report and calculation

SCHOOL OF ARCHITECTURE, BUILDING & DESIGN

BACHELOR OF SCIENCE (HONOURS) (ARCHITECTURE)

BUILDING SCIENCE 2 (ARC 3413)

PROJECT 2: INTERGRATION PROJECT WITH DESIGN STUDIO 5

(30% OF FINAL MARKS)

SENTUL COMMUNITY LIBRARY

LIGHTING AND ACOUSTICS PROPOSAL REPORT & CALCULATION

LEE JO YEE 0314880

TUTOR: MR.EDWIN YEAN LIONG CHAN

SUBMISSION DEADLINE: 11TH JULY 2016

LEE JO YEE 0314880 2

BUILDING SCIENCE 2

TABLE OF CONTENT

CONTENT

PAGE

1.O LIGHTING

1.1 NEIGHBOURHOOD WORKSHOP

1.1.1 DAYLIGHTING ANALYSIS

1.1.2 ARTIFICIAL LIGHTING PROPOSAL

1.1.3 PSALI ( Permanent Supplementary Artificial Lighting

of Interiors)

3

6

8

1.2 MULTIPURPOSE STAGE



1.2.3 PSALI ( Permanent Supplementary Artificial Lighting

of Interiors)

9

12

15

2.0 ACOUSTICS

2.1 SOUND PRESSURE LEVEL – External Noises

2.1.1 NEIGHBOURHOOD WORKSHOP v.s. BACK LANE

2.1.2 GENERAL LIBRARY v.s. JALAN IPOH

15

18

2.2 REVERBERATION TIME (RT)

2.2.1 AUDIO VISUAL ROOM

2.2.2 QUIET READING AREA

21

24

2.3 SOUND REDUCTION INDEX (SRI)

2.3.1 NEIGHBOURHOOD WORKSHOP v.s. BACK LANE

2.3.2 GENERAL LIBRARY v.s. JALAN IPOH

27

27

29

3.0 REFERENCES 31


BUILDING SCIENCE 2

1 LIGHTING

1.1 NEIGHBOURHOOD WORKSHOP


The selected studied area is the neighbourhood workshop on the first

floor (FFL 10.72), located at the rear of the building facing back lane as

highlighted in the first floor plan below. The floor height of this space is 3 meters

and the aim of the façade design of this selected area is to provide maximum

day lighting in the morning whereas remain shaded during evening when the

strong sunlight coming in from the west.

FIGURE 1 : FIRST FLOOR PLAN INDICATING THE LOCATION OF THE WORKSHOP

OPENINGS

BACKLANE

WORKSHOP


BUILDING SCIENCE 2

FIGURE 2: ZOOM IN PLAN AND LIGHT CONTOUR DIAGRAM OF NEIGHBOURHOOD WORKSHOP

According to MS1525, Day Lighting factor distribution is as below:

Zone Daylight Factor (%) Distribution

Very Bright >6 Too Bright with Thermal and Glare

problems

Bright 3-6 Good

Average 1-3 Fair

Dark 0-1 Poor

DAYLIGHING FACTOR CALCULATION

Floor Area (𝒎𝟐) 10.64 x 4.4 = 46.82𝒎𝟐

Area of façade exposed to sunlight (𝒎𝟐) (10.8 x 3) = 32.4

Area of skylight 0

Exposed Façade & Skylight Area to Floor

Area ratio/ Daylight Factor, DF

(32.4+0)

46.82

= 0.69

= 69% x 0.1

= 6.9%


BUILDING SCIENCE 2

NATURAL ILLUMINATION CALCULATION

ILLUMINANCE EXAMPLE

120,000 lux Very Bright Sunlight

110,000 lux Bright Sunlight

20,000 lux Clear Sky

1000-2000 lux Overcast day

400 lux Sunrise / Sunset on clear day

<200 lux Midday

40 lux Fully overcast

<1 lux Sunset, Storm cloud

External = 20 000 lux (Clear Sky )

DF= E_internal/E_external x 100%

= (6.9 x 20000)/100

= 1380 lux

CONCLUSION

The workshop has a daylight factor of 6.9% and natural illumination of

1380 lux. Based on the requirement of MS 1525, the space is brightly lit by

daylight as both of the values exceed the standards. For instance, the daylight

factor should be lower than 6% and the recommended light level for

workshops is 300 lux. This will cause thermal discomfort and glare to the users.

