05 0.25

Area (m2), A 93.5 11.5

0.15 0.46 per person

1.89

Sound Absorption (SA) 4.675 2.875

0.2835 1.38 Total Absorption 9.2135

0.16 đ?&#x2018;&#x2030; đ??´ 0.16Ă&#x2014;124.8 9.2135 2.17 s

104

REVERBERATION TIME ( Zone F ) Floor Area = 31.2 m2 Total Volume = 31.2 x 4.0 ( Floor to Ceiling Height ) = 124.8 m3 Material absorption coefficient at 2000 Hz for peak hour with 3 people occupying the space Component Wall Kitchen Counter Door 3 People

Material Concrete Stainless Steel Timber

Reverberation Time

= = =

Absorption Coefficient (2000Hz), S 0.05 0.15

Area (m2), A 93.5 11.5

0.15 0.51 per person

1.89

Sound Absorption (SA) 4.675 1.725

0.2835 1.53 Total Absorption 8.2135

0.16 đ?&#x2018;&#x2030; đ??´ 0.16Ă&#x2014;124.8 8.2135 2.43 s

105

REVERBERATION TIME ( Zone F ) Floor Area = 31.2 m2 Total Volume = 31.2 x 4.0 ( Floor to Ceiling Height ) = 124.8 m3 Material absorption coefficient at 500 Hz for non-peak hour with 1 people occupying the space Component Wall Kitchen Counter Door 1 People

Material Concrete Stainless Steel Timber

Reverberation Time

= = =

Absorption Coefficient (500Hz), S 0.05 0.25

Area (m2), A 93.5 11.5

0.15 0.46 per person

1.89

Sound Absorption (SA) 4.675 2.875

0.2835 0.46 Total Absorption 8.2935

0.16 đ?&#x2018;&#x2030; đ??´ 0.16Ă&#x2014;124.8 8.2935 2.41 s

106

REVERBERATION TIME ( Zone F ) Floor Area = 31.2 m2 Total Volume = 31.2 x 4.0 ( Floor to Ceiling Height ) = 124.8 m3 Material absorption coefficient at 2000 Hz for non-peak hour with 1 people occupying the space Component Wall Kitchen Counter Door 1 People

Material Concrete Stainless Steel Timber

Reverberation Time

= = =

Absorption Coefficient (2000Hz), S 0.05 0.15

Area (m2), A 93.5 11.5

0.15 0.51 per person

1.89

Sound Absorption (SA) 4.675 1.725

0.2835 0.51 Total Absorption 7.1935

0.16 đ?&#x2018;&#x2030; đ??´ 0.16Ă&#x2014;124.8 7.1935 2.78 s

107

3.5.3.1 REVERBERATION TIME ANALYSIS Zoning Of spaces Zone A, B, C, D, E Zone F

Non-Peak 500 Hz 1.29 s

Reverberation Time Peak 2000 Hz 500 Hz 1.49 s 1.22 s

2000 Hz 1.38 s

2.41 s

2.78 s

2.43 s

2.17 s

3.5.3.2 REVERBERATION TIME CONCLUSION Since zone A, zone B, zone C, zone D, zone E are combined together, the majority of activities takes

place

within

these

areas.

According

to

http://info.soundofarchitecture.com/blog/recommended-reverberation-times-for-7-key-spaces, the standard reverberation time for a restaurant dining area is 0.7 - 0.8 seconds. From our analysis of DK café, the reverberation time do not meet the standard requirement for a restaurant/café.

From our opinion, the reverberation time of DK café is longer because different kinds of spaces are combined together without partitioning. Longer reverberation time in zone A, B, C and D cause the noise to stay longer in these areas. This can also be attributed to the lack of sound absorbing materials in these zones which cause the reverberation time to be slightly longer than the standard value.

108

3.5.4 SOUND REDUCTION INDEX (SRI) Building Element Material

Wall 1 Wall 2 Door

Concrete Concrete Timber

Sound Reduction Index, SRI (dB) 44 44 20

Transmission Coefficient, T

Area (m2), S

3.98 x 10-5 3.98 x 10-5 1.0 x 10-2 â&#x2C6;&#x2018; Total Surface Area

28.6 4.48 1.89 34.97

1 ) đ?&#x2018;&#x2021;đ?&#x2018;&#x17D;đ?&#x2018;Ł

Transmission Loss, TL

= 10 đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D; (

đ?&#x2018;&#x2021;đ?&#x2018;&#x17D;đ?&#x2018;Ł

=

đ?&#x2018;&#x2021;đ?&#x2018;&#x203A; đ?&#x2018;&#x2020;đ?&#x2018;&#x203A;

= Transmission Coefficient of material = Surface Area of Material 1 = 10 đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D; ( ) đ?&#x2018;&#x2021;

