BUILDING SCIENCE 2 [ARC 3413]
Project 1
Lighting & Acoustic Performance Evaluation and Design
Case Study:
Food Industrie Cafe
(3, Jalan SS13/4, Subang Jaya,Subang Jaya, 47500, Selangor)
Angeline Kon 0302068
Ang Yik Chiu 0303443
Choo Ai Lin 0317253
Tan Hui Xian 0311719
Wong Kwok Kenn 0300146
Khoo Chee Mei 0303125
Table of Content 1.0 Introduction ………………………………………………………………………….. 1 - 3
1.1 Introduction 1.1 Aim and Objectives 1.3 Case study introduction 1.4 Limitation of Study 1.5 Measured Drawings
2.0 Precedent Studies……………………………………………………………………. 4 - 8
2.1 Lighting- Giacometti café
2.2 Conclusion 3.0 Lighting Study ………………………………………………………………………. 9 - 45
3.1 Research Methodology
-Description of Equipment - Data Collection Method
- Standard MS 1525 LUX Recommendation - Data Constrain -Lighting Analysis Calculation Method
Daylighting Factor (DF) Lumen Method Calculation
3.2 Case Study
3.2.1 Existing Lighting Condition - Natural Lighting (Daylight) -Artificial Lighting -Types of Artificial Light
3.2.2 Lighting Reflectance of Materials 3.3 Lighting Analysis
3.3.1 Lighting Data - Lux Data at peak and non-peak hour at 1m - Lux Data at peak and non-peak hour at 1.5m
3.3.2 Lux Contour Diagram - Peak hour- Lux Contour Diagram - Non-peak hour- Lux Contour Diagram
3.3.3 Lighting Analysis and Calculations
- Daylighting Factor (DF) - Lumen Method Calculations - Room Index (RI) -Zone A- Outdoor corridor -Zone B- Sitting area near entrance -Zone C- Sitting area at the center -Zone D- Sitting area at corner -Zone E- Bar and counter -Zone F- Sitting area next to zone D - Data Tabulation: Lux Meter Reading
4.0 Precedent Studies………………………………………………………………… 46 – 49 4.1 Acoustic- The Music Café, August Wilson Center 4.2 Conclusion
5.0 Acoustic Study ………………………………………………………………….. 50 - 101 5.1 Research Methodology
- Description of Equipment - Data Collection Method
- Standard MS 1525 dB Recommendation - Data Constrain - Acoustic Analysis Calculation Method
-Reverberation Time (RT) -Sound Pressure Level (SPL) -Sound Reduction Index (SRI)
5.2 Case Study 5.2.1 Existing Acoustic Condition
- External Noise Source - Site Context - Vehicular
- Internal Noise Source - Speaker - Ceiling Fan - Television - Juice Blender - Human Activities 5.2.2 Acoustical Characteristics of Materials
5.3 Acoustic Analysis
5.3.1 Acoustic Data - Non-Peak Hours Acoustic Data - Peak Hours Acoustic Data
5.3.2 Noise Contour Diagram - Non-peak Hours Noise Contour Diagram - Peak hours Noise Contour Diagram
5.3.3 Acoustic Ray diagram
5.3.4 Sound absorbance coefficient
5.3.5 Acoustic Analysis and Calculations -Zone A- Outdoor cooridor -Zone B- Sitting area near entrance -Zone C- Sitting area at the center -Zone D- Sitting area at corner -Zone E- Bar and counter -Zone F- Sitting area next to zone D
Reverberation time (RT) Calculations
Sound Pressure Level (SPL) Calculations
Sound Reduction Index (SRI) 6.0 Conclusion …………………………………………………………………………. 102
7.0 References ………………………………………………………………………… 103
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1.0 Introduction of Project
1.1 Introduction
The research is conducted for the study of lighting and acoustic characteristics requirement in a
suggested space and determine the characteristics function of day-lighting and artificial lighting
and acoustic performance within the intended space which we have chosen to conduct on a
cafe named as Food Industrie which is located in SS13. We have recorded and observed the
lighting at day and night and acoustic condition during morning, afternoon, evening and night.
The factors affecting the lighting and acoustic which include materials, spatial layout, colors,
textures and fittings in the café is identified to study how they affect the design of the space
itself. Site analysis and a complete set of documentation report which include the calculations of
the lighting and acoustic data.
1.2 Aim and objective
The aim and objectives throughout this projects is to understand and comprehend the day-
lighting and lighting and acoustic characteristic and acoustic requirement in the site selected
which is a cafe for our group. To determine the characteristics and function of day-lighting and
artificial lighting and sound and acoustic within the intended space. To critically report and
analyses the space and suggest remedies to improvise the lighting and acoustic quality within
the space.
1.3 Case study Introduction
Food Industrie is a food café which situated in the center of industrial area of SS13 which comprises of factories, commercial and office areas. This research site is located at 3, Jalan SS13/4, Subang Jaya,Subang Jaya, 47500, Selangor. Food Industrie is a welcoming set-up with its location with private parking spaces because there are another café and church within the compound. People who visits there are commonly church member of Harvest City KL, student and workers nearby. They operate from 12pm-10.30 pm from Tuesday to Friday, 12pm-9pm at Saturday and 8am to 3pm at Sunday. This cafe is a popular spot for meet up and chilling especially for church member and workers around the area to socialize around. Free wifi is provided and outside food is allowed in this café. The philosophy of this cafe is to provide a good platform for people to gather and share their thoughts.
Figure 1.3.1: Location of Food industrie (Source: Google map)
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Figure 1.3.2 : Exterior of Food Industrie.
Figure 1.3.3 : Artistic ambience of the café provides a comfortable area for dining.
Figure 1.3.4 Curtain wall design gives sufficient daylight to customers.
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1.4 Site limitation
The business premise operates from 12pm-10.30 pm from Tuesday to Friday, 12pm-9pm at Saturday and 8am to 3pm at Sunday. Therefore, morning is not operating for business except for Sunday and night do not operate for business on Sunday.
1.5 Measured Drawing
Figure Scale 1:200
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2.0 Precedent Study
2.1 Lighting case study- Café Giacometti
Introduction
The café sits on the first floor of the SG building, the Cafe Giacometti was selected. It is a café located at campus of École Polytechnique Fédérale de Lausanne, Switzerland.
Figure 2.1.1 :Cafe Giacometti, Switzerland.
Figure 2.1.2 : Interior of Café Giacometti.
Objective:
To test the concept of distinct light-syntax zones and develop a workflow for identifying these zones, a case study was performed on a daylit space with a changing flow of occupants.
Spaces criteria:
● a variety of daylight conditions, both direct and indirect
● a variety of spatial conditions, both open and secluded
● freedom of movement for occupants
● in use throughout the day
● used for more than one activity (i.e. studying or eating)
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● small enough for a single observer to take frequent, accurate observations
Both direct and indirect lighting are found in the cafe – direct in the southwest corner, where a large unshaded window allows sunlight to fall on the tables and indirect in the rest of the highly-glazed space – as well both an open and less open space. The views from each of these windows are roughly analogous, as one looks out on the BM laboratory building and one looks out of the SV laboratory building. The cafe is open between 8:00 AM until 4:00 PM or 6:00 PM, depending on the part of the year, allowing for observations to be made under varying light conditions. The cafe is a relatively compact space and generally has 83 seats, as well as three standing tables. The cafe is located in a classroom building largely dedicated to architecture and urbanism courses.
The Giacometti was also seen as ideal because the electric lighting is usually turned off during the day in the summer months due to the copious quantities of daylight, making simulations of the interaction of artificial and natural light unnecessary.
A. 8am to 12pm B. 12pm to 4pm C. 4pm to 8pm
Figure 2.1.3. Average simulated illuminance for the months of May and June in the café between the hours shown. Proposed window light zones are outlined in red.
Based on the diagram, the maximum and minimum illuminance varies in the central part of the cafe and the small secluded area in the southwest corner.
Morning- area closest to the eastern glazing peaks at almost 3000 lux and drops to about 1000 lux near the counter. By contrast, the unshaded window on the south results in a patch of 7000 lux, though near the wall it drops to about 500 lux.
Afternoon- central area is closer to 2000 lux. The secluded southwestern area still gets 6500 lux near the window.
Evening-- central area is closer to 800 lux. the secluded southwestern area still gets 1500 lux near the window.
Though the maximum and average horizontal illuminance vary significantly by time of day, the relative spatial illuminance variation remains roughly consistent. These variations are distinct between the area adjacent to the shaded glazing (the largest part of the cafe) and the area adjacent to the unshaded glazing (the secluded area in the southwest corner.) A section cut through the center of each glazing during the morning hours gives the image shown in figure 7.
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A. 8am to 12pm B. 12pm to 4pm C. 4pm to 8pm
Figure 2.1.4. Rate of change in illuminance as distance from the window during 3 different time zones. Changes in reflection are circled in red.
Discussion
In mostly daylit multifunctional spaces, natural light must provide enough light to work by while not causing discomfort. Levels of between 75 and 300 lux are suggested for interior spaces, depending on the nature of the activity performed there, from eating to reading [1,4]. Direct light on a horizontal work surface may be perceived as uncomfortable due to high contrast ratios. Presumably individuals who come to a cafe to work choose a space where they perceive they will have sufficient light for their task. While it seems likely that people might move to maximize their visual comfort in a space where this is possible, visual comfort is very difficult to assess in such a fluid environment. However, daylight also causes veiling glare on devices with screens, such as laptops and smartphones, which may form another basis for occupant decision-making when navigating and selecting a seat in a daylit space.
The occupancy rate, ORtot, was calculated with the following formula: ORtot = total 5-minute timesteps occupied during observation/total 5-minute timesteps observed The independent and dependent variables in the observation experiment are shown below in figure 2.1.5. (ORh = total 5-minute timesteps occupied during hour/total 5-minute timesteps observed during hour.)
