ARC3413 BUILDING SCIENCE 2
PROJECT 1: LIGHTING & ACOUSTIC PERFORMANCE EVALUATION AND DESIGN Wanaka the bungalow No.22, Lorong Dungun, Damansara Heights, Kuala Lumpur.
GROUP MEMBERS: GARNETTE DAYANG ROBERT
0315491
JOLENE HOR WEI FERN
0313751
TE LI THENG (JUSTINE)
0314198
OOI ZHI-QIAN (JANE)
0313999
CRYSTALLINA ALECIA KAYA
0318742
MAHI ABDUL MUHUSIN
0314421
DANAR JOVIAN ADITYA PUTRA
0314575
TUTOR:
MR. EDWIN CHAN YEAN LIONG
SUBMISSION DATE: 1st june 2016
TABLE OF CONTENT abstract 1.0 introduction 1.1 1.2 1.3 1.4
Aim and Objectives Reason of choice Zoning of building Building components and characteristics
4 5 6 7 – 21
2.0 lighting 2.1 Literature Review 2.1.1 INTRODUCTION TO LIGHT 2.1.2 IMPORTANCE OF LIGHT IN ARCHITECTURE 2.1.3 LUMEN 2.1.4 ILLUMINANCE 2.1.5 NATURAL DAYLIGHTING 2.1.6 ARTIFICIAL DAYLIGHTING 2.1.7 DAYLIGHTING FACTORS AND DISTRIBUTIONS 2.1.8 LUMEN METHOD
22 - 27
2.2 METHODOLOGY 2.2.1 PRECEDENT STUDIES 2.2.2 PREPARATION 2.2.3 MEASURING DEVICE 2.2.4 DATA COLLECTION
28 - 39
2.3 PRECEDENT STUDY 2.3.1 introduction to the building 2.3.2 floor plans 2.3.3 building design intenetion 2.3.4 lighting and daylight evaluation 2.3.5 methodolgy 2.3.6 recommendation 2.3.7 illuminance measurements 2.3.8 daylighting measurements 2.3.9 design interiors to maximize day lighting contribution 2.3.10 considerations from the analysis of cambria office building 2.4 NATURAL LIGHTING 2.4.1 DATA COLLECTION 2.4.2 DAYLIGHT FACTOR ANALYSIS
40 - 46
2.5 ARTIFICIAL LIGHTING 2.5.1 LIGHTING SPECIFICATIONS 2.5.2 LUMEN METHOD CALCULATION
47-60
2.6 analysis and lighting conditions of the zones
61-70
2.7 Conclusion
71-73
1
3.0 acoustic performance 3.1 Literature Review 3.1.1 introduction to acoustic 3.1.2 architecture acoustic 3.1.3 sound intensity level 3.1.4 reverberation time 3.1.5 sound reduction index
74-76
3.2 methodology 3.2.1 precedent studies 3.2.2 preparations 3.2.3 measuring device 3.2.4 data collection
77-78
3.3 precedent study 3.3.1 introduction to the building 3.3.2 floor plan indicating cafe 3.3.3 reverberation analysis 3.3.4 analysis of sound transmission class (stc) 3.3.5 new proposed baffled system 3.3.6 conclusion
79-85
3.4 site Study 3.4.1 OUTDOOR NOISE SOURCE 3.4.2 TABULATION OF DATA 3.4.3 INDOOR NOISE SOURCE 3.4.4 ACOUSTICS FIXTURE & SPECIFICATION 3.4.5 CALCULATION OF SIL 3.4.6 reverberation time 3.4.7analysis and conclucsion
86-131
References
132
2
1.0
Introduction
Lighting at work is an important issue as it affects the health and safety of the building’s occupants. Hazards are more easily avoided with good lighting. Poor lighting within the building could cause health issues such as migraine, eyestrain, and headaches. Suitable lighting is necessary to create the optimum environmental conditions for maximum productivity of the workers. Acoustics design is another important factor in order to control the levels of noise within different spaces. Requirements for every space differ based on its function. A good acoustic design preserves the desired noise and eliminates the unwanted sound to provide a comfortable environment for the users. In a group of seven, we have chosen the Wanaka Bungalow as our site of study. We visited the place several times in order to collect all the necessary data, which include measured drawings of the plan, measurement of lighting and acoustics.
Figure 1.0a – Entrance from the side of Jalan Dungun
3
1.1
aims and objectives
The aim and objectives are as followings: • To understand the day-lighting, artificial lighting and acoustic characteristic. • To determine the characteristics and function of day-lighting & artificial lighting and sound & acoustic within the intended space. •
To critically report and analyse the space and suggest ways to improve the lighting and acoustic qualities within the space.
•
To also be able to produce a complete documentation on analysis of space in relation to lighting requirement.
•
To able to evaluate and explore the improvisation by using current material and technology in relevance to present construction industry.
This projects also aims to help us to get basic understanding and analysis of lighting and acoustics design layout and arrangements by using certain methods or calculations. We will be choosing three spaces and by understanding the volume and area of each functional space will also help in determining the lighting requirements based on acoustical or lighting inadequacy that is reflected in the data collection.
4
1.2
REASON OF CHOICE Located in Damansara Heights, Kuala Lumpur, the Wanaka was once a bungalow
residence, which was then converted into an office. On some occasions, the house is used to hold small events and functions such as wedding receptions. This makes the building more interesting to study as we get to understand the lighting and acoustic in a space used for different functions. Besides that, we chose this building as a place to conduct our studies because of location that is strategic, and has a lot of potential in terms of our studies. It’s located right beside the road, which is interesting because then the acoustics would play an important role in this house as well as the light penetration within the building. We wanted to study how much the noise from the road affected the acoustic and noise in the building. There are many opening as well in the building which allow light to light the place. There is even an oculus at one part of the building which allow a lot of natural daylighting to the space. Materials installed interiorly create an ambiance, which differs each room’s ambiance and creates different kinds of usage for each room. However, since it was originally designed as a residential space rather than an office space which is what it is used as today, the lighting and acoustic standards might not be met or might be too high compared to the standards. Therefore, we have decided that this building was very suitable to conduct our lighting and acoustic
studies.
5
1.3
zoning of BUILDING
Ground floor
First floor
6
1.4
Building components and characteristics ZONE I :
OFFICE 1
Building Component - Wall
Component Detail WALL A1 Concrete Plaster finish White, Matte 5.65 x 3.0
Absorption Coefficient
Reflectance Value
Surface Area
CONCRETE 0.06
80
16.950
WALL A2 Concrete Plaster finish White, Matte 3.19 x 3.0
CONCRETE 0.06
80
SLIDING DOOR Clear glass panels 2.44 x 2.1
GLASS 0.18
8
4.446
5.124
7
WALL A3 Concrete Plaster finish White, Matte 4.81 x 3.0
CONCRETE 0.06
80
SLIDING DOOR Clear glass panels 4.12 x 2.1
GLASS 0.18
8
WALL A4 Concrete Plaster finish White, Matte 3.61 x 3.0
CONCRETE 0.06
SLIDING DOOR Clear glass panels 3.35 x 3.0
GLASS 0.18
WALL A5 Concrete Plaster finish White Matte 3.0 x 3.0
CONCRETE 0.06
WALL A6 Concrete Plaster finish White Matte 3.12 x 3.0
CONCRETE 0.05 PLASTER 0.02
80
8
80
80
5.778
8.652
0.78
10.05
9.0
9.36
8
WALL A7 Concrete Plaster finish White Matte 1.05 x 3.0
WALL A8 Concrete Plaster finish White, Matte 4.02 x 3.0
CONCRETE 0.06
CONCRETE 0.06
V-GROOVE DOOR WOOD Polished Wood 0.10 0.92 x 2.1
WALL A9 Concrete Plaster finish White, Matte 3.59 x 3.0
SLIDING DOOR Clear glass panels 2.44 x 2.1
80
80
10
CONCRETE 0.06
80
GLASS 0.10
8
3.15
10.128
1.932
5.646
5.124
9
Building Component - Floor
Component Detail FLOOR Terrazzo White, Black Polished
Absorption Coefficient TERRAZZO 0.015
Reflectance Value 60
Surface Area 48.70
Building Component - Ceiling
Component Detail OFFICE CEILING Wood Walnut
Absorption Coefficient
Reflectance Value
Surface Area
10
48.70
WOOD 0.22
Polished
10
ZONE 2 :
OFFICE 2
Building Component
Component Detail
Absorption Coefficient
WALL B1 Concrete Plaster finish White, Matte 1.42 x 3.0
CONCRETE 0.06
WALL B2 Concrete Plaster finish White, Matte 3.75 x 3.0 SLIDING DOOR Clear glass panels 2.44 x 2.1
Reflectance Value
Surface Area
80
4.260
CONCRETE 0.06
80
GLASS 0.18
8
6.126
5.124
11
WALL B3 Concrete Plaster finish White, Matte 4.51 x 3.0
WALL B4 Concrete Plaster finish White, Matte 2.12 x 3.0
WALL B5 Concrete Plaster finish White Matte 0.91 x 3.0
WALL B6 Concrete Plaster finish White Matte 1.65 x 3.0
WALL B7 Concrete Plaster finish White Matte 2.04 x 3.0
CONCRETE 0.06
80
CONCRETE 0.06
80
CONCRETE 0.06
CONCRETE 0.06
CONCRETE 0.06
80
80
80
13.530
6.360
2.730
4.950
6.120
12
WALL B8 Concrete Plaster finish White, Matte 1.84 x 3.0
CONCRETE 0.06
80
WALL B9 Concrete Plaster finish White, Matte 2.45 x 3.0
CONCRETE 0.06
80
PANEL DOOR Glossy finish beige 0.90 x 2.1
WOOD 0.18
10
WALL B10 Concrete Plaster finish White, Matte 0.86 x 3.0
CONCRETE 0.0
5.520
5.460
1.890
80
2.580
Building Component
Component Detail WALL B11 Concrete Plaster finish White, Matte 10.04 x 3.0 FIXED WINDOWS Clear glass window 8.81 x 1.0
Absorption Coefficient CONCRETE 0.06
GLASS 0.10
Reflectance Value 80
8
Surface Area
21.310
8.810
13
Building Component - Floor
Component Detail OFFICE FLOOR Terrazzo White, Black Polished
Absorption Coefficient TERRAZZO 0.015
Reflectance Value
Surface Area
60 54.70
Building Component - Ceiling
Component Detail OFFICE CEILING Plaster finish White, Matte
Absorption Coefficient PLASTER 0.02
Reflectance Value 80
Surface Area 54.70
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ZONE 3 :
kitchen
Building Component
Component Detail
Absorption Coefficient
WALL C1 Concrete Plaster finish White, Matte 3.88 x 3.0
CONCRETE 0.06
V-GROOVE DOOR Polished Wood 0.92 x 2.1
WALL C2 Concrete Plaster finish White, Matte 4.51 x 3.0
WOOD 0.18
CONCRETE 0.06
Reflectance Value
Surface Area
80 9.708
10
80
1.932
13.530
15
WALL C3 Concrete Plaster finish White, Matte 3.88 x 3.0
WALL C4 Concrete Plaster finish White, Matte 4.51 x 3.0
CONCRETE 0.6
CONCRETE 0.06
80
80
11.640
13.530
16
Building Component - Floor
Component Detail DRY KITCHEN FLOOR Terrazzo White, Black Polished
Absorption Coefficient TERRAZZO 0.015
Reflectance Value
Surface Area
60
17.40
Building Component - Ceiling
Component Detail DRY KITCHEN CEILING Plaster finish
Absorption Coefficient
Reflectance Value
PLASTER 0.02
Surface Area 17.40
80
White Matte
17
ZONE 4:
FOYER
Building Component
Component Detail
WALL D1 Concrete Plaster finish White, Matte
WALL D2 Concrete Plaster finish White, Matte 1.40 x 4.5 2.48 x 0.9
Absorption Coefficient
Reflectance Value
Surface Area
CONCRETE 0.06
80
13.451
CONCRETE 0.06
80
8.532
18
WALL D3 Concrete Plaster finish White, Matte 2.26 x 4.5
LOUVERED WINDOW Clear glass panels 0.80 x 3.0
CONCRETE 0.06
GLASS 0.18
80
80
WALL D4 Concrete Plaster finish White, Matte 4.70 x 3.0
CONCRETE 0.06
LOUVERED GLASS WINDOW Clear glass panels 1.26 x 1.0 (each)
GLASS 0.18
8
PANEL DOOR Walnut smooth finish wooden door 1.49 x 2.1
WOOD 0.10
10
CONCRETE 0.06
80
WALL D6 Concrete Plaster finish White Matte 2.00 x 3.0
80
21.239
2.400
8.451
2.520
3.129
4.005
19
FLUSH DOOR WOOD Polished Wood 0.10 0.95 x 2.1
10
WALL D7 Concrete Plaster finish White Matte 2.41 x 3.0
80
5.235
10
1.995
CONCRETE 0.06
FLUSH DOOR WOOD Polished Wood 0.10 0.95 x 2.1 Building Component
Component Detail WALL D5 Concrete Plaster finish White Matte 7.01 x 3.0
FLUSH DOOR Polished Wood 0.95 x 2.1
Absorption Coefficient
CONCRETE 0.06
WOOD 0.10
1.995
Reflectance Value
Surface Area
80
19.035
10
1.995
20
Building Component - Floor
Component Detail FOYER FLOOR Concrete Patches of different grey tones Smooth finish
Absorption Coefficient CONCRETE 0.05
Reflectance Value
Surface Area
80
35.66
Building Component
Component Detail FOYER CEILING Plaster finish White
Absorption Coefficient
Reflectance Value
PLASTER 0.02
Surface Area 35.66
80
Matt
21
2.0 Lighting 2.1
Lighting Literature Review
2.1.1
Introduction to Light
Light are electromagnetic radiation within a certain portion of electromagnetic spectrum. Light that can be detected by the human eye are usually known as visible light and have a wavelength in the range of 400–700 nanometres. Light source are mediums that produces light and the main source of light on Earth is the Sun. There are two types of lighting which are natural lighting and artificial lighting. Natural lighting comes from the source of the sun whereas artificial lighting comes from an instrument that produces light.
