Building Science 2: Calculation Report

Page 1

SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN (SABD)

Bachelor of Science (Hons) in Architecture

BUILDING SCIENCE 2 [BLD 61303] Project 2:

INTEGRATION PROJECT J A L A N TA R C O M M U N I T Y L I B R A R Y

NAME STUDENT ID LECTURER

: Chan Yi Qin : 0315964 : Mr. Azim


TABLE OF CONTENTS 1.0 Introduction

3

2.0 Lighting 2.1 Natural Daylighting 2.1.1 Space 1: Exhibition Gallery

4-7

2.1.2 Space 2: Multimedia and Internet Resources

8-11

2.2 Artificial Lighting + PSALI 2.2.1 Space 1: Foyer

12-16

2.2.2 Space 2: Cafe

17-21

3.0 Acoustic 3.1 External Noise Calculation

22-23

3.1.1 Space 1: Self Study Area

24-27

3.1.2 Space 2: Admin & Support (Office)

28-31

3.2 Reverberation Time 3.2.1 Space 1: Performance Theater

32-33

3.2.2 Space 2: Cafe

34-35

3.3 Transmission Loss 3.3.1 Space 1: Self Study Area

36-38

3.3.2 Space 2: Audio Library

39-41

4.0 References

42

2


1.0 INTRODUCTION As part of the Design Studio 5 integrated module, this project is to focus on the principles of lighting and acoustics in the context of the overall design proposal. With a given urban infill site at Jalan Tuanku Abdul Rahman (TAR), whereby the proposed building will be an intermediate shop lot, sandwiched by 2 other shop lots. Along with a few aordable living spaces, the new proposed building is going to be built as a Community Library. The biggest challenge of the site is the challenge of bringing more natural lighting into the interior space of the building as there are only front, rear facades and a roof contacted to the exterior. Besides that, traďŹƒc induced noise from the front of the site also poses as an issue which needs to be resolved. Last but not least, these materials and products are detailed n order to bring forth an aesthetic, eective and economical outcome. While the Community Library is designed to be human centric, it must be able to provide the best thermal comfort at an economical rate, while also allowing for a quiet place to catch a read and run community meetings. The end outcome is to create a vibrant and interesting place for the community, while welcoming individuals of all ages and all foundations. This will be a centre for an assortment of social, learning and recreational opportunities.

3


2.0 LIGHTING 2.1 Natural Daylighting 2.1.1 Space 1: Exhibition Gallery

A

EXHIBITION GALLERY

A

Ground Floor Plan

EXHIBITION GALLERY

Section A-A

4


Daylight Factor Calculation Zone

DF (%)

Distribution

Very Bright

>6

Very large with thermal and glare problem

Bright

3-6

Good

Average

1-3

Fair

Dark

0-1

Poor

NOTE. The figures are average daylight factors for windows without glazing. Table 1: Daylight Factors and Distribution (Department of Standards Malaysia, 2007)

Formula

Daylight Factor (DF) = (Ei / Eo) x 100%

Area of Space (m2)

85.89

Area of Skylight (m2)

0

Area of Penetration (m2)

10.60 (W) x 3.70 (H) = 39.22 [(Exposed Area + Area of Skylight) / Floor Area] x 100%

Daylighting Factor, DF (%)

= [(39.22 + 0) / 85.89] x 100% = 0.457 x 100% = 4.57% Table 2: Space 1 Daylight Factor Calculation

Conclusion The open exhibition gallery has a daylight factor of 4.57%. Based on the requirements of MS1525 (Table 1), this space is considered as bright zone with good natural daylighting as it is within the range of 3-6%. This space is well shaded by the first floor slab because it is located at the center of the library ground level. Therefore, it receives appropriate natural daylighting during the day.

