Building Science 2 (ARC 3413)
Project 1: Lighting and Acoustic Performance Evaluation and Design SOCSO Rehabilitation Centre, Melacca
Ang Jia Pin Christine Yap Zhe Xing Chuah Say Yin Joash Lim Yun-An Khor Xin Suan Teh Xue Kai
0315506 0316294 0315301 0317197 0316230 0317021
TABLE OF CONTENT 1.0 Introduction 1.1 Aims and objectives 1.2 Site study 1.3 Reason of selection 1.4 Measured drawing 1.5 Literature review of Light 1.5.1 Introduction of Light 1.5.2 Importance of Light in Architecture 1.5.3 Artificial Lighting 1.5.4 Natural Lighting 1.5.5 Lumen and Illuminance 1.5.6 Daylight factors and distribution 1.5.7 Lumen Method 1.5.8 Light Loss Factor (LLF) 1.5.9 Reflectance Value 1.5.10 Room Index 1.5.11 Room cavity ratio (RCR) 1.5.12 Coefficient of Utilization 1.6 Literature review of acoustic 1.6.1 Introduction of Acoustic 1.6.2 Importance of Sound in Architecture 1.6.3 Noise control 1.6.4 Sound Pressure level (SPL) 1.6.5 Reverberation Time 2.0 Precedent study 2.1 Lighting 2.2 Acoustic 3.0 Lighting 3.1 Site study and zoning 3.2 Research methodology 3.2.1 Precedent Studies 3.2.2 Equipment and Data Collection 3.3 Natural day lighting 3.3.1 Tabulation and interpretation of data 3.3.2 Lighting fixtures 3.3.3 Daylight factor analysis 3.4 Artificial lighting 3.4.1 Materiality 3.4.2 Lumen method calculation 3.5 Sun path analysis diagram 3.6 Analysis and lighting conditions of the zone 3.6.1 Housing constructing workshop and office 3.6.2 Storage and electrical workshop 3.6.3 On-site construction workshop and office
1 2 3 4-6 7-11
12
13-20 21-28
29-31 32-33
34-39
40-47
48-49 50-51
3.7. Conclusion of natural lighting and artificial lighting 3.8 Recommendations
4.0 Acoustic 4.1 Site study and Zoning 4.2 Research methodology 4.2.1 Precedent Studies 4.2.2 Measuring Devices 4.2.3 Procedure 4.2.4 Data Collection Method 4.3 Identification of Existing Acoustic 4.3.1 Internal Acoustic 4.3.1.1 Speaker 4.3.1.2 Ceiling Speaker 4.3.1.3 Air Conditioner Diffuser 4.3.1.4 Gym Equipment 4.3.1.5 Human Activity 4.3.2 External Acoustic 4.3.2.1 Air Handling Unit Room 4.3.2.2 Electrical Room 4.5 Material 4.6 Acoustic Analysis 4.6.1 Data Analysis 4.6.1.1 Peak and Non-Peak Hour Analysis 4.6.1.2 Peak Hour Analysis 4.6.1.3 Non-Peak Hour Analysis 4.6.1.4 External – Interior Acoustic Relationship 4.6.1.5 Acoustic Source Analysis 4.7 Acoustic Ray Bouncing Diagram 4.8 Calculation of Sound Intensity 4.8.1 Indoor Noise Source 4.8.2 Space Acoustic Analysis 4.8.3 Sound Reduction Index (SRI) 4.8.4 Reverberation Time 4.9 Conclusion of Acoustic 4.10 Recommendations Reference
52-53 54
55-56 57-59
60-74
75-76
77-79 80-90
91-93 94-131
132 133
1.0 INTRODUCTION Lighting and acoustic is a primary element in architecture design and interior architecture. Good lighting design will make a person appreciate the enclosed or open space more as they can clearly see the texture and colour of the surrounding. These will affect the level of comfort in visuals of an individual. Different spaces require different lighting design to introduce specific moods to the space. Acoustic design is as important as lighting as it will affect the comfort of the user in that space as well. Especially in enclosed space there will be concerns on how to contain the noise inside and also eliminating external noise source from penetrating in. In both designs the use of materials are very important. Materials would either enhance the quality of space to have desired sound and light or worsen the user experience as it does not provide proper requirement to a specific space. The site that we chose is SOSCO Rehabilitation Centre in Malacca. This project is conducted in group of six. We carry further our analysis by going to site visits and collecting data including measured drawings, lighting and acoustics measurement using the equipment provided. The method of data collection is also photographed for record. Then analysis and calculations done will be documented in a report format. 1.1 Aims and objectives The objectives of the project are as following: 1. To understand the day-lighting & lighting and acoustic characteristics & acoustic requirement in a suggested space. 2. To determine the characteristics and function of day-lighting & artificial lighting and sound & acoustic within the intended space. 3. To critically report and analyse the space. This project also aims to train our ability to produce a complete documentation on analysis of space in relation to lighting requirement. For example, natural and artificial lighting which could be shown in pictures, sketches and drawing and analysis of factors which effects the lighting design of a space. We are to explore and apply understanding of building physic eg. Lighting towards building / construction technology and building materials on existing building projects. Besides that we also should have the ability to evaluate and explore the improvisation by using current material and technology in relevance to present construction industry. Finally we learn the basic understanding and analysis of lighting layout and arrangements by using certain methods or calculations eg. Lumen method and PSALI as well as basic understanding and analysis of acoustic design layout and arrangements by using certain methods or calculations eg, Reverberation time and sound transmission and coefficient.
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1.2 Site study
Figure 1.2.1 Entrance at admission block.
Figure 1.2.2 Master plan of SOSCO Rehabilitation Centre. (Source: http://architizer.com/projects/socso-rehabilitation-centre/media/1031274/)
Case study: SOSCO Rehabilitation Centre Space of study: Gymnasium and Industrial Rehabilitation Centre Address: Lot PT7263 [H.S (D) 18923] Bandar Hijau,Hang Tuah Jaya, Melaka 75450 Malaysia This is the first rehabilitation centre in Malaysia. It combines the medical and vocational rehabilitation with an allied health institute. SOSCO’s ‘Return to Work’ programme helps disabled patients undergo physical and vocational rehabilitation in order to rejoin the workforce. Located on 55 acres of undulating landscape, a ‘primary spine’ for walking, wheelchair and buggy linked the various clusters of buildings sequentially. This green certified complex (under the Malaysian ‘Green Building Index’) was designed where nature via lush expansive landscape and ‘spirituality’ is an important element integral to the healing process. Employing universal ‘access for all’ concept and Malaysian Standard (M.S), this project was intended to represent the best planned rehabilitation facility suited to international standards.(“SOSCO Rehabilitation Centre”, n.d.)
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1.3 Reason of selection The site consists of mainly five blocks which are administration block, vocational rehabilitation block, medical rehabilitation block, allied health block and hostel and dining block. The block that we chose to focus on is the medical rehabilitation block. The reason for that choice is because in that area the quality of lighting and acoustics should be more soothing and comforting to avoid triggering any unnecessary psychological stress in the process of healing. The surrounding of that block is rather quiet and has some trees to help shade. The space that we chose to analyse lighting is the industrial rehabilitation area where the space tries to imitate the surrounding of an actual factory by having more artificial lighting than natural lighting and usage of hard material for flooring, walls and ceiling. The materials found include concrete, glass and steel. It is a double volume area as in an actual factory there should be space to place huge machineries inside and they did place a few minor machinery and a steel structural frame as well to add a more realistic feel to it. The other space that we chose to analyse acoustics is the gymnasium. The gymnasium area consists of not only just the usual equipment for gym but also some exercise area especially for the disabled. There is also space to conduct aerobic exercises. There are placements for speakers as well to make announcement in case of emergency. Since there are multiple activities carried on there, it has different noise level at different hour and the material use would affect the reflection of noise. 1.4 Measured drawing
Figure 1.4.1: Ground floor plan-Industrial rehab. (Source: SOCSO Rehabiltation Center)
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Figure 1.4.2: First floor plan-Gymnasium. (Source: SOCSO Rehabilitation Center)
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Figure 1.4.3: Gymnasium ground floor plan. (Source: SOCSO Rehabilitation Center)
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Figure 1.4.4: Industrial rehab plan. (Source: SOCSO Rehabilitation Center)
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1.5 Literature Review of Light 1.5.1 Introduction of Light Light visible by human and responsible to the sense of sight is known as visible light, which is called by scientists the electromagnetic radiation in the family of waves. Whereas light sources are the medium which produce light. The unit to measure light is Lux (IX), which describes the amount of light strikes the surface. The two type of lighting are natural lighting and artificial lighting. Natural lighting comes from the source of sun, which contrast with artificial lighting comes from an instruments that produce light. 1.5.2 Importance of Light in Architecture In lighting analysis, many would measure and rely on numeric and scaled light level, collected with the unit of lux. However, in the deeper relations and importance of light quality, it is much more intricate element that could be determined not only through measurement, but also our senses (Fontenelle, 2008). For instance, lighting condition often associates with the perception of space and influence the impression of texture, surface, colour and form. Besides, regardless of artificial lighting or natural daylighting, they also serves to provoke different sensations and visual experience to the occupants. Moreover, the properties of light in terms of its colours, spatial distribution of brightness, shadows it cast, reflections it form as well as the colour of lighting would all be giving impact to the visual feelings. 1.5.3 Artificial Lighting Artificial light are the technical instruments which produce light through the conversion of electrical energy into radiation and light. . There are two types of light source, namely incandescent lamp which generate light via the radiation of a filament at high temperature, and luminescent lamp which produce light through excited electrons (Raman, n.d.). Artificial lighting are important not only to provoke or achieve certain experience of the space, but also to certain range of visibility for the quality of the space. For instance, it is important to ensure the safety of the occupants in the warehouse and working performance in an office as well as comfort the people in a space. Below shows the maximum lighting power allowance for the spaces with particular usage.
Table 1.5.3: Unit power lighting. (including ballast loss allowance) (Source: “MS 1525�, 2007)
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1.5.4 Natural Lighting Natural lighting has to be properly designed in a building as it can bring great psychological impacts and benefits to the occupants, decrease sick time and increase productivity in a working environment. (Keith, n.d.) The amount of penetration of sunlight into a building depends on the orientation and size as well as the materials of the glazing. The visible transmittance of the daylight fenestration system should not be less than 50% in order to take advantage natural lighting. (“MS 1525”, 2007) Besides, it should be designed in such a way that prevent directs solar radiation while allowing diffused light to ensure effective daylight factor. This is because according to MS 1525 (2007), reduction of energy consumption for artificial lighting due to appropriate allowance for natural lighting is much more greater than cooling energy required due to extra glazed building envelop. As such, natural lighting has to be well-planned in order to ensure its effectivity in energy saving. 1.5.5 Lumen and Illuminance Lumen is the unit of measurement of the total amount of light source whereas Illuminance measures the incident light that strikes on the surface. Illuminance is expressed in the unit of footcandle or lux. The closer the illuminated area is to the light source, the higher the Illuminated values. The horizontal illuminance is referring to the incident ray landing on a horizontal surface whereas vertical illuminances describes the illuminance landing on a vertical surface. Illuminance produced during daylight include a vast range of 150,000 lux on a sunny day to 1,000 lux on a grey day in winter whereas moonlight is about 0.3 lux. (“Illuminance Explained”, 2012)
Table 1.5.5: Standard illuminance level and working height. (Source: https://www.wbdg.org/pdfs/usace_lightinglevels.pdf)
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1.5.6 Daylight factors and distribution Daylight factors describes the amount of illumination available indoors relative to illumination of the outdoor at the same time under overcast skies and it is expressed in percentage. In other word, it is the ratio of internal light level to external light level as shown below. It measures the quality of daylighting in a room and to determine the sufficiency of the natural lighting of a space. The higher the daylight factors, the more the natural light available inside a space. DF = (Ei / Eo) x 100% 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. Zone
DF (%)
Distribution
Very Bright
>6
Very large with thermal and glare problems
Bright
3-6
Good
Average
1-3
Fair
Dark
0-1
Poor
Note: The figures are average daylight factors for windows without glazing Table 1.5.6: Daylight factors and distribution. (Source: “MS 1525�, 2007)
1.5.7 Lumen Method 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 a space. It is done by calculating the number of lamp installed to ensure it has enough level of illuminance.
E= average illuminance over the horizontal working plane n= number of lamps in each luminaire N= number of luminaire F- Lighting design lumens per lamp, ie. Initial bare lamp luminous. UF= utilization factor for the horizontal working plane LLF= light loss factor A = area of horizontal working plane. 9|Page
1.5.8 Light Loss Factor (LLF) A numbers of environmental conditions will interfere the transmission of light when the light travels and leaves the light fixtures which results in wasted lumens. (“Light loss factor�, n.d.) As such, it the conditions has to be taken into consideration to ensure proper quantity and quality of light from the lighting system.
Table 1.5.8: LLF values for different spaces. (Source: http://www.fuzionlighting.com.au/technical/lighting-calculations.php)
1.5.9 Reflectance Value
Table 1.5.9: Reflectance value for different spaces. (Source: http://www.fuzionlighting.com.au/technical/lighting-calculations.php)
1.5.10 Room Index Room index is the ratio of room plan area to half the wall area between the working and luminaire planes.
L = length of the room W= width of the room Hm= Hm mounting height above the work plane.