Diagram 2.1a Visible Radiation
2.1.2
Importance of Light in Architecture.
The perception of space is directly connected to the way light integrates with it. What we see, what we experience and how we interpret the elements is affected by how light interacts with us and with the environment. Regarding architecture, in whatever dimension it can be analysed, either as space, as material or as colour, it is essentially dependant on the lighting situation that involves both the object and the observer. Light is not only related to the visual experience of form and space but also thermal qualities. The characteristics of light, heat, air movement and comfort are the key factors in determining a building’s energy consumption, and if careful considerations are paid to design then the use of artificial light can be minimized.
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2.1.3
Lumen
The lumen (symbol: lm) is the SI derived unit of luminous flux and it is a measure of the total quantity of visible light emitted by a source. It is equal to the amount of light emitted per second in a unit solid angle of one steadier from a uniform source of one candela. Luminous flux is the power in which light is emitted from a source. Therefore, the amount of light that is emitted from a source is measured in lumen value. The brighter the light is, the more lumen it measures, the dimmer the light is, the less lumen it measures. The following table shows the amount of lux needed for different applications at working (1.5m) height. AREA/ ACTIVITY Car parks, roadway Corridors, stores and warehouses, changing rooms and rest areas, bedrooms, bars Stairs, escalators, loading bays Washrooms, foyers, lounges, archives, dining rooms, assembly halls and plant rooms Background lighting e.g. IT office, packing, assembly (basic), filing, retail background, classrooms, sp assembly halls, foyers, gymnasium and swimming pools, General industry, working areas in warehouses, General lighting e.g. offices, laboratories, retail stores and supermarkets, counter areas, meeting rooms, general manufacturing, kitchens and lecture halls Detailed lighting e.g. manufacturing & assembly (detail), paint spraying and inspection Precision lighting e.g. precision manufacturing, quality control, examination rooms Fine precision lighting e.g. jewellery, watch making, electronics & fine working.
LUX LEVEL 20-30 <100 150 200 300
500
750 1000 1500
Table 2.1a Suggested Lux Level Source: Carbon Trust and lighting manufacturer Veelite
2.1.4
Illuminance
When light is emitted from a source, lumens will light up the surface. Illuminance is defined as the number of lumens falling at square meter of a surface. Illuminance is measure in the unit LUX and the measurements are normally recorded with the help of an illuminance meter or a photometer. The closer the illuminated area to the light source, the higher the illuminated values are. Incident rays landing on the horizontal surfaces are known as horizontal illuminance whereas vertical illuminance is referred to as rays landing on the illuminance landing on the vertical surfaces. On a normal sunny day, the illuminance produced during the
23
daylight has a range of 150,000 lux to 1,000 lux. On a grey winter day, the moonlight is about 0.3 lux.
2.1.5
Natural Daylighting
Natural daylighting is a passive method of lighting up a space. It is the controlled admission of natural sunlight and diffuse skylight into a building to reduce electric lighting and saving energy. By providing a direct link to the dynamic and perpetually evolving patterns of outdoor illumination, daylighting helps create a visually stimulating and productive environment for building occupants, while reducing as much as one-third of total building energy costs. According to MS 1525 (2007), the reduction of energy consumption for artificial lighting due to appropriate allowance for natural lighting is much more greater than cooling energy require due to extra glazed building envelope. Hence, daylight apertures such as skylights and windows are important to not only create a more pleasant experience but also to reduce electric power lighting. However, the fenestration must be carefully located to avoid the admittance of direct sunlight into the userâ&#x20AC;&#x2122;s eyes. The visible transmittance of the daylight fenestration system should not be less than 50% in order to take advantage of the natural lighting. (â&#x20AC;&#x153;MS 1525, 2007)
2.1.6
Artificial Lighting
Artificial lighting by definition is any light that does not come from sunlight. Artificial lighting are technical instruments that produces light through the conversion of electrical energy into radiation and light. Artificial lighting have two types of light source which is the incandescent lamp whereby light is generated when the filament is radiated at high temperature and luminescent lamp when light is produced through excited electrons. We do not receive sunlight 24 hours and therefore it is important to have artificial lighting as a substitute. Also, some spaces requires artificial lighting to create different experiences such as museums and galleries where dimmer lighting is preferred to create a more warmer and intimate space. Artificial lighting is also important to certain range of visibility for quality of the space. Example, it is essential to ensure that occupants have a clear visual of where they are as well as to ensure the comfort of the occupants. The table below shows the maximum lighting power allowance for the following types of spaces. TYPE OF USAGE Restaurants Office Classrooms/ Lecture Theatres Auditorium/ Concert Halls Hotel/ Guest Rooms Lobbies/ Atrium/ Concourse Supermarket/Departmental Stores/Shops Store/ Warehouse/ Stairs/ Corridors Car Parks
MAXIMUM LIGHTING POWER (W/m2) 15 15 15 15 15 20 25 10 5
Table 2.1b Maximum Lighting Power of Various Spaces Source: MS1525, 2007
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2.1.7
Daylight factors and distributions
The daylight factor (DF) is commonly used to determine the ratio of internal light level to external light level and is defined as follows: DF =
Ei  x  100% Eo
Where: DF: Daylight factors Ei: illuminance due to daylight at a point on the indoors working plane Eo: simultaneous outdoor illuminance on a horizontal plane from an unobstructed hemisphere of overcast sky.
There are a few factors that affects the Ei which are: i. ii. iii.
the sky component (SC): direct light from a patch of sky visible at the point considered; the externally reflected component (ERC): the light reflected from an exterior surface and then reaching the point considered the internally reflected component (IRC): the light entering through glazing and reflected from an internal surface
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: Figures are average daylight factors for windows without glazing Table 2.1c Distribution of Daylight Factor Source: MS1525, 2007
The light intensity decrease by the square of the distance from the point source. Therefore, 500 lux directed over ten square meters will be dimmer than the same amount spread over one square meter
Diagram 2.1b Importance of positioning in lighting. Illumination decreases by the inverse square law with distance from the light source.
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SPACE Discussion Group Residential Living Room Residential / Office Kitchen Office – Detail Work Office - Drafting Office – Corridor School – Classroom School – Art Rooms Hospital – Wards Hospital – Waiting Room Sports Facilities
DAYLIGHT FACTOR 14 1 2 4 6 0.5 2 4 1 2 2
Table 2.1d Suggested Daylight Factor Source: MS1525, 2007
2.1.8
Lumen Method
The quantity of light reaching a certain surface is usually the main consideration in designing a lighting system. This quantity of light is specified by illuminance measured in lux, and as this level varies across the working plane, an average figure is used. Lumen method is an indoor calculation methodology used to identify the number of luminaries or lamp fixtures required to achieve a given average illuminance level of space. It is done by calculating the number of lamp installed to ensure it has enough level of illuminance. The method is a commonly used technique of lighting design, which is valid, if the light fittings (luminaires) are to be mounted overhead in a regular pattern.
N=
E x A F x UF x MF
Where: N: number of lamps required. E: illuminance level required (lux) A: area at working plane height (m2) F: average luminous flux from each lamp (lm) UF: utilisation factor, an allowance for the light distribution of the luminaire and the room surfaces. MF: maintenance factor, an allowance for reduced light output because of deterioration and dirt.
26
Room index, RI is the ratio of room plan area to half the wall area between the working and luminaire planes :
RI =
L x W Hm x (L + W)
Where: L: length of room W: width of room Hm: Mounting height, i.e. the vertical distance between the working plan and the luminaire.
Mantenance factor, MF, is multiple of factors MF = LLMF x LSF x LMF x RSMF Where: LLMF: lamp lumen maintenance factor MSF: lamp survival factor LMF: luminaire maintenance factor RSMF: room surface maintenance factor Normally, when MF cannot be found, the value 0.8 is used.
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2.2 Methodlogy 2.2.1
PRECEDENT STUDIES
Precedent study chosen is to guide how light functions and affect a certain space. This enables to conduct the case study properly.
2. 2.2 PREPARATION 1. Preliminary study and identification of the type of spaces were studied to choose the suitable case study. 2. Precedent studies were done to have a better understanding of how lights functions or affect in a certain space. 3. In obtaining approval to use site as case study, visitations, calls and emails were made to the different chosen places. 4. The plan drawings were obtained from the management office. 5. The spaces were determined. 6. Grid lines with distance of 1.5m was plotted on the plan for recording purposes. 7. Digital Lux meter meter was supplied by tutors. 8. The equipment was tested before attending the site visit. 9. A basic standard and regulations such as CIBSE, ASHRAE and MS1525 were also studied before hand to analyze and compare the readings later on. 2.2.3 MEASURING DEVICE
Figure 2.2a Digital Lux meter
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2.2.4 DATA COLLECTON Data were collected at non peak hours between 10am-12pm and 5pm-6pm, and peak hours between 2pm-4pm. The readings were taken at 1m level above the ground at each corresponding time with both daylighting and artificial lightings. Materials used in the space were studied and recorded to indicate the coefficient value and reflectance value towards the daylighting and artificial lighting.
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2.3 Precedent studies 2.3.1 INTRODUCTION TO THE BUILDING DEPARTMENT OF ENVIRONMENTAL PROTECTION ( DEP ) CAMBRIA OFFICE, PENNSYLVANIA Pennsylvania Department of Environmental Protection (DEP) created this building as a district office that advance the concept of high-performance green buildings in Cambria. Most of the buildingâ&#x20AC;&#x2122;s 34,500 ft2 (3,205 m2) is used for office space, alongside a conference room, laboratory space and file storage rooms. The main objective for this building is to provide a comfortable and productive work environment and minimize its environmental obstructions to the workers. The building is oriented on an east-west axis to take advantage of north-south solar exposures and minimize east-west windows. South facing light shelves attached to the windows allow more indirect daylight in, reducing the need for artificial lighting. Small deciduous trees planted along the south side of the building help reduce a potential heat island effect, as heat emanating from the buildings and pavement can change the temperature in the surrounding area. The building has achieved a LEED 2.0 Gold Certification in the U.S. Green Building Council (USGBC 2004). Roof insulation, high-performance windows, ground-source heat pumps, daylighting, motion sensors on restroom lights, and an 18.2-kW photovoltaic (PV) system for on-site electricity production are some of the features that account for its successful reputation as a green building. Paint works and adhesives used in the building were low-level volatile organic compounds and finish materials were chosen with their potential for being recycled in the future.
Figure 2.3a Cambria DEP building
Building Statistics: Completion Date: September 2000 Cost: $90/square foot Size: 34,500 gross square feet User Group: Office Occupancy: 128 Staff
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2.3.2 FLOOR PLANS
Figure 2.3b First Floor Plan Of Cambria Office Building
Figure 2.3c Second Floor Plan Of Cambria Office Building
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2.3.3 BUILDING DESIGN INTENTION Reduced energy use for electrical lighting was identified as a critical issue to be addressed during the early stages of Cambria building design. Hence, the building configuration of Cambria Office was elongated along an east-west axis to gain better solar access and optimize daylight penetration into the building. The rooflines were sloped in order to allow the use of north- and south-facing clerestory windows on the second floor for day lighting, which also provided an angled surface for mounting PV panels. Light shelves were added on the south side of the first floor to help direct some daylight deeper into the office spaces. These day lighting features are illustrated in the figures below.
Figure 2.3d -Daylighting Design Features Of Cambria Office Building (Left ) And â&#x20AC;&#x153;Light Shelvesâ&#x20AC;? (Right) Which Shade Summer Sun And Bounce Natural Light Across The Ceiling Plane Much Deeper Into Open Office Spaces.