5


Natural Illumination Calculation Illuminance

Example

120,000 lux

Brightest sunlight

110,000 lux

Bright sunlight

20,000 lux

Shade illuminated by entire clear blue sky, Midday

1,000 - 2,000 lux

Typical overcast day, Midday

< 200 lux

Extreme of darkest storm clouds, Midday

400 lux

Sunrise of sunset on a clear day (Ambient illumination)

40 lux

Fully overcast, Sunset or sunrise

< 1 lux

Extreme of darkest storm clouds, Sunrise or sunset

Task

Illuminance (Lux)

Example of Application

20 100 100 100 100 Lighting for infrequently 150 used area 100 100

Minimum service illuminance Interior walkway and carpark Hotel bedroom Lift interior Corridor, passageway, stairs Escalator, travelator Entrance and exit Staff changing room, locker and cleaner room Entrance hall, lobbies, waiting room Inquiry desk Gate house

100 300 200 200 300-400

Lighting for working interiors

Localized lighting for exacting task

300-400 150 200 150-300 150 150 100 100 300-500 200-750

Infrequent reading and writing General offices, shops, and stores, reading, and writing Drawing office Restroom Restaurant, canteen, cafeteria Kitchen Lounge Bathroom Toilet Bedroom Classroom, library Shop, supermarket, department store

300

Museum and gallery

500 1,000 2,000

Proof reading Exacting drawing Detailed and precise work

Table 3: Recommended Average Illuminance Levels

6


Formula

DF = (E internal, Ei / external, Eo) x 100%

Given, Eo (Unobstructed sky of Malaysia)

20,000 lux

Daylight Factor, DF (%)

45.66 DF = (E internal, Ei / external, Eo) x 100% 45.66 = (Ei / 20,000) x 100%

Natural Illumination Calculation (lux) Ei = (45.66 x 20,000) / 100% = 9132.6 lux Table 4: Space 1 Natural Illumination Calculation

Conclusion According to the standard requirement in MS1525 (Table 3), the general illuminance level of a gallery is 300 lux. The illumination level in this open gallery space is 9132.6 lux which is exceedingly higher than the recommended level. Hence, problems such as thermal discomfort and glare may occur during specific hour of the day. Therefore, there is a need for shading device or double glazed low E-value glass for curtain walls. Besides, interior courtyard is proposed to be placed at the center of ground level. With its natural ventilation, a courtyard helps the library stay appropriately cool. During the day, a courtyard can bring down the building’s temperature and provide proper shade for the users.

7


2.1.2 Space 2: Multimedia and Internet Resources (Computer Lab)

A

A

MULTIMEDIA & INTERNET

Level 4 Plan

MULTIMEDIA & INTERNET

Section A-A

8


Daylight Factor Calculation Zone

DF (%)

Distribution

Very Bright

>6

Very large with thermal and glare problem

Bright

3-6

Good

Average

1-3

Fair

Dark

0-1

Poor

NOTE. The figures are average daylight factors for windows without glazing. Table 5: Daylight Factors and Distribution (Department of Standards Malaysia, 2007)

Formula

Daylight Factor (DF) = (Ei / Eo) x 100%

Area of Space (m2)

29.31

Area of Skylight (m2)

0

Area of Penetration (m2)

3.99 (W) x 3.20 (H) = 12.77 [(Exposed Area + Area of Skylight) / Floor Area] x 100%

Daylighting Factor, DF (%)

= [(12.77 + 0) / 29.31] x 100% = 0.436 x 100% = 4.36% Table 6: Space 1 Daylight Factor Calculation

Conclusion The computer lab has a daylight factor of 4.36%. Based on the requirements of MS1525 (Table 5), this space is considered as bright zone with a good natural daylighting as it is within the range of 3-6%. This space is well shaded by the fifth floor slab because it is located at the front of level 4. Hence, occupants can use computers in the space comfortably without having too much glares and thermal discomfort problems.

9


Natural Illumination Calculation Illuminance

Example

120,000 lux

Brightest sunlight

110,000 lux

Bright sunlight

20,000 lux

Shade illuminated by entire clear blue sky, Midday

1,000 - 2,000 lux

Typical overcast day, Midday

< 200 lux

Extreme of darkest storm clouds, Midday

400 lux

Sunrise of sunset on a clear day (Ambient illumination)

40 lux

Fully overcast, Sunset or sunrise

< 1 lux

Extreme of darkest storm clouds, Sunrise or sunset

Task

Illuminance (Lux)

20 100 100 100 100 Lighting for infrequently 150 used area 100 100 100 300 200

Lighting for working interiors

Localized lighting for exacting task

Example of Application Minimum service illuminance Interior walkway and carpark Hotel bedroom Lift interior Corridor, passageway, stairs Escalator, travelator Entrance and exit Staff changing room, locker and cleaner room Entrance hall, lobbies, waiting room Inquiry desk Gate house