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1.5.11 Room cavity ratio (RCR) Room cavity ratio is the ratio of room dimensions that used to determine how the light interacts with the room surfaces. RCR = (5*H*(L+W))/A L= length of room W= width of room A= area of room H= Mounting height of the fixtures (Source: http://www.controlbooth.com/wiki/?title=Room-Cavity-Ratio-RCR)
1.5.12 Coefficient of Utilization The coefficient of utilization is a factor use to measure the efficiency of the light fixtures in delivering the light. The value is depending on the type of the electrical fixtures, the numbers of the lamps, the distributions of the beam pattern, the reflectance of the ceiling, walls, floor as well as the room cavity ratio (RCR).
Table 1.5.12: Coefficient of utilization. (Source: http://phcjam.blogspot.my/2011/07/electric-lighting-lamps-efficacy.html)
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1.6 Literature Review of Acoustic 1.6.1 Introduction of Acoustic Acoustic is derived from the Greek term Akouein, meaning ready to hear. Sound is mechanical waves in acoustic. Sound is energy produced through vibration that can be transmitted by solid, liquid and solid. Sound is measured through logarithmic scale known as decibel (db). Sound waves have qualities such as frequency, velocity, wavelength and power. (Mehta, 1999) 1.6.2 Importance of Sound in Architecture Sound embraces and transcends the spaces in which it occurs, opening up a consummate context for the listener: the acoustic source and its surroundings unite into a unique auditory experience. (OASE78, 2009). Sound in terms of loudness, pitch, frequency affects the comfort level and experience of a space. Hence, noise control is important to allow the user to experience a comfortable space. (Szokolay, 2004) 1.6.3 Noise control There are passive design strategies that a designer that helps in noise control. It is ideal for buildings to be built away from industrial areas, airports, railways, highways and roads and development areas. Not only that, noise can be controlled internally by selection of quiet equipment or enclosing equipment. (Cowan. J, 2000) 1.6.4 Sound Pressure level Sound pressure formula: SPL = 10 log (
)
where, log is common logarithm P= Sound Pressure Po= Standard reference pressure of 20 micro Pascal 1.6.5 Reverberation Time Reverberation is the continued presence of audible sound after the source of sound has been stopped which was caused by rapid multiple reflections between surfaces of a room. The time when reverberation loses its intensity and the decay of sound level is reverberation time. Reverberation time depends on 3 factors: the volume of the room, total surface area and absorption coefficients of the surfaces. (Cavanaugh, W.J & Wilkes, J.A., 1999)
Formula: t= t= reverberation time (s) V= volume of the room (
)
A= total absorption of room coefficient
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2.0 PRECEDENT STUDIES 2.1 Lighting Introduction of Building Kresge Foundation Office Complex Troy, Michigan
Figure 2.1.1: Front view of the complex. (Source: http://www.asla.org/sustainablelandscapes/images/kresge/Kresge_3.jpg)
The Kresge Foundation is a non-profit organization which analyses the current energy and environmental performance of its own facilities. The construction of the foundation was completed in 2006 which seats on a 2.77 acre site in an urban site context in Troy, Michigan. The complex consists of a farmhouse (barn), courtyard office areas which houses 60 employees (Goins, 2011). The complex received an award of Leadership in Energy and Environmental Design (LEED) – Platinum Rating, as well as other award for its’s high performance design. Features of the Complex stated as below: (Goins, 2011). General – 1) 26,000 ft2 total 2) 19,000 ft2 new, 12,500 below ground level 3) Oriented (long elevation) facing north/south Occupant Comfort – 1) Daylighting and occupancy lighting controls 2) Low volatile organic compound (VOC) paints and finishes 3) Sun shades and light shelves 13 | P a g e
Glazing/Façade – 1) 2) 3) 4) 5) 6) 7) 8)
Overall 30-50% window to wall ration, solar heat gain coefficient = .38 Super – insulated walls. Heating, ventilation and air conditioning New areas: ground source heat pump with underfloor ventilation Old areas: ground source heat pump with underfloor ventilation Mid-efficiency variable speed axial fan air handling units, variable speed pumps. Ground source heat pump water-water service water heating Demand controlled ventilation.
The Center for the Built Environment (CBE) focuses on linking occupant experience in measuring the building performance and environmental quality of building through data collecting and comparison to CBE’s database of building occupant satisfaction results (Goins, 2011).
Figure 2.1.2: Floor plan of the foundation complex. (Source: http://kresge.org/sites/default/files/CBE_Kresge_Building_Study.pdf)
Lighting Background The complex manage to achieve satisfying lighting performance and meets the standard requirement of occupancy evaluation. Yet, CBE notices the lights are on in most offices even the natural day lighting are obvious and sufficient to lit the interior spaces. Occupants were reported no using the lighting control which was installed which resulted to opportunities in reducing lighting-related energy use. (Goins, 2011).
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Methodology Researchers analysed lighting survey data and physical measurement. An evaluation was conducted through observation of lighting system operational and informal interviews with the building engineer (Goins, 2011). The objectives of PMP-based lighting measurements are to: (Goins, 2011).
Determine the building occupants’ satisfaction with the lighting, Rate the building’s performance against benchmarks in a database of previously measured building, Identifying the problems with the lighting and obtain clues using the occupants responses base of questions. Taking measurement on various spots base of the important photometric parameters.
The first three objectives are covered by survey analysis and overall lighting evaluation while the fourth objectives are measure during the two site visits to the site, one in winter and the other in summer. These illuminance measurement were obtained from Minolta T-1H handheld illuminance meter, which contains liquid crystal display and detachable sensor which provides the output in lux. Three types of environments were tested: 1) private offices, 2) open-plan offices and 3) corridors. The measurement procedure differed in the three cases. The private and open-plan offices, the sensor was located over the desk. Illuminance at the point of work was measured with the worker in normal working position. For corridor, the sensor was located at 28 inches (0.70m) from the floor. Three lighting levels were measured in the private office: 1) overhead lights and desk lamp switched on, 2) only overhead lights switched on, and 3) no electrical light on. For the open-plan offices, only reading of lighting level is measured with overhead light on (Goins, 2011).
Daytime measurement were conducted during the winter visit, and nigh time measurement were conducted during the summer visit (Goins, 2011). Daylight condition, date, hour and weather condition were recorded to provide evidence of photometric measurement affection. Measurement were compared to illuminance levels recommended by the Illuminating Engineering Society of North America (IESNA) (Goins, 2011).
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Results Analysis The lighting receive the highest satisfaction rating among the IEQ areas. 80% of occupants were satisfied with the amount of light in their workspace meanwhile 71% were satisfied with the visual comfort in the workspace. The Complex scored 79th percentile on overall lighting satisfaction within the CBE survey database (Goins, 2011).
Table 2.1.1: IESNA – Recommended illuminance levels. (Source: http://kresge.org/sites/default/files/CBE_Kresge_Building_Study.pdf)
Diagram 2.1.1: First floor private office illuminance spot measurement (March 4, 2010 9:15AM – 10.30AM). (Source: http://kresge.org/sites/default/files/CBE_Kresge_Building_Study.pdf)
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Winter Visits (daytime measurements) Diagram 2.1.1 displays light levels with 1) all lights off, 2) only the overhead lights turned on, and 3) both overhead lights and task light turned on in the first floor private office. Analysis: There was sufficient daylight in the morning so most of the spaces did not require electrical lighting. Analysis 2: The corridor has exceeded the recommended illuminance level although some corridor lights are required for emergency exit safety, most corridor lights can be dimmed or turned off during adequate daylighting (Goins, 2011).
Figure 2.1.3: Southern open office area on first floor with evidence daylighting and light fixtures turned on. (Source: http://kresge.org/sites/default/files/CBE_Kresge_Building_Study.pdf)
Diagram 2.1.2: Corridor afternoon illuminance spot measurement (March 4, 2010 1:00PM – 1.30PM). (Source: http://kresge.org/sites/default/files/CBE_Kresge_Building_Study.pdf)
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Summer Visits (night time measurements)
Diagram 2.1.3: First floor private office evening illuminance spot measurement (10:50PM – 11.30PM). (Source: http://kresge.org/sites/default/files/CBE_Kresge_Building_Study.pdf)
Diagram 2.1.3 displays the night time light levels with only the overhead lights turned on compared to light levels with both overhead lights and task light turned on in the first floor private offices. The light levels measured when only the overhead lights were turned on were generally insufficient according to IESNA standards. When both the overhead and task light were turned on, the lighting level was sufficient. (Goins, 2011). Following are the Detailed Lighting Results:
Table 2.1.3: Illuminance measurement during evening of August 17th for open plan offices. (Source: http://kresge.org/sites/default/files/CBE_Kresge_Buil ding_Study.pdf)
/
Table 2.1.2: Illuminance measurement during evening of August 17th for private offices. (Source: http://kresge.org/sites/default/files/CBE_Kresge_Buil ding_Study.pdf)
Table 2.1.4: Illuminance measurement during evening of August 17th for corridors. (Source: 18 | P a g e http://kresge.org/sites/default/files/CBE_Kresge_Buil ding_Study.pdf)
Winter Measurements
Table 2.1.7: Illuminance measurement during morning of March 4th for corridors (Source: http://kresge.org/sites/default/files/CBE_Kresge_Buil ding_Study.pdf)
Table 2.1.5: Illuminance measurement during morning of March 4th for private offices. (Source: http://kresge.org/sites/default/files/CBE_Kresge_Buil ding_Study.pdf)
Table 2.1.6: Illuminance measurement during morning of March 4th for open plan offices. (Source: http://kresge.org/sites/default/files/CBE_Kresge_Buil ding_Study.pdf)
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Conclusion Recommendations below are based on survey results and lighting measurement performed during both the winter and summer visits:
Daylighting level was higher than the IESNA recommended level – indicates consumption of electricity is high. Suggestion of short guidance in explaining the importance in regulating lighting in the office and the benefit of doing so.
Computer screen inappropriately situated causing glare. Suggestion of placement of screen should be orthogonal to window.
Illuminance levels in corridors during the day with the overhead lights switched on display daylighting level was higher than needed. Recommendation of increasing the dimming range of the overhead lamps.
Night time task illuminance levels were sufficient when the desk light was used but were not sufficient when only the overhead light was used.
Overall the occupants were satisfied with the lighting system but the daylight harvesting system has not been tuned to achieve the desired lower energy consumption.
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2.2 Acoustic Introduction of Building Church Gym and Multipurpose Hall
Figure 2.1.4: The interior of church gym and multipurpose hall.
This case study is done by eNoise Control in Westfield, USA which provides a full range of products and consulting services for industrial noise control, noise cancelling, sound reduction, sound deadening, abatement and containment. It was about problem of unwanted sound reverberation in the gymnasiums. The client has complained about the gym being too noisy and the sound quality being poor. The distribution of the acoustic conditions throughout the space and the effects of the renovation on the distribution are determined by carrying out experiments before and after the renovation and installation. eNoise Control aimed to control the echo and make the environment comfortable for audiences. This has to be done by intercepting the path of the sound reflection and dissipate the noise – with the right measures the echo can be dropped to an acceptable level.
Diagram 2.1.4: Reverberation Chart.
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Acoustic Design Strategies Wall - Fabric Wrapped Wall Panels
Figure 2.1.5: Fabric wrapped wall panels used on wall surfaces.
These are compressed fiberglass panels designed for installation to wall surfaces. They come in a variety of colors and sizes and are ideal for gymnasiums, multipurpose rooms and churches for their sound absorption qualities. Fabric Wrapped Acoustic Panels are an aesthetically pleasing solution to reverberant noise problems. Also known as acoustical wall panels or acoustical clouds, these panels are typically 1″ – 2″ thick with a square or contoured chemically hardened edge and wrapped with a fire retardant fabric. The panels are mechanically hung on walls or ceilings in patterns or groupings that add to the rooms’ overall architecture.
Finishes A variety of decorator fabrics are available. The standard is Guilford of Maine FR701 Style 2100. Other factory approved fabrics include Deepa Textiles, Design Tex, Wolf Gordon, Momentum and Knoll. Customer specified fabrics can be applied if it meets the manufacturing requirements.
Figure 2.1.6: Various mounting options for finishes.
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Acoustical NRC Rating Dimension
Acoustic NRC Rating
1/2″
0.50 – 0.60
1″
0.80 – 0.90
1-1/2″
0.90 – 1.00
2″
1.05 – 1.15 Table 2.1.7: Dimension of the finishes with their corresponding acoustic NRC rating.
Fire Rating All components have a Class A/1 fire rating per ASTM E-84 Edge Detail
Figure 2.1.7: Edge Details.
Fibrous Wood Panel eNoise Control’s FWP acoustical panels are composed of aspen wood fibres, bonded with an exclusive inorganic hydraulic cement binder, and are formed in a continuous process under heat and pressure. They are abuse resistant and are able to withstand the impact of thrown or kicked balls in gyms, yet are lightweight.
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CEILING a) Baffles These units are 2′ x 4′ (other sizes available) fiberglass panels wrapped in PVC vinyl covering with grommets for vertical suspension from the ceiling. This free hanging suspension of baffles allows the material to interrupt the path of noise and curb the sound levels in a room. Baffles are available in a wide variety of colors and are a cost effective means of sound control for gymnasiums.
Figure 2.1.8: Baffles.