Hence, the wall exposed to the sunlight, is designed with openings of a

row of high wooden shutter windows (2200mm). The wooden shutters are

designed in a way to maximize natural daylight into the workshop and can

operated manually when sun shading is required. Wood is a good material with

low reflectance and will not cause glare to other adjacent building. Proposed

elevation is shown below.

FIGURE 3 : BACK ELEVATION WOODEN SHUTTER WINDOW


BUILDING SCIENCE 2


The neighbourhood workshop will held activities not just on the day but

night too. Hence, artificial lighting is vital in this area in order to produce a well-

lit, comfortable work area. Based on the study (ROOM ILLUMINATION LEVEL,

2016) and MS 1525, the required lux level for a standard workshop is 300 – 500.

LUMEN METHOD CALCULATION

Type of luminaire proposed:

Type of fixture Recessed LED luminaire

Type of model

Figure :PowerBalance RC600B recessed LED

luminaire, square

Company Philips

Geometry Width 0.6m x Length 0.6m

Lumen ( lm ) 3100

Watt 26

Color Designation Cool White

Dimension of room (L x W) 10.64 x 4.4

Floor Area (A) 46.82m2

Height of Ceiling (m) 3.0

Lumen (Lux) 3100

Height of Luminaire (m) 3

Height of Work Level (m) 0.8

Mounting Height (Hm) 2.2

Reflection Factors Ceiling: 0.7

Wall: 0.5


BUILDING SCIENCE 2

Floor: 0.2

Room Index/ RI (K) 10.64 𝑥 4.4

2.2 𝑥 (10.64 + 4.4)

= 1.42

Utilisation Factor (UF) 0.40

Maintenance Factor (MF) 0.80

Number of Lamps Required

N= 𝑬 𝒙 𝑨

𝑭 𝒙 𝑼𝑭 𝒙 𝑴𝑭

N= 300 𝑥 46.82

3100 𝑥 (0.4 𝑥 0.8)

= 14.16

= 14

Spacing to Height Ratio (SHR) SHR = 1

𝐻𝑚 X √

𝐴

𝑁

= 1

2.2 X √

46.82

14

= 0.83

SHR= 𝑆

2.2 = 0.83

S = 2.2 X 0.83 = 1.83

Fittings Layout Fittings required along 10.64m wall= 10.64

1.83

= 5.81

= 6 row

Number of lamps in each row = 14

6

= 2.33

= 3 Lamps

Spacing along 4.4m wall = 4.4

3

= 1.47m

FITTING LAYOUT

FIGURE 4: PROPOSED LUMINARIES FITTING LAYOUT OF WORKSHOP


BUILDING SCIENCE 2

CONCLUSION

In the end, the workshop is arranged with 3 rows of 5 Recessed LED

luminaire to be achieve the requirement of 300 lux in the room as stated in

MS1525. With the sufficient level of illumination, the community is able to carry

out different classes and workshops no matter day or night.

1.1.3 PSALI (Permanent Supplementary Artificial Lighting of Interiors)

Based on the calculation and light contour analysis, the total 15

luminaires in the workshop can be controlled using just two switches. Switch 1

controls the row (5 luminaires) facing the façade and switch 2 controls the

following two rows (10 luminaires). Reason being is the workshop will receive a

strong daylight distribution of 6.9% during the day from the façade. Switch 1

can be switch off and switch 2 be switch on during that period of time so that

electrical cost can be saved.

FIGURE 5: PROPOSED REFLECTED CEILING PLAN AND SWITCH ARRANGEMENT


BUILDING SCIENCE 2

1.2 MULTIPURPOSE STAGE


The selected studied area is the multipurpose stage on the upper ground

floor (FFL 3.36), located at the hearth of the building with skylight shone from

the roof. The floor height of this space is 4 meters and the skylight penetrated

to this floor through the opening on the first floor level as shown in figure.