200

Infrequent reading and writing

300-400

General offices, shops, and stores, reading, and writing

300-400 150 200 150-300 150 150 100 100 300-500 200-750 300

Drawing office Restroom Restaurant, canteen, cafeteria Kitchen Lounge Bathroom Toilet Bedroom Classroom, library Shop, supermarket, department store Museum and gallery

500 1,000 2,000

Proof reading Exacting drawing Detailed and precise work

Table 7: Recommended Average Illuminance Levels

10


Formula

DF = (E internal, Ei / external, Eo) x 100%

Given, Eo (Unobstructed sky of Malaysia)

20,000 lux

Daylight Factor, DF (%)

43.57 DF = (E internal, Ei / external, Eo) x 100% 43.57 = (Ei / 20,000) x 100%

Natural Illumination Calculation (lux) Ei = (43.57 x 20,000) / 100% = 8713.7 lux Table 8: Space 1 Natural Illumination Calculation

Conclusion According to the standard requirement in MS1525 (Table ), the general illuminance level of a computer lab is 300-400 lux. The illumination level in this computer lab space is 8713.7 lux which is exceedingly higher than the recommended level. This proves that the computer lab itself is receiving too much daylight during the day time. Thus, few solutions must be taken in order to counter the issue mentioned such as installing shading devices or double glazed low E-value glass for curtain walls.

11


2.2 Artificial Lighting + PSALI 2.2.1 Space 1: Foyer

FOYER

A

A

Ground Floor Plan

FOYER

Section A-A

12


Foyer is the space connects the entrance to various other spaces upstairs. Foyer functions as the boundary between the outside world and library. That being said, the aid from artificial light is needed to provide suďŹƒcient amount of illuminance, especially when the day turns into night. Artificial light is important in order to deliver a welcoming ambience when the users enter the library and can be used to complement the area where the natural light is not suďŹƒcient. Philips Corepro LED Lamp is chosen to light up this space. Lighting Schedule Philips Corepro LED Lamp E27 6W (40W)

Type of Fixture

Vertical Lone Light Fixture

Type of Light

Fluorescent Light

Type of Light Bulb Used

LED Bulb

Lighting Function

Task Lighting

Type of Luminaries

Warm White

Power, W

15W

Voltage, V

230V

Luminous Flux, Im

1142 Im

Color Temperature, K

3000K

Color Rendering Index, CRI

100

Average Life (at 2.7 hrs/day)

15.2 years

Lifetime of Lamp (hrs)

15000 hrs

Lumen Maintenance Factor

0.7

Features

Ernest without glare and harsh shadows

13


Table 9: Utilization Factors (UF) (Source: Lecture Notes)

Lumen Method Calculation Location

Foyer

Dimension (m)

Length (L) = 5.75m Width (W) = 5.77m Height of ceiling = 3.70m

Total Floor Area, A (m2)

5.75 x 5.77 = 33.18

Standard Illuminance Required (lux) according to MS1525, E

150

Lumen of lighting fixtures, Im

1142

Height of luminaire (m)

3.0

Work level (m)

0.8

Mounting Height, Hm (m)

2.4

Assumption of Reflective Value

Ceiling: 0.7 Wall: 0.5 Floor: 0.2

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Location

Foyer K=

Room Index, RI (K)

L xW (L + W )Hm

5.75x 5.77 (5.75 + 5.77)2.4

=

= 1.20 Utilization Factor, UF

0.6 (Refer to Table 5)

Maintenance Factor, MF

0.7 N=

Lumen Calculation, N

=

Ex A F xUF x MF

150x 33.18 1142x 0.6x 0.7

= 10.38 bulbs ≈11 LxN W = Number of luminaries across

5.75x11 5.77

= 3.31 ≈ 4 Therefore, each spacing would be 5.75 ÷ 4 = 1.44m Wx N L =

Number of luminaries along

5.77x11 5.75

= 3.32 ≈ 4 Therefore, each spacing would be 5.77 ÷ 4 = 1.44m

Table 10: Space 1 Lumen Method Calculation

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PSALI & Light Fittings Layout

Conclusion 11 fluorescent lamps are used to achieve minimum of 150 lux for this space that stated in MS1525. With the suďŹƒcient level of illumination, the users will experience comfort, safety and happiness while they first enter the library. First impressions make a big impact, the users can only relax themselves and enjoy the time they spend in other spaces of the library when they feel safe in the environment. Besides, when the day turns into night, this foyer is the only building shines along the street. This makes foyer lighting an integral factor in the overall impression visitors will have of the entire library. Lastly, switch is located near the front desk at main entrance due to the reason it is more convenient for the workers to switch it on or o before or after working hours.