To further enhance the success of the day lighting, the second floor plan was designed to place the large open office spaces adjacent to exterior walls and locate enclosed offices in the center of the building rather than at the perimeter. As a result, these private offices do not block access to daylight, and the vast majority of occupants are afforded access to this daylight and visceral advantages. In addition, a major programming effort was undertaken by the DEP to ensure that most of the occupants were located in these large open office spaces on the second floor because of their access to day lighting. The first floor was designed to accommodate meeting spaces, storage, support functions, and workspace for field staff who spend the majority of their time away from the office.
Figure 2.3e Private Vs Public Office/Meeting Rooms And Its Spatial Division With Consideration To Natural Daylight
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DEP decided on the use of a lighting system that provided 30 fc (foot candles) of ambient light with under cabinet task lighting at workstations for supplemental light. Foot-candle is a non-SI unit of illuminance or light intensity which conveys the illuminance cast on a surface by a onecandela source one foot away. Daylighting was a very significant part of the design of Cambria office Building and resulted in the use of clerestory windows, overhangs, light shelves, and a dimming system. Orientation of the building reduces heat gain and encourages day-lighting. The light shelves pro-vide shade from the hot summer sun and simultaneously, bounce natural light through the top of the window, across the highly re-flective ceiling plane and deep into the office spaces.
Figure 2.3f Illustration of the high-performance features of the Cambria building
The initial lighting design called for a lighting power density (LPD) of 0.82 W/ft2 (8.8 W/m2). Subsequent refinement of the lighting system resulted in a final design LPD of 0.75 W/ft2 (8 W/m2), not including task lighting. The LPD of the task lighting in the office areas is approximately 0.5 W/ft2 (5.4 W/m2). The second floor is primarily open office plan and houses the majority of building occupants. Virtually all fenestration faces either north or south and the lighting design incorporates clerestory windows facing north and south along the center of the building. The south-facing clerestory windows are equipped with motorized sunscreens controlled by a photosensor to block direct- beam radiation..
2.3.4 LIGHTING AND DAYLIGHT EVALUATION The lighting systems at the Cambria building were evaluated to determine the illuminance distribution delivered by the lighting design and to determine the energy performance of both the day lighting and artificial lighting systems. Goals of the analysis are as follows:
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1. Quantitatively assess the illumination distribution. 2. Determine the energy savings due to the lighting design without daylighting controls. 3. Determine the amount of electric lighting offset by daylighting and the energy saved in lighting. 4. Analyze the operation of the daylighting design and optimize its performance. 5. Document successes and weakness of the lighting design.
2.3.5 METHODOLOGY
Figure 2.3g Photometers
Figure 2.3h Outdoor Illuminance
The outdoor and indoor illumination levels were continuously recorded from Friday to Monday, July 13â&#x20AC;&#x201C; 16, 2001. Figure 2.3h shows the outdoor illuminance. The first three days were mostly sunny with occasional cumulus clouds, and the final day was cloudy in the morning with some clearing by the afternoon. The indoor light levels were measured on the working surfaces in cubicles along a northsouth cross section in the first-floor, southwest quadrant and the second-floor, southwest and northwest quadrants. On the first floor, three photometers were placed in each cubicle, one in front of the keyboard and one on the working surfaces on either side of the cubicle. On the second floor, two photometers were placed in each cubicle, one in front of the keyboard and one on the working surface to the left of the keyboard.
2.3.6 RECOMMENDATION Measurement of the illuminance from the electric lights only was taken between 9:00 p.m. and 10:00 p.m. on Friday, July 13. The recommended minimum illuminance level on a horizontal surface for open offices is 30 to 50 fc (300 to 500 lux). For general reading of handwriting with a pen or printed materials in 8â&#x20AC;&#x201C;10 point font, the recommended minimum illuminance is 30 fc (300 lux).
34
2.3.7 ILLUMINANCE MEASUREMENTS WORKSTATIONS FOR THE FIRST-FLOOR OFFICE AREA ( SOUTHWEST )
Figure 2.3i Illuminance Measurements at Workstations for the First-Floor, Southwest Office Area from July 13–16, 2001
Measured illuminance levels in the first-floor office area are shown in the figure above. The ambient electric lights were on during Friday and Monday during working hours and Friday evening for testing. The task lights were off in the cubicles 18 and 26 ft (5.5 and 7.9 m) from the south wall, and they were on for part of the testing period in the cubicle 10 ft (3.0 m) from the south wall. The ambient electric lights provided 25– 35 fc (250–350 lux) on the working planes. The natural light added 10 fc (100 lux) at the cubicle closest to the outside wall to 3 fc (30 lux) at the cubicle furthest from the outside wall. These light levels are at the minimum levels for working at a computer terminal and performing easy reading tasks; however, some individuals prefer more light for reading. The task lights raise the light levels on the side working surfaces to 60–100 fc (600–1,000 lux). The reflected light from the light shelves only penetrates approximately 3 ft (1 m) along the ceiling. The light shelves are not sufficiently effective as 1234-
the glass area is too minium as the wide window frames block much of the incident light, low reflectance off the light shelves The high angle of the summer sun. Absence of useful day lighting (i.e., dimming of electric lighting) in the first-floor office area during this testing period.
35
Figure 2.3j - Lighting conditions on the first floor on June 7, 2001
Cambriaâ&#x20AC;&#x2122;s east-west orientation is an essential strategy of its day lighting system. Overhangs shade the second-floor windows on the south elevation. Light shelves are installed on the south-facing first-floor windows. These light shelves, combined with shading devices, help reflect the light to the ceiling plane and minimize direct gain through the view glass as seen by the figure above. The interior finishes were selected to improve the light reflection and provide contrast. The first floor ceiling tiles have a light reflectance of 89%, the second floor has high vaulted white ceilings with an open truss construction, the bottom 2.5 ft (0.8 m) of the walls are a light, natural wood color, the top portion of the walls are painted off-white (light reflectance of 75%), and the cubicle dividers are off- white.
Figure 2.3k - Lighting conditions in the second-floor, northwest office area, with the overhead electric lights on and view of the dark interior carpets
The daylighting on the second floor is reduced because of the poor reflection off the high ceiling, blockage by the roof trusses, the dark floor, and the windows on the outside walls are too low to provide light beyond the first row of cubicles. In addition, the illuminance levels on the second floor would be improved with direct lighting luminaires.
36
2.3.8 DAYLIGHTING MEASUREMENTS WORKSTATIONS FOR THE SECOND-FLOOR, OFFICE AREA ( SOUTHWEST )
Diagram 2.3a - Illuminance measurements at workstations for the second-floor, southwest office area
Illuminance from the ambient electric lights was measured Friday evening between 9:00 p.m. and10:00 p.m. Illuminance levels at the workstations with only the ambient electric lights were approximately 15 fc (150 lux). This is lower than the first floor because the indirect luminaires do not reflect well off the high ceiling with trusses. The combination of the ambient electric lights and daylighting provided 20–40 fc (200–400 lux) at midday. The natural light levels over the weekend were 10–25 fc (100–250 lux) on the working surfaces and 20–30 fc (200–300 lux) in the open circulation areas. ANALYSIS: 1- The daylighting on the second floor is reduced because of the poor reflection off the high ceiling, 2- Daylighting blockage is further caused due to blockage by the roof trusses, the dark floor, and the windows 3- The outside walls are too low to provide light beyond the first row of cubicles. 4- The illuminance levels on the second floor would be improved with direct lighting luminaires. 5- The light levels with day lighting and the ambient electric lights are below the recommended minimum levels in all the areas except for the cubicles on the south side that are 10 and 26 ft (3.0 and 7.9 m) away from the outside wall. Task lighting would probably be used to increase the illuminance on the working surfaces.
37
WORKSTATIONS FOR THE SECOND-FLOOR, OFFICE AREA ( NORTHWEST )
Diagram 2.3b - Illuminance measurements at workstations for the second-floor, northwest office area
Figure above shows the lighting conditions in the northwest office area near midday on June 2001 with the ambient electric lights on. The light distribution is fairly even as expected from the illuminance measurements.
ANALYSIS 1- 1-The ceiling is bright near the clerestory windows and has a darker area in the middle 2- The south-facing clerestory windows can be the source of undesirable lighting conditions at certain times. 3- At low sun angles, clerestory windows admit direct beam radiation, and they can be very bright at other times, causing contrast and glare problems. Automatic sunshades are installed on the interior of the windows to block the direct beam radiation. The sunshades are controlled by an exterior photo sensor. 4- The sunshades block an excessive amount of light and defeat the purpose of the clerestory windows. Other options for these windows are to diffuse the incoming light with frosted or patterned glass or a light-diffusing film on the glass or direct the beam radiation to the ceiling with a louver system The drawback of these solutions is the view of the sky will be lost .The natural light levels on the north side were slightly reduced because the east half of the clerestory sun shades were down position for maintenance.
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2.3.9 DESIGN INTERIORS TO MAXIMIZE DAYLIGHTING CONTRIBUTION. From the analysis of the two floors of cambria office building, it can be concluded that daylighting and indirect lighting fixtures benefit from lightly colored interior surfaces that reflect light. Dark colors are counter to design for daylighting. Dark ceilings and structural elements were negative contributors to reduced savings and poor daylighting distribution. Finishing the interior, especially the ceiling, would provide surfaces with higher reflectivity and brighten the space, which would allow for increased use of daylighting and less waste from the indirect fluorescents and exposed trusses. Measurements indicate that daylight is sufficient because of the large amount of glazed area. However, the dark colors absorb much of the light and provide contrast to the bright outdoors. This results in a visually difficult environment. The distribution of natural daylight and indirect electric lighting would be improved with lighter colored interior finishes
2.3.10 CONSIDERATIONS FROM THE ANALYSIS OF CAMBRIA OFFICE BUILDING The illuminance levels In cambria office building are low due to lower than expected daylight contributions, low LPDs, indirect lighting used throughout the building, and high ceilings on the second floor.
2- Indirect lighting should effectively only be used close to highly reflective ceilings. In the case for Cambria Office building, The indirect lighting on the first floor works well, but the indirect lighting on the second floor does not function to its maximum potential because the light source is too far from the ceiling and the roof trusses obstruct some of the light penetrating through the windows. Direct lighting or a combination of direct and indirect lighting would work better for the second floor. 3- The light shelves on the first floor are ineffective at providing light to the space. The ceilings are too low, there is not enough glass area, and the reflectance off the light shelves is too low to provide adequate light. 4- On the second floor, light from the clerestory windows does not penetrate beyond the first row of cubicles. There is not enough light entering through the windows and the roof trusses block some of the light. The day lighting along the perimeter walls is not sufficiently effective because the windows are too low, the glass area is not large enough, the large wood frames limit the glass area and block some of the light, and the first row cubicle walls are too high and block daylight penetrating into these cubicles.
5- The rows of electric lights should run parallel to the daylight sources and should be controlled separately so that they can be dimmed as necessary as the daylight levels vary with distance from the source.
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2.4 NATURAl LIGHTING 2.4.1
Data collection
Peak , Morning Readings at 1.0m, Readings at 1.5m Ground Floor
Diagram 2.4a Illuminance at Ground Floor- Day
First Floor
Diagram 2.4b Illuminance at First Floor- Day
40
Non-peak , Evening Readings at 1.0m, Readings at 1.5m Ground Floor
Diagram 2.4c Illuminance at Ground Floor- Evening
First Floor
Diagram 2.4d Illuminance at First Floor - Night
41
2.4.2 Daylight Factor Analysis
Zone
Daylight Level in Malaysia, Eo (Lux)
Suggested Daylight Factor
16400
4 Office
Illuminance due to daylight at a point indoors Â
đ??&#x192;đ??&#x2026;đ??ąđ??&#x201E;đ??¨ Â đ?&#x;?đ?&#x;&#x17D;đ?&#x;&#x17D;
=
4  x  16400  100
=
4  x  16400  100
=
2  x  16400  100
=656
Zone 1: Office 1
16400
4 Office = 656
Zone 2: Office 2
16400
2 Kitchen = 328
Zone 3: Kitchen
16400
0.5 Walkway / Corridor
=
0.5  x  16400  100
= 82
Zone 4: Foyer Table 2.4a Calculations to find suggested indoor illuminance
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Office 1 Suggested illuminance due to daylight at office 1 is 656
COORDINATES A1 A2 A3 A4 A5 A6 A7 B1 B2 B3 B4 B5 B6 B7 C1 C2 C3 C4 C5 C6 C7 D1 D2 D3 D4 E1 E2 E3 E4 F1 F2
PEAK (DAY) (lux) 1m 1.5m 462 2100 1530 264 246 210 164 579 1140 543 306 225 197 219 553 493 402 262 267 194 210 469 287 283 236 297 246 10 242 156 123
413 1689 1213 189 210 163 123 475 869 426 248 151 178 187 475 410 367 213 326 153 179 346 254 197 245 213 217 19 276 75 92
NON PEAK (EVENING) (lux) 1m 1.5m 99 83 72 79 109 98 75 187 213 184 159 241 178 116 178 236 189 136 256 196 164 186 227 168 142 124 229 23 121 104 214
53 55 46 45 94 70 52 136 289 132 142 123 112 98 146 122 178 98 301 110 103 97 123 111 100 98 115 34 97 78 110
Daylight (lux) 360 1634 1167 144 116 93 71 339 580 294 106 28 66 89 329 288 189 115 25 43 76 249 131 86 145 115 102 -15 179 -3 -18
Table 2.4b Daylight amount at Zone 1
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Observation Point A2 and A3 shows the highest reading of illuminance obtained in zone 1. Discussion Point A2 and A3 is located right at the opening where natural lighting enters office 1 and receives the most natural daylighting. Because of the angle of light diffusion, the reading at 1.0m is higher compared to 1.5.