Acoustic baffles are a low cost and non-intrusive solution to many common noise control problems. These ceiling or overhead baffles absorb reflected noise bouncing off hard flat walls, floors, or ceilings. Baffles are an absorptive board or sound barricade that can be placed around or between acoustic sources to provide sound isolation or deadening and reduce acoustic leakage. A fundamental tool of noise mitigation is the use of sound baffles. Most baffle products are easy to install and come in many styles such as PVC, Poly, Sailcloth, FDA, sound curtain, and foam. They are an effective noise barrier when applied to walls and ceilings in building interiors to absorb sound energy and thus lessen reverberation. Sound baffles are ideal for reducing reverberation times anywhere you encounter airborne sound transmission. Typically suspended from the ceiling, sound baffles may be used as acoustic wall panels as well to assist in reducing reflective or reverberating noise. By definition, a sound baffle is any object designed to reduce airborne sound.
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b) Acoustic Banners Multi-purpose facilities require a sound environment conducive to both athletic events and musical performances. Acoustic banners combine ideal acoustical properties with cost-effective shipping and installation methods. Acoustical banners can be hung in a loose catenary fashion or installed flush to the roof deck for a flat appearance with minimum festoon. They allow free flow of air and integrate exceptionally well with existing sprinklers, lighting, and HVAC systems and banners are completely encapsulated in moisture-resistant PVC. Acoustic banners reduce reverberation time and sound intensity levels in harsh acoustical environments which results in increased speech intelligibility, better communication and improved quality of sound systems.
Figure 2.1.9: Acoustic Banners.
Acoustic Banners are large, visually and architecturally pleasing sound absorbers. They can be hung in a loose flowing fashion or installed flush to the roof deck for a flat appearance. They allow free flow of air and integrate exceptionally well with existing sprinklers, lighting, and HVAC systems. Acoustic banners are completely encapsulated in moisture-resistant PVC which protects the environment from any airborne fibers. Installation of these materials reduce reverberation time in harsh acoustical environments from a disconcerting 4 to 9 seconds to a pleasant 1/2 to 2 seconds. Sound intensity levels are reduced simultaneously, which helps to create a more peaceful environment. This results in increased speech intelligibility, better communication and improved quality of sound systems.
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STAGES OF INSTALLATION AND MEASUREMENTS Stage 1 – Initial Measurement & Test Installation On first measurement the reverberation time was a whopping 3.8 seconds. This was done using an RT60 reading (see reading in blue below) which is the time required for reflections of a direct sound to decay by 60dB.
Diagram 2.1.4: Initial RT60 reading showing reverberation time of 3.8 seconds.
1.5 seconds is considered an acceptable reverberation time for multi-purpose Gymnasiums, Halls & Events Centers however this can only be attained with significant acoustic treatment. Stage 2 – Installation of 90% of Panels Encouraged by the initial results Stan and his helpers then installed panels on all the upper walls of the Gym (except the top section at both ends which will be completed in the next school holidays).
Figure 2.1.10: Interior of the gym
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A third reading was then completed and the results were a dramatic reduction in reverberation times from 3.00 seconds to 1.8 seconds as shown below:
Diagram 2.1.5: Third RT60 reading showing reverberation time reduced from 3.0 to 1.8 seconds .
Diagram 2.1.6: Fourth RT60 reading showing a reverberation reduction from 1.8 to just under 1.5 seconds.
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Table 2.1.8: Reverb Analysis Program.
Conclusion According to the reverberation time experiments carried out along the installation processes, a significant improvement can be noticed in terms of the acoustic performance. The change in the acoustic environment of the gym due to the suggested strategies can be seen clearly for all the acoustic parameters. As a result of the renovations, the RT values decreased to the optimum reading. The design strategies specifically solved the issues by applying the acoustic panels to the wall. The wood panels used in this case also reflect the considerations given by the eNoise Control regarding the typology of activities take place. Ceiling wise, baffles and banners are two different approach to the issues but effective and suitable in the same way. Both strategies are common to be utilized in sports orientated spaces. Overall performance of those strategies are effective and now the gym is noise-free and having the echo level at the optimum rate.
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3.0 LIGHTING 3.1 Site study and zoning The Industrial rehabilitation area intends to stimulate the real industrial condition to help patient heal mentally by overcoming their fear of working on site. Hence, it is separated into 5 different zones to give variety of industrial work condition. The four columns in the center of the area is to further define the space. In order to make it more realistic the space is placed next to a basement parking where the patients could hear lorry moving in and out of the area. Besides that, they have also specially added sound effects for the entrance when it is open and closed. The two roller shutters placed there functions as an access for the patients as well as visually enhancing the atmosphere of a stimulated industrial area. The double volume area is also to mimic an actual factory condition.
Figure 3.1.1: Exterior landscape of industrial rehab
Figure 3.1.2: Zone 1- Storage.
The storage area has handles at different height in order to help the patients with disability when they are placing equipment on the shelves. There is also space on the floor to place materials such as wire mesh and PVC pipes.
Figure 3.1.3: Zone 2-Electrical workshop.
In this area they provide electrical circuit board for the patients to practice. Equipment are placed there to enhance the accuracy of an actual industrial area.
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Figure 3.1.4: Zone 3- On-site construction workshop.
The activity carried out at this area would be moving material by using machine up and down the small slope. Besides that, the construction material found in the boxes would be for them to practice the action of digging, lifting and moving.
Figure 3.1.5: Zone 4-Office.
A simple office design with a desk and a computer.
Figure 3.1.6: Zone 5- Housing construction workshop.
A one storey steel frame structure placed there so that they could carry activity usually conducted at a housing construction site. 30 | P a g e
ZONE 2
ZONE 1
ZONE 3
ZONE 4
ZONE 5
Figure 3.1.7: Zoning on plan.
Zone 1: Storage Zone 2: Electrical workshop Zone 3: On site construction workshop Zone 4: Office Zone 5: Housing construction workshop
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3.2 RESESEARCH METHODOLOGY 3.2.1 Precedent Studies Research journal of lighting were studied in detail for application of precedent studies to the research case study. The source obtained of the research journal is through online website, due to the unavailability of research journal of lighting performance evaluation, the closest research journal that is applicable to our case study would be the Kresge Foundation Office Complex. The research journal acts as a referral point of the research case study through understanding the method of extracting diagrams and valuable information in conducting the research case study. 3.2.2 Equipment and Data Collection
Figure 3.2.2.1: Skylon 30m and Lutron digital lux meter LX101.
The drawings (plans) obtained from the management office were studied and grids were set accordingly to 1.5 meter. Due to the vast area of the space, the node (intersection grid point) were recorded at 3 meters apart. An electrical device was used to generate the lighting data on site which was the Lutron digital lux meter LX101 which was supplied by our tutor. Fortunately pebbles was found on site and used to indicate the intersection point of grid minimalizing error in locating the intersection point furthermore reducing the time in relocating the intersection grid.
Figure 3.2.2.2: On site indication of grid.
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Data collection was obtained from the reading of data (measured) in the morning 10 a.m, afternoon 2.30 p.m, and evening 5.30p.m. Peak hour of lighting was taken in the morning as the day lighting was prominent at the east faรงade where the curtain wall window were located in following, peak hour of artificial lighting was taken in the morning.
Figure 3.2.2.3: Peak hour of the site (morning) with daylighting and artificial lighting.
The reading were taken at 1 meter and 1.5 meter above ground, at each corresponding time interval of 10 a.m., 2.30 p.m. and 5.30 p.m. with daylighting and artificial lighting. At each recording the condition of sky was recorded to indicate the weather condition during the reading measurement.
Figure 3.2.2.4: Sky condition at 10 a.m, 2.30 p.m and 5.30 a.m respectively.
The reading were analyzed and compared with the standard such as the CIBSE, ASHRAE, MS1525 and other applicable standards. The materiality of the building was also studied and recorded to indicate the coefficient value and reflectance value towards the daylighting and artificial lighting. The zones were identified base of the space function and programme and the reading were tabulated based on the colour zone. The analysis was conducted through the study of lighting contour diagram in using REVIT software to analyse the lighting performance and section was cut at various zone to portray the lighting evaluation of light source.
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3.3 NATURAL DAYLIGHTING 3.3.1 Tabulation and interpretation of data
Table 3.3.1: Tabulation for non-peak hours. The table above shows the data for non-peak hours. At this hour the industrial rehabilitation area is soon to shut down, hence the little natural daylight does not affect the usage of the area. Even if working hours has to be extended, the artificial lighting is sufficient for the patients. 34 | P a g e
Table 3.3.2: Tabulation for peak hours.
The table 3.3.2 shows the data collected during the peak hours. The area that got most of the sunlight is the storage, onsite construction workshop and the housing construction workshop as it is placed to a curtain wall. The office and electrical workshop has less sunlight as it is located further inside but could be supported by artificial lighting in order to maintain working efficiency.
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3.3.2 Lighting fixtures
Figure 3.3.1: Industrail rehabilitation area
Figure 3.3.2: Specification of lighting fixtures.
Product Length Power Lamp Luminous Flux (EM) Rated Colour Temperature Colour Rendering Index Beam Angle Voltage Bulb Finish Placement
Goodlite GLC 254 A2 GE 2x54W 1520mm 2(tube) x 54W 3900k 70-79 Ra 140D 240V Frosted Wall and Column
Table 3.3.3: Tabulation of specification of lighting fixtures.
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3.3.3 Daylight Factor Analysis Daylight factor calculation based on zoning Date: 23 September 2015 Time: 5.10 pm to 5.50 pm Weather: Cloudy
Zone
Daylight level in malaysia, Eo (lux)
Average lux reading based on collected data, Eᵢ (lux)
Daylight factor, DF DF = (Eᵢ/Eo) x 100%
Zone 1: Storage
32000
670.5
32000
776.6
DF = (Eᵢ/Eo) x 100% = (670.5/32000) x 100% = 2.1
Zone 2: Electrical workshop
DF = (Eᵢ/Eo) x 100% = (776.6/32000) x 100% = 2.4
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Zone
Daylight level in malaysia, Eo (lux)
Average lux reading based on collected data, Eᵢ (lux)
32000
639.2
32000
12.78
Daylight factor, DF DF = (Eᵢ/Eo) x 100%
Zone 3: On site construction workshop
DF = (Eᵢ/Eo) x 100% = (639.2/32000) x100% = 2.0
Zone 4: Office
DF = (Eᵢ/Eo) x 100% = (127.8/32000) x 100% = 0.4
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Zone
Daylight level in malaysia, Eo (lux)
Average lux reading based on collected data, Eᵢ (lux)
32000
394.4
Daylight factor, DF DF = (Eᵢ/Eo) x 100%
Zone 5: Housing construction workshop
DF = (Eᵢ/Eo) x 100% = (394.4/32000) x 100% = 1.2
Table 3.3.4: Calculation of daylighting factor.
Based on the calculation, most of the zones have average distribution of daylight which ranges from 1-3, except of zone 4 which falls under the category 0-1 which means poor distribution. The standards for DF can refer to table 1.5.6. The reason for this is that it is situated too far away from the curtain wall. Zone
DF (%)
Distribution
Very Bright
>6
Very large with thermal and glare problems
Bright
3-6
Good
Average
1-3
Fair
Dark
0-1
Poor
Note: The figures are average daylight factors for windows without glazing Table 1.5.6: Daylight factors and distribution. (Source: “MS 1525”, 2007)
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3.4 ARTIFICIAL LIGHTING The industrial rehabilitation area intends to mimic the actual condition. In the industrial working condition, it should have sufficient sunlight to prevent accidents from happening or low visual ability. After analysis based on calculation of data collected, we have concluded that most of the spaces meet the requirements of a standard industrial condition. 3.4.1 Materiality All material used in this compound is the same for every spaces, so we have concluded it in the table below. 1) Roof (ceiling) – Cement Plaster 2) Wall – Concrete (cladding exterior) 3) Window – Aluminum frame + Low – E Tempered Glass 4) Floor – Concrete + Finishes Component Ceiling Wall Window Floor
Materials Plastered cement Concrete Aluminium Tinted glass Concrete screed with finishes
Colour White Yellow Black Translucent Grey
Surface Smooth Smooth Matte Transparent Polished
Reflectance value, % 45 40 10 6 70
Table 3.4.1: Specification of material. Coefficient of Thermal Expansion 10-6/°F
10-6/°C Aggregate Granite Basalt Limestone Dolomite Sandstone Quartzite Marble Cement Paste (saturated) w/c = 0.4 w/c = 0.5 w/c = 0.6 Concrete Steel
7-9 6-8 6 7-10 11-12 11-13 4-7 18-20 18-20 18-20 7.4-13 11-12 Table 3.4.2: Coefficient values for concrete.