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2.2.2. Space 2: Cafe

A

A CAFE

Ground Floor Plan

CAFE

Section A-A

17


This book cafe is a space where users are able to refuel themselves while getting lost in the city of books. The cafe is located at the ground floor facing the back lane where the back lane has a drop o point to east the visitors entering the building. Hence, artificial lighting is importance in order to provide visitors a comfortable and inviting illuminance when they step into the library through the cafe. Besides, since the daylight can hardly penetrate to the back of the library space, Philips LuxSpace Recessed Low Light is chosen to lit up the space. Type of Luminaire Used Philips LuxSpace Recessed Low Light, DN571B

Type of Fixture

Recessed Downlight

Type of Light

Fluorescent Light

Type of Light Bulb Used

LED Bulb

Lighting Function

Task Lighting

Type of Luminaries

Warm White

Power, W

36W

Voltage, V

240V

Luminous Flux, Im

2200Im

Color Temperature, K

4000K

Color Rendering Index, CRI

100

Lifetime of Lamp (hrs)

70000 hrs

Lumen Maintenance Factor

0.7

Features

Ernest without glare and harsh shadows

18


Lumen Method Calculation Location

Cafe

Dimension (m)

Length (L) = 5.92m Width (W) = 5.51m Height of ceiling = 3.70m

Total Floor Area, A (m2)

5.92 x 5.51 = 32.62

Standard Illuminance Required (lux) according to MS1525, E

150

Lumen of lighting fixtures, Im

2200

Height of luminaire (m)

3.5

Work level (m)

0.8

Mounting Height, Hm (m)

2.7

Assumption of Reflective Value

Ceiling: 0.7 Wall: 0.5 Floor: 0.1 K=

Room Index, RI (K)

L xW (L + W )Hm

5.92x 5.51 (5.92 + 5.51)2.7

=

= 1.06 Utilization Factor, UF

0.6 (Refer to Table 5)

Maintenance Factor, MF

0.8 N=

Lumen Calculation, N

=

Ex A F xUF x MF

150x 32.62 2200x 0.6x 0.8

= 4.63 bulbs ≈ 5 LxN W = Number of luminaries across

5.92x 5 5.51

= 2.32 ≈ 3 Therefore, each spacing would be 5.92 ÷ 3 = 1.97m

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Location

Cafe Wx N L =

Number of luminaries along

5.51x 5 5.92

= 2.16 ≈ 3 Therefore, each spacing would be 5.51 á 3 = 1.84m

Table 11: Space 2 Lumen Method Calculation

20


PSALI & Light Fittings Layout

Conclusion The cafe has 5 recessed downlight as required. However, lights have to be switched on most of the time for indoor activity to fulfill the requirement of MS1525. In short, this book cafe draws in people who come in for coffee, but stay to read a book. It allows many opportunities for community connection. With sufficient level of illumination, it is able to increase the pleasant and peaceful ambience when visitors enter the space. Users get to drink and savor freshly make organic tea and in house-roasted coffee comfortably, while browse themselves in any of the books, magazines and newspapers available there. Besides, switch is located near to the main entrance due to the reason that it is more convenient for the workers to switch it on or off before and after working hours. 21


3.0 ACOUSTIC 3.1 External Noise (Sound Pressure Level) Given the site is facing towards the main road of Jalan Tuanku Abdul Rahman (TAR), most of the outdoor noise source is hence contributed by vehicular traffic along this route, gradually increasing during peak traffic hours. In addition, very minimal outdoor noise can be heard from the back due to the fact that people or vehicles rarely pass by the back lane. Since the site was give to be an urban infill site, whereby the proposed building will be an intermediate shoplift sandwiched by 2 other shop lots, there will be some activity noise coming from the five-foot walkway, too. Assuming the external noises, Sources of Noise