Figure 2.1.5 Independent and dependent variables in observation experiment.
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Figure 2.1.6. Occupancy (ORtot) heat map for A. morning observation block B. midday observation block C. afternoon observation block.
The overall occupancy is much higher on diffuse light condition days – probably due to weather conditions. The cafe tends to empty out into the neighboring courtyard when it is sunny. The difference in occupancy patterns between light conditions is not because occupants are preferentially choosing to sit by the window when that zone is better defined, but because the much higher ratio of occupants on diffuse light condition days (overcast skies) forces them to occupy even less-desirable seats, such as the aisle seats.
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Limitations
The zone definition with regards to light and the correlations developed in the analysis are both based on simulations in this report. It would be useful to validate these daylight profiles with lux measurements carried out in the space. These real-life measurements could be used to tailor the zone boundaries and the correlations appropriately.
2.2 Conclusion
Figure 2.2.1 Work Flow (for reference)
In conclusion, the case study in the Giacometti suggested that segmenting a space by visual integration values is a useful way to identify parts of a public indoor area with significantly different occupancy rates. The impact of light remains less sure because areas of high illuminance in the cafe overlap almost perfectly with areas of low physical connectivity. While exterior light condition has a significant effect on occupancy rates, it cannot be put down with certainty to the response of occupants to light – or to the weather. While the case study in the Giacometti café can apply into our site, Food industrie by considering the weather changes, people occupancy, furniture arrangement and artificial light arrangement and designing.
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3.0 Lighting study
3.1 Research methodology
3.1 Research Methodology
3.1.1 Methodology Step of data collection:
1. Press Leq once to switch on the lux meter.
2. Switch to correct measuring range (10 Lux).
3. Holding lux meter at 1m height when recording.
4. Collect data displayed on the meter.
5. Repeat step 3 & 4 at 1.5m height for second reading.
Diagram 3.1.1a - Position of the meter (1m) Diagram 3.1.1b - Position of the meter
(1.5m)
Calculation Formula
Daylight Factor Daylight factor is the percentage of ratio that represents the amount of
illumination available indoors relative to the illumination present outdoors at the same time
under overcast sky. (Malaysia standard outdoor daylight level: 32000 lux)
Formula: DF = Ei / Eo x 100%
DF = Daylight factor
Ei = Indoor illuminance Eo = Outdoor illuminance
Figure3.1.2 Lumen Method (Source: Department of Standards Malaysia (MS 1525:2007)
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The Lumen Method is used to determine the number of lamps that should be installed for a
given area or room.
Formula: N x n = (E x A) / (F x UF x MF)
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 luminaries at the room
surfaces.
MF = Maintenance factor, an allowance for reduced light output because of deterioration
and dirt.
Figure 3.1.3 The recommended average illuminance (Source: Department of Standards
Malaysia (MS 1525:2007)
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3.2 Case Study
3.2.1 Existing Lighting Condition
Located in Subang Jaya, Food Industrie Cafe is set in City Harvest Church as shown in Figure 3.2.1.1. The café has three façade which is east, facing carpark space, north façade facing front entrance and south façade which is next to Grey Sky Morning Café.
The feature of local climate, sun path and appearance of Grey Sky Morning Café such as its height, colour tone and shadows will be taken into consideration while conducting lighting analysis.
City Harvest Church Car Park
Food Industrie Cafe Grey Sky Morning Cafe
Figure 3.2.1.1 Site map
Figure 3.2.1.2 Front Entrance of the Food Industrie Cafe
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Figure 3.2.1.3 Car Parking space in front of the Food Industrie Cafe
Figure 3.2.1.4 Grey Sky Morning Café is just at the next door
of the Food Industrie Cafe
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3.2.2 Lighting Reflectance of Materials
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3.3 Lighting Analysis
3.3.1 Lighting Data
Coordinate A B C D E F G H I
Non-Peak hour (9am-11am) reading, Lux
1 _ _ 62 112 143 64 48 _ _
2 53 65 123 84 46 53 58 _ _
3 56 91 85 92 84 93 87 _ _
4 62 182 126 163 105 122 93 _ _
5 64 197 184 144 163 212 58 _ _
6 60 216 215 247 258 402 513 _ _
7 47 426 387 502 325 789 1113 1457 2486
8 _ _ 638 695 686 1412 1873 1765 2743
9 _ _ 327 300 288 305 300 235 284
Peak Hour (1pm-3pm) reading, Lux
1 _ _ 74 77 126 85 75 _ _
2 74 85 75 55 115 85 55 _ _
3 117 56 96 106 84 86 77 _ _
4 106 104 86 97 104 46 84 _ _
5 65 93 107 196 154 148 119 _ _
6 95 78 165 207 165 226 195 _ _
7 59 67 226 307 397 476 487 1408 3557
8 _ _ 659 555 687 668 997 1705 4216
9 _ _ 155 116 104 103 142 123 350
Table 3.1.1.1 Data Tabulation during Non-peak Hour and Peak hour at a height of 1.0m.
Coordinate A B C D E F G H I
Non-Peak hour (9am-11am) reading, Lux
1 _ _ 133 91 136 57 42 _ _
2 42 48 57 62 42 46 31 _ _
3 42 45 52 57 56 54 78 _ _
4 43 55 94 102 96 84 75 _ _
5 56 84 86 17 105 124 94 _ _
6 74 85 89 18 83 187 398 _ _
7 62 98 125 24 246 654 814 1074 1463
8 _ _ 152 214 283 964 1168 1217 1268
9 _ _ 187 130 107 127 227 120 168
Peak Hour (1pm-3pm) reading, Lux
1 _ _ 64 83 285 105 64 _ _
2 57 56 63 54 174 126 43 _ _
3 93 52 105 82 64 94 53 _ _
4 87 117 94 84 63 84 76 _ _
5 73 74 83 115 106 107 63 _ _
6 84 77 115 157 204 207 183 _ _
7 54 53 197 217 305 194 294 854 2338
8 _ _ 516 397 473 457 735 1054 3284
9 _ _ 74 61 57 75 106 106 212
Table 3.1.1.2 Data Tabulation during Non-peak Hour and Peak hour at a height of 1.5m.
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Figure 3.1.1.3 Zoning Diagram
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Figure3.1.1.4: Lighting data at 9am
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Figure3.1.1.5: Lighting data at 1pm
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Figure3.1.1.6: Lighting data at 4pm
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Figure3.1.1.7: Lighting data at 7pm
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The lux reading is divided into both peak and non-peak hours, with the peak hours being the
duration with a higher amount of people, and the non-peak hours being the duration with a
lower amount of people. The period between 9am and 11am is set as the non-peak hour,
and the period between 1pm and 3pm is set as the peak hour. The artificial lights were
partially switched on during the data collection.
The front of the building faces the East, and since the sun rises from the East, the space
receives a great amount of direct sunlight through the curtain glass at the front of the
building. The space is brightly lit and therefore, the readings would be higher during the
morning. Whereas when the sun sets in the West, the back of the building is against the
direction of the sun. The space is not as brightly lit, thus the readings would be lower during
the evening. Based on the data collected, some of the luminance values for the interior
spaces are below average as these spaces are enclosed, unable to receive sunlight.
3.3.2 Lux Contour Diagram
Daytime Lux Contour Diagram
Diagram 3.3.2.1 Sun path diagram
Diagram 3.3.2.1 shows the sun path of 9am morning, where the natural daylight are
obtainable through the openings around the building. Front and front right part of the
building are covered with single glazed glass opening, hence natural daylighting are able to
transmit into the interior of the building. But due to the building on the left, which shaded the
whole left part of the building, preventing the natural daylighting from transmitting.
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Non-peak hours
Diagram 3.3.2.2(a) 1 meter height lux contour map recorded at 9 AM
Lux contour diagram shown in diagram 3.3.2.2(a), readings were recorded at height of 1
meter in the morning, approximately around 9 AM. Showing that the blue coloured part of the
interior hardly receive any daylight hence higher luminance artificial lighting is needed to light
up the interior spaces. The front outdoor and indoor sitting area close to the glass opening,
receive sufficient daylight throughout the day shaded by a few columns in front of the
building.
Diagram 3.3.2.2(b) 1.5 meter height lux contour map recorded at 9 AM
Lux contour diagram shown in diagram 3.3.2.2(b), readings were recorded at height of 1.5
meter in the morning, approximately around 9 AM. Since the measuring height are higher, it
does affect the readings by half. According to our analysis, the higher it goes, the harder for
the daylight to transmit into the building. In our conclusion, height of ceiling directly affects
the building and spaces from obtaining sufficient daylight.
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Peak hours
Diagram 3.3.2.2(c) 1 meter height lux contour map recorded at 1 PM
Lux contour diagram shown in diagram 3.3.2.2(c), readings were recorded at height of 1
meter in the afternoon, approximately around 1 PM. During peak hours the blue coloured
part interior receive lesser daylight compared to non-peak hours, both of them are measure
at the same height which is 1 meter. According to our analysis, users activities has prevent
part of the interior from receiving daylight during peak hours. The more activities occurring
inside the interior, the lesser the interior receive daylight.
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Diagram 3.3.2.2(d) 1.5 meter height lux contour map recorded at 1 PM
Lux contour diagram shown in diagram 3.3.2.2(d), readings were recorded at height of 1.5
meter in the afternoon, approximately around 1 PM. Since the human activities and
measuring height affects the interior from receiving light, diagram 3.3.2.1(d) have the worst
light transmit among all the other diagrams above. It’s affected by both the measuring height
and human activities that prevent light from entering the interior, as mentioned in analysis
before.
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3.3.3 Lighting Data Analysis
Zone A (Outdoor)
Area: 39 m2
Figure 3.3.3.1 Zoning plan and photo of outdoor corridor area
Zone A is the exterior open space in front of the building. This space receives the most light
especially during the morning. This is because the front of the building faces the East and
since the sun rises from the East, the space receives a great amount of direct sunlight
especially during the morning. The space is brightly lit and therefore, the readings at zone A
would be higher compared to the other zones.