The multipurpose stage consists of functions like talks, reading spaces,

children storytelling area and acts as the building lobby at the same time. The

recommended light levels is between 300 – 500 lux. (ROOM ILLUMINATION

LEVEL, 2016) (www.noao.edu, 2016)

MULTIPURPOSE

STAGE

SKYLIGHT OPENING

TO BELOW

FIGURE 6: UPPER GROUND FLOOR PLAN

INDICATING THE AREA OF MULTIPURPOSE

STAGE

FIGURE 7: FIRST FLOOR PLAN INDICATING THE

SKYLIGHT OPENING ABOVE THE UPPERFLOOR

LEVEL

LEE JO YEE 0314880 10

BUILDING SCIENCE 2

FIGURE 8: LIGHT CONTOUR DIAGRAM OF THE MULTIPURPOSE STAGE

According to MS1525, Day Lighting factor distribution is as below:

Zone Daylight Factor (%) Distribution

Very Bright >6 Too Bright with Thermal and Glare

problems

Bright 3-6 Good

Average 1-3 Fair

Dark 0-1 Poor

DAYLIGHING FACTOR CALCULATION

Floor Area (𝒎𝟐) Multipurpose hall area

𝑨 = 𝝅𝒓𝟐

= 𝝅 𝟓. 𝟏𝟖𝟓 2

= 84.46 𝒎𝟐

Area of façade exposed to sunlight (𝒎𝟐) 0

Area of skylight Opening at First Floor Area 𝐴 = 𝜋𝑟2

= 𝜋 3.5 2

= 38.48 𝒎𝟐

Exposed Façade & Skylight Area to Floor

Area ratio/ Daylight Factor, DF

(38.48+0)

84.46

= 0.46

= 46% x 0.1

= 4.6%

LEE JO YEE 0314880 11

BUILDING SCIENCE 2

NATURAL ILLUMINATION CALCULATION

ILLUMINANCE EXAMPLE

120,000 lux Very Bright Sunlight

110,000 lux Bright Sunlight

20,000 lux Clear Sky

1000-2000 lux Overcast day

400 lux Sunrise / Sunset on clear day

<200 lux Midday

40 lux Fully overcast

<1 lux Sunset, Storm cloud

External = 20 000 lux (Clear Sky )

DF= E_internal/E_external x 100%

= (4.9 x 20000)/100

= 980 lux

CONCLUSION

The multipurpose stage has a day lighting factor 4.6% after calculation.

Based on the chart above, the space is brightly lit by daylight within the

optimum zone which is 3-6%. However, the natural illuminance value obtained

is 980 lux which is higher than the recommended values. The excessive daylight

can cause thermal discomfort at the court and people will refrain from

enjoying the space.

Hence, a glazing roof or double-glazed low-emissive glass can be

applied on the roof to solve the glare problem and to reduce heat gain in this

area. Ceiling design can be an option to diffuse or reflect the daylight from

directly shone into the multipurpose stage.

LEE JO YEE 0314880 12

BUILDING SCIENCE 2


Based on the study (ROOM ILLUMINATION LEVEL, 2016) and MS 1525,

the required lux level for the multipurpose stage above is 300 – 500 lux.

LUMEN METHOD CALCULATION

Type of luminaire proposed:

Type of fixture (Recessed) LED Downlight

Type of model

Figure 9:Philips CorePro LED Downlight

Company Philips

Geometry Round, 305mm – 610mm in diameter

Lumen ( lm ) 3000

CRI 80

Watt 36

Color Designation Warm White

Dimension of room (𝐴 = 𝜋𝑟2) 𝜋 𝟓. 𝟏𝟖𝟓 2

Floor Area (A) 84.46 m2

Height of Ceiling (m) 4

Lumen (Lux) 3000

Height of Luminaire (m) 4

Height of Work Level (m) 0.8

Mounting Height (Hm) 3.2

Reflection Factors Ceiling: 0.7

Wall: 0.5

Floor: 0.2

Room Index/ RI (K) 𝜋 𝟓. 𝟏𝟖𝟓 2

3.2 𝑥 (2𝜋 5.185/2 )