Sound Pressure Level, SPL(dB)

Traffic noise

80 dB

Activity noise from five-foot walkway

60 dB

Back lane noise

50 dB

Formula, L = 10log10 ( I / Io) Intensity

Calculation 70 = 10 log10

Traffic Noise

Itra f f ic Io

AntiLog 7.0 =

Itra f f ic

1x10−12

Itra f f ic = (107 )(1x10−12 ) Itra f f ic = 1x10−5 60 = 10 log10 Activity Noise

Iactivit y

AntiLog 7.0 =

Io

Iactivit y

1x10−12

Iactivit y = (106 )(1x10−12 ) Iactivit y = 1x10−6

22


50 = 10 log10

Ibacklane Io

AntiLog 5.0 =

Back Lane Noise

Ibacklane 1x10−12

Ibacklane = (10 5)(1x10−12 ) Ibacklane = 1x10−7 Total Intensity, Itotal = Itra f f ic + Iactivit y + Ibacklane = (1x10−5) + (1x10−6 ) + (1x10−7 ) = 1x10−18 Combined SPL = 10 log10 = 10 log

Itotal Io

= 10 log10

p2 , where po = 1x10−12 po 2

1x10−18 [ 1x10−12 ]

= 60 dB

Conclusion The external noise with a combined SPL of 60 dB generated from traffic noise, street activity noises and noises from back lane travels into the library compound without passing through walls that will cause transmission loss. Therefore, the combined SPL of the external noise is approximately the total sound pressure level in the library. The required sound pressure level for a library is 35 dB but the sound pressure level calculated has highly exceeded at 60 dB. Appropriate and necessary actions have to be taken to reduce the sound pressure level into the library.

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3.1.1 Space 1: Self Study Area

A

A

SELF STUDY AREA

Level 5 Plan

SELF STUDY AREA

Section A-A

24


Sound Pressure Level Calculation: Peak Hour Power Addition Calculation Formula: L = 10 log10 Highest Reading = 65 dB 65 = 10 log10

Lowest Reading = 59 dB

I Io

AntiLog 6.5 =

I Io

59 = 10 log10

I 1x10−12

I Io

AntiLog 5.9 =

I 1x10−12

I = (106.5)(1x10−12 )

I = (10 5.9 )(1x10−12 )

I = 3.16x10−6

I = 7.94x10−7

Total Intensity, Itotal = (3.16x10−6 ) + (7.94x10−7 ) = 3.95x10−6 Combined SPL = 10 log10 = 10 log

Itotal Io

= 10 log10

p2 , where po = 1x10−12 po 2

3.95x10−6 [ 1x10−12 ]

= 65.95 dB

Rule of Thumb Method Difference between the 2 values

Add to larger SPL

0,1

+3

2,3

+2

4-9

+1

10 or greater

0

When Highest Reading = 65 dB; Lowest Reading = 59 dB, Difference between 2 values = Highest Reading - Lowest Reading = 65 dB - 59 dB = 6 dB (difference) 25


Hence, 65 dB + 59 dB = 66 dB Sound Pressure Level Calculation: Non-Peak Hour Power Addition Calculation Formula: L = 10 log10 Highest Reading = 60 dB 60 = 10 log10

Lowest Reading = 52 dB

I Io

AntiLog 6.0 =

I Io

52 = 10 log10

I 1x10−12

I Io

AntiLog 5.2 =

I 1x10−12

I = (106 )(1x10−12 )

I = (10 5.2 )(1x10−12 )

I = 1x10−6

I = 1.58x10−7

Total Intensity, Itotal = (1.x10−6 ) + (1.58x10−7 ) = 1.16x10−6 Combined SPL = 10 log10 = 10 log

Itotal Io

= 10 log10

p2 , where po = 1x10−12 po 2

1.16x10−6 [ 1x10−12 ]

= 60.64 dB

Rule of Thumb Method Difference between the 2 values

Add to larger SPL

0,1

+3

2,3

+2

4-9

+1

10 or greater

0

When Highest Reading = 65 dB; Lowest Reading = 59 dB, Difference between 2 values = Highest Reading - Lowest Reading 26


= 60 dB - 52 dB = 8 dB (dierence) Hence, 60 dB + 52 dB = 61 dB

Table 12: Recommended RC and NC Values for Unoccupied Spaces (Source: Lecture Notes)

Conclusion As a result, the average external sound pressure level for self-study area during peak and non-peak hour are 65.96 dB and 60.64 dB. Besides that, rule of thumb method is used in order to prove the power addition calculation is correct.