Observation At point E3, the lowest reading of -15 is obtained. Discussion The point is located at a corner behind a wall which blocks any daylight that enters the site. There is no artificial lighting installed which will help to illuminate the point leaving it dark in the dark.
Observation Looking at point D1, E1 and F1, the readings decrease drastically even though the points are located at the same column near the window. Discussion The sliding door opening stops at D1 and there are no other openings to illuminate point E1 and F1. Besides being far away from the opening and does not get illuminate as much by natural daylighting, there is very little artificial lighting that is installed to brighten the space based on the required standards.
Observation The suggested illuminance due to daylight of zone 1 is 656. Unfortunately, the average readings of zone is about 100lux. Discussion There is only one unobstructed opening that allows light to penetrate into office 1. Other than that, the rest of the part of office 1 receives very little daylight and mostly depend on artificial lighting to light up the space.
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Office 2 Suggested illuminance due to daylight at office 1 is 656 COORDINATES A8 A9 B8 B9 B10 B11 C8 C9 C10 C11 C12 D8 D9 D10 D11 D12 E8 E9 E10 E11 F8 F9 F11
PEAK (DAY) (lux) 1 1.5 1124 1523 1355 1754 1485 909 2908 2934 1432 952 1247 1578 1120 889 854 986 404 755 475 685 786 846 85 108 224 326 251 350 265 463 366 478 164 253 104 175 114 134 123 377 1789 1253 1563 1123 80 115
NON PEAK (EVENING) (lux) 1 1.5 154 103 143 98 354 411 288 165 216 167 121 96 100 87 112 94 143 101 284 158 276 199 162 177 84 56 212 153 294 216 231 112 87 163 149 71 218 316 299 174 123 85 236 339 103 70
Daylight (lux) 1420 1656 498 2769 785 1482 802 892 654 527 647 -69 270 197 247 366 90 104 -84 203 1168 784 45
Table 2.4c Daylight amount at Zone 2
Observation The suggested illuminance due to daylight is 656. Based on this chart, it is clear that at most of the points in this space is well lighted with daylight. In fact, some of the points have way too much daylight penetrating into the building. Discussion There is a large opening that allows a lot of light to penetrate into the building.
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Observation Daylight reading and illumination reading at point B9 has the highest value in the whole space. At night, the reading is no longer the highest. Discussion Point B9 is located right under the oculus in zone 2 where the space receives direct sunlight into the office. The reading at point 1.0m is lower than the reading taken at point 1.5m since it is further away from the light source and therefore the density of light energy is less. At night, when the room is dependable on artificial lighting, B9 no longer is the point with the highest illumination level since the high illumination level was due to the oculus.
Observation Daylight level is high at A8 and A9 Discussion A8 and A9 is located at a point near to the window opening that allows a lot of daylight into the office therefore it is the most illuminated point in zone 2 during the day.
Observation Daylight level is low at D8 even though it is fairly near to the opening. Discussion Although point D8 is near to the opening where the space receives daylight, however, as there is a cabinet in a way, it produces shadows which blocks the daylight from illuminating point D8. On top of that, there is an indoor planter box where there is a tree that blocks the daylight at that point.
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Dry kitchen Suggested illuminance due to daylight at office 1 is 328 Coordinates D5 D6 D7 E5 E6 E7 F5 F6 F7
PEAK (DAY) (lux) 1m 1.5m 138 123 167 142 194 156 115 146 122
98 103 121 97 105 110 95 107 116
NON PEAK (EVENING) (lux) 1m 1.5m 131 173 120 146 167 179 102 197 173
95 93 108 95 97 108 93 100 104
Daylight (lux) 3 10 13 2 8 2 2 7 12
Table 2.4c Daylight amount at Zone 3
Observation At point E6, reading at 1.0m which is the working plane for the kitchen is the highest during the day Discussion Point E6 is illuminated by 3 artificial lightings in the kitchen and therefore is the most well illuminated point. Observation At point F5 and E7 there is little to no daylight illuminating the space. The daylight reading shows the lowest number which is 2. Discussion The point is located in the corners of the kitchen and therefore there is very little daylight at the area. Observation D7 shows the highest reading of illumination due to daylight. Discussion Point D7 is located near to the kitchen wall which has an opening for daylight from zone 2 to enter the space. Therefore, the reading obtain reflects the amount of daylight from zone 2 that penetrates into the building.
47
FOYER Suggested illuminance due to daylight at office 1 is 82 COORDINATES C3 C4 D3 D4 D5 D6 E3 E4 E5 E6 F3 F4 F5 F6
PEAK (DAY) (lux) 1m 1.5m 106 65 98 50 71 123 147 110 87 119 126 139 145 197
75 79 53 87 54 68 100 156 62 96 187 198 139 97
NON PEAK (EVENING) (lux) 1m 1.5m 113 246 85 100 43 64 58 111 91 69 98 105 81 53
36 98 137 74 87 96 67 84 135 103 53 65 116 87
Daylight (lux) 39 -19 -84 13 -33 -28 33 72 -73 -7 134 133 23 10
Table 2.4d Daylight amount at Zone 4
Observation D3 shows a very low negative reading Discussion There are no window openings nearby and therefore no natural daylighting. The space is lit up solely by artificial lighting only.
Observation The readings at F3 and F4 show high reading in the day and low reading in the evening resulting in a high daylight value. Discussion Point F3 and F4 are located nearest to the window opening and therefore receive the most daylight.
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2.5
Artificial LIGHTING
2.5.1
Lighting specifications
Name of Light Types of Light Type of Fixture Type of Light Bulb Used Light Bulb Brand Lighting Function Type of Luminaries Power, W Light Output, lm Color Temperature, K Color Rendering Index, CRI Average Life (at 2.7hrs/day) Lifetime of Lamp (hrs) Lumen Maintenance Factor
Round Pendant Light Artificial Light Vertical Lone Light Fixture Compact Fluorescent Spiral Bulb Philips Task Lighting Cool Daylight 12 1760 3300 77 (Good) 6 6000 0.8
Table 2.5a Light Specification for Compact Flurescent Spiral Bulb
49
Name of Light Types of Light Type of Fixture Type of Light Bulb Used Light Bulb Brand Lighting Function Type of Luminaries Power, W Light Output, lm Color Temperature, K Color Rendering Index, CRI Average Life (at 2.7hrs/day) Lifetime of Lamp (hrs) Lumen Maintenance Factor
Round Pendant Light Artificial Light Vertical Lone Light Fixture Compact Fluorescent Stick Bulb Philips Task Lighting Warm White 18 1500 2700 90 (Excellent) 6 6000 0.8
Table 2.5b Light Specification for Compact Fluorescent Stick Bulb
50
Name of Light Types of Light Type of Fixture Type of Light Bulb Used Light Bulb Brand Lighting Function Type of Luminaries Power, W Light Output, lm Color Temperature, K Color Rendering Index, CRI Average Life (at 2.7hrs/day) Lifetime of Lamp (hrs) Lumen Maintenance Factor
LED Surface Mounted Light Artificial Light Ceiling Mounted Light Fixture LED Bulb Philips Ambient Lighting Warm White 8.5W 740lm 2700K 80 (Very Good) 15.2 years 15000 hours 0.7
Table 2.5c Light Specification for LED Bulb
51
Name of Light Types of Light Type of Fixture Type of Light Bulb Used Light Bulb Brand Lighting Function Type of Luminaries Power, W Light Output, lm Color Temperature, K Color Rendering Index, CRI Average Life (at 2.7hrs/day) Lifetime of Lamp (hrs) Lumen Maintenance Factor
LED Wall Mounted Light Artificial Light Wall Mounted Light Fixture LED Bulb Philips Ambient Lighting Warm White 8.5W 740lm 2700K 85 (Very Good) 15.2 years 15000 hours 0.8
Table 2.5d Light Specification for LED Bulb
52
Name of Light Types of Light Type of Fixture Type of Light Bulb Used Light Bulb Brand Lighting Function Type of Luminaries Power, W Light Output, lm Color Temperature, K Color Rendering Index, CRI Average Life (at 3hrs/day) Lifetime of Lamp (hrs) Lumen Maintenance Factor
LED Track Light Artificial Light Linear Track Lighting Fixture Reflector Bulb Philips Accent Lighting Warm White 8W 900lm 3000K 84 (Very Good) 25 years 25000 hours 0.8
Table 2.5e Light Specification for Reflector Bulb
53
Name of Light Types of Light Type of Fixture Type of Light Bulb Used Light Bulb Brand Lighting Function Type of Luminaries Power, W Light Output, lm Color Temperature, K Color Rendering Index, CRI Average Life (at 3hrs/day) Lifetime of Lamp (hrs) Lumen Maintenance Factor
LED Wall Mounted Light Artificial Light Wall Mounted Light Fixture Candle LED Bulb Philips Ambient Lighting Warm White 6.5W 700lm 2700K 80 (Very Good) 25 years 25000 hours 0.8
Table 2.5f Light Specification for Candle LED Bulb
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2.5.2 Lumen Method Calculation Zone 1: Office 1
Total Floor Area (m! ) Type of Lighting Fixtures Number of Lighting Fixtures/ N Lumen of Lighting Fixtures/ F (lm) Height of Luminaire/ H (m) Work Level (m) Mounting Height/ H (m) Assumption of Reflectance Value (Refer to Table in page*) Room Index / RI (k)
48.7 Compact Fluorescent Spiral Bulb 11 1760 0.30 0.85 1.9 Ceiling – 0.7 Wall- 0.5 =
5.0 x 9.4 1.65 5.0 + 9.4 = 1.97
Utilization Factor (UF) Standard Illuminance (lux)
0.65 300 IT Office standard illumination is used as all of the staffs working there are on their laptops.
Illuminance Level (lux) E=
11 ( 1760 x 0.65 x 0.8) 48.70
E=
4004 48.70
55
E = 206.72 lux
Number of Lighting Fixture required to reach the required illuminance
300 lux – 206.72 lux = 93.28 lux 93.28 more lux is required to fulfil the MS1525. E x A N= F x UF x MF N=
93.28 x 54.7 1760 x 0.58 x 0.8 N=
5102.42 816.64
N = 6.2 lamps N = 7 lamps 7 more compact fluorescent spiral lamps are required to be installed to fulfil the MS1525 standards. Table 2.5g Lumen Calculation Zone 1
Based on the lumen method calculations, the first office depend a lot on artificial lighting. There is insufficient natural daylighting in this space. This is as Wanaka Bungalow was built as a house and the first office was meant to be a living room before it was converted into an office. Hence, it was built to create a warmer and intimate space.
56
Zone 2: Office 2
Total Floor Area (m! ) Type of Lighting Fixtures Number of Lighting Fixtures/ N Lumen of Lighting Fixtures/ F (lm) Height of Luminaire/ H (m) Work Level (m) Mounting Height/ H (m) Assumption of Reflectance Value (Refer to Table in page*) Room Index / RI (k)
Compact Fluorescent Stick Bulb 7 1500
54.7 Reflector Bulb
LED Bulb
2 900
4 740
0.5 1.0 1.65 Ceiling – 0.7 Wall- 0.5
=
6 x 5.8 1.65 (6 + 5.8) = 1.79
Utilization Factor (UF) Standard Illuminance (lux) Illuminance Level (lux)
0.58 300 IT Office standard illumination is used as all of the staffs working there are on their laptops. E=
7 x 1500 x 0.58 x 0.8 54.7 =
4872 54.7
= 89.07 lux
E
2 x 900 x 0.58 x 0.8 = 54.7 835.25 = 54.7
E=
4 x 740 x 0.58 x 0.8 54.7 =
1373.44 54.7
= 25.11 lux
= 15.27 lux
89.07 + 15.27 + 25.11 =129.45 lux 300 lux – 129.45 lux = 170.55 lux 170.55 more lux is required to fulfil the MS1525.
57
Number of Lighting Fixture required to reach the required illuminance
N= N=
E x A F x UF x MF
170.55 x 54.7 1500 x 0.58 x 0.8
N=
9329.085 696
N = 13 lamps 12 more compact fluorescent stick lamps are required to be installed to fulfil the MS1525 standards. Table 2.5h Lumen Calculation Zone 2
Compared to zone 1, the illuminance level in zone 2 is higher. 12 more compact fluorescent stick lamp are needed to meet the standards. The space at night is not very suitable to carry out work. The space is not installed with the right amount of lighting.