Calculation:
Time
Weather
Luminance,
lx (Im)
Average
Luminance,
lx
Luminance,
lx (I.5m)
Average
Luminance,
lx
9am - 11pm Clear Sky 235 - 327 281 107 - 227 167
1pm - 3pm Clear Sky 103 - 350 226.5 57 - 212 134.5
Average Lux Reading 9am – 11am 1pm – 3pm
At 1m walking plane
(sitting position), lx
281
226.5
At 1.5m walking plane
(standing position), lx
167
134.5
Average lux value, lx 224 180.5
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9am - 11am
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (224/32000) x 100
= 0.7 %
1pm - 3pm
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (180.5/32000) x 100
= 0.56 %
The average lux value of Zone A during non-peak hour ( 9am to 11 am) is 224 lux, while
peak hour (1pm to 3 pm) is 180.5 lux. Although the zone is facing the east, but due to the
presence of a long and large overhang over that zone, which hinders the zone from
receiving direct sunlight. Daylight factor of non-peak hour is 0.7% and peak hour, 0.56%.
Location Zone A (Outdoor)
Dimension L= 13.644m, W= 2.858
Area 39m²
Height of ceiling 3.7m
Height of luminaries 3.2m
Height of work level 0.8m
Vertical distance from work place to
luminaries
2.4m
Standard Illuminance 100 lux
Reflection Factors Ceiling: Exposed concrete (0.3)
Wall: Glass (0.9)
Floor: concrete (0.3)
Room Index = (LxW)/((L+W)xH)
= (13.644x2.858)/((13.644+2.858)x2.4)
= 0.98
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Utilization Factor 0.39 / 39%
Maintenance Factor 0.8
Type of light Cylindrical black ceiling light (short)
Warm white, 30W, 66lm/W, 2000lm
Illuminance level required E = (n x N x F x UF x MF)/A
= (1x4x2000x0.39x0.8)/39
= 64 lux
100lux - 64lux = 36lux
According to MS1525, Zone A lacks of 36
lux to fulfill the requirement.
Number of light required For using Cylindrical black ceiling light
(short) at I lamps per luminaire:
N = (E x A)/(F x UF x MF)
= (100x39)/(2000x0.39x0.8)
= 7 lamps
According to MS1525, Zone A needs 7
lamps to fulfill the requirement.
7 lamps – (1x4) lamps = 3 lamps
According to MS1525, Zone A lacks of 3
lamps to fulfill the requirement.
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Zone B
Area: 61.8 m2
Figure 3.3.3.2 Zoning plan and photo of sitting area near entrance
Zone B is the interior space closest to the entrance of the space. This spaces receives a lot
of light as well because it is the closest space to the curtain glass wall which envelops the
front façade of the space. Therefore, the readings at zone B are rather high as well.
Calculation:
Time
Weather
Luminance,
lx (Im)
Average
Luminance,
lx
Luminance,
lx (I.5m)
Average
Luminance,
lx
9am - 11pm Clear Sky 247- 2743 1495 18 - 1463 740.5
1pm - 3pm Clear Sky 165 - 4216 2190.5 157 – 3284 1720.5
Average Lux Reading 9am – 11am 1pm – 3pm
At 1m walking plane
(sitting position), lx
1495
740.5
At 1.5m walking plane
(standing position), lx
2190.5
1720.5
Average lux value, lx 1842.75 1230.5
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9am - 11am
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (1842.75/32000) x 100
= 5.76 %
1pm - 3pm
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (1230.5/32000) x 100
= 3.85 %
The average lux value of Zone A during non-peak hour ( 9am to 11 am) is 1842.75 lux, while
peak hour (1pm to 3 pm) is 1230.5 lux. It has the highest average lux value and Daylight
Factor, which is 5.76% during non-peak hour and 3.85% during peak hour. This is because
the zone is surrounded by full curtain glass wall which allows direct sunlight to enter the
space.
Location Zone B
Dimension L= 13.644m, W= 4.53
Area 61.8m²
Height of ceiling 3.7m
Height of luminaries 3.2m
Height of work level 0.8m
Vertical distance from work place to
luminaries
2.4m
Standard Illuminance 100 lux
Reflection Factors Ceiling: Exposed concrete (0.3)
Wall: Glass (0.9)
Wall: Concrete with paint (0.3)
Floor: concrete (0.3)
Room Index = (LxW)/((L+W)xH)
= (13.644x4.53)/((13.644+4.53)x2.4)
= 1.42
Utilization Factor 0.46 / 46%
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Maintenance Factor 0.8
Type of light Cylindrical black ceiling light
Warm white, 30W, 88lm/W, 790lm
Illuminance level required E = (n x N x F x UF x MF)/A
= (1x7x790x0.46x0.8)/61.8
= 32.93 lux
100lux – 32.93lux = 67.07lux
According to MS1525, Zone B lacks of
67.07 lux to fulfill the requirement.
Number of light required For using Cylindrical black ceiling light at I
lamps per luminaire:
N = (E x A)/(F x UF x MF)
= (100x61.8)/(790x0.46x0.8)
= 22 lamps
According to MS1525, Zone B needs 22
lamps to fulfill the requirement.
22 lamps – (1x7) lamps = 15 lamps
According to MS1525, Zone B lacks of 15
lamps to fulfill the requirement.
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Zone C
Area: 60.87 m2
Figure 3.3.3.3 Zoning plan and photo of Sitting area at the centre near speakers
Zone C is brighter towards the entrance of the space, but towards the back it gets darker,
because the light intensity of the sun streaming in from the curtain glass entrance decreases
over distance. Therefore, the readings gradually decrease in value from the front to the back
of zone C.
Time
Weather
Luminance,
lx (Im)
Average
Luminance,
lx
Luminance,
lx (I.5m)
Average
Luminance,
lx
9am - 11pm Clear Sky 58- 212 135 17 - 124 70.5
1pm - 3pm Clear Sky 46 - 196 121 53 – 115 84
Average Lux Reading 9am – 11am 1pm – 3pm
At 1m walking plane
(sitting position), lx
135
121
At 1.5m walking plane
(standing position), lx
70.5
84
Average lux value, lx 102.75 102.5
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9am - 11am
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (102.75/32000) x 100
= 0.32 %
1pm - 3pm
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (102.5/32000) x 100
= 0.32 %
Zone C is a well shaded area with a daylight factor of only 0.32% for both non-peak and
peak hour. Their average lux value do not differ much as well.
Location Zone C
Dimension L= 7.725, W= 7.88
Area 60.87 m²
Height of ceiling 3.7m
Height of luminaries 3.2m
Height of work level 0.8m
Vertical distance from work place to
luminaries
2.4m
Standard Illuminance 200 lux
Reflection Factors Ceiling: Exposed concrete (0.3)
Wall: Concrete with paint (0.3)
Floor: concrete (0.3)
Room Index = (LxW)/((L+W)xH)
= (7.725x7.88)/((7.725+7.88)x2.4)
= 1.63
Utilization Factor 0.49/ 49%
Maintenance Factor 0.8
Type of light Cylindrical black ceiling light
Warm white, 30W, 88lm/W, 790lm
Black Ceiling Track Light
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Warm white, 5W, 60lm/W, 300lm
Illuminance level required E = (n x N x F x UF x MF)/A
= (1x7x790x0.49x0.8)/60.87
= 35.6 lux
E = (n x N x F x UF x MF)/A
= (1x6x300x0.49x0.8)/60.87
= 11.6lux
200lux - 35.6lux – 11.6lux = 152.8lux
According to MS1525, Zone C lacks of
152.8 lux from the requirement.
Number of light required For using Cylindrical black ceiling light at I
lamps per luminaire:
N = (E x A)/(F x UF x MF)
= (200x60.87)/(790x0.49x0.8)
= 40 lamps
According to MS1525, Zone C needs 40
lamps to fulfill the requirement.
40 lamps – [(1x7)+(1x6)] lamps = 27 lamps
According to MS1525, Zone C lacks of 27
lamps to fulfill the requirement.
Page | 34
Zone D
Area: 55.6 m2
Figure 3.3.3.4 Zoning plan and photo of sitting area at the corner
Zone D has a wall of curtain glass as well, however there is another building next to it, which
invariably blocks the sunlight from entering the building. Therefore the reading in zone D is
much lower, because its source of light is from the front entrance of the building.
Time
Weather
Luminance,
lx (Im)
Average
Luminance,
lx
Luminance,
lx (I.5m)
Average
Luminance,
lx
9am - 11pm Clear Sky 47- 426 236.5 42 - 98 70
1pm - 3pm Clear Sky 56 - 117 86.5 52 – 117 84.5
Average Lux Reading 9am – 11am 1pm – 3pm
At 1m walking plane
(sitting position), lx
236.5
86.5
At 1.5m walking plane
(standing position), lx
70
84.5
Average lux value, lx 153.25 85.5
Page | 35
9am - 11am
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (153.25/32000) x 100
= 0.48 %
1pm - 3pm
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (85.5/32000) x 100
= 0.27 %
Zone D has an average value of 153.25 during non-peak hour and 85.5 during peak hour.
Although there is a curtain glass wall on the side of the zone, however, the building next to it
has block the sunlight from directly entering the zone. The Daylight Factor of Zone D are
0.48% and 0.27% respectively.