Overall SRI

đ?&#x2018;&#x2020;1 đ?&#x2018;&#x2021;1 + đ?&#x2018;&#x2020;2 đ?&#x2018;&#x2021;2 + â&#x2039;Ż đ?&#x2018;&#x2020;đ?&#x2018;&#x203A; đ?&#x2018;&#x2021;đ?&#x2018;&#x203A; đ?&#x2018;&#x2021;đ?&#x2018;&#x153;đ?&#x2018;Ąđ?&#x2018;&#x17D;đ?&#x2018;&#x2122; đ?&#x2018;&#x2020;đ?&#x2018;˘đ?&#x2018;&#x;đ?&#x2018;&#x201C;đ?&#x2018;&#x17D;đ?&#x2018;?đ?&#x2018;&#x2019; đ??´đ?&#x2018;&#x;đ?&#x2018;&#x2019;đ?&#x2018;&#x17D;

Concrete Wall 1 TL

=

44

=

Antilog 4.4

=

T

=

1 10 đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D; ( ) đ?&#x2018;&#x2021; 1 10 đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D; ( ) đ?&#x2018;&#x2021; 1 ( ) đ?&#x2018;&#x2021; 3.98 x 10-5

Concrete Wall 2 TL

=

44

=

Antilog 4.4

=

T Timber Door

=

1 10 đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D; ( ) đ?&#x2018;&#x2021; 1 10 đ?&#x2018;&#x2122;đ?&#x2018;&#x153;đ?&#x2018;&#x201D; ( ) đ?&#x2018;&#x2021; 1 ( ) đ?&#x2018;&#x2021; 3.98 x 10-5

109

1 10 𝑙𝑜𝑔 ( ) 𝑇 1 10 𝑙𝑜𝑔 ( ) 𝑇 1 ( ) 𝑇

TL

=

20

=

Antilog 2.0

=

T

=

1.0 x 10-2

Tav

=

(28.6)(3.98 𝑥 10−5 ) + (4.48)(3.98 𝑥 10−5 ) + (1.89)(1.0 𝑥 10−2 ) (28.6 + 4.48 + 1.89)

Tav

=

5.78 x 10−4

Overall SRI

=

10 𝑙𝑜𝑔 (

=

32 dB

1 ) 5.78 𝑥 10−4

110

3.6 CONCLUSION FOR ACOUSTICAL ANALYSIS OF D KAFFÉ The acoustic issues that are present in D Kaffé are mostly due to the large volume of spaces that are combined together without partitioning. Therefore, the sound from the speakers, coffee machine, dart game machine and air conditioner is transferred more easily to the connected areas. This causes acoustical disturbance to different areas since they have different purposes. By introducing better enclosed partitioning to act as acoustical buffer, it can reduce the acoustical disturbance that occur within the large volume space.

The acoustical environment of a space also depends on the selection of materials with different acoustic absorption characteristics. Hence, appropriate usage of materials can assist in providing optimum reverberation time as well as less sound transferred from one space to another. One of the solution to alleviate this issue is to use absorbing acoustic panels and soundproofing to eliminate sound reflections at D Kaffé.

111

References Ander, G. D. (2014). Daylighting. Retrieved November 03, 2016, from Whole Building Design Guide : http://www.wbdg.org/resources/daylighting.php Comfortable Low Energy Architecture . (N/D). Daylight Factors . Retrieved November 3 , 2016, from Comfortable Low Energy Architecture : http://www.newlearn.info/packages/clear/visual/daylight/analysis/hand/daylight_factor.html Konica Minolta. (2016). Luminance vs. Illuminance. Retrieved November 03, 2016, from Konica Minolta: http://sensing.konicaminolta.us/2015/08/luminance-vs-illuminance/ Mahbub, A., Kua, H., & Lee, S. (2011, June 9). A Total Building Performance Approach to Evaluating Building Acoustics Performance. Architectural Science Review(53), 213-223. doi:10.3763/asre.2009.0032 McKeegan, A. (2013). Lumen Method . Retrieved November 2016, from Student Notes : http://studentnotes.co.uk/2360/lumen_method.php N/A. (2013). Artificial Lighting Types and Design. Retrieved November 3, 2016, from Electrical Know How : http://www.electrical-knowhow.com/2012/03/artificial-lighting-types-and-design.html Nedhal, A., Syed, F. S., & Adel, A. (2016, September). Relationship between Window to Floor Area Ratio and Single Point Daylight Factor in Varied Residential Rooms in Malaysia.

Indian Journal of Science and Technology, 9(33). doi:10.17485/ijst/2016/v9i33/86216 Palacio, V. (2015, January 27). Light in Architecture. Retrieved November 2016, from International Year of light 2015: https://light2015blog.org/2015/01/27/light-in-architecture/

Stark, G. (2016). Light. Retrieved November 2016, from Encyclopaedia Briannica: https://global.britannica.com/science/light

112