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Zone 3: kitchen
Total Floor Area (m! ) Type of Lighting Fixtures Number of Lighting Fixtures/ N Lumen of Lighting Fixtures/ F (lm) Height of Luminaire/ H (m) Work Level (m) Mounting Height/ H (m) Assumption of Reflectance Value (Refer to Table in page*) Room Index / RI (k)
20.16 Vertical Lone Light Fixture 3 1760 2.50 0.85 1650 Ceiling –0.5 Wall- 0.3
=
4.2 X 4.8 HM (4.2 + 4.8) =
20.16 1650 (9.0)
=
20.16 18.3
= 1.1 Utilization Factor (UF) Standard Illuminance (lux) Illuminance Level (lux)
0.48 300 E= E=
N x F x UF x MF A
3 x 1760 x 0.48 x 0.8 20.16
59
E=
2027.52 20.16
E = 100.57 lux
Number of Lighting Fixture required
300 lux – 100.57 lux = 199.43 lux 199.43 more lux is required to fulfil the MS1525. E x A N= F x UF x MF N=
199.43 x 20.16 1760 x 0.48 x 0.8 N=
4020.50 675.84
N = 5.92 = 6 lamps 6 more lamps are required to be installed to fulfil the MS1525 standards. Table 2.5i Lumen Calculation Zone 3
After calculations, 199.43 more lux is required to fulfil the MS1525. 6 more lamps are required to be installed to fulfil the MS1525 standards. Accidents may happen in the kitchen if there is insufficient lighting in the kitchen.
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Zone 4: foyer
Total Floor Area (m! ) Type of Lighting Fixtures Number of Lighting Fixtures/ N Lumen of Lighting Fixtures/ F (lm) Height of Luminaire/ H (m) Work Level (m) Mounting Height/ H (m) Assumption of Reflectance Value (Refer to Table in page*) Room Index / RI (k)
16.20 Candle LED Bulb 3 700
Reflector Bulb 2 900
2.7 1.5 1.2 Ceiling – 0.5 Wall - 0.3
=
5.85 x 3.75 1.65 (5.85 + 3.75) =
21.94 15.84
=1.38 0.55 200
Utilization Factor (UF) Standard Illuminance (lux) Illuminance Level (lux) E= =
N x F x UF x MF A
3 x 700 x 0.55 x 0.8 16.2
=
924 16.2
= 57.04 lux
E= =
N x F x UF x MF A
2 x 900 x 0.55 x 0.8 16.2
=
792 16.2
= 48.89 lux
61
57.04 + 48.89 =105.93 lux 200 lux – 105.93 lux = 94.07 lux 94.07 more lux is required to fulfil the MS1525. Number of Lighting Fixture required
N= N=
E x A F x UF x MF
94.07 x 20.16 900 x 0.55 x 0.8
N=
1896.45 396
N = 4.79 = 5 lamps 5 more reflector lamps are required to be installed to fulfil the MS1525 standards. Table 2.5j Lumen Calculation Zone 4
94.07 more lux is required to fulfil the MS1525.
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2.6
Analysis and lighting conditions of the zones
Diagram 2.6a Section of Wanaka Office
Diagram 2.6b Placement of artificial lighting and angle of light
Diagram 2.6c Light Contour Section â&#x20AC;&#x201C; Day
63
Diagram 2.6d Light Contour Section â&#x20AC;&#x201C; Night
Light contour Ground Floor, Day time
Diagram 2.6e Zone Light Contour of ground floor- day
64
First Floor, Day time
Diagram 2.6f Zone Light Contour of first floor- day
Ground Floor, night time
Diagram 2.6g Zone Light Contour of ground floor- night
65
First Floor, night time
Diagram 2.6h Zone Light Contour of first floor- night
Zone 1: Office 1 It can be concluded based on the daylight factor analysis that zone 1 has insufficient natural daylighting. This is as Wanaka Bungalow was built as a house and the first office was meant to be a living room before it was converted into an office. Hence, it can be assumed that the building was initially built to create a warmer and more intimate space. There is a patio that allows light to illuminate office 1 as its four sides are glass. Light diffuses into the patio then into the office. However, there is a white board that is opaque and blocks the light coming through the patio into the office. There are also grills installed that blocks some of the light entering the space. Also due to the angle of penetration of light from the outdoors into the patio and then into the office, not all of the light is able to enter into the office. This causes the space to be darker than it should be. Figure 2.6a shows the openings that allow daylight into office 1.
66
Figure 2.6a Zone 1 Office
There is also a big tree that grows right outside office 1. When the readings are obtained and compared outside the building and also outside the compound of Wanaka, there is a big difference in illuminance measurement. This also adds up to the reason on why office 1 is poorly light up with natural daylight. The first office depends a lot on artificial lighting. There is insufficient natural daylighting in this space. After the lumen method calculation to find the illumination level, the results show that even the artificial lighting of the zone 1 is insufficient. 93.28 lux is need to meet the MS1525 standards. To full fill the requirement, 7 more compact florescent spiral lamps should be installed. In addition, the lamps installed has a temperature of 3300K, which is categorised as warm lighting. Should the office use lamps with higher temperate, perhaps the space will feel less dim and the people working there will feel less strain to their eyes while doing work. At night, the place is very dim.
67
Figure 2.6b Zone 1 Office
Figure 2.6c Zone 1 Office in the evening
Figure 2.6d Tree outside zone 1 office
Figure 2.6e Tree shading the office 1
68
Zone 2: Office 2 There is a large opening above 1.0m that allows daylight into the office 2. There is also an oculus that allows even more natural lighting into the space. In the daylight factor analysis (part 2.4.2) it can be observed that there is sufficient daylight during the day and artificial lighting is unnecessary. During all our site visits, we realised that the lights in this space were never turned on unless there was no more daylight. Unlike the precedent study case that we have chosen, Cambria Office, Pennsylvania which have windows that are low and does not allot much light to penetrate, the large openings that are slightly higher has proven that openings above 1.0m can light the space up well.
Figure 2.6f Zone 2 Office illuminated by natural daylight
Figure 2.6g Oculus at zone 2 that allows direct sunlight into the space
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Figure 2.6h sufficient daylight to illuminate the whole space
In the morning until late afternoon around 4pm, the blinds are needed to block the excessive daylight that comes into the office that causes disturbance glare. Even with the blinds down, the space is still well illuminated. This is because the oculus in the office lets in a lot of direct sunlight. Compared to zone 1 which is also an office, this space is better illuminated. This is as zone 2 do not have any trees outside which blocks the daylight from coming into the office unlike zone 1. Also, the height where the window is places allows a lot of light to penetrate into the building. When the sun starts to fall, the right back part of the office may not receive sufficient daylight and artificial lighting is needed to illuminate the space. There are two windows are the back of the room that allows light to come into the space resulting in less problems during dawn. On top of that, the white plaster walls has a high reflective index that reflects light well, adding to the illumination of the space. As this space is well lit and there is a lot of daylight, some of the light travels into zone 1, office 1 and also zone 2, kitchen. Both the spaces are separated from zone 2 by sliding glass doors which allow light to penetrate.
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Figure 2.6i Lighting of the office when the blinds are down during the day
Zone 3: Office 3
Figure 2.6g Lighting of zone 3: kitchen. Figure 2.6h Paper pasted on the glass that blocks the light penetrating into the space.
By looking at figure 2.6g, it can be seen that the lighting in the kitchen is very warm and not safe for a kitchen. The bulb used for this space is 3300k which has a warm temperate can be shown easily in figure 2.6g. Accidents may happen frequently as there is not enough lighting in this space. The shadow by the cabinets on the kitchen workspace makes it even darker. Natural lighting or cool temperature light is a more suitable choice of lightbulb for the kitchen. Under cabinet track light can be installed to fix the safety if the warm temperature of the room is kept. The warm lighting of the space creates more dim shadows in the space. The high cabinets in the space also creates shadows. Not much natural lighting is allowed into the space as firstly, there is not direct windows to the outdoor. However, there is a glass sliding door that allows some light to penetrate into zone 3, kitchen but since there are opaque papers stuck on the glass the light is blocked from coming into the space. All in all, the kitchen is not well lighted to suit its function as a kitchin as there is not enough of lighting for it to be a safe place to cook and prepare food.
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Zone 4: Foyer
Figure 2.6i Shadows created at the foyer making the space dark Figure 2.6j Window that allows the light to penetrate into the foyer area
There are two big opening at the foyer that allows light to penetrate into the foyer. However, firstly, the car porch outside is shaded with a tensile roof fabric to prevent the interiors of cars parked on the porch from getting heated. On top of that, there are a lot of cars on the porch that indirectly shades the foyer from the sun by the shadow created. Nearer to the window, it might seem like there is a lot of light. However, at a point slightly further away from the window where there are shadows created, the illumination readings shows low measurements. On top of that, the furniture and paintings at the foyer has very dull colours which has a lower reflective value and therefore light cannot be reflected to illuminate the space better. There is an opening at the other side of the foyer that allows quiet and adequate amount of light into the foyer. However, the beam blocks and reflects most of the light before it actually reaches the foyer. After the lumen method calculation, we can conclude that 5 more lamps in the area would be able to light the space up well at night.
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2.7 conclusion on lighting analysis of Wanaka bungalow
The design of the spaces that we analysed were successful in term of the placement of the openings such as the windows and also the sliding door especially at zone 2 where there is a lot of daylight that is able to penetrate in and artificial lighting is not needed at all during the day which can save cost. Zone 2 really depends on daylight to illuminate the space during the day. The high opening at office 2 is very successful in terms of illuminating the whole office making it undependable with artificial lighting. On top of that, the oculus also helps a lot in providing direct daylighting into the space. Of course at night it is inevitable that artificial lighting is needed. However, at spaces such as zone 1, there is not enough daylight. This is as the space is not initially designed as an office instead as a home. Zone 1 was designed as a living room and less daylight was needed in the space to reduce the glare should there be a television. The intention of the architect was to create a warmer and intimate space rather than an open office with a lot of group interactions. Therefore, in terms of converting zone 1 into an office is not a good idea and not encouraged. The artificial lighting installed in all of the spaces studied is not acceptable and does not meet the MS1252 standards. After all the lumen calculations has been done in this analysis, the results shows that there are still a number of lamp that needs to be installed in each of the spaces including zone 2. Without calculations, it is also quite obvious that spaces such as zone 1 which is office 1 and also zone 3 which is the kitchen does not have enough lighting. The artificial lighting should be improved to create a more productive environment for the people working there. Bulb with higher power or more blubs can be added to solve this issue. The warm lighting at the kitchen and office 1 is definitely not suitable for its functions as it creates a darker and warmer space, it is dangerous for those who are doing food preparation or cooking as they do not have good vision. All in all, Wanaka the bungalow does have a lot of potentials since it has many openings that allows a lot of light to enter the space. However, artificial lighting is still needed in the spaces to aid the users in the building. Converting the house into an office does not seem like a too bad idea however, there are a few changes that needs to be done such as installing more artificial lighting with cooler temperature rather than warm temperature for a more conducive and productive environment at the office. Overall, considerations have to be taken not only to illuminate the spaces but at the same time take care of the well-being of the users in the spaces by making sure their eyes do not strain while doing work in the space.
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3.1
ACOUSTIC Literature Review
3.1.1
Introduction to ACOUSTIC
Acoustics is the branch of physics or the science concerned with the production, control, transmission, reception, and effects of sound. Its origins began with the study of mechanical vibrations and the radiation of these vibrations through mechanical waves in gases, liquid and solid, and still continues today. Research was done to look into the many aspects of the fundamental physical processes involved in waves and sound and into possible applications of these processes in modern life. Many people mistakenly think that acoustics is strictly musical or architectural in nature. While acoustics does include the study of musical instruments and architectural spaces.
Diagram 3.1a â&#x20AC;&#x201C; Lindsayâ&#x20AC;&#x2122;s Wheel on acoustical studies
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3.1.2
architecture ACOUSTIC
Architectural acoustics is concerned with improving the sound in rooms: we might want to reduce the background noise in a recording studio; improve the design of a public address system to make speech more intelligible in railway stations, or put acoustic treatments on walls to make music in a concert hall sound better. We carry out research into new methods for measuring and predicting how sound moves within rooms and buildings such as schools and auditoria. Another key element is measuring peoplesâ&#x20AC;&#x2122; responses to sound so we can understand what people want from a room design. This enables us to develop innovative ways to design rooms and building elements.
3.1.3
Sound intensity level
Sound intensity is measured as a relative ratio to some standard intensity, lo. The response of the human ear to sound waves follows closely to a logarithmic function of the form R = k log I, where R is the response to a sound that has an intensity of I, and k is a constant of proportionality. So, the formula of the sound intensity level is
The formula: đ?&#x2018;şđ?&#x2018;°đ?&#x2018;ł = đ?&#x;?đ?&#x;&#x17D; đ?&#x2019;?đ?&#x2019;?đ?&#x2019;&#x2C6;đ?&#x;?đ?&#x;&#x17D; Â
3.1.4
đ?&#x2018;° đ?&#x2018;°đ?&#x2019;?