Location Zone D
Dimension L= 12.428, W= 4.474
Area 55.6 m²
Height of ceiling 3.7m
Height of luminaries 3.2m
Height of work level 0.8m
Vertical distance from work place to
luminaries
2.4m
Standard Illuminance 200 lux
Reflection Factors Ceiling: Exposed concrete (0.3)
Wall: Exposed Brick Wall (0.3)
Wall: Glass (0.9)
Floor: concrete (0.3)
Room Index = (LxW)/((L+W)xH)
= (12.428x4.474)/((12.428+4.474)x2.4)
= 1.37
Utilization Factor 0.46/ 46%
Maintenance Factor 0.8
Type of light Cylindrical black ceiling light
Page | 36
Warm white, 30W, 88lm/W, 790lm
Black Ceiling Track Light
Warm white, 5W, 60lm/W, 300lm
Illuminance level required E = (n x N x F x UF x MF)/A
= (1x6x790x0.46x0.8)/55.6
= 31.4lux
E = (n x N x F x UF x MF)/A
= (1x4x300x0.46x0.8)/55.6
= 7.9 lux
200lux – 31.4lux – 7.9lux = 160.7 lux
According to MS1525, Zone D lacks of
160.7 lux from the requirement.
Number of light required For using Cylindrical black ceiling light at I
lamps per luminaire:
N = (E x A)/(F x UF x MF)
= (200x55.6)/(790x0.46x0.8)
= 39 lamps
According to MS1525, Zone D needs 39
lamps to fulfill the requirement.
39 lamps – [(1x6)+(1x4)] lamps = 29 lamps
According to MS1525, Zone D lacks of 29
lamps to fulfill the requirement.
Page | 37
Zone E
Area: 27.1 m2
Figure 3.3.3.5 Zoning plan and photo of bar and counter
Zone E is the counter and dry kitchen area, an enclosed interior space set at the back of the
building. This space receives the least amount of sunlight. However, it is well lit by artificial
lights to provide a source of illuminance in running the café, which includes basic cleaning
and washing and preparing the drinks or dessert.
Time
Weather
Luminance,
lx (Im)
Average
Luminance,
lx
Luminance,
lx (I.5m)
Average
Luminance,
lx
9am - 11pm Clear Sky 46 - 143 94.5 31 - 136 83.5
1pm - 3pm Clear Sky 55 - 126 90.5 43 - 285 164
Average Lux Reading 9am – 11am 1pm – 3pm
At 1m walking plane
(sitting position), lx
94.5
90.5
At 1.5m walking plane
(standing position), lx
83.5
164
Average lux value, lx 89 127.25
Page | 38
9am - 11am
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (89/32000) x 100
= 0.28 %
1pm - 3pm
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (127.25/32000) x 100
= 0.4 %
The Average lux value and Daylight Factor of Zone E is particularly low as it is an enclosed
interior space set at the back of the building which receives the least amount of sunlight.
Location Zone E
Dimension L= 8.7, W= 3.115
Area 27.1 m²
Height of ceiling 3.7m
Height of luminaries 3.2m
Height of work level 0.8m
Vertical distance from work place to
luminaries
2.4m
Standard Illuminance 150 lux
Reflection Factors Ceiling: Exposed concrete (0.3)
Wall: Exposed Brick Wall (0.3)
Floor: concrete (0.3)
Room Index = (LxW)/((L+W)xH)
= (8.7x3.115)/((8.7+3.115)x2.4)
= 0.96
Utilization Factor 0.39/ 39%
Maintenance Factor 0.8
Type of light LED Light Bulb
Warm white, 13W, 92.3lm/W, 1200lm
Page | 39
Black Ceiling Track Light
Warm white, 5W, 60lm/W, 300lm
Illuminance level required E = (n x N x F x UF x MF)/A
= (1x5x1200x0.39x0.8)/27.1
= 69 lux
E = (n x N x F x UF x MF)/A
= (1x9x300x0.39x0.8)/27.1
= 31 lux
150lux – 69 lux – 31lux = 50 lux
According to MS1525, Zone E lacks of 50
lux from the requirement.
Number of light required For using LED Light Bulb at I lamps per
luminaire:
N = (E x A)/(F x UF x MF)
= (150x27.1)/(1200x0.39x0.8)
= 11 lamps
According to MS1525, Zone E needs 11
lamps to fulfill the requirement.
11 lamps – [(1x5)+(1x9)] lamps = -2 lamps
According to MS1525, Zone E provided
extra 2 lamps.
Page | 40
Zone F
Area: 26.19 m2
Figure 3.3.3.6 Zoning plan and photo of sitting Area next to Zone D
Zone F is well lit towards the front, but it gets dark towards the back because the light
intensity of the sun streaming in from the curtain glass entrance decreases over distance.
Therefore, the readings gradually decrease in value from the front to the back of zone F.
Based on the data collected, some of the luminance values for the interior spaces are below
average as these spaces are enclosed, unable to receive sunlight.
Time
Weather
Luminance,
lx (Im)
Average
Luminance,
lx
Luminance,
lx (I.5m)
Average
Luminance,
lx
9am - 11pm Clear Sky 85 - 387 236 52 - 125 88.5
1pm - 3pm Clear Sky 86 - 226 156 83 - 197 140
Average Lux Reading 9am – 11am 1pm – 3pm
At 1m walking plane
(sitting position), lx
236
156
At 1.5m walking plane
(standing position), lx
88.5
140
Average lux value, lx 162.25 148
Page | 41
9am - 11am
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (162.25/32000) x 100
= 0.51 %
1pm - 3pm
DF = (E internal/ E external) x 100, E external = direct sunlight = 32000 lx
= (148/32000) x 100
= 0.46 %
Zone F is located in the middle, surrounded by other zones. The sunlight that has been
transmitted from other zones especially zone B, contributed to the reading of Average lux
value and Daylight Factor of the Zone F.
Location Zone F
Dimension L= 12.486m, W= 2.098
Area 26.19²
Height of ceiling 3.7m
Height of luminaries 3.2m
Height of work level 0.8m
Vertical distance from work place to
luminaries
2.4m
Standard Illuminance 200 lux
Reflection Factors Ceiling: Exposed concrete (0.3)
Wall: Exposed Brick Wall (0.3)
Floor: concrete (0.3)
Room Index = (LxW)/((L+W)xH)
= (12.486x2.098)/((12.486+2.098)x2.4)
= 0.75
Utilization Factor 0.35 / 35%
Maintenance Factor 0.8
Page | 42
Type of light Cylindrical black ceiling light
Warm white, 30W, 88lm/W, 790lm
Illuminance level required E = (n x N x F x UF x MF)/A
= (1x3x790x0.35x0.8)/26.19
= 25.3 lux
200lux – 25.3lux = 174.7lux
According to MS1525, Zone F lacks of
174.7 lux to fulfill the requirement.
Number of light required For using Cylindrical black ceiling light at I
lamps per luminaire:
N = (E x A)/(F x UF x MF)
= (200x26.19)/(790x0.35x0.8)
= 24 lamps
According to MS1525, Zone F needs 24
lamps to fulfill the requirement.
24 lamps – (1x3) lamps = 19 lamps
According to MS1525, Zone F lacks of 19
lamps to fulfill the requirement.
Page | 43
Point coordinates with unusually high or low lux readings.
Points E1 and F1 have an unusually high reading compared to the average because of the
presence of a refrigerator at that spot. The refrigerator is brightly lit to display its contents,
therefore the reading at those points are higher.
Figure3.3.3.7 Showing the brightly lit refrigerator Points A2 and A3 have an unusually lower reading compared to the average during the non-peak hours in the evening because it is the area below the television that is propped up on the wall. There are no artificial lights below to illuminate the area, leaving it dark, which explains the lower readings at those points.
Figure3.3.3.8 Showing the television propped up on the wall Points I7 and I8 in zone B have an unusually higher reading compared to the average
because those points are situated closest to the curtain glass at the corner which is exposed
to a large amount of sunlight.
Page | 44
Figure3.3.3.9 Showing the curtain glass corner
Figure3.3.3.10 Front section diagram showing the distribution of artificial light from the lighting fixtures placed in specific points in the interior to illuminate the space.
Figure3.3.3.11 Side section diagram showing the distribution of artificial light from the lighting fixtures placed in specific points in the interior to illuminate the space.
Page | 45
Figure3.3.3.12 Side section diagram showing the distribution of sunlight within the space. During the day, sunlight streams in from the front of the building, which faces the direction of the sun, and is distributed to the back of the building which is enclosed. The light intensity decreases as it travels the distance from the front to the back.
Figure3.3.3.13 Side section diagram showing how the rays enter the building when the sun is higher up in the sky. Sunlight is the source of natural light which illuminates the space, but it is unevenly distributed as the light intensity decreases as it moves towards the enclosed spaces at the back of the building. Natural daylight is sufficient in illuminating the spaces within the building during the morning, when the sun is low and its rays are able to penetrate the space directly. However, as the day moves towards the afternoon, the sun moves higher up in the sky, and less rays are able to enter the space. Since daylight is insufficient in illuminating the space, artificial light is required to provide illuminance to the space. Light fixtures are evenly spaced and positioned throughout the interior space, to ensure an even distribution of light. The artificial lights are switched on during the evening when the sun has moved towards the West, and at night when the sun has set and it is dark.
Page | 46
4.0 Precedent Study
4.1 Acoustic Case Study- The Music Café, August Wilson Center
The Music Café is located at the sidewalk level of August Wilson Center. It is accessible
from the street and from within the center.
The café is designed to accommodate an on‐going menu of programs and to function as an
alternative performance space for intimate performances with limited seating for jazz,
spoken word, poetry and other new performance and turns into a speakeasy music café at
night.
Figure 4.1.1 Exterior view of August Wilson Center
Figure 4.1.2 Street view to the Music Café, August Wilson Center
Figure 4.1.3 The space is a large rectangular box with three glass sides, a hard floor
absorbing treatment on the ceiling although it is behind baffles and ductwork.
Page | 47
There is sound with hanging metal baffles and acoustical blanket over 80% of the underside
of the floor structure above. It does recognize the need for acoustical design elements.
Figure 4.1.4 Plan of Music Café, August Wilson Center
Figure 4.1.5 Interior rendering view of the
Music Café
Figure 4.1.6 Exterior rendering view of the
Music Café
Page | 48
Based on the use description provided by the architect, a reverberation time of
approximately 1.0 second would be ideal. The table shows the existing reverberation times
are far from ideal.