4-5 3.3-4.4 3.3 4-5.5 6.1-6.7 6.1-7.2 2.2-4 10-11 10-11 10-11 4.1-7.3 6.1-6.7
Coefficient value – Low-e tempered glass = Coefficient of thermal expansion = 8.5x10-6/C Coefficient value – cement plaster = Coefficient of thermal expansion = 9.2x10-6/F Coefficient value – Aluminum frame cladding system = Coefficient of thermal expansion is 23x10-6/C The materials of the room especially the ceiling and the wall are in bright colour and has high reflectance value. Although the floor are in grey colour, it is however polished concrete that has the highest reflectance value compared to other materials. As such, the natural lighting enter into the space are reflected which causes the room to even brighter. 40 | P a g e
3.4.2 Lumen method calculation Zone 1: Storage
Dimension of room/ (m)
6.0mx9.0m
Total floor area/ (m²)
54m²
Type of lighting fixtures
wall
Number of lighting fixtures/ N
10
Lumen of lighting fixtures/ F (lux)
3240
Height of lumainaire (m)
3.23
Work level (m) Mounting height / H (m) Assumption of reflectance value
1 2.23 ceiling = 0.5 wall= 0.3 floor = 0.2
Room index / RI (K)
6x9/(6+9)(2.23)=1.61
Utilization factor / UF
0.7
Standard illuminance (lux)
300
Illuminance level (lux)
E=[10(2x3240x0.7x0.7)/54] =588
Table 3.4.3: Calculation for zone 1.
According to IESNA, the standard requirement is 300 lux. However according to calculation, zone 1 have far exceeded the standard hence the number of artificial lighting installed is redundant and causes glare. 41 | P a g e
Zone 2: Electrical workshop
Dimension of room/ (m)
10.5mX6.0m
Total floor area/ (m²)
63m²
Type of lighting fixtures
wall
Number of lighting fixtures/ N
3
Lumen of lighting fixtures/ F (lux)
3240
Height of lumainaire (m)
3.23
Work level (m) Mounting height / H (m) Assumption of reflectance value
1 2.23 ceiling = 0.5 wall= 0.3 floor = 0.2
Room index / RI (K)
10.5X6/(10.5+6)(2.23)=1.77
Utilization factor / UF
0.7
Standard illuminance (lux)
300
Illuminance level (lux)
E=[3(2x3240x0.7x0.7)/63] =151.2
Table 3.4.4: Calculation for zone 2.
According to IESNA, the standard requirement is 300 lux. However, according to calculation zone 2 does not meet the requirement. This might endanger the patients as they have low vision range and could cause accidents. 42 | P a g e
Zone 3: On site construction workshop
Dimension of room/ (m) Total floor area/ (m²)
15.0m x9.0m 135m²
Type of lighting fixtures
wall
Number of lighting fixtures/ N
15
Lumen of lighting fixtures/ F (lux)
3240
Height of lumainaire (m)
3.23
Work level (m) Mounting height / H (m) Assumption of reflectance value
1 2.23 ceiling = 0.5 wall= 0.3 floor = 0.2
Room index / RI (K)
15x9/(15+9)(2.23)=2.52
Utilization factor / UF
0.7
Standard illuminance (lux)
300
Illuminance level (lux)
E=[15(2x3240x0.7x0.7)/135] =352.8
Table 3.4.5: Calculation for zone 3.
According to IESNA, the standard requirement should 300 lux. However, according to calculation zone 3 meet the requirement. 43 | P a g e
Zone 4: Office
Dimension of room/ (m) Total floor area/ (m²)
15.0m x 4.5m 67.5m²
Type of lighting fixtures
wall
Number of lighting fixtures/ N
13
Lumen of lighting fixtures/ F (lux)
3240
Height of lumainaire (m)
3.23
Work level (m)
0.8
Mounting height / H (m)
2.43
Assumption of reflectance value
ceiling = 0.5 wall= 0.3 floor = 0.2
Room index / RI (K)
15x4.5/(15+4.5)(2.43)=1.42
Utilization factor / UF
0.7
Standard illuminance (lux)
400
Illuminance level (lux)
E=[13(2x3240x0.7x0.7)/67.5] =611.52
Table 3.4.6: Calculation for zone 4.
According to IESNA, the standard requirement should 400 lux. However, according to calculation zone 4 have far exceeded the standard hence the number of artificial lighting installed is redundant. 44 | P a g e
Zone 5: Housing construction workshop
Dimension of room/ (m)
15.0m x 6.0m
Total floor area/ (m²)
90m²
Type of lighting fixtures
wall
Number of lighting fixtures/ N
6
Lumen of lighting fixtures/ F (lux)
3240
Height of lumainaire (m)
3.23
Work level (m) Mounting height / H (m) Assumption of reflectance value
1 2.23 ceiling = 0.5 wall= 0.3 floor = 0.2
Room index / RI (K)
15x6/(15+6)(2.23)=1.92
Utilization factor / UF
0.7
Standard illuminance (lux)
300
Illuminance level (lux)
E=[6(2x3240x0.7x0.7)/90] =211.68
Table 3.4.7: Calculation for zone 5.
According to IESNA, the standard requirement should 300 lux. However, according to calculation zone 5 does not meet the requirement. Hence, it is not suitable for moderate heavy duty construction activity to carry on daily. 45 | P a g e
3.5 SUN PATH ANALYSIS DIAGRAM
Diagram 3.5: Sun orientation on 10.00 a.m.
Diagram 3.5: Sun orientation on 2.00 p.m.
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Diagram 3.5: Sun orientation on 5.10 p.m.
Morning is the peak hour that the building receives the most natural lighting whereas evening is the least as the angle of the sun is very low. The interior spaces of the building are brighten up by daylighting via curtain wall. There are a large piece of curtain wall at the front faรงade that is facing southern east direction that helps to bring the most natural lighting into the interior spaces in the morning. Whereas the other openings that helps bringing sunlight is the 4 pieces of curtain wall at the western south faรงade of the building. Lastly, there are also a strips of window at the back of the building that is facing the interior pathway, which helps to bring only a little natural lighting to illuminate the industrial rehab. Although there are a few trees planting in front of the building, the foliage of the trees are not dense and allow the diffusion of sunlight to penetrate through the curtain wall. Besides, the trees help to prevent direct sunlight that might heat up the building. All in all, there are a lot of openings that helps lighten up the space throughout the period of the day.
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3.6 ANALYSIS AND LIGHTING CONDITIONS OF THE ZONES 3.6.1 Office and Housing Constructing Workshop
Double Volume Curtain wall Glass Door
v
Diagram 3.6.1: (Section A-A) office and housing constructing workshop for natural daylighting 10.00 a.m.
Graph 3.6.1.: Illuminance level of office area and housing constructing workshop 10.00 a.m. (on grid m).
Graph 3.6.2: Illuminance level of office area and housing constructing workshop 5.10 p.m. (on grid m).
Diagram 3.6.1 illustrated the condition of the zoning lighted up by natural lighting during 10.00 a.m., the peak hour. From the diagram, it can be seen that the zone of housing constructing workshop is brightened from the natural daylighting coming through the curtain wall. However, the majority of the zone are still dark due to the installation of mock-up construction site that block the lighting especially at the area farer away from the curtain wall. Besides, it can be seen that the office area are brighter compared to majority space of housing constructing workshop even though the large installation of housing constructing workshop may have caused it to be darker. This is because the entrance made of glass door has permitted the transmittance of light into the interior spaces. Not only then, the double volume of the space and high curtainwall has allowed more natural lighting to brighten up the spaces including the office area as it is able to receive sunlight from both low angle of the sun and high angle. Moreover, graph 3.6.1 and graph 3.6.2 shows that the constructing workshop zone adjacent to the office area are instantly darker even with artificial lighting on due to the light fixtures at the housing constructing workshop area are not functioning. This would cause the patients to feel uncomfortable and may cause accidents to happen during the late evening as the area would be very dark. 48 | P a g e
3.6.2 Storage and Electrical Workshop
Curtain Wall
Fluorescent light that is not functioning
Strips of window
Electrical Circuit Board
Diagram 3.6.2: (Section C-C) Storage and electrical workshop for natural daylighting 10.00 a.m.
Graph 3.6.3: Illuminance level of storage and electrical workshop 5.10 p.m. (on Grid C)
Diagram 3.6.2 illustrated the daylighting condition during 10.00 a.m., the peak hour of the day. It can be seen that the partition wall that use to locate the tools for storage has blocked the curtain wall at the back. However, the space are still bright as it is still being lighted up by the curtain wall of the front faรงade as well as the curtain wall at the upper part of the wall as seen in the diagram. In fact, the brightness are quite sufficient for the zone during morning and afternoon. As such, the curtain wall at the back of the partition wall is not appropriately designed based on the needs of the space. Besides, from the diagram, it can also be observed that the electrical workshop are darker than the storage area. This is because the strips of window above the electrical workshop are facing the interior pathway that does not bring in much light. In fact, as shown in the graph 3.6.3, the natural daylighting are not adequate during 5.10 p.m. Moreover, the electrical circuit board for the practice of the patients are positioned in such a way the back of the patient are facing the curtain wall. This would cause the shadow of persons to be blocking the source of daylight and cause it to be even darker. Other than that, the fluorescent tube at the electrical workshop are not functioning when it needs more light compare to storage area.
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3.6.3 On-Site Construction Workshop and Office
Strips of window
Diagram 3.6.3: (Section B-B) On-site construction workshop and office for natural daylighting 10.00 a.m
Graph 3.6.4: Illuminance level of on-site construction workshop and office for natural daylighting 10 a.m. (on grid g)
Graph 3.6.5: Illuminance level taken at 1m and 1.5m at Office Area
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Diagram 3.6.3 are showing the condition of the zoning during the peak hour of 10.00 am. The diagram shows that the zone of on-site construction are extremely bright. This is because the equipment are all positioned flatly on the ground which causes no hindrance to the entering of the sunlight. However, there are four columns in the space which block some of the daylighting. Nevertheless, it does not influence much to the patients as most of the activities are only happening in the center which are not being blocked. Moreover, 2 fluorescent light are installed at each of the columns, which further brighten up the space. Other than that, finishes of the ground are polished concrete, which reflects the lights off and causes the area to be even brighter. Nevertheless, the office area are much darker compared to the on-site construction area as shown in the graph 3.6.4. Its daylight factor is 0.4%, which is listed as poorly lit-up under MS 1525. This because the office are farer away from the curtain wall and does not gain as much as lighting even with high curtain wall and high ceiling. Besides, similar to the electrical workshop adjacent to the office, the strips of window on the top are facing the interior pathway that does not contribute much to the entering of daylighting. Besides, referring to the graph 3.6.5, the lighting gain at the height of 1.5m regardless of the time are higher compared to 1m especially during afternoon and it increases drastically from morning to evening. This is because the curtain wall of the front faรงade are orientated to southern east direction. As such, the angle of the sun are eventually going higher which brighten up the upper part of the room. However, in the office zone, the design should ensure that 1m is brighter compared to 1.5m as the people will most of the time be sitting than standing. As such, artificial lighting are very important to be used at the office to ensure sufficient illuminance of the working area.
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3.7 CONCLUSION OF NATURAL LIGHTING AND ARTIFICIAL LIGHTING
Diagram 3.7.4: Natural daylighting contour diagram
Diagram 3.7.5: Artificial lighting contour diagram
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Dimension of room/ (m) Total floor area/ (m²)
21.0m x 19.5m 409.5m²
Type of lighting fixtures
wall
Number of lighting fixtures/ N
47
Lumen of lighting fixtures/ F (lux)
3240
Height of lumainaire (m)
3.23
Work level (m) Mounting height / H (m) Assumption of reflectance value
1 2.23 ceiling = 0.5 wall= 0.3 floor = 0.2
Room index / RI (K)
21x19.5/(21+19.5)(2.23)=4.53
Utilization factor / UF
0.7
Standard illuminance (lux)
300
Illuminance level (lux)
E=[47(2x3240x0.7x0.7)/409.5]=364.43
Table 3.7: Total Floor Area
In conclusion, design of the room in the aspect of the orientation and positioning of the windows as well as the installation of the electrical light has not been very successful to create an industrial mock-up area. This is because the architect consider that the view of a calming environment as well as natural daylighting are important to create the soothing aura for the patients during the training which in turn, contradict to the atmosphere of the industrial area. This is because an industrial area such as factories and warehouse are usually in a space that does not have much natural daylighting and views to the outside. Additionally, the openings that allow natural lighting are usually from the strips of window high of the wall or skylight which do not provide view. As shown in the diagram 3.7.4, natural daylighting has been playing a very important role especially in lighting up the majority of the spaces particularly on-site construction and storage area. However, the housing constructing workshop, office and electrical workshop are all highlighted in red colour which indicates low natural lighting and in needs of artificial lighting. Nevertheless, the spaces are still having a low brightness with the lighting switched on as shown in diagram 3.7.5. Therefore, the installation of vast amount of fluorescent light in order to imitate the industrial area has not been successful as it is not positioned based on the needs of each zone. For instance, the natural lighting are too bright at the 53 | P a g e
center of the room that the artificial lighting is made redundant during the day time whereas for the back of the room are not provided with adequate artificial lighting. Besides, the positioning of the electrical lighting and the final arrangement of the construction equipment in the space are not compatible to the intention of the architect. This is because the overall lumen reading for artificial lighting of the whole room are actually sufficient, 364.43 lux as shown in the table 3.7 which meet the requirement of 300 lux but could actually be reduced a little to prevent glare while some of the other individual zones have not met the standard. For instance, the electrical workshop has only the 151.2 lux when the standard requirement are 300 lux. This is dangerous to the patients as the lighting are important to ensure the visibility and thus their safety during the training. Other than that, the house constructing workshop area has the reading of only 211.68 lux when the standard are 300 lux. Not only then, some has far exceed the requirement such as the storage area are having the reading of 588 lux when the requirements are only 300 lux. As such, the zoning of the spaces by the interior designer are not following the intention of the architect. All in all, the intention of making the space to become a mock-up industrial rehab has not been very successful as the aura are failed to provoke due to the imbalance installation of the electrical lighting as well as the presence of too much natural lighting at certain area.