= 1.62

Utilisation Factor (UF) 0.48

Maintenance Factor (MF) 0.80

Number of Lamps Required

N= 𝑬 𝒙 𝑨

𝑭 𝒙 𝑼𝑭 𝒙 𝑴𝑭

N= 300 𝑥 84.46

3000 𝑥 (0.48 𝑥 0.8)

= 21.9947

= 22 lamps

LEE JO YEE 0314880 13

BUILDING SCIENCE 2

Spacing to Height Ratio (SHR) SHR = 1

𝐻𝑚 X √

𝐴

𝑁

= 1

3.2 X √

84.46

22

= 0.61

SHR= 𝑆

3.2 = 0.61

S = 3.2 X 0.61 = 1.95

Fittings Layout Fittings required along the

circumference of the court = 32.58

1.95

= 16.7

= 17 lamps

Number of lamps in each row = 22

17

= 1.29

= 2 Lamps

Spacing along the radius = 5.185

2

= 2.6m

FITTING LAYOUT

FIGURE 10: PROPOSED LUMINARIES FITTING LAYOUT OF MULTIPURPOSE STAGE

LED DOWNLIGHTS GRID LINES

LEE JO YEE 0314880 14

BUILDING SCIENCE 2

CONCLUSION

Based on the approximation of the fitting layout, the luminaires of the

multipurpose stage are arranged into 3 rows (circumference) of 8 recessed LED

down lights, which in total a maximum of 24 luminaries to be installed. With the

aid of the artificial lighting, the space is able to meet a requirement of 300-400

lux as stated in MS1525.

1.1.3 PSALI (Permanent Supplementary Artificial Lighting of Interiors)

Referring to the daylight analysis above, the multipurpose stage has a

good day lighting factor of 4.9% which means the space receives sufficient

day light from the skylight opening. On the other hand, the calculation shows

that the place require a number of 22 lamps in order to illumine the space. By

applying the PSALI principles, the luminaries are divided into three switches,

ranging from the outer ring to the inner ring. It is straight forward.

During the day when the day light is concentrate at the centre of the

stage, switch 3 can be turned off whereas switches 1 and 2 can be turned on

to illumine areas that are further from the core. Switch 2 can be turned off

when daylight is too strong and leaving switch 3 to illuminate the outer ring of

the court.

FIGURE 11: PROPOSED REFLECTED CEILING PLAN AND SWITCH ARRANGEMENT

LEE JO YEE 0314880 15

BUILDING SCIENCE 2

2 ACOUSTICS

2.1 EXTERNAL NOISE SOUND PRESSURE LEVEL

2.1.1 NEIGHBOURHOOD WORKSHOP

The neighbourhood workshop on the upper ground floor plan is

selected as a space to analyse and compare the external noise sound

pressure level at back lane. Readings are collected at both peak hour (8am

to 10am) and non-peak hour (8pm to 10pm).

FIGURE 12: FIRST FLOOR PLAN INDICATING WORKSHOP AND BACK LANE LOCATION

BACK LANE

JALAN IPOH

LEE JO YEE 0314880 16

BUILDING SCIENCE 2

Peak Hour (8am to 10am)

Highest reading= 65dB

Using the formula,

SIL= 10 log10 ( 𝐼

𝐼𝑜 )

65= 10 log10 ( 𝐼

1 𝑥 10−12 )

106.5= 𝐼

1 𝑥 10−12

I= 1x 10-12 X 106.5

= 3.162 X 10-6

Lowest reading= 53dB

Using the formula,


𝐼𝑜 )

53= 10 log10 ( 𝐼

1 𝑥 10−12 )

105.3= 𝐼

1 𝑥 10−12

I= 1x 10-12 X 105.3

= 1.995 X 10-7

Total Intensity, I= (3.162 X 10-6) + (1.995 X 10-7)

= 3.362 x 10-6

Using the formula, Combined SPL= 10 log10 ( 𝑝2

𝑝𝑜2 ), where po = 1 x 10-12

Combined SPL= 10 log 10 ( 𝟑.𝟑𝟔𝟐 𝐱 𝟏𝟎−𝟔

1 𝑥 10−12 )