The use of glass doors and partitions between the spaces create some noise distractions.
Based on the analysis, the sound transmission class (STC) on the wall between the café and
the main lobby reveals a potential for unwanted noise transfer between the spaces. At 46,
the calculated STC falls far below the ideal value of 60+. Changing the glass type from ½”
tempered glass to ½” laminated glass improves the STC to 49, but this is only a marginal
increase.
REVERBERATION TIME SUMMARY: MUSIC CAFÉ (EXISTING)
Freq. (Hz.) 125 250 500 1000 2000 4000
T60 = 1.677 2.596 0.801 0.798 0.807 0.752
Table 4.1.8 Reverberation Time of the music cafe
Figure 4.1.7 Music Café Reflected Ceiling Plan – Existing Design (reflected ceiling plan
and reverberation time of the existing café)
Page | 49
Figure 4.2.1 Existing hanging metal baffle
system
Figure 4.2.2 Proposed
Alpro Metal Acoustical
Baffles for the new design
4.2 Conclusion
August Wilson Centre is a giant picture window framing the constant transformation,
evolution and influence of African culture, active and glowing proudly from within. Due to the
programmatically specific volumes and flexible uses of the spaces in the music café which
are organized behind the north-facing glassy façade that extends 328 linear feet along one
of the major downtown thoroughfares. With optimum solar orientation, this transparency
invites the surrounding historic context in to enrich the interior experience and engage the
place in the city.
Significant changes to the architecture are required to really improve this potentially
undesirable condition of the music cafe. These changes may include changing the glass to
another material such as wood or creating a small vestibule at the entrances. These
changes, however, would significantly alter the architecture.
Hence, another solution to the situation is to improving the reverberation time by eliminated
the metal baffles and acoustical blanket as shown in Figure 2.3.1, replacing them with
floating fiberglass sound absorbing panels that are faced in perforated metal as shown in
Figure 2.3.2. According to Architectural Acoustics: Principles and Design, optimum
reverberation times at 125 hertz should be 1.3 times the ideal reverberation time at 500 hertz
and a multiplier of 1.15 should be used at 250 hertz.
Minor changes were necessary in the location and type of HVAC diffusers and sprinkler
heads. With the new ceiling system will provide superior acoustical performance at a
reduced cost.
Page | 50
5.0 Acoustic Study
5.1 Research Methodology
Equipment used: Sound level meter, camera, and .measuring tape
Features of Sound level meter
Standard References IEC 804 and IEC 651
Grade of Accuracy Not assigned
Quantities displayed Lp, Lp Max, Leq
Display: LCD/display
resolution
1 dB
Frequency weighting: A/ Time
weighting (Lp)
Fast
Time integration (Leq Free or user defined
Measurement range 30 –120 dB/ Range: 30 -90 & 60 –120 dB
Linearity ± 1.5 dB
Overload from (± 1.5 dB maximum) 93 dB and 123 dB Peak
Dimensions/ Weight 160 x 64 x 22 mm/ 150g without battery
Battery/ battery life Alkaline (6LR61)/ min 30 h (20°C)
Environment: Relative
humidity
Storage < 95% / measurement< 90%
Temperature Storage < 55 °C/ 0 °C. <measurement < 50 °C
CE marking Comply with: EN 50061 -1 and EN 50062 -1
Figure 5.1.1 Equipment used for data collection
(i) Sound Level Meter (ii) Camera (iii) Measuring tape
Page | 51
Data collection method
For acoustic level readings, these are the measuring procedure that will be applied on each
point indicated by a grid of 2m x 2m system. Plans with gridlines used as guidelines to
ensure a well distributed and accurate reading is made in the selected space. For
comparison, the readings were taken at 2 different times of the day within peak and non-
peak hours.
To acquire consistent readings, the sound level meter was placed 1.5m above the ground
level at every point. This standard is being used as it enables the reading of sound level
meter to be more accurate. The data collector is not allowed to talk and make any noise so
that the readings will not be affected. Each recording was done by facing the similar direction,
to synchronize the result. Same process is repeated for interior and exterior space at
different time intervals.
Data Constrain
There will be several constrains that would affect the readings due to the weather and the
number of time taken to collect data. Nevertheless, it is easy to obtain readings using the
sound level meter. However, there are some factors which affect the readings.
Incomplete definition
Different height levels of the device placement will affect the readings, different readings will
be collected as each individual who operate the devices are of different heights. Shadow
casted by the data collector might unintentionally affect the readings.
Different grid point placement would affect the readings such as human error. Besides, peak
reading might vary due to random site circumstance.
Failure to account
The data recording might vary due to inappropriate operating hours, where assumable peak
and non-peak hours do not seem to be properly utilized. For example, certain occasions
which might increase the number of customers for the particular day, such as birthday event.
Page | 52
Environment factors
Any additional external noises rain and lightning strike would affect the the dB value. During
rainy day, higher dB value would be obtained due to supplementary noise factor.
Acoustic Analysis Calculation Method
Step1: Reverberation Time (RT) Reverberation time is the primary descriptor of an acoustic environment which to calculate the reverberation time of an enclose space. Equation:
RT =
, where V = volume of space
Step 2: Sound Pressure Level (SPL) The sound pressure level is the average sound level at a space. The sound pressure level (SPL) at the zone 1, Entrance area is at below:
SPL =
, where
=
Step 3: Sound Reduction Index (SRI)
To calculate transmission loss on materials, using the formula below: , where Tav = Average transmission
Page | 53
Acoustic Standard ANSI (2008) S12.2-2008
Type of interior, task or activity
Sound Level (dB)
Small Auditorium (<500 seats) 35-39
Large Auditorium (>500 seats) 30-35
Open Plan Classroom 35
Meeting Room 35-44
Office (Small, Private) 40-48
Corridors 44-53
Movie Theatres 39-48
Small Churches 39-44
Courtrooms 39-44
Restaurant 48-52
Shops and Garage 57-67
Circulation Path
48-52
Computer Room 48-53
Hotel Room 39-44
Open Plan Office 35-39
Table 5.1.2: Recommendation sound level at respective area (Source: ANSI 2008, S12.2-2008)
As shown in table 5.1.2, recommendation sound level for restaurant falls on the range 48-
52dB.
Page | 54
5.2 Case Study 5.2.1 Existing acoustic condition
Figure5.2.1.1 External Noise Source & Internal Noise Source
Page | 55
5.2.2 Acoustical Characteristics of Materials
Food Industrie Café to creating good restaurant acoustics offer a more pleasing
environment as restaurant noise reduction is achieved. The building having the following
features: bare tables, concrete floors, hard-surfaced.
Concrete wall, beams, floor and exposed concrete ceiling of the café contributes to good
insulation of sound which is required to give adequate levels of privacy to the occupants as
shown in Figure 4.2.2.1 and Figure 4.2.2.2 and Figure 4.2.2.3..
However, internal noise within the interior space has also become a greater problem as the
exterior walls are installed with glass panels as shown in Figure 4.2.2.2. The problem of
impact sound has increased with the popularity of lightweight form of the building
Figure 5.2.2.2 Exposed concrete ceiling
Figure 5.2.2.3 Concrete beams and columns for separates
and internal dividing elements.
Figure 5.2.2.1 Concrete floor in the interior
space
Page | 56
Figure 5.2.2.4 Wood decoration at the counter
construction. The echoes from all sides of sound absorption of glass, which reflects noises
and increase reflection of sound. Generally, this condition increases the sound level of the
interior space.
Food Industrie cafe utilizes wood decoration as part of their café industry concept, which
helps to absorb sound. Most of the furniture found in cafe are also made up of timber. This is
due to the high sound absorption coefficient of timber, which can absorb the noises created
and reduce sound reflection, and thus decrease sound level in general.
Figure 5.2.2.6 Glass wall along the main entrance
Figure 5.2.2.5 Various arrangements of
tables and chairs
Page | 57
5.3 Acoustic Analysis 5.3.1 Acoustic Data
Figure 5.3.1.1 Acoustic Zoning
Page | 58
Non-Peak Hours Acoustic Data
Figure 5.3.1.2 Acoustic data at 9am
Page | 59
Figure 5.3.1.3 Acoustic data at 4pm
Page | 60
Figure 5.3.1.4 Acoustic data at 7pm
Page | 61
Peak Hours Acoustic Data
Figure 5.3.1.5 Acoustic data at 1pm
Page | 62
5.3.2 Noise Contour Diagram
The acoustic contour diagram as shown are created to illustrate the recorded data in a
coloured contour. The sound level range is set between 55dB and 80dB, which is the sound
level range of the café. Areas marked with the lighter colour are areas recorded with a higher
sound level, and areas marked with a darker colour are areas recorded with a lower sound
level.
Figure 5.3.2.1 Non-peak hour acoustic data taken at 9am.
Page | 63
Figure5.3.2.2 Shows acoustic contour during non-peak hour (9am-11am)
Figure5.3.2.1shows the acoustic contour recorded during non-peak hours, which is from
9am to 11am. During the non-peak hours, the main sources of sound are from the counter
and bar area, where preparations are made during the opening hours of the café. The sound
level during the non-peak hours are generally lower because there are very few customers in
the café during the morning hours.
The highest sound level recorded in the café during the non-peak hours is at point E2 at
Zone E, with a reading of 79dB. This is where the counter and the cashier is, where orders
and transactions are made, which contributes to the higher sound level as compared to the
other areas.
Page | 64
Figure 5.3.2.3 Peak hour acoustic data taken at 1pm.
Page | 65
Figure5.3.2.4 Acoustic contour during peak hour (1pm-3pm)
Figure5.3.2.2 shows the acoustic contour recorded during peak hours, which is from 1pm to
3pm. During the peak hours, the main sources of sound are from the voices of the
customers, which have increased during lunchtime. There is an event happening in the café
during the peak hour when the sound level is being recorded, a company buffet lunch which
is allocated to zone D and zone F. That is why the sound level recorded in those zones are
relatively a little higher compared to the other areas of the café.