27


3.1.2 Space 2: Admin & Support (Office)

A

A

ADMIN & SUPPORT

Level 4 Plan

ADMIN & SUPPORT

Section A-A

28


Sound Pressure Level Calculation: Peak Hour Power Addition Calculation Formula: L = 10 log10 Highest Reading = 66 dB 67 = 10 log10

Lowest Reading = 63 dB

I Io

AntiLog 6.7 =

I Io

64 = 10 log10

I 1x10−12

I Io

AntiLog 6.4 =

I 1x10−12

I = (106.7 )(1x10−12 )

I = (106.4 )(1x10−12 )

I = 5x10−6

I = 2.51x10−6

Total Intensity, Itotal = (5x10−6 ) + (2.51x10−6 ) = 7.51x10−6 Combined SPL = 10 log10 = 10 log

Itotal Io

= 10 log10

p2 , where po = 1x10−12 po 2

7.51x10−6 [ 1x10−12 ]

= 68.76 dB

Rule of Thumb Method Difference between the 2 values

Add to larger SPL

0,1

+3

2,3

+2

4-9

+1

10 or greater

0

When Highest Reading = 66 dB; Lowest Reading = 63 dB, Difference between 2 values = Highest Reading - Lowest Reading = 66 dB - 63 dB

29


= 3 dB (difference) Hence, 66 dB + 63 dB = 68 dB Sound Pressure Level Calculation: Non-Peak Hour Power Addition Calculation Formula: L = 10 log10 Highest Reading = 51 dB 50 = 10 log10

Lowest Reading = 45 dB

I Io

AntiLog 5.0 =

I Io

45 = 10 log10

I 1x10−12

I Io

AntiLog 4.5 =

I 1x10−12

I = (10 5)(1x10−12 )

I = (10 4.5)(1x10−12 )

I = 1x10−7

I = 3.16x10−8

Total Intensity, Itotal = (1x10−7 ) + (3.16x10−8) = 1.32x10−7 Combined SPL = 10 log10 = 10 log

Itotal Io

= 10 log10

p2 , where po = 1x10−12 po 2

1.32x10−7 [ 1x10−12 ]

= 51.21 dB

Rule of Thumb Method Difference between the 2 values

Add to larger SPL

0,1

+3

2,3

+2

4-9

+1

10 or greater

0

30


When Highest Reading = 51 dB; Lowest Reading = 45 dB, Difference between 2 values = Highest Reading - Lowest Reading = 51 dB - 45 dB = 6 dB (difference) Hence, 51 dB + 45 dB = 52 dB Conclusion As a result, the average external sound pressure level for administration office during peak and non-peak hour are 68.76 dB and 51.21 dB. The drastic change of sound level occurs in the office due to the amount of people occupying the space. Besides that, rule of thumb method is used in order to prove the power addition calculation is correct.

31


3.2 Reverberation Time, RT

Table 13: Typical Reverberation Times of Spaces (Source: Lecture Notes)

3.2.1 Space 1: Performance Theater

PERFORMANCE THEATER

Level 4 Plan

32


Reverberation time is deliberated to define the space quality in relation to human comfort. The space performance theater is chosen due to the reason that different types of events, such as conferences, film screening and story sharing sessions, or even operas can be held here, thus an optimum acoustic surrounding must be provided. Reverberation Time Calculation Room Height

6.4m

Standard Reverberation Time for Theaters

0.7 to 1.0s

Volume of Theater, (m3)

(5.92m x 5.51m) x 6.4m = 209.82m 3

Surface Area, m 2

Absorption Coefficient, α (sabin)

Sound Absorption, Sa (m 2sabin)