= 65.27 dB

Non-peak Hour (8pm to 10pm)


Using the formula,


𝐼𝑜 )

40= 10 log10 ( 𝐼

1 𝑥 10−12 )

104= 𝐼

1 𝑥 10−12

I= 1x 10-12 X 104

= 1X 10-8


Using the formula,


𝐼𝑜 )

38= 10 log10 ( 𝐼

1 𝑥 10−12 )

103.8= 𝐼

1 𝑥 10−12

I= 1x 10-12 X 103.8

= 6.31 X 10-9

Total Intensity, I= (1X 10-8) + (6.31 X 10-9)

= 1.631 x 10-8


𝑝𝑜2 ), where po = 1 x 10-12

Combined SPL= 10 log 10 ( 1.631 𝑥 10−8

1 𝑥 10−12 )

= 42.13 dB

LEE JO YEE 0314880 17

BUILDING SCIENCE 2

CONCLUSION

According to the calculation above, the combined sound pressure level

of the back lane during peak and non-peak hours are 65.27dB and 42.13 dB

respectively. The noise criteria for a workshop, under the category of lecture

and classroom (Noise Criterion, 2016) is between the NC ranges of 25 – 30. The

noises from the back lane will affect the acoustics of the workshop.

Hence, different solutions can applied in solving such case like using

materials with lower absorption coefficient at the exterior such as concrete,

brick, tiles to reflect the noises away, or applying sound buffer panels as the

exterior façade.

FIGURE 13: LIGHTING AND ACOUSTICS CONDITION AT THE BACKLANE AT NIGHT

LEE JO YEE 0314880 18

BUILDING SCIENCE 2

2.1.2 GENERAL LIBRARY

The general library section on the upper ground floor plan facing the

main road is selected as a space to analyse and compare the external noise

sound pressure level at Jalan Ipoh. Readings are collected at both peak hour

(8am to 10am) and non-peak hour (8pm to 10pm).

FIGURE 14: FIRST FLOOR PLAN INDICATING THE GENERAL LIBRARY AND JALAN IPOH

BACK LANE

JALAN IPOH

LEE JO YEE 0314880 19

BUILDING SCIENCE 2

Peak Hour (8am to 10am)


Using the formula,


𝐼𝑜 )

80= 10 log10 ( 𝐼

1 𝑥 10−12 )

108= 𝐼

1 𝑥 10−12

I= 1x 10-12 X 108

= 1 X 10-4


Using the formula,


𝐼𝑜 )

65= 10 log10 ( 𝐼

1 𝑥 10−12 )

106.5= 𝐼

1 𝑥 10−12

I= 1x 10-12 X 106.5

= 3.162 X 10-6

Total Intensity, I= (1 X 10-4) + (3.162 X 10-6)

= 1.032 x 10-4


𝑝𝑜2 ), where po = 1 x 10-12

Combined SPL= 10 log 10 ( 𝟏.𝟎𝟑𝟐 𝐱 𝟏𝟎−𝟒

1 𝑥 10−12 )

= 80.14 dB

Non-peak Hour (8pm to 10pm)


Using the formula,


𝐼𝑜 )

63= 10 log10 ( 𝐼

1 𝑥 10−12 )

106.3= 𝐼

1 𝑥 10−12

I= 1x 10-12 X 106.3

= 1.995X 10-6


Using the formula,


𝐼𝑜 )

54= 10 log10 ( 𝐼

1 𝑥 10−12 )

105.4= 𝐼

1 𝑥 10−12

I= 1x 10-12 X 105.4

= 2.512 X 10-7

Total Intensity, I= (1.995X 10-6) + (2.512 X 10-7)

= 2.246 x 10-6


𝑝𝑜2 ), where po = 1 x 10-12

Combined SPL= 10 log 10 ( 𝟐.𝟐𝟒𝟔 𝐱 𝟏𝟎−𝟔

1 𝑥 10−12 )

= 63.52 dB

LEE JO YEE 0314880 20

BUILDING SCIENCE 2

FIGURE 15: LIGHTING AND ACOUSTICS CONDITION DURING THE DAY

AND NIGHT AT JALAN IPOH

CONCLUSION

According to the calculation above, the combined sound pressure level

of Jalan Ipoh during peak and non-peak hours are 80.14dB and 63.52 dB

respectively. The noise criteria for a general library (Noise Criterion, 2016) is

between the NC ranges of 35-40. The noises from the main road will affect the

library interiors badly with noises from vehicles, traffic and general public noises.