3.8 RECOMMENDATIONS
Fluorescent light that is not functioning
Diagram 3.8.6: Recommendation for the Arrangement of the Equipment and Electrical Lighting Condition
There are few recommendations to improve the space. For one, the positioning of the storage and housing constructing workshop area should be switched. This is because even though the partition of the storage are currently blocking the curtain wall and thus the natural daylighting, it is still adequately brighten up. Therefore, it does not requires the daylighting of the blocked curtain wall. Therefore, by switching the housing constructing workshop to the area, it can utilize the natural lighting for the space to ensure a better working environment. Not only then, the current partition wall are being wasted for not being able to view to the outside. As a result, the housing construction workshop are able to make use of the view, for the construction area are located at outdoor in real condition. Secondly, the installed rows fluorescent lights at the electrical workshop should be repaired and made sure it is functioning to ensure it is bright enough for the electrical training activities.
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4.0 ACOUSTIC 4.1 Site Study and Zoning
Gymnasium is a place to help the patients in order to strengthen their strength, improve their movement and stability after injury. There are therapists and staff who assist them in physiotherapy, aerobic and gym sessions. Machine, gym equipment and materials are provided in the gym for all the activities carry out. The gymnasium is divided into five zones based on the furniture, walls and partition for the ease of analysis.
Diagram 4.1.1: Floor plan of gymnasium.
Interior: Zone 1 & Zone 2 Exterior: Zone 3, Zone 4 & Zone 5
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Zone 1
Figure 4.1.1: Physiotherapy and aerobic session carried out at Zone 1. Zone 2
Figure 4.1.2: Gym equipment are provided in Zone 2. Zone 3, 4, 5
Figure 4.1.3: The exterior of gymnasium.
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4.2 Research Methodology 4.2.1 Precedent Studies Research journals of acoustic were studied in detail for application of precedent studies to the research case study. The source obtained of the research journal is through online website, due to the unavailability of research journal of acoustic performance evaluation, the closest research journal that is applicable to our case study would be the Church Gym and Multipurpose Hall. The research journal acts as a referral point of the research case study through understanding the method of extracting diagrams and valuable information in conducting the research case study. 4.2.2 Measuring Devices a) Sound Level Meter Sound level meter is used to measure the sound level in a space. The acoustic unit for sound level is decibel (dB).
Specification Model Range Resolution Accuracy
01dB 60-120 dBA, 30-90 dBA 1dB Âą1dB
b) Digital Single-Lens Reflex DSLR is used to capture the source of noise, furniture and record the activities in the space.
c) Measuring Tapes Measuring Tapes are used to measure the height of the position of the sound level meter, which is at 1 meter high. Furthermore, we use the measuring tapes to measure 1.5m x 1.5 m grid on the floor while taking the reading.
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4.2.3 Procedure Steps: 1. 2. 3. 4. 5. 6.
Draw grid lines of 1.5m x 1.5m on the site floor plan to identify the position for data collecting. Place the device on the intersection of grid lines at 1 m from the ground. Record the data reading on the sound level meter until it gets stable with the surrounding noise. Specify the noise source that might affect the readings. Repeat the steps on the next intersection point. Repeat the same steps for peak hour and non-peak hour to analyze different acoustic condition at different hour. 7. Tabulate and calculate all collected data and justify the acoustic quality based on Chartered Institution of Building Service Engineers (CIBSE) standard. 4.2.4 Data Collection Method Zones The floor plan of gymnasium is divided into 5 zones based on the interior partition and surrounding circumstances. There are two interior zones and three exterior zones. This zoning is helpful for the analysis later. Gridlines Gridlines are plotted perpendicularly on the floor as a guideline. The gridlines are spaced 1.5meters in x-axis and yaxis.
1.5m
1.5m
Diagram 4.2.1: Different colour indicates different zoning of spaces. Gridlines are spaced 1.5
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Position
1m
Two people did the data collection. One is responsible for measuring while another is recording. The sound level meter is placed at the same height from ground throughout the data collection, which is 1 meter to ensure accurate readings. The person holding the sound level meter will be the same for a set of data to prevent change in accuracy. The person has to stand still and will not make any noise or movement while taking the data readings so that the readings will not be affected. Each reading is done by facing the device to the same direction as the effort to obtain fair results. The same standard is repeated in the interior and exterior at different time zone.
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4.3 Identification of Existing Acoustic
Figure 4.3.1 (Left): The reception area of gymnasium. Figure 4.3.2 (Right): The interior of gymnasium.
4.3.1 Internal Acoustic The interior of the gymnasium is an enclose space. There are windows situated on each side of the wall but they are closed every time to prevent air- conditioning air from escaping. The wall of the gym is made of bricks. There is a 13m-partition wall in the gym dividing the space into 2 zones, which contributes to different internal acoustic level between them. Zone 1 has an open space for user to perform activities on the floor while Zone 2 provides equipment for the patient’s physiotherapy.
Figure 4.3.3 & 4.3.4: Zone 1 (Left) and Zone 2 (Right).
The main source of interior acoustic is from the speaker. Music is played throughout the therapy session that makes the speaker the main source for the gym’s internal acoustic. The secondary source comes from the equipment, air conditioner diffuser and the chattering of people.
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Diagram 4.3.1: Diagram showing Zone 1 and Zone 2 separated by an internal partition.
Source of Noise Speaker Ceiling Speaker Air Conditioner Diffuser Equipment Activity
Zone 1 one four six yes yes
Zone 2 none four eight yes none
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4.3.1.1 Speaker There is only a set of speaker installed to the computer. The speakers are used throughout the day to play music and songs. Different type of music is chosen for various type of activities carried out. Upbeat music and songs are normally chosen for aerobic exercise. The noise level depends on the rhythm of the song. Slow classical music is played during the physiotherapy session to create relaxing ambiance. The volume will be adjusted every time according to the sound condition.
Figure 4.3.5: Speaker system for computer.
Diagram 4.3.5: Location of the speaker in Zone 1.
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Diagram 4.3.3: Section showing the position of the speaker in the space. Stereo speaker is installed to the computer as music is needed for the activities happen in Zone 1. Music is played throughout the operation hour.
Figure 4.3.6: Altec Lansing VS2521 speaker system for PC
Specification Type System type Quantity System configuration Woofer size (inches) Nominal output power (total) Response bandwidth Signal- to- noise ratio
Satellite speaker, subwoofer PC multimedia speaker system 2 speakers, subwoofer 2.1-channel 2.5”m 28 watt 30 – 20000Hz 85 dB
Output level (SPL)
99 dB
Nominal (RMS) Output Power Frequency Response
14 watt, 7 watt 180 – 20000Hz, 30 – 180 Hz
Table 4.3.1: Specification of the speaker used in the gymnasium.
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4.3.1.1.2 Ceiling Speaker There are eight ceiling speakers in total. These speakers did not function to play songs and music. The speakers are used during the emergency for instance fire when special announcements are needed only. Hence, they did not produce any noise in a normal day.
Figure 4.3.7 (Left) & 4.3.8 (Right): The location of ceiling speaker in the gym at 6m high.
Diagram 4.3.6: Location of ceiling speakers in the room.
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Figure 4.3.9: JBL Ceiling Speaker Control 24C/CT
Specification Material Frequency range Coverage Power Capacity Nominal sensitivity Directivity Factor (Q) Directivity Index (DL) Low frequency transducers High frequency transducer
Coaxially mounted 100mm woofer with butyl rubber surround and 19mm (3/4 in) titanium coated diffraction-loaded tweeter 80 HZ-20 KHz 150 degree 80 watts continuous program power 40 watts continuous pink noise 86 dB SPL at 1m 2.4 average 500 Hz to 4 kHz 3.8 average 500 Hz to 4 kHz 100mm (4.0 in) Polypropylene, 1� coil on aluminum former 19mm (0.75 in) titanium coated polyester
Table 4.3.2: Specification of ceiling speaker used in the space Source: https://www.leisuretec.co.uk/products/details/webjbl00015
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4.3.1.3 Air Conditioner Diffuser The air conditioner diffusers that attached to the wall have slight affect to the acoustic level. The noise generated by the rotation of the control disc. Although the noise produced by the diffusers is not significant, but this factor needed to be concerned to improve user experience in the space.
Figure 4.3.9 (Left) & 4.3.10 (Right): Air conditioner diffusers at Zone 1 and Zone 2.
Diagram 4.3.7: Location of diffusers at both zones.
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4m
Diagram 4.3.8: Section showing the number and the location of diffusers.
Figure 4.3.11: Diffuser for ventilation
Specification Material Size Capacity Function
Galvanized steel 315mm High Circular air pattern, by rotating the control disc
Table 4.3.3: Specification of diffuser used in the space.
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4.3.1.4 Gym Equipment The equipment are carefully selected and imported by the SOCSO Rehabilitation Center. These machines are especially design to provide more comfortable usage to cater for the patients. These machines have greatly helped the patients during the physiotherapy sessions. Not only that, the center also provides a wide variety of equipment to help patients regain their strength.
Diagram 4.3.9: The location for all equipment in the gym.
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Figure 4.3.12: Parallel bar
Type of Equipment Quantity (in the space) Function
Parallel Bar 2 Help the patient to regain their strength to balance when standing up.
Figure 4.3.13: Biodex Dynamometer
Type of Equipment Quantity (in the space) Function
Biodex Dynamometer 1 Use for prescreening of patients such as heart rate, blood pressure and strength. Prescreening monitored by the therapist.
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Figure 4.3.14: Biodex Treadmill
Type of Equipment Quantity (in the space) Function
Biodex Treadmill 3 Treadmill designed for physical rehabilitation clinic. Use for running and walking.
Figure 4.3.15: Kettler Ergomete RE7
Type of Equipment Quantity (in the space) Function
Kettler Ergomete RE7 4 Use for cycling. It has comfortable backseat to prevent muscle injury.
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Figure 4.3.16: Multi-station Gym equipment
Type of Equipment Quantity (in the space) Function
Multi-station Gym equipment 2 Provides a variety of exercises for example weight lifting that focus on the shoulder, triceps and biceps.
Figure 4.3.17: Kettle Ergometer E1
Type of Equipment Quantity (in the space) Function
Kettler Ergometer E1 4 Use for training of cardio through cycling movement.
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Figure 4.3.18: Kettler Ergometer
Type of Equipment Quantity (in the space) Function
Kettler Ergometer 3 For full body workout and strengthen the body muscular system.
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4.3.1.1.5 Human Activity
Figure 4.3.19: Physiotherapy session at Zone 1
a) Physiotherapy for the patients On the daily basis, the patients would have interactive physiotherapy session with their friendly therapist. The duration of the session is one to two hours depends on the patients’ needs. Conversations that strike upon meeting their daily acquaintances contribute to the noise level in the gym. The music played throughout the day also creates a cheerful and lively space.
Figure 4.3.20: Gym Session at Zone 2.
b) Gym excercising At Zone 2, it is relatively more quiet space. The patients performing their daily physiotherapy is more independent from their therapist. Conversation still strikes among the patients. However occasional sound made by the equipment used is more distinct and louder. A faint echo of music from the adjacent space adds to the ambience of this space.
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Figure 4.3.21: Aerobic exercise at Zone 1.
c) Aerobic activity Group activity like aerobic exercising is held in the evening. Counting of steps by instructors’ echo throughout the space. This contributes to increased noise production in the space. Occasional counting with the instructor by the patients also occurs at the same time.
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4.3.2 External Acoustic External noise surrounding the gym is important, as unwanted noise level outside should be control to prevent unwanted noise from entering the interior of the gym. The exterior of the gym is divided into 3 zones. Zone 3 is the area where it is close to the AHU room, zone 4 is facing a plain garden and zone 5 is close to the electric room.
Action Leaves rustling Normal conversation Traffic noise Airplane taking off Alarm siren
dB (A) 20 50 80 110 150
Table 4.3.4: The example of noise levels that occurs outdoors.
Diagram 4.3.10: The exterior is analyzed by dividing into three zones.
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4.3.2.1 Air Handling Unit (AHU) Room
Figure 4.3.22: AHU room located at the adjacent building near Zone 3
There’s noise coming from the AHU room situated close to Zone 3. The contribution of this noise is from the blower of the ventilation system.
4.3.2.2 Electrical Room In the Electrical Room, the sound made by the motor equipment can be heard from Zone 5.
Figure 4.3.23: Exterior of the gym
The external noise of gymnasium is not significant. It is rather quiet compare to the exterior of industrial rehabilitation area.
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4.4 Material
Material
Absorption Coefficient 125 Hz 500 Hz 2000Hz 4000Hz
Floor
Location Gymnasium Zone 1 and 2.
Rubber/cork tiles (thin) on solid floor
0.02
0.05
0.10
0.05
Wall Concrete, unglazed, painted
0.01
0.02
0.02
0.03
Gymnasium Zone 1 and 2.
Plaster, gypsum or lime, smooth finish on lath
0.14
0.06
0.04
0.03
In between Zone 1 and 2.
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Ceiling 0.15 Plasterboard (12mm (1/2�) in suspended ceiling grid)
0.04
0.07
0.08
Gymnasium Zone 1 and 2.
Openings Open doors and windows
1.00
1.00
1.00
1.00
Gymnasium Zone 1 and 2.