Reverberation time
Reverberation time (RT) is defined as the length of time required for sound to decay from its initial level. This study is the most important factor for acoustical engineers and architects when assessing a space with noise problems. A reverberation is created when a sound or signal is reflected causing a large number of reflections to build up and then decay as the sound is absorbed by the surface of objects in the space including the furniture, the people and the air. This happens when the reflection of the sound continues even when the source of the sound has already stopped, also causing a decrease in its amplitude until it reaches zero.
The formula: đ?&#x2018;šđ?&#x2018;ť =
đ?&#x;&#x17D;.đ?&#x;?đ?&#x;&#x201D;đ?&#x2018;˝ đ?&#x2018;¨
where RT is reverberation time, s V is volume of the room, đ?&#x2018;&#x161;! A is absorption coefficient
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Every architectural space needs to have its own analysis of specific reverberation time in order to achieve its optimum performance based on the function of the space. For example, spaces with a higher RT would encounter problems with noise as sound travels room with a high RT generally has a problem with noise as sound travels for long distances without being absorbed. Rooms with a high RT almost always have an issue with echo as sound is reflected from hard surface to hard surface.
3.1.5
Sound reduction index
Sound Reduction Index is used to measure the level of sound insulation provided by a structure such as a wall, window, door, or ventilator. The understanding of a sound reduction index is important to incorporate acoustic system design into a given space to decrease the possibility of sound from permeating from a loud space to a quiet space.
đ?&#x;?
The formula: đ?&#x2018;şđ?&#x2018;šđ?&#x2018;° = đ?&#x;?đ?&#x;&#x17D; đ??Ľđ??¨đ??  (đ?&#x2018;ť) where SRI is sound reduction index, dB T is transmission of sound frequency
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3.2 Methodlogy 3.2.1
PRECEDENT STUDIES
Precedent study chosen helps to have a better understanding how surrounding sound, materials, appliances affects the acoustics of a certain space. Â 3.2.2 preparations 1.
Preliminary study and identification of the type of spaces were studied to choose the suitable case study.
2.
Precedent studies were done to have a better understanding of how acoustics functions and affecting my the surrounding in a certain space.
3.
In obtaining approval to use site as case study, visitations, calls and emails were made to the different chosen places.
4.
The plan drawings were obtained from the management office.
5.
The spaces were determined.
6.
Grid lines with distance of 1.5m was plotted on the plan for recording purposes.
7.
Sound level meter meter was supplied by tutors.
8.
The equipment was tested before attending the site visit.
9.
A basic standard and regulations such as CIBSE, ASHRAE and MS1525 were also studied before hand to analyze and compare the readings later on.
Â
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3.1.3
Measuring device
Figure 3.2a - Sound level meter
Figure 3.2b - Digital Single Lens Reflex 3.1.4
data collection
Data were collected at non peak hours between 10am-12pm and 5pm-6pm, and peak hours between 2pm-4pm. The acoustics’ readings were taken according to the intersection of the grid lines at 1m above ground. It was ensured that the sound level meter stabilizes with the surrounding noise before the readings were taken. The noise source, furnitures and materials used in the spaces were analyzed and recorded as these may affect the sound level recorded.
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3.3 precedent study 3.3.1
introduction to the building
MUSIC CAFÉ, AUGUST WILSON CENTRE FOR AFRICAN AMERICAN CULTURE Prominently located on Liberty Avenue, The August Wilson Center for African American Culture is designed to be a signature element of downtown Pittsburgh. Rich materials and bold geometric forms set the stage for a magnificent cultural experience in which any visitor is sure to participate. It is timeless, flexible and powerful in its simplicity The facility is a center for the visual and performing arts for international music and education. Designed by Perkins+Will, the two-story, 64,500 gsf facility includes a 486-seat proscenium theater, 11,000 gsf of exhibit galleries, a flexible studio, a music café, and an education center. The building exploits the solar orientation of this tight triangular urban infill. The north facing façade takes full advantage of this limited solar exposure with a predominately glass wall that is transparent yet able to incorporate graphics and projected images, visually permeable by day and a stage for dramatic lighting at night. The acoustic properties of the Music Café has been analyzed and a new design has been proposed with dimensions, to compare and make a conclusion about the features that can enhance the existing acoustic design. As a signature building filled with performance spaces, the acoustics of the August Wilson Center are a key element to the building’s success and function.
Figure 3.3a - View from Liberty Avenue of the existing design for the August Wilson Cente
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DESIGN INTENTION MULT-IPURPOSE MUSIC CAFÉ, AUGUST WILSON CENTRE
Figure 3.3b- Interior perspectives of music cafe
The café is located transparent to the sidewalk, accessible directly from the street and also from within the center. The music café’ is designed to function as a multi purpose space as both a traditional museum café and sidewalk café during the day. A seating terrace is located outside and adjacent to the café. Wired for Internet access and designed to accommodate a wide range of emerging technologies, the Café provides an electronic link to visitors worldwide. The Café’ also function as an alternative performance space for intimate performances for special occasions such as indoor jazz concerts , spoken word, poetry and other new performance in a club setting at night.
Figure 3.3c - Interior of music cafe
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3.3.2 FLOOR plan indicating cafe SPACE DESCRIPTION
Diagram 3.3a - First floor plan of august wilson centre indicating the location of the music café
The music café’ is a large rectangular box covered by glass walls, a hard floor, and sound absorbing treatment on the ceiling behind baffles and ductwork. The space is designed to acknowledge the café’s mechanical and natural sound produced, need for acoustical design elements, with hanging metal baffles and acoustical blanket over 80% of the underside of the floor structure above. Based on the user description provided by the architect of August Wilson center, a reverberation time of approximately 1.0 second is ideal for such multi-purpose spaces. This would place the space somewhere between speech and speech/music use. According to the Architectural Acoustics: Principles and Design a significally high STC value of over 60+ is desirable across the music café and the user lobby. This is important to both spaces, as two different functions might simultaneously be carried out in either space. A spoken word performance or a public speech performance in the café could be disturbed if a large crowd was gathering in the lobby for a performance in the main theater causing noise diffusion into the café. Similarly, the lobby must remain quiet during a performance in the main theater if patrons are entering or exiting the auditorium since a main set of doors is directly across from the café. This function is very important as it relates back to our chosen site, where spaces are multi functionary and divided by shared walls, which do not separate the spaces completely.
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3.3.3 reverberation analysis Reverberation is the persistence of sound after a sound is produced. A reverberation, or reverb, is created when a sound or signal is reflected causing a large number of reflections to build up and then decay as the sound is absorbed by the surfaces of objects in the space – which could include furniture, people, and air. The reverberation times for the music cafe’ were calculated in order to understand how the space achieves its acoustic function
Diagram 3.3b - Music Café Reflected Ceiling Plan – Existing Design
Table 3.3a - Music Café Reverberation Time – Existing Design.
Figure x illustrates that the existing reverberation times do not support the ideal time recommended for such spaces. One important consideration, however, is that the acoustical data of the metal baffle ceiling system (Chicago Metallic) is not regarded in the measurements as it is not provided by the manufacturer. Including the baffles in the calculation would reduce the very high reverberation times at the lower frequencies, but it would also reduce the reverberation times at the higher frequencies, which are already lower than ideal number for the space, in relation to its usage.
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3.3.4 analysis of sound transmission class (stc) Sound Transmission Class (or STC) is an index rating of how well a building partition attenuates airborne sound. Analysis of the sound transmission class (STC) on the wall between the café and the main lobby reveals a potential for unwanted noise transfer between the two spaces. At 46, the calculated STC falls far below the ideal value of 60+. This problem is generated due to the use of glass doors and partitions between the spaces instead of proper separating walls. Changing the glass type from 1⁄2” tempered glass to 1⁄2” laminated glass improves the STC to 49, but this is only a marginal increase. To really improve this potentially negative situation, architectural changes can be applied to counter the passage of unwanted noises. Figure 3.3d – Proposed baffle system
These changes may include changing the glass to another material such as wood or creating a small vestibule at the entrances.. Adding absorptive insulation (e.g., fiberglass batts, blow-in cellulose, recycled cotton denim batts) in the wall cavity increases the STC for fiberglass to more than 50 with cotton denim, depending on stud and screw spacing. Doubling up the drywall in addition to fiberglass insulation can yield an even higher STC provided the wall gaps and penetrations are sealed properly In contrast to that, improving the reverberation time is a much more realistic change. In order to do this, a new baffle system is proposed by eliminating the metal baffles and acoustical blanket, replacing them with floating fiberglass sound absorbing panels that are faced in perforated metal.
Figure 3.3e - Existing hanging metal baffle system from Chicago Metallic.
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3.3.5 new proposed baffled system
Diagram 3.3c - Music Café Reflected Ceiling Plan – New Design
Table 3.3b - Music Café Reverberation Time – New Design
Table 3.3c - Music Café New Baffle Schedule of Materials
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3.3.6 conclusion The proposed solution for improving reverberation times is both economical and aesthetically pleasing for the analyzed space, the multi-purpose music cafe. The noise reduction qualities of the barriers separating these spaces from the lobbies that surround them have also been identified as problematic, but solutions to these problems are far more complex and are not feasible within the current architectural design. As a designer working with an architect, it is ultimately the architectâ&#x20AC;&#x2122;s decision to maintain a visual quality or sacrifice appearance for performance. Although it successfully delivers as a visual treat and a convenient resting spot for cafĂŠ-goers and music lovers, the music cafĂŠ does not acoustically deliver to its maximum potential. Proposals for a better acoustic system would be also be in terms of materiality. Improving the reverberation time by eliminating the metal baffles and acoustic blanket and replacing them with floating fiberglass sound absorbing panels that are faced in perforated metal seems like the ideal option to counter this problem. The new reverberation times are very close to the ideal values that are optimum as acoustic reverberation. 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. These multipliers are used to correct for the fact that the human ear is less sensitive at lower frequencies. With these factors included, the new design is very near the target. The new ceiling system will provide superior acoustical performance at a reduced cost. Overall, the biggest challenge in analyzing and working with the systems of the August Wilson Center has been the unique character of the architecture. The spaces created are far from standard and certainly strive to embody signature qualities. However, as is often the case, this unyielding visual character makes the engineering of the building systems a complex task.
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3.4 site study 3.4.1
outdoor noise source
Figure 3.4a â&#x20AC;&#x201C; Location of site in relation to Site Plan
Given our siteâ&#x20AC;&#x2122;s close proximity to Jalan Dungun highway, Damansara, most of the outdoor noise source is contributed by vehicular traffic along this route, gradually increasing during peak traffic hours. In addition to that, outdoor noise is also received from lorong dungun on either sides of the block. There is also very little outdoor noise from the adjacent housing lots next to the bungalow and the parking areas nearby, Howver the main external noise sources are from the vehicular traffic.
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3.4.2 tabulation of data
Diagram 3.4a – Ground Floor Plan – Office 1
DATE: 27th April 2016
DATE: 27th April 2016
TIME: 10am-12pm
TIME: 2pm- 4pm
HEIGHT: 1.5m
HEIGHT: 1.5m
GRID
A
B
C
D
E
F
GRID
A
B
C
D
E
F
1
43
43
43
45
50
48
1
45
45
44
50
53
55
2
43
43
43
45
51
51
2
45
48
47
55
55
57
3
45
45
45
48
50
3
47
50
49
57
57
4
48
48
48
48
50
4
52
52
52
62
68
5
48
48
48
5
57
58
58
6
45
45
45
6
56
58
58
7
45
45
45
7
55
56
56
Table 3.4a – Data tabulated for Office 1
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Diagram 3.4b – Ground Floor Plan – Office 2
DATE: 27th April 2016
DATE: 27th April 2016
TIME: 10am -12pm
TIME: 2pm -4pm
HEIGHT: 1.5m
HEIGHT: 1.5m
GRID
A
B
C
D
E
F
GRID
A
B
C
D
E
F
8
45
45
48
45
45
45
8
47
51
51
59
57
55
9
45
45
48
45
45
45
9
50
53
53
55
56
57
10
48
50
48
50
50
10
55
55
55
60
66
11
48
50
50
50
11
55
55
60
66
48
50
57
60
12
12
Table 3.4b – Data tabulated for Office 2
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Diagram 3.4c – Ground Floor Plan – Kitchen
DATE: 27th April 2016
DATE: 27th April 2016
TIME: 10am – 12pm
TIME: 2pm – 4pm
HEIGHT: 1.5m
HEIGHT: 1.5m
GRID
D
E
F
GRID
D
E
F
5
45
48
45
5
63
66
63
6
45
48
45
6
68
73
70
7
45
48
45
7
65
70
71
Table 3.4c – Data tabulated for Kitchen
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Diagram 3.4d – Ground Floor Plan – Foyer
DATE: 27th April 2016
DATE: 27th April 2016
TIME: 10am – 12pm
TIME: 2pm – 4pm
HEIGHT: 1.5m
HEIGHT: 1.5m
GRID
C
D
E
F
GRID
C
D
E
F
3
50
50
55
54
3
55
60
74
58
4
50
50
60
56
4
55
60
68
60
5
43
43
45
5
70
60
60
6
43
43
48
6
60
70
75
Table 3.4d – Data tabulated for Foyer
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3.4.3 indoor noise source
AIR CIRCULATORS
Diagram 3.4e â&#x20AC;&#x201C; Placement of fans in First Floor
Fans are essential in buildings in order to circulate the air in the rooms as well as cool down the air. These are highly efficient air moving devices. Fans are placed in both the stair way and foyer In order to provide a cool entrance and a comfortable and conductive foyer space for visitors. The fans produce a certain amount of noise in these rooms compared to the air conditioners. Air conditioners produce less noise pollution compared to fans. Fan noise levels however can be reduced by replacing or maintaining them on a regular schedule. Additional energy losses and noise is produced when fan motors are operated in higher loads. A small, perfectly balanced, clean, modern ceiling fan in pristine condition should be whisper quiet. But the reality is that with almost any ceiling fan, over time the weight shifts, the blades move slightly, and screws can loosen, meaning that without skilled care, theyâ&#x20AC;&#x2122;re probably going to go from a quiet whirr to a slightly more pronounced motor sound that could keep light sleepers awake or be slightly distracting in a quiet room.