Therefore, one of the solutions is to create green buffer zone in front of

the building with its role to filter out all noises. Secondly, soundproofing windows

can be added to the existing openings to reduce noises from outside as shown

in figure. Thirdly, soundproof the wall that is facing the main road by filling

sufficient insulation layers within the wall.

FIGURE 16: EXAMPLE OF SOUNDPROOFING WINDOWS

LEE JO YEE 0314880 21

BUILDING SCIENCE 2

2.2 REVERBERATION TIME (RT)

2.2.1 AUDIO VISUAL ROOM

FIGURE 17: SECOND FLOOR PLAN INDICATING THE LOCATION OF AUDIO VISUAL ROOM

Standard Reverberation Time= 1.5 - 2.5 seconds

Space Volume= Length x Width x Height

= 9.2 x 4.8 x 3

= 132.48 𝑚3

Material absorption coefficient at 500Hz at non-peak hour with 6 person in

the space.

Building

Elements

Materials Absorption

Coefficient

(500Hz)

Surface

Area (m2) /

Quantity

Sound

Absorption, Sa

(500Hz)

Floor Concrete Strain 0.02 44.16 0.883

Wall Concrete Brick Wall 0.05 79.87 3.99

Glass 0.12 2.37 0.284

Door Plywood 0.06 1.76 0.106

Ceiling Plaster Finish 0.015 44.16 0.662

LEE JO YEE 0314880 22

BUILDING SCIENCE 2

Furniture Sofa 0.73 14.2 10.37

Cushion seats 0.44 0.16x4 = 0.64 0.282

Laminated Wooden

Book Shelves

0.07 35.4 2.48

People - 0.46/P 6 2.76

Total absorption, A 21.82

500Hz

Reverberation Time, RT= 0.16 𝑋 𝑉

𝐴

= 0.16 𝑋 132.48

21.82

=0.97s

Material absorption coefficient at 2000Hz at non-peak hour with 6 person in

the space.

Building

Elements


Coefficient

(2000 Hz)

Surface

Area (m2) /

Quantity

Sound

Absorption, Sa

(2000Hz)



Glass 0.08 2.37 0.19

Door Plywood 0.10 1.76 0.18


Furniture Sofa 0.89 14.2 12.64

Cushion seats 0.32 0.16x4 = 0.64 0.2

Laminated Wooden

Book Shelves

0.09 35.4 3.186

People - 0.51/P 6 3.06


2000Hz

Reverberation Time= 0.16 𝑋 𝑉

𝐴

= 0.16 𝑋 132.48

25.21

= 0.84s

LEE JO YEE 0314880 23

BUILDING SCIENCE 2

CONCLUSION

The reverberation time for the audio visual room at 500Hz and 2000Hz is

0.97s and 0.84s respectively. Both of the values falls outside the desired comfort

reverberation of 1.5 – 2.5s which shows an overly-adequate of acoustic

absorption materials in the audio-visual. To increase the reverberation time so

that the room acoustics will be “live” and echoy, materials with lower

absorption coefficient can be applied such as plaster walls and tiled floor.

Secondly, enhancements like acoustics reflectors can be applied and installed

on the wall or ceiling of the audio-visual room to allow reflection and bouncing

of sound waves.