Glass door panel
0.18
0.04
0.02
0.02
Gymnasium Zone 1 and 2.
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Furniture Benches ( cushioned seats and backs, empty)
0.32
0.42
0.43
0.48
Gymnasium Zone 1.
Benches (wooden, empty)
0.1
0.08
0.08
0.08
Gymnasium Zone 1 and 2.
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4.6 Acoustic Analysis 4.6.1 Data Analysis 4.6.1.1 Peak and Non-Peak Hour Analysis Date:23/9/2015
Time: 10 am
Zone 1
Height: 1m
Zone 2 Table 4.6.1: Acoustic level of the gym at 10am.
Date:23/9/2015
Time: 4pm
Zone 1
Height: 1m
Zone 2 Table 4.6.2: Acoustic level of the gym at 4pm.
From the data above it has been observed that peak time occurs at 10am, as there are higher noise production from both Zone 1 and Zone 2 compared to 4pm. The highest acoustic level (70db) is recorded during this period. During the peak hour, more patients visited the gymnasium for physiotherapy session with their respective therapist. Moreover, aerobic and gym session are provided within the period.
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4.6.1.2 Peak Hour Analysis Date:23/9/2015
Time: 10 am
Zone 1
Height: 1m
Zone 2
Table 4.6.3: Acoustic level of the gym during peak hour.
Zone 1
Zone 2
Graph 4.6.1: Graph showing higher noise level at Zone 1 compare to Zone 2.
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Physiotherapy Speaker
Gym session
6M
Diagram 4.6.1: Longitudinal section showing different activities in Zone 1 and 2.
At Zone 1, the highest noise level is recorded at a level of 70db. The main source of sound that contribute to the interior acoustic level is the stereo speakers used to play music and songs. The up-beat music played throughout the day created a joyful atmosphere to bring up the mood of the patients. Furthermore, there are various activities carried out in the zone have effect on the acoustic level. The activities are physiotherapy and aerobic sessions. At Zone 2, the highest noise level is recorded at a level of 64dB. The main source of noise came from the gym equipment. In addition, the interaction among the patients increase the overall sound level. According to the graph, Zone 1 has higher noise level compare to Zone 2. This is because the sound intensity of the speaker produced is highest among all sources of noise. In addition, the cubic volume in Zone 1 is smaller therefore the reflection of acoustic rays are higher which subsequently increase the noise level.
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4.6.1.3 Non-Peak Hour Analysis Date:23/9/2015
Time: 4pm
Height: 1m
Zone 1
Zone 2
Table 4.6.4: Acoustic level of the gym during non peak hour.
Zone 1
Zone 2
Graph 4.6.2: Graph showing higher noise level at Zone 1 compare to Zone 2.
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Based on the observation, Zone 1 has higher noise level than Zone 2 as the sound produced by the speaker contribute the most to the overall acoustic level. Overall, the sound level during non-peak hour is lower than in peak hour. At Zone 1, no extra activities carried out in the gymnasium as most patients have gone back to their domes or home. At this period, therapists will take rest and do some discussion while listening to music. At Zone 2, lesser patients stayed at the place for gym session. Hence, the noise level at Zone 1 has gone lower compared to the peak hour. According to the graph, the difference of the existing noise level between two zones is less significant. This is because there is transmission of sound produced from Zone 1, especially the speaker to Zone 2. The recorded readings near the partition wall are higher than the readings away from the partition wall. The absorption properties of plasterboard is insufficient to absorb all noise produced from Zone 1.
Partition wall
6M
Diagram 4.6.2: Section showing the space divided by a full height partition wall.
As illustrated on the diagram above, the full height partition wall used to separate the big space into two zones has proved to reduce the amount of sound transmission from Zone 1 to Zone 2. Thus, music can still be heard at Zone 2 but at a lower volume.
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4.6.1.4 Exterior – Interior Acoustic Relationship
Date:23/9/2015
Time: 10 am
Height: 1m
Table 4.6.5: Acoustic level of the gym during peak hour.
Date:23/9/2015
Time: 4pm
Height: 1m
Table 4.6.6: Acoustic level of the gym during non-peak hour.
The exterior sound level is ranged from 44 dB to 57 dB. By comparing the readings at two time zone, the external noise level are the same. The external noises did not contribute to the internal acoustic but in fact they are affected by the interior sounds.
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Date:23/9/2015
Time: 4pm
Height: 1m
According to the data above, Zone 3 and Zone 5 have higher sound level compared to Zone 4. An air handling unit (AHU) room and a motor room are located at the adjacent buildings of Zone 3 and Zone 5 respectively.
Figure 4.6.1: Air Handling Unit (AHU) Room
6M
Diagram 4.6.3: Section showing Zone 1 (Interior) and Zone 4 (Exterior)
Neither patients nor the staff will stay at the exterior for more than 15 minutes hence human activity does not affect the exterior sound level. 86 | P a g e
Date:23/9/2015
Time: 4pm
Height: 1m
Table 4.6.7: Acoustic level of the gym during non-peak hour.
Figure 4.6.2: Casement window in gymnasium
At position Y6 and Y8, there are slight increase of sound level. The opening of window located at the position allows transmission of interior noise towards outside.
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Date:23/9/2015
Time: 4pm
Height: 1m
Table 4.6.8: Acoustic level of the gym during non-peak hour.
Figure 4.6.2: Glass Sliding Door
At position Z6 and Z8, the sound level is higher within the zone. The gaps between the sliding doors facilitate the transmission of sound to the exterior. Moreover, the sliding doors open automatically when they detected any human movement.
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Date:23/9/2015
Time: 4pm (Speaker On)
Height: 1m
Table 4.6.9: Acoustic level of the gym when speaker is on.
Date:23/9/2015
Time: 4.30pm (Speaker Off)
Height: 1m
Table 4.6.10: Acoustic level of the gym when speaker is off.
A huge difference in noise levels when radio is switched on and off. Noise level decreased from an average of 60db to 50 db.
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Date:23/9/2015
Time: 4pm (Speaker On)
Zone 1
Height: 1m
Zone 2
Graph 4.6.3: Graph at non-peak hour with speaker on.
Date:23/9/2015
Time: 4.30pm (Speaker Off)
Zone 1
Height: 1m
Zone 2
Graph 4.6.4: Graph at non-peak hour with speaker off.
According to the graphs, Zone 1 has higher sound level compared to Zone 2 when the speaker is turned on. However, when the speaker is turned off, the sound level in Zone 1 has become lower. During this period, Zone 2 no longer influence by the stereo speaker but the air conditioner diffusers and existing equipment. As we analyze the graph contours, the sound level at non-peak hour fluctuates between 53 dB to 69 dB. This is due to the sudden ups and down rhythm of the songs and music played throughout the period. In addition, the volume of the music is adjusted frequently to accommodate the activities in the space. When the speaker is turned off, the sound level contour became smoother. The factors that affect the noise have narrowed down to air conditioner diffusers only where human activity is low. During this period, the sound level in the gymnasium fluctuates within 47 db to 55 dB. 90 | P a g e
4.7 Acoustic Ray Bouncing Diagram
Zone 1
Zone 2
Diagram 4.7.1: Acoustic Ray Bouncing Diagram of gymnasium (Speaker)
Figure 4.7.1: Partition Wall
According to the diagram, acoustic rays that generated by the speaker are concentrated at Zone 1. Thus, this causes the high readings at Zone 1. Most of the rays are blocked by the plaster board partition. However, the openings at both sides of the partition allow transmission of acoustic rays towards the adjacent space. Therefore, the speaker has slight influence on acoustic level of Zone 2. 91 | P a g e
Zone 1
Zone 2
Diagram 4.7.2: Acoustic Ray Bouncing Diagram of gymnasium (Air Conditioner Diffuser)
Figure 4.7.2: Air Conditioner Diffuser
The diagram shows the acoustic rays generated by a diffuser. As the secondary source of noise, the diffuser generated lesser acoustic rays and bounce to the room. However, smaller cubic volume in Zone 1 has increase the compactness of these rays which subsequently increase the noise level. These rays did not penetrate across the partition wall and hence they did not contribute to the acoustic level at Zone 2. 92 | P a g e
Zone 1
Zone 2
Diagram 4.7.3: Acoustic Ray Bouncing Diagram of gymnasium (Air Conditioner Diffuser)
Figure 4.7.3: Double volume in Zone 2.
The diagram shows the acoustic rays generated by a diffuser at Zone 2. The compactness of acoustic rays is lower as Zone 2 has bigger cubic volume. Acoustic rays diffuse within the larger surface area of the space and are absorbed by the materials. Hence, they have less effect on noise level in Zone 2.
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4.8 Calculation of Sound Intensity 4.8.1 Indoor noise source By using the formula, SIL = 10 log ( Where
đ??ź đ??ź0
)
SIL
= the sound intensity level
I
= the intensity of sound being measured, (W/đ?‘š2 )
đ??ź0
= the intensity of the threshold of hearing, taken as 10−12 W/đ?‘š2
Ceiling Speaker The maximum sound power level of the speaker is around 86 dB. đ??ź
SIL
= 10 log ( đ??ź )
86
= 10 log (
8.6
= log ( đ??ź )
108.6
=đ??ź
I
= 108.6 x 10−12
0
đ??ź đ??ź0
)
đ??ź
0
đ??ź 0
= 3.981 x 10−4 W/đ?‘š2
Speaker System The maximum sound power level of the speaker is around 99 dB. đ??ź
SIL
= 10 log ( đ??ź )
99
= 10 log ( đ??ź )
9.9
= log (
109.9
=đ??ź
I
= 109.9 x 10−12
0
đ??ź
0
đ??ź đ??ź0
)
đ??ź 0
= 7.943 x 10−3 W/đ?‘š2
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4.8.2 Space Acoustic Analysis ZONE 1
Non-peak hour Highest reading: 69dB đ??ź
SIL
= 10 log ( đ??ź )
69
= 10 log ( đ??ź )
6.9
= log ( đ??ź )
106.9
=đ??ź
I
= 106.9 x 10−12
0
đ??ź
0
đ??ź
0
đ??ź 0
= 7.943 x 10−6 W/đ?‘š2
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Lowest reading: 60dB đ??ź
SIL
= 10 log ( đ??ź )
60
= 10 log ( đ??ź )
6.0
= log ( đ??ź )
106
=
I
= 106 x 10−12
0
đ??ź
0
đ??ź
0
đ??ź đ??ź0
= 1.0 x 10−6 W/đ?‘š2 Total intensity, I = (7.943 x 10−6) + (1.0 x 10−6) = 8.943 x 10−6 W/đ?‘š2 SIL
= 10 log (
đ??ź đ??ź0
)
= 10 log (8.943 x 10−6 / 1.0 x 10−12) = 69.51dB The sound intensity level at zone 1 during non-peak hour is 69.51dB.
PEAK HOUR Highest reading: 70dB đ??ź
SIL
= 10 log ( đ??ź )
70
= 10 log ( đ??ź )
7.0
= log ( đ??ź )
107
=đ??ź
I
= 107 x 10−12
0
đ??ź
0
đ??ź
0
đ??ź 0
= 1.0 x 10−5 W/đ?‘š2
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Lowest reading: 60dB đ??ź
SIL
= 10 log ( đ??ź )
60
= 10 log ( đ??ź )
6.0
= log ( đ??ź )
106
=
I
= 106 x 10−12
0
đ??ź
0
đ??ź
0
đ??ź đ??ź0
= 1.0 x 10−6 W/đ?‘š2 Total intensity, I = (1.0 x 10−5) + (1.0 x 10−6) = 1.1 x 10−5 W/đ?‘š2
SIL
đ??ź
= 10 log ( đ??ź ) 0
= 10 log (1.1 x 10−5 / 1.0 x 10−12) = 70.41dB The sound intensity level at zone 1 during peak hour is 70.41dB.
ZONE 2
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NON-PEAK HOUR Highest reading: 62dB đ??ź
SIL
= 10 log ( đ??ź )
62
= 10 log ( đ??ź )
6.2
= log (
106.2
=đ??ź
I
= 106.2 x 10−12
0
đ??ź
0
đ??ź đ??ź0
)
đ??ź 0
= 1.585 x 10−6 W/đ?‘š2
Lowest reading: 53dB đ??ź đ??ź0
SIL
= 10 log (
)
53
= 10 log ( đ??ź )
5.3
= log ( đ??ź )
105.3
=
I
= 105.3 x 10−12
đ??ź
0
đ??ź
0
đ??ź đ??ź0
= 1.995 x 10−7 W/đ?‘š2
Total intensity, I = (1.585 x 10−6) + (1.995 x 10−7) = 1.7845 x 10−6 W/đ?‘š2
SIL
đ??ź
= 10 log ( đ??ź ) 0
= 10 log (1.7845 x 10−6 / 1.0 x 10−12 ) = 62.52dB The sound intensity level at zone 2 during non-peak hour is 62.52dB.