The highest sound level recorded in the café during the peak hours is at point C8 at Zone B,
with a reading of 84dB. This is the point close to the entrance of the café, where people are
Page | 66
constantly moving in and out, opening and closing the door, which contributes to the higher
sound level at that particular area.
Sound transmission from the exterior of the building is generally low as the café is situated in
a more isolated industrial factory area, where the amount of traffic is low. There is a car park
across from the café, and another café next to it. Sound transmission from the exterior is
minimal during non-peak hours. However, during peak hours, and especially before and after
City Harvest church services, the sound transmission level is higher due to the large amount
of people passing by the café.
Page | 67
Direct
Figure 5.3.3.1 Acoustic Ray of Television at 500 Hz
5.3.3 Acoustic Ray diagram
With the static acoustic rays settings shown an indecipherable mass of lines in
Ecotect model at different location at Food Industrie Cafe, being all of the rays and
their subsequent bounces displayed simultaneously.
As shown in Figure 5.3.3.1, the television noise is turned on at moderately volume
can be transmitted to Zone B. It is the main source of acoustic ray at Zone D. Only a
partial of the acoustic ray is transmitted to Zone E.
Figure 5.3.3.2 Acoustic Ray of Television at 2000 Hz
Page | 68
Besides, the acoustic rays for speakers have been generated to show the possible
sound distribution in the interior space as shown in Figure 5.3.3.3. Speakers are
identified as main internal noise source at Zone B. The sound ray can be transmitted
to Zone D.
Figure 5.3.3.3 Acoustic Ray of Speakers at 500 Hz
Figure 5.3.3.4 Acoustic Ray of Speakers at 2000 Hz
Page | 69
Figure 5.3.3.5 shows the acoustic rays generated by reception counter at Zone E.
Reception is the main source of sound at zone E which is also a food service area.
Figure 5.3.3.5 Acoustic Ray of Reception at 500 Hz
Figure 1 Figure 5.3.3.6 Acoustic Ray of Reception at 500 Hz
Page | 70
5.3.4 Sound Absorbance Coefficient Sound absorption coefficient on the building materials.
Zone Category Material Absorption Coefficient Colour Surface Texture
500 Hz
2000 Hz
4000 Hz
Grey Smooth
A-F
Ceiling Wall Floor
Smooth Unpainted Concrete
0.02 0.02 0.05
D
Wall Column
Red Brick
0.03 0.05 0.07 Red Rough
B
Curtain Glass (6mm)
Wall
0.04 0.02 0.02 Trans-parent
Smooth
Page | 71
Zone Category Material Absorption Coefficient
Colour Surface Texture
500 Hz
2000 Hz
4000 Hz
Brown Smooth
E
Reception
Linear acoustic panel
0.42 0.83 0.68
A-D
Furniture (Adult in wooden chairs & table )
Timber
0.4 0.43 0.4 Dark Brown
Rough
F
Furniture (Adult in plastic chairs & table)
Plastic
0.4 0.43 0.4 White Smooth
Page | 72
5.3.5 Acoustic Analysis and Calculations
(i) Volume of space
The reverberation time of main interior space in Food Industrie Café is calculated. The
space includes:
Zone A outdoor corridor area
Zone B sitting area at the centre near speakers
Zone C area at the centre near speakers
Zone D sitting area at the corner
Zone E bar and counter area
Zone F sitting Area next to Zone D
(ii) Volume of main interior space = Zone A + Zone B + Zone C +Zone D + Zone E
+ Zone F
= 39 m² + 61.8 m² + 60.87 m² + 55.6 m² + 27.1 m²
+ 26.19 m²
= 270.56 m²
(ii) Acoustical absorption in the space
Materials has different absorption coefficient in different frequencies.
Acoustical absorption of materials in the following frequencies: 500Hz, 2000Hz
and 4000Hz are taken as reference to calculate reverberation time. The
optimum reverberation time for cafeteria is between 0.8-1.3s.
According to Table 5.4.5.1, the total sound absorption at 500Hz during non-
peak hour and peak hour
Figure 5.3.5.1 Main interior space
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Zone A- Outdoor Corridor
Figure 5.3.5.2 Zoning plan and photo of outdoor corridor area
It has the highest dB reading during night time at 7pm because there are church members
who always gather there after servive. Moreover, it was cooler at night. During daytime,
people preferable to sit indoor with there are air-conditioning.
AREA: 39 m²
Peak hour: 1pm
The dB value in zone A during the peak hour is rather low because there are not many people in that area. This is because it is very hot and sunny during the afternoon, and people will rather stay indoors where the space is air-conditioned.
Non-peak hour: 9am
The dB value in zone A during the non-peak hour is unusually high during the morning because the café workers are preparing for the opening of the café by unloading the materials and utensils in that area, which is well lit by the morning sun. Since this is an open space, the sound is dispersed into the air when it is emitted. However, since this space is right next to the interior of the café, the noise from the exterior is easily transmitted into the interior of the café.
Page | 74
Sound Pressure Level (SPL) The sound pressure level is the average sound level at a space. The sound pressure level (SPL) at the Zone A (Outdoor Corridor Area):
SPL =
, where Iref =
Page | 75
Zone A Coordinate Non-peak hour reading (dB)
Peak hour reading (dB)
Highest reading 71 65
Lowest reading 63 60
Total intensities, ITOTAL = (1.26 x 10--5) + (2.00 X 10
-6 )
= 1.46 x 10-5
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (1.46 x 10-5 / (1 × 10-12)
SPL = 71.64 dB, at Zone A during non- peak hour
Total intensities, ITOTAL = (1.99 x 10-6) + (1.00 X 10
-6 )
= 2.99 x 10-6
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (2.99 x 10-5 / (1 × 10-12)
SPL = 74.76 dB, at Zone A during peak hour
Therefore, the average sound level at Zone A (Outdoor corridor area) during non-peak hour
and peak hour are 71.64 dB and 74.76 dB.
Non-peak hour
Highest reading = 71 dB
SPL = 10 log10 IH / (Iref)
71 = 10 log10 × (IH / (1 × 10-12)
7.1 = log10 (IH / (1 × 10-12)
log-1 7.1 = log-1 log (IH / 1 x 10-12)
IH = 1.26 x 10-5
Peak hour
Highest reading = 65 dB
SPL = 10 log10 IH / (Iref)
65 = 10 log10 × (IH / (1 × 10-12)
6.5 = log10 (IH / (1 × 10-12)
log-1 6.3 = log-1 log (IH / x 10-12)
IH = 1.99 x 10-6
Lowest reading = 63 dB
SPL = 10 log10 IL / (Iref)
63 = 10 log10 × (IL / (1 × 10-12)
6.3 = log10 (IL / (1 × 10-12)
log-1 6.3 = log-1 log (IL / 1 x 10-12)
IH = 2.00 x 10-6
Lowest reading = 60 dB
SPL = 10 log10 IL / (Iref)
60 = 10 log10 × (IL / (1 × 10-12)
6.0 = log10 (IL / (1 × 10-12)
log-1 6.0 = log-1 log (IL / 1 x 10-12)
IL = 1.00 x 10-6
Page | 76
Zone B – Sitting Area near entrance
Figure 5.3.5.3 Zoning plan and photo of sitting area near entrance
It has the highest dB reading during peak hour because there is the main entrance for
people to go in and leave. Apparently, the sitting area near entrance is less preferable
because people movement is fast and open and closing of doors may disturb the customers.
Therefore, Zone B has slightly higher dB reading compared to others at any time because it
was the main circulation of the café. It has a moderate reading between range of 66dB to 78
dB because it has air-conditioning that create moderate noise. It has the highest dB reading
during evening from 4pm to 7pm because this was the sitting place with better view. On the
other hand, it shows lower dB during morning and afternoon session because there are too
much glaring.
AREA: 61.8 m²
Peak hour: 1pm
The dB value in zone B during the peak hour ranges from low to moderate level, as there are lesser customers and activities in that zone. This zone has a full glass curtain wall which is exposed to direct sunlight, so people do not favor sitting in that area. Moreover, there is an air-conditioning unit at the center of the zone that causes the reading to deviate.
Page | 77
Non-peak hour: 9am
The dB value in zone B during the non-peak hour is relatively high, due to the presence of workers in that area, who are constantly moving in and out of the entrance as they prepare for the opening of the café.
Page | 78
Sound Pressure Level (SPL) The sound pressure level (SPL) at the Sitting area near entrance
SPL =
, where Iref =
Page | 79
Zone B
Total intensities, ITOTAL, = (1.00 x 10-5-) + (1.00 x 10-6)
= 1.1 x 10-5
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (1.1 x 10-5 / (1 × 10-12)
SPL = 70.42 dB, at Zone b during non-peak hour
Total intensities, ITOTAL = (2.51 x 10-4) + (1.00 x 10-6
)
= 2.52 x 10-4
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (2.52 x 10-4 / (1 × 10-12)
SPL = 84.01 dB, at Zone B during peak hour
Therefore, the average Sound Pressure Level at Zone B (Sitting area near entrance) during
non-peak hour and peak hour are 70.42 dB and 84.01 dB.