FIGURE 18: ONE OF THE EXAMPLES - OVATION SOUND REFLECTOR/DIFFUSER PANELS

FIGURE 19: ACHIEVE SOUND CONTROL BY USING COMPLEX CURVES AND UNDULATING

SHAPES TO GENERATE RANDOM SOUND DIFFUSION AND ADD TO THE VISUAL EXPERIENCE OF

THE ROOM AS WELL (Peter J. Arsenault, 2014)

LEE JO YEE 0314880 24

BUILDING SCIENCE 2

2.2.2 QUIET STUDY AREA

FIGURE 20: FIRST FLOOR PLAN INDICATING THE LOCATION OF QUIET STUDY AREA

Standard Reverberation Time= 0.5 – 1seconds

Space Volume= Length x Width x Height

= 5.7 x 4.4 x 3

= 75.24 𝑚3

LEE JO YEE 0314880 25

BUILDING SCIENCE 2

Material absorption coefficient at 500Hz at peak hour with 6 person in the

space.

Building

Elements


Coefficient

(500Hz)

Surface

Area (m2) /

Quantity

Sound

Absorption, Sa

(500Hz)



Glass 0.12 15.57 1.87

Door Glass (sliding door) 0.12 1.76 0.21


Furniture Plastic Table 0.14 2.5 x5=12.5 1.75

Plastic seats 0.10 1.092x10=

10.92

1.09

People - 0.46/P 6 2.76


500Hz

Reverberation Time, RT= 0.16 𝑋 𝑉

𝐴

= 0.16 𝑋 75.24

10.72

=1.12s

LEE JO YEE 0314880 26

BUILDING SCIENCE 2

Material absorption coefficient at 2000Hz at peak hour with 6 person in the

space.

Building

Elements


Coefficient

(2000 Hz)

Area (m2) Sound

Absorption, Sa

(2000 Hz)



Glass 0.08 15.57 1.25

Door Glass (sliding door) 0.08 1.76 0.14


Furniture Plastic Table 0.21 2.5 x5=12.5 2.6

Plastic seats 0.15 1.092x10=

10.92

1.64

People - 0.51/P 6 3.06


2000Hz

Reverberation Time= 0.16 𝑋 𝑉

𝐴

= 0.16 𝑋 75.24

11.85

= 1.02s

CONCLUSION

Based on the calculation above, the reverberation time for the quiet study

room at 500Hz and 2000Hz is 1.12s and 1.02s respectively. Both of the values

fall at the border of the desired comfort reverberation of 0.5 – 1 seconds

which shows as a good selection of materials for this space. Improvement

can be made by adding higher absorption coefficient materials or furniture

into the space such as adding a layer of thick carpet on the floor or

replacing the plastic furniture to wood/ fabrics made desks and chairs.

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BUILDING SCIENCE 2

2.3 SOUND REDUCTION INDEX (SRI)

2.3.1 NEIGHBOURHOOD WORKSHOP

FIGURE 21: SECOND FLOOR PLAN INDICATING THE NEIGHBOURHOOD WORKSHOP

Building

Elements

Material Surface Area

(𝒎𝟐)

SRI ( dB) Transmission

Coefficient, T

Wooden

Shutter

Wood 2.64x4 = 10.56 31 7.943 x 10-4

Wall Brick Wall 31.92 54 3.981 x 10-6

BACK

LANE

STUDIED WALL

LEE JO YEE 0314880 28

BUILDING SCIENCE 2

CALCULATION OF TRANSMISSION COEFFICIENT

Wooden Shutters Sound Reduction Index, SRI= 10 log10 (1

𝑇𝑎𝑣)

31= 10 log10 (1

𝑇𝑎𝑣)

103.1= 1

𝑇

T= 7.943 x 10-4

Brick Wall

Sound Reduction Index, SRI= 10 log10 (

1

𝑇𝑎𝑣)

54= 10 log10 (1

𝑇𝑎𝑣)

105.4= 1

𝑇

T= 3.981 x 10-6

Average Transmission Coefficient of Materials

Tav= ( 10.56 𝑥 7.943 𝑥 10−4 )+( 31.92 𝑥 3.981 𝑥 10−6 )

( 10.56+31.92 )

= 2.004 x 10-4

SRI= 10 log10 (1

𝑇)

= 10 log10 (1

2.004 𝑥 10−4)

= 36.98 dB

External Sound Pressure Level (Back lane*)= 65.27dB

= 65.27 – 36.98

= 28.29dB

*Kindly refer to clause 2.1.1 external noises

CONCLUSION

The sound reduction index of the façade is 36.98dB. Taking the value

from the previous calculation, the highest reading of external noises from the

back lane which is 65.27dB, the noise that is transmitted into the

neighbourhood workshop after sound reduction is 28.29dB. The value is slightly

higher than the desired the noise criteria for a workshop of 25 – 30dB (Noise

Criterion, 2016). Enhancement can be made by applying double façade such

as applying a layer of glass panels/railings before the wooden shutter to

cancel the noise from the back lane. Absorption panels can be installed on

the ceiling or walls to further reduce the noise.