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PEAK HOUR Highest reading: 66dB đ??ź
SIL
= 10 log ( đ??ź )
66
= 10 log ( đ??ź )
6.6
= log (
106.6
=đ??ź
I
= 106.6 x 10−12
0
đ??ź
0
đ??ź đ??ź0
)
đ??ź 0
= 3.98 x 10−6 W/đ?‘š2
Lowest reading: 55dB đ??ź đ??ź0
SIL
= 10 log (
)
55
= 10 log ( đ??ź )
5.5
= log ( đ??ź )
105.5
=
I
= 105.5 x 10−12
đ??ź
0
đ??ź
0
đ??ź đ??ź0
= 3.16 x 10−7 W/đ?‘š2 Total intensity, I = (3.98 x 10−6) + (3.16 x 10−7) = 4.296 x 10−6 W/đ?‘š2
SIL
đ??ź
= 10 log ( đ??ź ) 0
= 10 log (4.296 x 10−6 / 1.0 x 10−12) = 66.33dB The sound intensity level at zone 2 during peak hour is 66.33dB.
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ZONE 3
NON-PEAK HOUR Highest reading: 52dB đ??ź
SIL
= 10 log ( đ??ź )
52
= 10 log ( đ??ź )
5.2
= log (
105.2
=đ??ź
I
= 105.2 x 10−12
0
đ??ź
0
đ??ź đ??ź0
)
đ??ź 0
= 1.585 x 10−7 W/đ?‘š2
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Lowest reading: 49dB đ??ź
SIL
= 10 log ( đ??ź )
49
= 10 log ( đ??ź )
4.9
= log ( đ??ź )
104.9
=
I
= 104.9 x 10−12
0
đ??ź
0
đ??ź
0
đ??ź đ??ź0
= 7.943 x 10−8 W/đ?‘š2
Total intensity, I = (1.585 x 10−7) + (7.943 x 10−8) = 2.3793 x 10−7 W/đ?‘š2
SIL
đ??ź
= 10 log ( đ??ź ) 0
= 10 log (2.3793 x 10−7/ 1.0 x 10−12) = 53.76dB The sound intensity level at zone 3 during non-peak hour is 53.76dB.
PEAK HOUR Highest reading: 52dB đ??ź
SIL
= 10 log ( đ??ź )
52
= 10 log ( đ??ź )
5.2
= log ( đ??ź )
105.2
=đ??ź
I
= 105.2 x 10−12
0
đ??ź
0
đ??ź
0
đ??ź 0
= 1.585 x 10−7 W/đ?‘š2
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Lowest reading: 49dB đ??ź
SIL
= 10 log ( đ??ź )
49
= 10 log ( đ??ź )
4.9
= log ( đ??ź )
104.9
=
I
= 104.9 x 10−12
0
đ??ź
0
đ??ź
0
đ??ź đ??ź0
= 7.943 x 10−8 W/đ?‘š2
Total intensity, I = (1.585 x 10−7) + (7.943 x 10−8) = 2.3793 x 10−7 W/đ?‘š2 SIL
đ??ź
= 10 log ( đ??ź ) 0
= 10 log (2.3793 x 10−7/ 1.0 x 10−12) = 53.76dB The sound intensity level at zone 3 during peak hour is 53.76dB. ZONE 4
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NON-PEAK HOUR Highest reading: 48dB đ??ź
SIL
= 10 log ( đ??ź )
48
= 10 log ( đ??ź )
4.8
= log (
104.8
=đ??ź
I
= 104.8 x 10−12
0
đ??ź
0
đ??ź đ??ź0
)
đ??ź 0
= 6.310 x 10−8 W/đ?‘š2
Lowest reading: 44dB đ??ź đ??ź0
SIL
= 10 log (
)
44
= 10 log ( đ??ź )
4.4
= log ( đ??ź )
104.4
=
I
= 104.4 x 10−12
đ??ź
0
đ??ź
0
đ??ź đ??ź0
= 2.512 x 10−8 W/đ?‘š2
Total intensity, I = (6.310 x 10−8) + (2.512 x 10−8) = 8.822 x 10−8 W/đ?‘š2
SIL
= 10 log (
đ??ź đ??ź0
)
= 10 log (8.822 x 10−8/ 1.0 x 10−12) = 49.46dB The sound intensity level at zone 4 during non-peak hour is 49.46dB.
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PEAK HOUR Highest reading: 48dB đ??ź
SIL
= 10 log ( đ??ź )
48
= 10 log ( đ??ź )
4.8
= log (
104.8
=đ??ź
I
= 104.8 x 10−12
0
đ??ź
0
đ??ź đ??ź0
)
đ??ź 0
= 6.310 x 10−8 W/đ?‘š2 Lowest reading: 44dB đ??ź đ??ź0
SIL
= 10 log (
)
44
= 10 log ( đ??ź )
4.4
= log ( đ??ź )
104.4
=đ??ź
I
= 104.4 x 10−12
đ??ź
0
đ??ź
0
đ??ź 0
= 2.512 x 10−8 W/đ?‘š2
Total intensity, I = (6.310 x 10−8) + (2.512 x 10−8) = 8.822 x 10−8 W/đ?‘š2
SIL
đ??ź
= 10 log ( đ??ź ) 0
= 10 log (8.822 x 10−8/ 1.0 x 10−12) = 49.46dB The sound intensity level at zone 4 during peak hour is 49.46dB.
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ZONE 5
NON-PEAK HOUR Highest reading: 57dB đ??ź
SIL
= 10 log ( đ??ź )
57
= 10 log ( đ??ź )
5.7
= log (
105.7
=đ??ź
I
= 105.7 x 10−12
0
đ??ź
0
đ??ź đ??ź0
)
đ??ź 0
= 5.012 x 10−7 W/đ?‘š2
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Lowest reading: 52dB đ??ź
SIL
= 10 log ( đ??ź )
52
= 10 log ( đ??ź )
5.2
= log ( đ??ź )
105.2
=
I
= 105.2 x 10−12
0
đ??ź
0
đ??ź
0
đ??ź đ??ź0
= 1.585 x 10−7 W/đ?‘š2
Total intensity, I = (5.012 x 10−7) + (1.585 x 10−7) = 6.597 x 10−7 W/đ?‘š2
SIL
đ??ź
= 10 log ( đ??ź ) 0
= 10 log (6.597 x 10−7/ 1.0 x 10−12) = 58.19dB The sound intensity level at zone 5 during non-peak hour is 58.19dB.
PEAK HOUR Highest reading: 57dB đ??ź
SIL
= 10 log ( đ??ź )
57
= 10 log ( đ??ź )
5.7
= log ( đ??ź )
105.7
=đ??ź
I
= 105.7 x 10−12
0
đ??ź
0
đ??ź
0
đ??ź 0
= 5.012 x 10−7 W/đ?‘š2
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Lowest reading: 52dB đ??ź
SIL
= 10 log ( đ??ź )
52
= 10 log ( đ??ź )
5.2
= log ( đ??ź )
105.2
=
I
= 105.2 x 10−12
0
đ??ź
0
đ??ź
0
đ??ź đ??ź0
= 1.585 x 10−7 W/đ?‘š2
Total intensity, I = (5.012 x 10−7) + (1.585 x 10−7) = 6.597 x 10−7 W/đ?‘š2
SIL
đ??ź
= 10 log ( đ??ź ) 0
= 10 log (6.597 x 10−7/ 1.0 x 10−12) = 58.19dB The sound intensity level at zone 5 during peak hour is 58.19dB.
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4.8.3 SOUND REDUCTION INDEX (SRI) Formula: 1
TL
= 10 log ( � )
���
=
đ?‘‡đ?‘?đ?‘›
= transmission coefficient of material
��
= surface area of material
TL
= transmission loss
Overall SRI
= 10 log ( )
đ?‘Žđ?‘Ł
đ?‘†1 đ?‘Ľ đ?‘‡đ?‘?1 + đ?‘†2 đ?‘Ľ đ?‘‡đ?‘?2+â‹Ż đ?‘†đ?‘› đ?‘Ľ đ?‘‡đ?‘?đ?‘› Total surface area
1 T
ZONE 1 & ZONE 2
Building element
Material
Wall
Concrete with paint
Sound reduction Index, SRI (dB) 44
Transmission coefficient, T 3.981 x 10−5
Area, S (đ?‘š2 ) 75
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Concrete wall 1
TL
= 10 log ( T )
44
= 10 log ( T )
4.4
= log ( T )
104.4
=
T
= 3.981 x 10−5
���
= (3.981 x 10−5 x 75) / 75
1
1
1 T
= 3.981 x 10−5 Overall SRI
1
= 10 log ( T ) 1
= 10 log ( 3.981 x 10−5 ) = 44 dB Combined SPL at zone 1 is 70.41dB during peak hour, while at zone 2 is 66.33dB during peak hour, with the difference of 4.08dB. However, the SRI between zone 1 & zone 2 is 44dB, which is much higher than 4.08 dB. This may be due to the gap after the partition wall, allowing sound to be transferred between two zones.
ZONE 1 & ZONE 3
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Building element
Material
Wall Window Door
Concrete with paint Glass Glass
Sound reduction Index, SRI (dB) 44 30 30
Transmission coefficient, T 3.981 x 10−5 1.0 x 10−3 1.0 x 10−3
Area, S (đ?‘š2 ) 70 11 5
Concrete wall 1 T
TL
= 10 log ( )
44
= 10 log ( T )
4.4
= log ( T )
104.4
=T
T
= 3.981 x 10−5
1
1
1
Window 1
TL
= 10 log ( T )
30
= 10 log ( T )
3.0
= log ( T )
103
=T
T
= 1.0 x 10−3
1
1
1
Door 1
TL
= 10 log ( T )
30
= 10 log ( T )
3.0
= log ( T )
103
=
T
= 1.0 x 10−3
1
1
1 T
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���
= [(3.981 x 10−5 x 70) + (1.0 x 10−3x 11) + (1.0 x 10−3x 5)]/ (70+11+5) = 0.0187867 / 86 = 2.1845 x 10−4
Overall SRI
1
= 10 log ( T ) 1
= 10 log ( 2.1845 x 10−4 ) = 36.61 dB
Combined SPL at zone 1 is 70.41dB during peak hour, while at zone 3 is 53.76dB during peak hour, with the difference of 16.65dB. However, the SRI between zone 1 & zone 3 is 36.61dB, which is much higher than 16.65 dB. This is because the windows on the wall kept opened, allowing sound to be transferred between two zones.
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ZONE 1 & ZONE 4
Building element
Material
Wall Window
Concrete with paint Glass
Sound reduction Index, SRI (dB) 44 30
Transmission coefficient, T 3.981 x 10−5 1.0 x 10−3
Area, S (đ?‘š2 ) 53 8
Concrete wall 1
TL
= 10 log ( T )
44
= 10 log ( T )
4.4
= log ( T )
104.4
=T
T
= 3.981 x 10−5
1
1
1
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Window 1
TL
= 10 log ( T )
30
= 10 log ( T )
3.0
= log ( T )
103
=
T
= 1.0 x 10−3
���
= [(3.981 x 10−5 x 53) + (1.0 x 10−3x 8)]/ (53+8)
1
1
1 T
= 0.01010993 / 61 = 1.657 x 10−4 Overall SRI
1
= 10 log ( T ) = 10 log (
1 1.657 x 10−4
)
= 37.81 dB
Combined SPL at zone 1 is 70.41dB during peak hour, while at zone 4 is 49.46dB during peak hour, with the difference of 20.95dB. However, the SRI between zone 1 & zone 4 is 37.81dB, which is much higher than 20.95 dB. This is because the windows on the wall kept opened, allowing sound to be transferred between two zones.
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ZONE 2 & ZONE 4
Building element
Material
Wall Window Door
Concrete with paint Glass Glass
Sound reduction Index, SRI (dB) 44 30 30
Transmission coefficient, T 3.981 x 10−5 1.0 x 10−3 1.0 x 10−3
Area, S (đ?‘š2 ) 66 9 5
Concrete wall 1
TL
= 10 log ( T )
44
= 10 log ( T )
4.4
= log ( T )
104.4
=
T
= 3.981 x 10−5
1
1
1 T
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Window 1
TL
= 10 log ( T )
30
= 10 log ( T )
3.0
= log ( T )
103
=
T
= 1.0 x 10−3
1
1
1 T
Door 1
TL
= 10 log ( T )
30
= 10 log ( )
3.0
= log ( T )
103
=T
T
= 1.0 x 10−3
���
= [(3.981 x 10−5 x 66) + (1.0 x 10−3x 9) + (1.0 x 10−3x 5)]/ (66+9+5)
1 T
1
1
= 0.01662746 / 80 = 2.0784 x 10−4 Overall SRI
1
= 10 log ( T ) 1
= 10 log ( 2.0784 x 10−4 ) = 36.82 dB Combined SPL at zone 2 is 66.33dB during peak hour, while at zone 4 is 49.46dB during peak hour, with the difference of 16.87dB. However, the SRI between zone 2 & zone 4 is 36.82dB, which is much higher than 16.87 dB. This is because the windows on the wall kept opened, allowing sound to be transferred between two zones.