Non-peak hour reading (dB)
Peak hour reading (dB)
Highest reading 70 84
Lowest reading 60 60
Non-peak hour Highest reading = 70 dB SPL = 10 log10 IH / (Iref)
70 = 10 log10 (IH / (1 × 10-12)
log-1 7.0 = log-1 log (IH / 1 x 10-12)
IH = 1.00 x 10-5
Lowest reading = 60 dB
SPL = 10 log10 IL / (Iref)
60 = 10 log10 (IL / (1 × 10-12)
log-1 6.0 = log-1 log (IL / (1 × 10-12)
IL = 1.00 x 10-6
Peak hour Highest reading = 84 dB
SPL = 10 log10 IH / (Iref)
84 = 10 log10 (IH / (1 × 10-12)
log-1 8.4 = log-1 log (IH / 1 x 10-12)
IH = 2.51 x 10-4
Lowest reading = 60 dB
SPL = 10 log10 IL / (Iref)
60 = 10 log10 (IL / (1 × 10-12)
log-1 6.0 = log-1 log (IL / (1 × 10-12)
IL = 1.00 x 10-6
Page | 80
Zone C- Sitting area at the centre
Figure 5.3.5.4 Zoning plan and photo of sitting area at the centre near speakers
Zone C sitting area was the most preferable sitting for customers as we observe because
the workers circulation from kitchen and bar would not pass there unless they are delivering
food. The dB reading was always high because most customers like to sit there and there is
a speaker and A/C placed at Zone C.
AREA: 60.87 m²
Peak hour: 1pm
The dB value in zone C during the peak hour ranges from moderate to high, as there are many people sitting in that area, where it is well shaded and cool. The sound level reading is particularly high due to the presence of a speaker at point G6, which plays music from time to time. People who enjoy listening to music would prefer to sit at zone C.
Page | 81
Non-peak hour: 9am
The dB value in zone C during the non-peak hour ranges from moderate to high as well, especially along the horizontal gridline 3, which is largely due to the presence of workers moving in and out of the kitchen as part of their preparation for the opening of the café.
Page | 82
Sound Pressure Level (SPL)
The sound pressure level (SPL) at the Zone C (Sitting area at the centre near speakers)
SPL =
, where Iref =
Page | 83
Zone C
Total intensities, ITOTAL, = (5.01 x 10-6) + (1.00 x 10-6
)
= 6.01 x 10-6
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (6.01 x 10-5 / (1 × 10-12)
SPL = 77.8 dB, at Zone C during non-peak hour
Total intensities, ITOTAL = (6.31 x 10-5) + (3.16 x 10-6
) = 6.63 x 10-5
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (6.63 x 10-5/ (1 × 10-12)
SPL = 78.22 dB, at Zone C during peak hour
Therefore, the average Sound Pressure Level at Zone C (Sitting area at the centre near
speakers) during non-peak hour and peak hour are 77.8 dB and 78.22 dB.
Non-peak hour reading (dB)
Peak hour reading (dB)
Highest reading 67 78
Lowest reading 60 65
Non-peak hour Highest reading = 67 dB SPL = 10 log10 IH / (Iref)
67 = 10 log10 (IH / (1 × 10-12)
log-1 6.7 = log-1 log (IH / 1 x 10-12)
IH = 5.01 x 10-6
Lowest reading = 60 dB
SPL = 10 log10 IL / (Iref)
60 = 10 log10 (IL / (1 × 10-12)
log-1 6.0 = log-1 log (IL / (1 × 10-12)
IL = 1.00 x 10-6
Peak hour Highest reading = 78 dB SPL = 10 log10 IH / (Iref)
78 = 10 log10 (IH / (1 × 10-12)
log-1 7.8 = log-1 log (IH 1 x 10-12)
IH = 6.31 x 10-5
Lowest reading = 65 dB
SPL = 10 log10 IL / (Iref)
65 = 10 log10 (IL / (1 × 10-12)
log-1 6.5 = log-1 log (IL / (1 × 10-12)
IL = 3.16 x 10-6
Page | 84
Zone D- Sitting area at the corner
Figure 5.3.5.5 Zoning plan and photo of sitting area at the corner
The dB readings are high because there is a speaker placed at Zone D. It has the higest dB
reading during daytime of 1pm and 4pm because people would tend to sit at a more chilling
place during daytime which is near A/C. Moreover, this place was likely for the customers
who likes to listen to the music louder.
AREA: 55.6 m²
Peak hour: 1pm
The dB value in zone D during the peak hour is rather high especially along grid 5 to 7, where many people prefer to sit, where it is well shaded from the sun. Two speakers are located at A2 and A6 which plays music from time to time. Customers like to sit here as the spaces are deemed more private.
Non-peak hour: 9am
The dB value in zone D during the non-peak hour ranges from low to moderate as there are not many customers during that time, and the workers are busy moving about the space in preparation for the café opening.
Page | 85
Figure 5.3.5.6 Sound Absorption and Reflection at Zone D, E and F
Page | 86
Non-peak hour Highest reading = 65 dB SPL = 10 log10 IH / (Iref)
65 = 10 log10 (IH / (1 × 10-12)
log-1 6.5 = log-1 log (IH / 1 x 10-12)
IH = 3.16 x 10-6
Lowest reading = 60 dB
SPL = 10 log10 IL / (Iref)
60 = 10 log10 (IL / (1 × 10-12)
log-1 6.0 = log-1 log (IL / (1 × 10-12)
IL = 1.00 x 10-6
Page | 87
Total intensities, ITOTAL, = (3.16 x 10-6) + (1.00 x 10-6
)
= 4.16 x 10-6
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (4.16 x 10-6 / (1 × 10-12)
SPL = 66.19 dB, at Zone D during non-peak hour
Total intensities, ITOTAL = (6.31 x 10-5) + (3.98 x 10-6
)
= 6.71 x 10-5
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (6.71 x 10-5/ (1 × 10-12)
SPL = 78.27 dB, at Zone D during peak hour
Therefore, the average Sound Pressure Level at Zone D (Sitting area at the corner) during
non-peak hour and peak hour are 66.19 dB and 78.27 dB.
Peak hour Highest reading = 78 dB
SPL = 10 log10 IH / (Iref)
78 = 10 log10 (IH / (1 × 10-12)
log-1 7.8 = log-1 log (IH 1 x 10-12)
IH = 6.31 x 10-5
Lowest reading = 66 dB
SPL = 10 log10 IL / (Iref)
66 = 10 log10 (IL / (1 × 10-12)
log-1 6.6 = log-1 log (IL / (1 × 10-12)
IL = 3.98 x 10-6
Page | 88
Zone E- Bar and counter
Figure 5.3.5.7 Zoning plan and photo of bar and counter
The readings shown was high at the grid line 1 compared to gridline 2 especially during
peak hours because there are opening to deliver cooked food at G1, and there are
refrigerator, coffee maker and blender placed align gridline 1. Grid line 2 was slightly less
noisy because there is only an order counter and cake chiller compared to the heavy
machinery on gridline 1.
Figure 5.3.5.8 Sound Absorption and Reflection between Zone A and Zone B
Page | 89
AREA: 27.1 m²
Peak hour: 1pm The dB value in zone E during the peak hour is relatively high because it is where the bar
and counter is, and this is where orders are taken and transactions happen. The noise
comes from basic washing and cleaning, as well as in the preparation of drinks.
Non-peak hour: 9am
The dB value in zone E during the non-peak hour is relatively high as well, as the workers are busy preparing for the café opening. The café supervisor does the daily auditing in the morning, by moving around the counter area checking items, therefore the reading in that area is particularly higher.
Page | 90
Page | 91
Sound Pressure Level (SPL)
The sound pressure level (SPL) at the Zone E (Bar and Counter area)
SPL =
, where Iref =
Zone E
Total intensities, ITOTAL, = (7.94 x 10-5) + (1.26 x 10-6
)
= 8.07 x 10-5
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (8.07 x 10-5 / (1 × 10-12)
SPL = 79.07 dB, at Zone E during non-peak hour
Total intensities, ITOTAL = (6.31 x 10-5) + (3.98 x 10-6
)
= 6.71 x 10-5
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (6.71 x 10-5/ (1 × 10-12)
SPL = 78.26 dB, at Zone D during peak hour
Therefore, the average Sound Pressure Level at Zone E (Bar and Counter area) during non-
peak hour and peak hour are 79.07 dB and 78.26 dB.
Non-peak hour reading (dB)
Peak hour reading (dB)
Highest reading 79 78
Lowest reading 61 68
Non-peak hour Highest reading = 79 dB SPL = 10 log10 IH / (Iref)
79 = 10 log10 (IH / (1 × 10-12)
log-1 7.9 = log-1 log (IH / 1 x 10-12)
IH = 7.94 x 10-5
Lowest reading = 61 dB
SPL = 10 log10 IL / (Iref)
61 = 10 log10 (IL / (1 × 10-12)
log-1 6.1 = log-1 log (IL / (1 × 10-12)
IL = 1.26 x 10-6
Peak hour Highest reading = 78 dB SPL = 10 log10 IH / (Iref)
78 = 10 log10 (IH / (1 × 10-12)
log-1 7.8 = log-1 log (IH 1 x 10-12)
IH = 6.31 x 10-5
Lowest reading = 68 dB
SPL = 10 log10 IL / (Iref)
68 = 10 log10 (IL / (1 × 10-12)
log-1 6.8 = log-1 log (IL / (1 × 10-12)
IL = 6.31 x 10-6
Page | 92
Zone F – Sitting area next to Zone D
Figure 5.3.5.9 Zoning plan and photo of sitting Area next to Zone D
This sitting area is less preferable for customers because there is a door to access to
washroom which will create noise that disturb customers. The speaker and A/C was placed
at Zone E makes the reading fluctuate more and less on human noise.
AREA: 26.19 m²
Peak hour: 1pm
The dB value in zone F during the peak hour is relatively high due to the fact that it is close to the toilet and entrance, where the movement of people are high. There is an air-conditioner fixed on the ceiling at point C6, which contributes to the noise in that area.
Non-peak hour: 9am
The dB value in zone F during the non-peak hour is relatively low because there are not many customers moving about that area during the morning.