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Diagram 3.4f â&#x20AC;&#x201C; Placement of fans in ground floor
The ground floor has a combination of both fans and air conditioners. Running a ceiling fan and an air conditioner at the same time can increase room comfort as well as save energy. The windows of the air conditioned rooms and offices are usually closed, due to this less outside sound enters the rooms. Even the noise from the air-conditioners are fairly low. Due to this there is quietness inside the rooms. The noise inside the air conditioned room can be further reduced by soundproofing the room.
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HUMAN ACTIVITY
Diagram 3.4g â&#x20AC;&#x201C; Nodes of Human Activity in First floor
The human noise in the first floor is caused in the stairway which is a circulation node and also in the entrance of the foyer contributed by exterior noise by human activity outside.
Diagram 3.4h - Nodes of Human Activity in the Ground Floor
The nodes of human activity on the Ground floor is contributed mainly by the Office spaces and the kitchen, which is also used a multi-purpose meeting room. Since the offices are used for telecommunication operation, outsourcing information, the noise production is fairly moderate throughout the day, slightly rising during peak hours.
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3.4.5 acoustics specifications
acoustic equipment specifications
Name of Unit Model Total Cooling Capacity (Btu / h) Input Power (W) Running Current (A) Power Source ( V/Ph/Hz ) Refrigerant Type / Control Indoor Air Flow ( Cfm ) Sound Pressure Level ( Dba ) Unit Dimension ( Panel ) – H x W x D ( mm ) Indoor Unit Outdoor Unit Unit Weight ( kg ) Indoor Unit Outdoor Unit
Ceiling Cassette Unit Yck 10C 10000 942 4.16 220 – 240 / 1 / 50 R-22 / Outdoor Cap. Tube 410 41 250 x 570 x 570 ( 20 x 640 x 640 ) 540 x 700 x 250 16 + 2 29
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Name of Unit Model Total Cooling Capacity (Btu / h) Input Power (W) Running Current (A) Power Source ( V/Ph/Hz ) Refrigerant Type Indoor Air Flow ( Cfm ) Sound Pressure Level ( Dba ) Unit Dimension ( Panel ) – H x W x D ( mm ) Indoor Unit Outdoor Unit Unit Weight ( kg ) Indoor Unit Outdoor Unit
Ceiling Suspended Unit ACM 10 C/ALC 10C 10000 942 4.16 220 – 240 / 1 / 50 R-22 300 41 235 x 824 x 666 ( 305 x 910 x 730 ) 540 x 700 x 250 30 28
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Name of Unit Model Total Cooling Capacity (Btu / h) Input Power (W) Running Current (A) Power Source ( V/Ph/Hz ) Refrigerant Type Indoor Air Flow ( Cfm ) Sound Pressure Level ( Dba ) Unit Dimension ( Panel ) – H x W x D ( mm ) Indoor Unit Outdoor Unit Unit Weight ( kg ) Indoor Unit Outdoor Unit
Wall Mounted Unit AWM 10NP – ALC 10CN 10000 980 4.16 220 – 240 / 1 / 50 R-22 342 38 288 x 800 x 203 ( 340 x 874 x 274 ) 494 x 600 x 245 9 25
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Name of Unit Model Colour Blade Size Dimension Fan Size ( cm ) Low High Air Delivery ( m3 / min ) Low High Motor HP Motor Type Noise Level ( dB ) Nett Weight ( kg ) Length from pully to PCB cover ( mm ) Length from pully to blade ( mm )
Regulator 3 Blades Ceiling Fan F-M 15A0 (60”) White 150 cm ( 60” ) 1500 mm ( W ) x 439 mm ( H ) 81 – 118 216 – 264 15 – 20 67 – 82 0.11 14 Pole Condenser Motor <54 7.3 439 348
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3.4.6 calculation of sound intensity level Office 1 Non-peak hour Highest reading: 51dB SIL
=
10 log I , 1ref =1x10 Iref
51
=
10 log I
10
=
I
=
5.1
−12
Iref
I -12
1x10
−7
1.259x10
Lowest reading : 43dB SIL
=
10 log I , 1ref =1x10 Iref
43
=
10 log I
10
=
I
=
4.3
−12
Iref
I -12
1x10
−8
1.995x10
Total intensity = 1.259x10−7 + 1.995x10−8 = 1.459x10−7
Total SIL
1.459x10- 7 = 10 log 1x10- 12 = 52dB
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Peak hour Highest reading : 68dB SIL
=
10 log I , 1ref =1x10 Iref
68
=
10 log I
10
=
I
=
6.8
−12
Iref
I -12
1x10
−6
6.310x10
Lowest reading : 62dB SIL
=
10 log I , 1ref =1x10 Iref
62
=
10 log I
10
=
I
=
6.2
−12
Iref
I -12
1x10
−6
1.585x10
Total intensity = 6.310x10−6 +1.585x10−6 = 7.895x10−6
Total SIL
= 10 log
7.895x10- 6 1x10- 12
= 69dB
The average noise level during peak hours is higher compared to the average noise data collected during non-peak hours. The drastic change of sound level occurs in office 1 is due to the amount of people occupying the space.
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Office 2 Non-peak hour Highest reading : 50dB SIL
=
10 log I , 1ref =1x10 Iref
50
=
10 log I
10
=
I
=
5
−12
Iref
I -12
1x10
−7
1x10
Lowest reading : 45dB SIL
=
10 log I , 1ref =1x10 Iref
45
=
10 log I
10
=
I
=
4.5
−12
Iref
I -12
1x10
−8
3.162x10
Total intensity
= 1.259x10−7 + 1.995x10−8 = 1.459x10−7
Total SIL
= 10 log = 52dB
1.459x10- 7 1x10- 12
100
Peak hour Highest reading : 66dB SIL
=
10 log I , 1ref =1x10 Iref
66
=
10 log I
6.6
10
=
I
=
−12
Iref
I -12
1x10
−6
3.981x10
Lowest reading : 57dB SIL
=
10 log I , 1ref =1x10 Iref
57
=
10 log I
5.7
10
=
I
=
Total intensity
Total SIL
−12
Iref
I -12
1x10
−7
5.012x10
= 3.981x10−6 + 5.012x10−7 = 4.482x10−6
4.482x10- 6 = 10 log 1x10- 12 = 67dB
The average noise level during peak hours is higher compared to the average noise data collected during non-peak hours. The drastic change of sound level occurs in the office 2 due to the amount of people occupying the space.
101
Kitchen Non-peak hour Highest reading : 48dB SIL
=
10 log I , 1ref =1x10 Iref
48
=
10 log I
−12
Iref
10
=
I
= 6.310x10
4.8
I -12
1x10 −8
Lowest reading : 45dB SIL
=
10 log I , 1ref =1x10 Iref
45
=
10 log I
10
=
I
=
4.5
−12
Iref
I -12
1x10
−8
3.162x10
Total Intensity = 6.310x10− 8 + 3.162x10− 8 = 9.472X10− 8 Total SIL
-8 = 10 log 9.472x10
= 51dB
1x10- 12
102
Peak hour Highest reading : 73dB SIL
=
10 log I , 1ref =1x10 Iref
73
=
10 log I
7.3
−12
Iref
10
=
I
= 1.995x10−5
I -12
1x10
Lowest reading : 65dB SIL
=
10 log I , 1ref =1x10 Iref
65
=
10 log I
6.5
10
=
I
=
−12
Iref
I -12
1x10
−6
3.162x10
Total intensity = 1.995x10−5 + 3.162x10−6 = 2.311x10−5
Total SIL
2.311x10- 5 = 10 log 1x10- 12 = 75dB
The average noise level during peak hours is higher compared to the average noise data collected during non-peak hours. The drastic change of sound level occurs in the kitchen due to the amount of people occupying the space.
103
Foyer Non-peak hour Highest reading :60dB SIL
=
10 log I , 1ref =1x10 Iref
60
=
10 log I
6
10
=
I
=
−12
Iref
I -12
1x10
−6
1x10
Lowest reading :56dB SIL
=
10 log I , 1ref =1x10 Iref
56
=
10 log I
5.6
10
=
I
=
Total intensity
−12
Iref
I -12
1x10
−7
3.981x10
= 1x10−6 + 3.981x10−7 = 1.398x10−6
Total SIL
1.398x10- 6 = 10 log 1x10- 12 = 62dB
104
Peak hour
Highest reading : 70dB SIL
=
10 log I , 1ref =1x10 Iref
70
=
10 log I
7
10
=
I
−12
Iref
I -12
1x10 =
−5
1x10
Lowest reading : 68dB SIL
=
10 log I , 1ref =1x10 Iref
68
=
10 log I
6.8
10
=
I
=
Total intensity
−12
Iref
I -12
1x10
−6
6.310x10
= 1x10−5 + 6.310x10−6 = 1.631x10−5
Total SIL
= 10 log
1.631x10- 5 1x10- 12
= 72dB
The average noise level during peak hours is higher compared to the average noise data collected during non-peak hours. The drastic change of sound level occurs in the foyer due to the amount of people occupying the space.
105
ZONE 1 & ZONE 3
Diagram 3.4i -
Building element
Material
Sound Reduction Index, SRI (dB)
Transmission
Area, S ( m2 )
Coefficient, T
Wall
Concrete plaster with finishes
44
3.981x10
Door
Polished wood
28
1.585x10
−5
−3
23.238 1.932
Concrete Wall TL
= 10 log
(
44
= 10 log
(
4.4
10 T
=
(
1
T
1
T 1
T
)
)
)
= 3.981x10−5
106
Door TL
= 10 log
(
28
= 10 log
(
2.8
10
=
(
1
T
T
1
T 1
T
)
)
)
= 1.585x10−3
T
av
= ( 3.981x10− 5 x 23.238) + ( 1.585x10− 3 x 1.932) / 25.17 = 3.987x10− 3 / 25.17 = 1.584x10− 4
Overall SRI
= 10 log
= 10 log (
(
1
T
)
1 1.584X10- 4
)
= 38dB
The sound intensity level data calculated during peak hour in zone 1 is 69dB whereas zone 3 is 75dB. Based on the overall SRI, this shows that the sound level in these zones are able to reduce to 38dB. This may be due to the air gap that exist between the walls and also the door that is usually closed. The sealed door of Zone 3 (dry kitchen) occupying some of the area of a concrete wall reduces the average SRI of that wall from 44 dB to 38 dB. The final sound insulation is influenced by relative areas but is always closer to the insulation of the poorer component than to the better component.
107
ZONE 2 & ZONE 3
Building element
Material
Concrete plaster with finishes
Wall
Sound Reduction Index, SRI (dB)
Transmission
44
3.981x10
Area, S ( m2 )
Coefficient, T −5
13.530
Concrete Wall TL
= 10 log
(
44
= 10 log
(
4.4
10 T
=
(
1
T
1
T 1
T
)
)
)
= 3.981x10−5
108
T
av
= ( 3.981x10− 5 x 13.530) / 130 = 3.981x10− 5 / 130 = 3.981x10− 5
Overall SRI
= 10 log
= 10 log (
(
1
T
)
1 3.981X10- 5
)
= 44dB
The sound intensity level data calculated during peak hour in zone 1 is 69dB whereas zone 3 is 75dB. Based on the overall SRI, this shows that the sound level in these zones are able to reduce to 44dB. This may be due to the air gap that exist between the walls .