LEE JO YEE 0314880 29

BUILDING SCIENCE 2

2.3.2 GENERAL LIBRARY

FIGURE 22: FIRST FLOOR PLAN INDICATING THE GENERAL LIBRARY

Building

Elements

Material Surface Area

(𝒎𝟐)

SRI ( dB) Transmission

Coefficient, T

Circular Glass

Window

Glass 0.79 x 8 = 6.32 26 2.51 x 10-3

Wall Brick Wall 55 54 3.981 x 10-6

CALCULATION OF TRANSMISSION COEFFICIENT

Glass Sound Reduction Index, SRI= 10 log10 (1

𝑇𝑎𝑣)

26= 10 log10 (1

𝑇𝑎𝑣)

102.6= 1

𝑇

T= 2.51 x 10-3

JALAN IPOH

STUDIED WALL

LEE JO YEE 0314880 30

BUILDING SCIENCE 2

Brick Wall

Sound Reduction Index, SRI= 10 log10 (

1

𝑇𝑎𝑣)

54= 10 log10 (1

𝑇𝑎𝑣)

105.4= 1

𝑇

T= 3.981 x 10-6

Average Transmission Coefficient of Materials

Tav= ( 6.32 𝑥 2.51 𝑥 10−3 )+( 55 𝑥 3.981 𝑥 10−6 )

( 55+6.32)

= 2.623 x 10-4

SRI= 10 log10 (1

𝑇)

= 10 log10 (1

2.623 x 10−4)

= 35.81 dB

External Sound Pressure Level (Jalan Ipoh*)= 80.14dB

= 80.14 – 35.81

= 44.33dB

*Kindly refer to clause 2.1.2 external noises

CONCLUSION

The sound reduction index of the façade is 35.81dB. Taking the value

from the previous calculation, the highest reading of external noises from the

main road, Jalan Ipoh which is 80.14 dB, the noise that is transmitted into the

general library after sound reduction is 44.33dB. This value falls outside of the

desired noise criteria for a workshop of 25 – 30dB (Noise Criterion, 2016).

To reduce a further 14- 20db in the library, several amendments can be

opt. Ceilings to be installed and designed with absorption panels or foam in

order to absorb the external noise from the heavy traffic at the main road.

FIGURE 23: EXAMPLES OF CEILING DESIGN USING ACOUSTICS FOAMS

LEE JO YEE 0314880 31

BUILDING SCIENCE 2

3.0 REFERENCES

(2016, JULY 10). Retrieved from www.noao.edu:

https://www.noao.edu/education/QLTkit/ACTIVITY_Documents/Safety/

LightLevels_outdoor+indoor.pdf

Izdihar, I. A. (2013, APRIL 9). MS1525 (2013/2014) 2nd Revision. Retrieved from

http://www.eria.org/events/6.%20UBBL%202012%20Amendments%20on

%20EE%20and%20MS1525%20-%20Ir%20Ahmad%20Izdihar.pdf

Noise Criterion. (2016, July 10). Retrieved from

http://www.engineeringtoolbox.com/:

http://www.engineeringtoolbox.com/nc-noise-criterion-d_725.html

Peter J. Arsenault, F. N. (2014, November). Total acoustical design - reflectors.

Retrieved from https://continuingeducation.bnpmedia.com :

https://continuingeducation.bnpmedia.com/course.php?L=5&C=1260

&P=3

ROOM ILLUMINATION LEVEL. (2016, JULY 8th). Retrieved from PioneerLighting

website : http://www.pioneerlighting.com/new/pdfs/IESLuxLevel.pdf