Pane Glass

23.50

0.04

0.94

Plaster Board

94.48

0.15

14.17

Hung Curtain, Heavy

33.06

0.55

18.18

Rockwool Foam

94.48

0.90

85.03

Floor

Carpet, Heavy, on Reinforced Concrete

32.62

0.14

4.57

Ceiling

Reinforced Concrete

32.62

0.02

0.65

Door

Plywood

28.35

0.06

1.70

Seat

Timber Padded Retractable Tip-up Seat

37.88

0.15

5.68

Component

Wall

Material

Total Absorption, AT (m 2sabin)

130.92

Table 14: Total room surface absorption

Formula: Reverberation Time, RT =

0.16V 0.16x 209.82m 3 = 0.256s ≈ 0.3s = AT 130.92m 2 sa bin

Conclusion The reverberation time for this performance theater is 0.3s. According to the standards of reverberation time, the ideal reverberation time for theaters is between 0.7 to 1.0s. Hence, the reverberation time of the proposed theater design is lower than the optimum reverberation time. To increase reverberation time, one could increase the volume of the room, or reduce the amount of absorption in the room. 33


3.2.2 Space 2: Cafe

CAFE

Ground Floor Plan Implementing sound absorption strategies on cafe can be tricky. Properly done, it will improve speech intelligibility and clarity; too much and space seems dead; too little and patrons complain. Dierent people perceive dierent noise levels in their own ways. But since this is a library dedicated for young people, and young people tend to gravitate towards environments that are louder and livelier, a vibrant (but not extremely noisy) surrounding must be provided. Reverberation Time Calculation Room Height

3.7m

Standard Reverberation Time for Cafes

0.7 to 0.8s

Peak Hour Capacity

20 people

Volume of Cafe, (m3)

(5.92m x 5.51m) x 3.7m = 120.69m 3

34


Surface Area, m 2

Absorption Coefficient, Îą (sabin)

Sound Absorption, Sa (m 2sabin)

Pane Glass

70.53

0.04

2.82

Plaster Board

75.77

0.15

11.37

Floor

Reinforced Concrete

32.62

0.14

4.57

Ceiling

Reinforced Concrete

32.62

0.02

0.65

Door

Pane Glass

28.35

0.04

1.13

Table

Timber

20.5

0.2

4.10

0.98 (per pcs)

0.28 (per seat)

0.27

Component

Material

Wall

Chair (20pcs) Fabric

Total Absorption, AT (m 2sabin)

24.91

Table 15: Total room surface absorption

Formula: Reverberation Time, RT =

0.16x120.69m 3 0.16V = 0.78s ≈ 0.8s = 24.91m 2 sa bin AT

Conclusion The reverberation time for the book cafe during peak hours is 0.8s. According to the standards of reverberation time, the ideal reverberation time for cafes is between 0.7 to 0.8s. Hence, the reverberation time of the proposed cafe design on 2000Hz is within the optimum reverberation time.

35


3.3 Sound Transmission Loss Formula: T L = 10 log

Tav =

1 Tav

(T 1x A1) + (T 2x A2) + (T 3x A3) + . . . (T n x A n) Total Sur fa ce Ar ea

Tcn = The transmission coeďŹƒcient of material Sn = The surface area of the material

3.3.1 Space 1: Self Study Area

TERRACE

SELF STUDY AREA

Level 5 Plan This self study area is located on the fifth floor at the middle part of the library. There is an open terrace opposite where it may bring a lot of noise to the audio library. Hence, transmission loss from terrace to audio library should be minimal.

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Components

Materials

Transmission Coefficient, T

Area (m 2)

Sound Reduction Index (SRI)

Curtain wall

Glass

3.16x10−4

35.1

35

Door

Glass

3.16x10−4

8.1

35

Wall

Concrete

6.31x10−5

22.88

42

Transmission Coefficient of Materials Curtain Wall and Glass Door

SRI (glass) = 10 log

35 = 10 log

( Tglass ) 1

( Tglass )

AntiLog 3.5 =

1

Wall

SRI (concrete) = 10 log

42 = 10 log

1

Average Transmission Coefficient of Materials S1TC + S 2TC 2...SnTCn

Total

Sur fa ce

Ar ea

−4 −4 −5 (3.16x10 ) + (3.16x10 ) + (6.31x10 ) Tav = 35.1 + 8.1 + 22.88

Tav = 6.951x10−4 Total Sound Reduction Index, SRI SRI = 10 log10

1

1

Tconcrete

Tconcrete = 6.31 x10−5

Tconcrete = 3.16 x10−4

Tav =

( Tconcrete )