109
ZONE 1 & ZONE 2
Building element
Material
Sound Reduction Index, SRI (dB)
Transmission
Area, S ( m2 )
Coefficient, T
Wall
Concrete plaster with finishes
44
3.981x10
Door
Glass
30
1x10
−5
−3
6.126 5.124
Concrete Wall TL
= 10 log
(
44
= 10 log
(
4.4
10 T
=
(
1
T
1
T 1
T
)
)
)
= 3.981x10−5
110
Door TL
= 10 log
(
30
= 10 log
(
3
10
=
(
1
T
T
1
T 1
T
)
)
)
= 1x10−3
T
av
= ( 3.981x10− 5 x 6.126) + ( 1x10− 3 x 5.124) / 11.25 = 5.368x10− 3 / 11.25 = 4.771x10− 4
Overall SRI
= 10 log
= 10 log (
(
1
T
)
1 4.771X10- 4
)
= 33dB
The sound intensity level data calculated during peak hour in zone 1 is 67dB whereas zone 3 is 69dB. Based on the overall SRI, this shows that the sound level in these zones are able to reduce to 33dB. This may be due to the air gap that exist between the walls that consists of a glass sliding door which too increases the transmission loss.
111
3.4.6 reverberation time Reverberation time is calculated to determine the amount of sound energy that is absorbed into different types of construction materials in the structure as well as the interior elements such as building occupants and furniture that are housed within the closed space. The reverberation time are done in form of data collection in order to study the result of successive reflections in the enclosed spaces of the bungalow after the sound source is turned off. The building components and other relevant information such as the type of materials used, the dimension specifications and the absorption coefficients are collected and tabulated to achieve the optimum accuracy on understanding the behaviour of sound in terms of the reflection and absorption efficiency.
Calculated Space
Ground Floor Office 1 Reverberation times are calculated based on different material absroption coefficient at 500Hz for peak hours and non- peak hours. -
Material Absorption Coefficient at 500 Hz for peak hours. Material Absorption Coefficient at 500 Hz for non-pek hours.
112
Surface area, S (đ?&#x2019;&#x17D;đ?&#x;? )
Absorption coefficient, s
Sound Absorption, SA
Wall â&#x20AC;&#x201C; Concrete
65.238
0.06
3.914
Door â&#x20AC;&#x201C; Glass
28.950
0.18
5.211
Door â&#x20AC;&#x201C; Wood
1.932
0.10
0.193
Ceiling â&#x20AC;&#x201C; Wood
48.70
0.10
4.870
Floor â&#x20AC;&#x201C; Terrazzo
48.70
0.015
0.731
19
0.46
8.740
Surface type
Occupants
Total absorption
A
= 23.659
V
= (1a+1b+1c)
23.659
= 68.88 + 24.84 + 43.2 + 7.92 = 144.84
đ?&#x2018;&#x2026;đ?&#x2018;&#x2021; =
đ?&#x2018;&#x2026;đ?&#x2018;&#x2021; =
0.16đ?&#x2018;&#x2030; đ??´
0.16(144.84) 23.659
đ?&#x2018;&#x2026;đ?&#x2018;&#x2021; =
23.174 23.659
đ?&#x2018;šđ?&#x2018;ť = đ?&#x;&#x17D;. đ?&#x;&#x2014;đ?&#x;&#x2013; Â đ?&#x2019;&#x201D;
113
Ground Floor Office 2
Surface area, S (đ?&#x2019;&#x17D;đ?&#x;? )
Absorption coefficient, a
SA
Wall â&#x20AC;&#x201C; Concrete
78.946
0.06
4.737
Door â&#x20AC;&#x201C; Glass
5.124
0.18
0.922
Door â&#x20AC;&#x201C; Wood
1.890
0.10
0.189
Window â&#x20AC;&#x201C; Glass
8.810
0.18
1.586
Ceiling â&#x20AC;&#x201C; Plaster
54.70
0.02
1.094
Floor â&#x20AC;&#x201C; Terrazzo
54.70
0.015
0.821
16
0.46
7.360
Surface type
Occupants
Total absorption
16.709
114
A
= 16.709
V
= 164.10
𝑅𝑇 =
𝑅𝑇 =
0.16𝑉 𝐴
0.16(164.10) 16.709
𝑅𝑇 =
26.256 16.709
𝑹𝑻 = 𝟏. 𝟓𝟕 𝒔
115
Ground Floor Kitchen
Surface area, S (đ?&#x2019;&#x17D;đ?&#x;? )
Absorption coefficient, a
SA
Wall â&#x20AC;&#x201C; Concrete
48.408
0.06
2.904
Door â&#x20AC;&#x201C; Wood
1.932
0.10
0.193
Ceiling â&#x20AC;&#x201C; Plaster
17.40
0.02
0.348
Floor â&#x20AC;&#x201C; Terrazzo
17.40
0.015
0.261
6
0.46
2.760
Surface type
Occupants
Total absorption
6.466
116
A
= 6.466
V
= 57.60
𝑅𝑇 =
𝑅𝑇 =
0.16𝑉 𝐴
0.16(57.60) 6.466
𝑅𝑇 =
9.216 6.466
𝑹𝑻 = 𝟏. 𝟒𝟑 𝒔
117
Surface area, S (đ?&#x2019;&#x17D;đ?&#x;? )
Absorption coefficient, a
SA
Wall â&#x20AC;&#x201C; Concrete
79.948
0.06
4.797
Door â&#x20AC;&#x201C; Wood
9.114
0.10
0.911
Window - Glass
2.40
0.18
0.432
Ceiling â&#x20AC;&#x201C; Plaster
35.66
0.02
0.713
Floor â&#x20AC;&#x201C; Concrete
35.66
0.06
2.140
9
0.46
4.140
Surface type
Occupants
Total absorption
13.133
118
A
= 13.133
V
= 132.02
𝑅𝑇 =
𝑅𝑇 =
0.16𝑉 𝐴
0.16(132.02) 13.133
𝑅𝑇 =
21.123 13.133
𝑹𝑻 = 𝟏. 𝟔𝟏 𝒔
119
3.4.7 analysis and conclusion ANALYSIS Zone 1 : OFFICE 1
Figure 3.4a Meeting room
Figure 3.4b Working space
120
Figure 3.4c Entrance of Office 1
Figure 3.4d Staircase
It is mentioned that Wanaka was a residence and currently used as an office building. The primary noises that contributes to Office 1 is the human activities as the business that they run involves assisting virtually through phone calls. Human voices could reach up to 93dB. Secondary noises comes from the surrounding appliances such as ceiling ventilations, telephone ringing and the use of computer. During peak hours, the data collected is the highest compared to non-peak hours. The sound intensity level calculated for peak hours is 69dB whereas for non-peak hours is 52dB. The drastic change from
121
peak hours to non-peak hours is caused by the amount of occupancy in Office 1. Office 1 does not only function as a working space but also they held their discussions or meetings in this space.
Figure 3.4e Acoustic Ray Diagram Office 1
Based on the acoustical ray diagram above, it shows a result of high echo effect in the meeting room. The meeting room is known to be the most active area with its high readings of sound intensity level and higher rate of human activity in this area according to the observation. Zone 1, or office 1 has a total volume of 144.84đ?&#x2018;&#x161;! enclosed by solid concrete walls with four sliding doors. In this enclosed workspace, the sound sources come from the air circulators such as ceiling fan and air conditioners, and the human activity such as group meetings and discussions during the peak hours. Based on the tabulated RT table, the sound produced is calculated to decay in 0.98s after multiple reflections between walls A4 and A6 from its source. The maximum distance between the two walls is 9.12m for the travelling of sound produced during discussions. The large volume of office 1, with its maximum distance allows the sound to decay in short time. Based on the SRI, the SIL in the office 1 could be reduced to 38dB. The partition wall between zone 1 and zone 3 functions to reduce the transmission of airborne sound.
122
Zone 2 : OFFICE 2
Figure 3.4f Working space
Figure 3.4g Secondary noise source
123
Figure 3.4h Barrier between Office 1 and Office 2
Similar to Office 1, the primary noises that contributes to Office 2 is also human activities and the secondary noises are the surrounding appliances. However, the readings collected in Office 2 is slightly different compared to Office 1. Data collected highest is during peak hours compared to non-peak hours. The sound intensity level calculated during peak hours is 67dB and at peak hours is 52dB. The reason why there is a slight difference in readings between Office 1 and Office 2 is because Office 2 has more openings and a sliding door in between Office 1 and Office 2.
Figure 3.4i Acoustic Ray Diagram Office 2
124
Based on the acoustical ray diagram above, it shows a result of echo effect in the office. Zone 2, or office 2 has a total volume of 164.10đ?&#x2018;&#x161;! . In this enclosed workspace, the sound sources come from the group discussions during the peak hours. Based on the tabulated RT table, the sound produced is calculated to decay in 1.57s after multiple reflections from its source. The large volume of office 2, with its maximum distance also allows the sound to decay in short time. Based on the SRI, the SIL in the office 2 could be reduced to 33dB. The partition wall with sliding door that splits zone 2 and zone 3 helps to reduce the transmission of airborne sound from leaking into other spaces.
125
Zone 3 : KITCHEN
Figure 3.4j Interior space
Figure 3.4h Entrance to the kitchen
The primary noises that contributes to the kitchen is also human activities. This space functions not only as an eating area but also a discussion and socializing area. Secondary noises in the kitchen are caused by the kitchen appliances such as microwave, sink, espresso machine, and refrigerator. The data collected shows that during peak hours has higher intensity level compared to non-peak hours.
126
Figure 3.4k Acoustic Ray Diagram Kitchen
Based on the acoustical ray diagram above, zone 3, or the dry kitchen with a total volume of 57.60đ?&#x2018;&#x161;! has drastic reflection on sound behaviour between the surfaces. The sound produced is calculated to decay in 1.43s after multiple reflections from its source. The small volume of dry kitchen, with its minimum distance allows the sound to decay in longer time. In this enclosed environment, the sound sources come from the group discussions during the peak hours. Based on the calculation, the SIL during peak hours is 75dB and 51dB during non-peak hours. Based on the SRI, the SIL in the kitchen could be reduced to 44dB. The partition wall and door opening between zone 2 and zone 3 functions to reduce the transmission airborne sound.
127
Zone 4 : Foyer
Figure 3.4l Interior space of foyer
Figure 3.4m Entrance towards foyer
128
Figure 3.4n Interior space of foyer
Figure 3.4o Interior space of foyer leading towards the staircase
The foyer is located on the first floor of the Wanaka. This space is hardly in used, hence most of the time this place is usually very quiet. When there is a noise source in the space, the SIL increases. Human activity is the primary noise that contributes to the space whereas the secondary noises are the ceiling ventilation. The readings are highest when taken during peak hours and lowest during the nonpeak hours. The SIL calculated during peak hours is 72dB and lowest is 62dB.
129
Figure 3.4p Acoustic Ray Diagram Foyer
Based on the acoustical ray diagram above of zone 4 which is the foyer, it shows a poor result on the reverberation process compared to the echo. The distance between the two walls is only 3.87đ?&#x2018;&#x161; span for the travelling of sound produced from the air circulators which is the ceiling fan. The sound produced is calculated to decay in 1.57s after multiple reflections between the walls from its source. With its small volume, the decaying process takes a longer second to end, therefore leads to its high sound intensity within the space despite the lack of human activity in the zone.
130
Conclusion
In conclusion, the reverberation time for Office 1 is 0.98s, which is suitable for an office space. Since it is a working space, the reverberation time should be short so it does not disrupt other people when one is talking or doing work on their computers. For kitchen, the reverberation time is 1.43s which is also suitable for the space, as a kitchen does not usually occupies a big amount of people. The reverberation time for foyer is 1.57s which is too, a suitable duration of time for the noises to decay because foyer is usually an open space so noise decays easily to the surroundings.
However, for Office 2, the reverberation time is 1.53s which is not suitable for an office space. The suitable reverberation time is 1.0s. Based on the analysis of Office 2, this space is more enclosed compared to Office 1.
Despite the unsuitable reverberation time for Office 2, in overall, the acoustics in Wanaka is efficient enough to prevent noises from leaking from one room to another room allowing privacy in the spaces. Although, to improve the acoustics of Wanaka, baffled system is suggested in between Office 1 and Office 2 to prevent noises from leaking and disrupting the daily routines of people.
131
REFERENCES Acoustics Froontiers. (2013). Retrieved from Room Acoustics Analysis: http://www.acousticfrontiers.com/services/design/room-acoustic-analysis/ Acoustics, B. (2015). Retrieved from Acoustics Research Group: https://acoustics.byu.edu/content/what-acoustics Control the Noise. (n.d.). Retrieved from Sound Insulation: http://www.controlthenoise.com/17 Telfor Journal. (2013). Analysis of Reverberation Time Field Measurmeents Result in Building Acoustics, 145 - 150. Retrieved from Telfor Journal: http://journal.telfor.rs/Published/Vol5No2/Vol5No2_A12.pdf
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