Page | 93
Page | 94
Sound Pressure Level (SPL) The sound pressure level (SPL) at the Zone F (Bar and Counter area)
SPL =
, where Iref =
Zone F
Total intensities, ITOTAL, = (2.51 x 10-6) + (1.00 x 10-6
)
= 3.51 x 10-5
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (3.51 x 10-5 / (1 × 10-12)
SPL = 79.07 dB, at Zone E during non-peak hour
Total intensities, ITOTAL = (6.31 x 10-5) + (3.98 x 10-6
)
= 6.71 x 10-5
SPL = 10 log10 (ITOTAL / Iref )
= 10 log10 × (6.71 x 10-5/ (1 × 10-12)
SPL = 78.26 dB, at Zone D during peak hour
Therefore, the average sound level at Zone E (Bar and Counter area) during non-peak hour
and peak hour are 79.07 dB and 78.26 dB.
Non-peak hour reading (dB)
Peak hour reading (dB)
Highest reading 64 76
Lowest reading 60 67
Non-peak hour Highest reading = 64 dB SPL = 10 log10 IH / (Iref)
64 = 10 log10 (IH / (1 × 10-12)
log-1 6.4 = log-1 log (IH / 1 x 10-12)
IH = 2.51 x 10-6
Lowest reading = 60 dB
SPL = 10 log10 IL / (Iref)
60 = 10 log10 (IL / (1 × 10-12)
log-1 6.0 = log-1 log (IL / (1 × 10-12)
IL = 1.00 x 10-6
Peak hour Highest reading = 76 dB
SPL = 10 log10 IH / (Iref)
76 = 10 log10 (IH / (1 × 10-12)
log-1 7.6 = log-1 log (IH 1 x 10-12)
IH = 6.31 x 10-5
Lowest reading = 67 dB
SPL = 10 log10 IL / (Iref)
687 = 10 log10 (IL / (1 × 10-12)
log-1 6.7 = log-1 log (IL / (1 × 10-12)
IL = 6.31 x 10-6
Page | 95
Sound Reduction Index (SRI)
The sound reduction index is a measure of the insulation against the direct transmission of air-borne sound. In this project, bar and counter area, To calculate transmission loss on materials, using the formula below:
where Sn = Surface area of material, = transmission coefficient of material
Figure 5.3.5.10 Plan showing the wall between Zone A and Zone E
Curtain Wall Timber Door
Painted Concrete Wall
Figure 5.3.5.11 Section showing the wall between Zone A and Zone E
Page | 96
Building Elements Materials Surface area, S (m2)
SRI (dB) Transmission Coefficient (Tcn)
Sn x Tcn
Wall Concrete 48.65 42 6.31 x 10-5 4.66 x 10-3
Curtain wall Glass 18.5 26 2.51 x 10-3 4.26 x 10-1
Door Timber 3.15 36 2.51 x 10-4 2.21 x 10-3
Total 70.3 0.432
Concrete Wall
= 10 log (1/T)
concrete = 42
42 = 10 log (1/T)
4.2 = log (1/T)
log-1 4.2 = log-1 (log10 1/Tconcrete)
104.2 = 1/Tconc
Transmission Coefficient of Concrete, Tconcrete
= 3.98 x10-5
Glass Wall Panels
= 10 log (1/T)
glass = 26
26 = 10 log (1/T)
2.6 = log (1/T)
log-1 2.6 = log-1( log10 1/T)
102.6 = 1/T
Transmission Coefficient of Glass, T
= 2.51 × 10-3
Timber Door
=
glass = 36
3.6 =
log-1 3.6 =log-1(
)
103.6= 1/T
Transmission Coefficient of Glass, Ttimber= 2.51 X 10-4
Page | 97
Average Transmission Coefficient of Materials Tav = (3.07 x 10
-3) + (4.64 x 10
-2) + (7.91 x 10
-4)
= 5.03 x 10
-2
1.04 x 102
= 4.84 x 10
-4
Overall SRI of the wall
overall = 10 log (1/Tav) = 10 log (1/ 4.84 x 10
-4)
= 33.15 dB
As shown in calculations above, 33.15dB of noise level had reduced during transmission
from outdoor dining area to indoor dining area.
Zone A combine SPL = non-peak 71.64dB to 74.76dB peak
Zone B combine SPL = non-peak 84.01dB to 70.42dB peak
Zone C combine SPL = non-peak 77.80dB to 78.22dB peak
Zone E combine SPL = non-peak 79.07dB to 78.26dB peak
Conclusion
Zone B highest SPL- highest peak 84.01dB deduct the transmission lost after sound pass
through the wall: 84.01dB – 33.15dB= 50.86 dB
(Total surface reflection index, SRI wall overall 33.15 dB)
Based on the calculation, the sound transmission lost through the wall between Zone A and
Zone E is acceptable.The calculation shows that it is not match with the combine SPL of the
zone A (outdoor corridor area) and zone E (bar and counter area) with the sound
transmission lost of the wall of 42.09dB. This is due to the sound transmission is not only
from zone A and zone E as there are also sound sources transmitted from other dining area
and output music from the speakers at the interior space of the building.
42+26+36
Page | 98
Figure 5.3.5.12 Section showing the wall between Zone D and Zone E
Figure 5.3.5.13 Section showing the wall between Zone D and Zone E
Brick Wall Timber Door
Page | 99
Building Elements Materials Surface area, S (m2)
SRI (dB) Transmission Coefficient (Tcn)
Sn x Tcn
Wall Brick 48.35 44 3.98 x 10-5 1.92 x 10-3
Door Timber 5.67 36 2.51 x 10-4 1.42 x 10-3
Total 70.3 0.0033
Average Transmission Coefficient of Materials Tav = (48.35 x 3.98 x 10
-5) + (5.67 x 2.51 x 10
-4)
= 3.34 x 10
-3
54.02
= 6.18 x 10
-5
Overall SRI of the wall
overall = 10 log (1/Tav) = 10 log (1/ 6.18 x 10
-5)
= 42.09 dB
As shown in calculations above, 42.09dB of noise level had reduced during transmission
from outdoor dining area to indoor dining area.
Zone D combine SPL = non-peak 66.19dB to 78.27dB peak
Zone E combine SPL = non-peak 79.07dB to 78.26dB peak
Zone F combine SPL = non-peak 79.07dB to 78.26dB peak
Timber Door
=
glass = 36
3.6 =
log-1 3.6 =log-1(
)
103.6= 1/T
Transmission Coefficient of Timber, Ttimber= 2.51 X 10-4
Brick Wall
=
brick = 44
4.4 =
log-1 4.4 =log-1(
)
104.4= 1/T
Transmission Coefficient of Brick, Tbrick= 3.98x 10-5
54.02
Page | 100
Conclusion
Zone D highest SPL- highest peak 78.27 dB deduct the transmission lost after sound pass
through the wall between Zone D and Zone E
78.27dB - 42.09dB= 36.18 dB
(Total surface reflection index, SRIwall overall = 42.09dB)
Summary of Analysis
Based on the calculation, the sound transmission lost through the wall between Zone D and
Zone E is acceptable.The calculation shows that it is not match with the combine SPL of the
zone D (sitting area at the corner) and zone E (bar and counter area) with the sound
transmission lost of the wall of 42.09dB. This is due to the sound transmission is not only
from zone D and zone E as there are also sound sources transmitted from other dining area
and output music from the speakers at the interior space of the building.
Table 5.3.5.14 Common Sound Level
(Source: http://continuingeducation.construction.com)
Page | 101
According to Table 5.3.5.1, it shows that the wall between Zone A and Zone E has SRI index
of 33.15dB, it falls under marginal level of noise control. This is due to the wall are mostly
glass panel where sound can be transmit easily. Adding sound insulation can help to absorb
noise and improve the quality of noise. Adding sound insulation can help to absorb noise
and improve the quality of noise.
For the wall between Zone D and Zone E which has SRI index of 42.09dB which is good in
noise control. This is due to the brick wall is good sound absorber as it blocks most of the
noises into the dining area, creating a good acoustics for the comfort the occupants.
Page | 102
6.0 Conclusion
After analysing lighting and acoustic of Food Industry, based on the data and research, we
understand how important it is to perform such calculations to achieve comfortable
surroundings. To analyse the site critically, analysis software Ecotect, measuring tools for
collection of data on site, then finally calculations to sum up the condition of the interior
space.
After the analysis are done, the results are being compared to a standard level of lighting
environment should be. The lighting condition in Food Industry is insufficient for users to
carry on with their activities, only spaces close to the glass openings are provided with
sufficient lighting. Skylight and artificial lighting with higher luminance are recommended, to
provide better lighting environment.
For the acoustic analysis part, absorption materials such as carpet or fabric wall finishes
should be added to reduce sound reflection. The area near to the order counter are facing
high level noise condition, mainly because of the output created by the speakers installed
along the ceiling corner. Other than that, the order counter zone E are also facing high level
noise condition. Workers are busy to serve, and customers are busy to order, which creates
a lot of noise during the progress.
Finally, to improve and reduce the acoustic condition, the café owner should install high
absorption materials to improve the high noise level condition. Especially on the areas with
speakers installed along the ceiling corners, and also areas which are near to the bar
counter.
Page | 103
7.0 References
James Ambrose; Jeffrey E. Ollswang. (1995). Simplified Design For Building Sound Control.
New York: John Wiley & Sons, Inc.
Lechner, N. (2009). Lighting; Daylighting; Electric Lighting. In N. Lechner, Heating, Cooling,
Lighting 3rd Edition (pp. 343-460). New Jersey: John Wiley & Sons, Inc.
Pritchard, D. C. (1999). Lighting 6th Edition. Harlow: Addison Wesley Longman Limited.
Fraser, N. (2008). Lighting and Sound. Oxford: Phaidon Press.
Schiller, M. (1992). Simplified Design of Building Lighting. New York: John Wiley & Sons, Inc.
Standards Department Malaysia, (2007). Malaysian Standard MS1525:2007 (2007).
Malaysian standards Sirim Bhd.[pg. 5-6 (Daylight factors and distribution.), pg.21- 22
(Recommended average illuminance levels) ].
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