AntiLog 4.2 =

Tglass

1 ( Tav )

37

( Tconcrete ) 1


SRI = 10 log10

1 ( 6.951x10−4 )

SRI = 32 dB Noise Level in Self Study Area = 65 dB - 32 dB = 33 dB Conclusion The overall transmission loss from open terrace is 32dB. Assume that the sound pressure level in the open terrace area is 32dB, the sound that is transmitted through the wall and curtain walls into the self study area is 33dB. According to the noise criteria environment perception, 33dB is below soft whisper noise which is considered as quiet range. It is considered as an ideal value for the self study area as it is a place for study and reading zone without noise disturbance from the open terrace.

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3.3.1 Space 2: Audio Library

READING AREA

AUDIO LIBRARY

Level 3 Plan

This audio library is located at front part of Level 3. It is a space showcases rich collections of music, e-books, audio books, and movies. CDs, DVDs/Blue-Rays are available for check-out. All of the tracks from CD archives totaling more than 10,000 albums are freely sampled at seated stations, where users can browse themselves in the music city while enjoying a cup of coffee bought from the cafe downstairs. The noise control of the entire area shall thus be controlled in order to preserve the peaceful and relaxing ambience.

Components

Materials

Transmission Coefficient, T

Area

(m 2)

Sound Reduction Index (SRI)

Window

Glass

3.16x10−4

0.96

35

Door

Glass

3.16x10−4

3.99

31

Wall

Concrete

6.31x10−5

17.05

42

39


Transmission Coefficient of Materials Window

Door

( Tglass ) 1

SRI (glass) = 10 log

35 = 10 log

( Tglass )

AntiLog 3.5 =

SRI (concrete) = 10 log

31 = 10 log

1

1

( Tconcrete ) 1

AntiLog 3.1 =

−4

Tconcrete = 3.16 x10

SRI (concrete) =

( Tconcrete )

1

Tglass

Tconcrete = 7.94 x10−4

S1TC + S 2TC 2...SnTCn

Total

Sur fa ce

1

Tconcrete

Average Transmission Coefficient of Materials Tav =

Wall

Ar ea

−4 −4 −5 (3.16x10 ) + (7.94x10 ) + (6.31x10 ) Tav = 0.96 + 3.99 + 17.05

Tav = 5.332x10−5 Total Sound Reduction Index, SRI SRI = 10 log10

1 ( Tav )

SRI = 10 log10

1 ( 5.332x10−4 )

SRI = 43 dB Noise Level in Audio Library = 55 dB - 43 dB = 12 dB 40

10 log

( Tconcrete )

42 = 10 log

1

( Tconcrete )

AntiLog 4.2 =

1

1

Tconcrete

Tconcrete = 6.31 x10−5


Conclusion The overall transmission loss from hallway to audio library is 43dB. Assume that the sound pressure level in the hallway is 55dB, the sound that is transmitted through the walls into the audio library is approximately 12dB. According to the noise criteria environment perception, 12dB is below the whisper noise. Hence, it is an ideal value for the audio library as users can browse themselves in the music city comfortably without noise disturbance from other spaces.

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4.0 REFERENCES Chan, E. (2017) Room Acoustic Sources. Lecture, Taylor’s Lakeside. Grondzik, W. T., & Kwok, A. G. (2015). Mechanical and electrical equipment for buildings (12th ed.). Hoboken, NJ: Wiley. Moore, J. (1961). Design for Good Acoustics. London : Architectural Press. Schmolked, B. (2011) Theaters and Concert Halls: Construction and Design Manual. Singapore : Page One. Sound of Architecture. (2015) Taking Sound of Architecture. Retrieved 15th July 2017, from http://info.soundofarchitecture.com/blog/recommended-reverberation-times-for-7-keyspaces Sulaiman, A. (2017) Artificial Light Sources. Lecture, Taylor’s Lakeside. Trevor, J., & Peter, D. (2009). Acoustic Absorbers and Diffusers: Theory, Design and Application. London : Taylor & Francis.

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