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ZONE 2 & ZONE 5
Building element
Material
Wall Window Door
Concrete with paint Glass Glass
Sound reduction Index, SRI (dB) 44 30 30
Transmission coefficient, T 3.981 x 10−5 1.0 x 10−3 1.0 x 10−3
Area, S (đ?‘š2 ) 70 11 5
Concrete wall 1
TL
= 10 log ( T )
44
= 10 log ( T )
4.4
= log ( T )
104.4
=
T
= 3.981 x 10−5
1
1
1 T
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Window 1
TL
= 10 log ( T )
30
= 10 log ( T )
3.0
= log ( T )
103
=
T
= 1.0 x 10−3
1
1
1 T
Door 1
TL
= 10 log ( T )
30
= 10 log ( )
3.0
= log ( T )
103
=T
T
= 1.0 x 10−3
���
= [(3.981 x 10−5 x 70) + (1.0 x 10−3x 11) + (1.0 x 10−3x 5)]/ (70+11+5)
1 T
1
1
= 0.0187867 / 86 = 2.1845 x 10−4 Overall SRI
1
= 10 log ( T ) 1
= 10 log ( 2.1845 x 10−4 ) = 36.61 dB Combined SPL at zone 2 is 66.33dB during peak hour, while at zone 5 is 58.19dB during peak hour, with the difference of 8.14dB. However, the SRI between zone 2 & zone 5 is 36.61dB, which is much higher than 8.14 dB. This is because there is an AHU room in zone 5 which releases a lot of noise and the windows on the wall are kept opened, allowing sound to be transferred between two zones.
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4.8.4 REVERBERATION TIME
ZONE 1
Space volume, V = 8.8 x 13 x 6.6 – 3.3 x 40 = 623 �3
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Material absorption coefficient at peak hour (125 Hz) Building element
Material
Ceiling Plasterboard Wall Painted concrete Floor Rubber Door Glass Window Glass Chair Cushion Furniture Wooden Furniture Plastic/metal Equipment Rubber Opening Human Total absorption, A 0.16 đ?‘Ľ đ?‘‰ RT = đ??´ =
Absorption coefficient, a (125 Hz) 0.15 0.01 0.02 0.18 0.18 0.32 0.10 0.07 0.15 1.00 0.25
Area, S (đ?‘š2 ) Or Quantity 114 248 114 5 16 3 4 4 15 14 12
Sxa 17.1 2.48 2.28 0.9 2.88 0.96 0.40 0.28 2.25 14.0 3.0 46.53
0.16 đ?‘Ľ 623 46.53
= 2.14 s The reverberation time for the zone 1 in 125 Hz (peak hour)of absorption coefficient is 2.14 s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 125 Hz is over the standard comfort reverberation time.
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Material absorption coefficient at non-peak hour (125 Hz) Building element
Material
Ceiling Wall Floor Door Window Chair Furniture Furniture Equipment Opening Human Total absorption, A
Plasterboard Painted concrete Rubber Glass Glass Cushion Wooden Plastic/metal Rubber -
RT
=
0.16 đ?‘Ľ đ?‘‰ đ??´
=
0.16 đ?‘Ľ 623 44.53
Absorption coefficient, a (125 Hz) 0.15 0.01 0.02 0.18 0.18 0.32 0.10 0.07 0.15 1.00 0.25
Area, S (đ?‘š2 ) Or Quantity 114 248 114 5 16 3 4 4 15 14 4
Sxa 17.1 2.48 2.28 0.9 2.88 0.96 0.40 0.28 2.25 14.0 1.0 44.53
= 2.24 s
The reverberation time for the zone 1 in 125 Hz (non-peak hour) of absorption coefficient is 2.24 s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 125 Hz is over the standard comfort reverberation time.
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Material absorption coefficient at peak hour (500 Hz) Building element
Material
Ceiling Wall Floor Door Window Chair Furniture Furniture Equipment Opening Human Total absorption, A
Plasterboard Painted concrete Rubber Glass Glass Cushion Wooden Plastic/metal Rubber -
RT
=
0.16 đ?‘Ľ đ?‘‰ đ??´
=
0.16 đ?‘Ľ 623 44.74
Absorption coefficient, a (500 Hz) 0.04 0.02 0.05 0.04 0.04 0.42 0.08 0.14 0.50 1.00 0.42
Area, S (đ?‘š2 ) Or Quantity 114 248 114 5 16 3 4 4 15 14 12
Sxa 4.56 4.96 5.7 0.2 0.64 1.26 0.32 0.56 7.5 14.0 5.04 44.74
= 2.23 s
The reverberation time for the zone 1 in 500 Hz (peak hour) of absorption coefficient is 2.23s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 500 Hz is over the standard comfort reverberation time.
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Material absorption coefficient at non-peak hour (500 Hz) Building element
Material
Ceiling Wall Floor Door Window Chair Furniture Furniture Equipment Opening Human Total absorption, A
Plasterboard Painted concrete Rubber Glass Glass Cushion Wooden Plastic/metal Rubber -
RT
=
0.16 đ?‘Ľ đ?‘‰ đ??´
=
0.16 đ?‘Ľ 623 41.38
Absorption coefficient, a (500 Hz) 0.04 0.02 0.05 0.04 0.04 0.42 0.08 0.14 0.50 1.00 0.42
Area, S (đ?‘š2 ) Or Quantity 114 248 114 5 16 3 4 4 15 14 4
Sxa 4.56 4.96 5.7 0.2 0.64 1.26 0.32 0.56 7.5 14.0 1.68 41.38
= 2.41 s
The reverberation time for the zone 1 in 500 Hz (non-peak hour) of absorption coefficient is 2.41s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 500 Hz is over the standard comfort reverberation time.
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Material absorption coefficient at peak hour (2000 Hz) Building element
Material
Ceiling Wall Floor Door Window Chair Furniture Furniture Equipment Opening Human Total absorption, A
Plasterboard Painted concrete Rubber Glass Glass Cushion Wooden Plastic/metal Rubber -
RT
=
0.16 đ?‘Ľ đ?‘‰ đ??´
=
0.16 đ?‘Ľ 623 57.43
Absorption coefficient, a (2000 Hz) 0.07 0.02 0.10 0.02 0.02 0.43 0.08 0.14 0.70 1.00 0.50
Area, S (đ?‘š2 ) Or Quantity 114 248 114 5 16 3 4 4 15 14 12
Sxa 7.98 4.96 11.4 0.1 0.32 1.29 0.32 0.56 10.5 14.0 6.0 57.43
= 1.74 s
The reverberation time for the zone 1 in 2000 Hz (peak hour) of absorption coefficient is 1.74s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 2000 Hz is over the standard comfort reverberation time.
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Material absorption coefficient at non-peak hour (2000 Hz) Building element
Material
Ceiling Wall Floor Door Window Chair Furniture Furniture Equipment Opening Human Total absorption, A
Plasterboard Painted concrete Rubber Glass Glass Cushion Wooden Plastic/metal Rubber -
RT
=
0.16 đ?‘Ľ đ?‘‰ đ??´
=
0.16 đ?‘Ľ 623 53.43
Absorption coefficient, a (2000 Hz) 0.07 0.02 0.10 0.02 0.02 0.43 0.08 0.14 0.70 1.00 0.50
Area, S (đ?‘š2 ) Or Quantity 114 248 114 5 16 3 4 4 15 14 4
Sxa 7.98 4.96 11.4 0.1 0.32 1.29 0.32 0.56 10.5 14.0 2.0 53.43
= 1.87 s
The reverberation time for the zone 1 in 2000 Hz (non-peak hour) of absorption coefficient is 1.87s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 2000 Hz is over the standard comfort reverberation time.
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ZONE 2 Space volume, V = 12 x 13 x 6.6 – 3.3 x 30 = 931 �3
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Material absorption coefficient at peak hour (125 Hz) Building element
Material
Ceiling Wall Floor Door Door Window Furniture Equipment Opening Human Total absorption, A
Plasterboard Painted concrete Rubber Glass Wooden Glass Plastic/metal Metal -
RT
=
0.16 đ?‘Ľ đ?‘‰ đ??´
=
0.16 đ?‘Ľ 931 61.06
Absorption coefficient, a (125 Hz) 0.15 0.01 0.02 0.18 0.14 0.18 0.07 0.27 1.00 0.25
Area, S (đ?‘š2 ) Or Quantity 156 300 156 10 4 20 4 15 17.5 15
Sxa 23.4 3.0 3.12 1.8 0.56 3.6 0.28 4.05 17.5 3.75 61.06
= 2.44 s
The reverberation time for the zone 2 in 125 Hz (peak hour) of absorption coefficient is 2.44s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 125 Hz is over the standard comfort reverberation time.
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Material absorption coefficient at non-peak hour (125 Hz) Building element
Material
Ceiling Wall Floor Door Door Window Furniture Equipment Opening Human Total absorption, A
Plasterboard Painted concrete Rubber Glass Wooden Glass Plastic/metal Metal -
RT
=
0.16 đ?‘Ľ đ?‘‰ đ??´
=
0.16 đ?‘Ľ 931 58.56
Absorption coefficient, a (125 Hz) 0.15 0.01 0.02 0.18 0.14 0.18 0.07 0.27 1.00 0.25
Area, S (đ?‘š2 ) Or Quantity 156 300 156 10 4 20 4 15 17.5 5
Sxa 23.4 3.0 3.12 1.8 0.56 3.6 0.28 4.05 17.5 1.25 58.56
= 2.54 s
The reverberation time for the zone 2 in 125 Hz (non-peak hour) of absorption coefficient is 2.54s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 125 Hz is over the standard comfort reverberation time.
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Material absorption coefficient at peak hour (500 Hz) Building element
Material
Ceiling Wall Floor Door Door Window Furniture Equipment Opening Human Total absorption, A
Plasterboard Painted concrete Rubber Glass Wooden Glass Plastic/metal Metal -
RT
=
0.16 đ?‘Ľ đ?‘‰ đ??´
=
0.16 đ?‘Ľ 931 55.89
Absorption coefficient, a (500 Hz) 0.04 0.02 0.05 0.04 0.06 0.04 0.14 0.67 1.00 0.42
Area, S (đ?‘š2 ) Or Quantity 156 300 156 10 4 20 4 15 17.5 15
Sxa 6.24 6.0 7.8 0.4 0.24 0.8 0.56 10.05 17.5 6.3 55.89
= 2.67 s
The reverberation time for the zone 2 in 500 Hz (peak hour) of absorption coefficient is 2.67s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 500 Hz is over the standard comfort reverberation time.
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Material absorption coefficient at non-peak hour (500 Hz) Building element
Material
Ceiling Wall Floor Door Door Window Furniture Equipment Opening Human Total absorption, A
Plasterboard Painted concrete Rubber Glass Wooden Glass Plastic/metal Metal -
RT
=
0.16 đ?‘Ľ đ?‘‰ đ??´
=
0.16 đ?‘Ľ 931 51.69
Absorption coefficient, a (500 Hz) 0.04 0.02 0.05 0.04 0.06 0.04 0.14 0.67 1.00 0.42
Area, S (đ?‘š2 ) Or Quantity 156 300 156 10 4 20 4 15 17.5 5
Sxa 6.24 6.0 7.8 0.4 0.24 0.8 0.56 10.05 17.5 2.1 51.69
= 2.88 s
The reverberation time for the zone 2 in 500 Hz (non-peak hour) of absorption coefficient is 2.88s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 500 Hz is over the standard comfort reverberation time.
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Material absorption coefficient at peak hour (2000 Hz) Building element
Material
Ceiling Wall Floor Door Door Window Furniture Equipment Opening Human Total absorption, A
Plasterboard Painted concrete Rubber Glass Wooden Glass Plastic/metal Metal -
RT
=
0.16 đ?‘Ľ đ?‘‰ đ??´
=
0.16 đ?‘Ľ 931 72.13
Absorption coefficient, a (2000 Hz) 0.07 0.02 0.10 0.02 0.10 0.02 0.14 0.87 1.00 0.50
Area, S (đ?‘š2 ) Or Quantity 156 300 156 10 4 20 4 15 17.5 15
Sxa 10.92 6.0 15.6 0.2 0.4 0.4 0.56 13.05 17.5 7.5 72.13
= 2.07 s
The reverberation time for the zone 2 in 2000 Hz (peak hour) of absorption coefficient is 2.07s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 2000 Hz is over the standard comfort reverberation time.
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Material absorption coefficient at non-peak hour (2000 Hz) Building element
Material
Ceiling Wall Floor Door Door Window Furniture Equipment Opening Human Total absorption, A
Plasterboard Painted concrete Rubber Glass Wooden Glass Plastic/metal Metal -
RT
=
0.16 đ?‘Ľ đ?‘‰ đ??´
=
0.16 đ?‘Ľ 931 67.13
Absorption coefficient, a (2000 Hz) 0.07 0.02 0.10 0.02 0.10 0.02 0.14 0.87 1.00 0.50
Area, S (đ?‘š2 ) Or Quantity 156 300 156 10 4 20 4 15 17.5 5
Sxa 10.92 6.0 15.6 0.2 0.4 0.4 0.56 13.05 17.5 2.5 67.13
= 2.22 s
The reverberation time for the zone 2 in 2000 Hz (non-peak hour) of absorption coefficient is 2.22s. According to the standard of reverberation time, the comfort reverberation is between 1.0s – 1.5s. The reverberation time of the case study in 2000 Hz is over the standard comfort reverberation time.
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4.9 Conclusion of Acoustic The reverberation time of the gym is higher than the standard which is 1.0s – 1.5s, this is due to the design of the interior does not really emphasize on the acoustic enhancement besides the flooring which has thin rubber on the solid floor. However, the reverberation time of zone 1 is slightly shorter than zone 2 because there are quite an amount of soft elements such as yoga mats and fitness gym balls. After all, the reverberation time is not satisfying for a gym as noise are produced within the zones although it is not really sensible, but in a long period within the space one could feel discomfort.
Figure 4.9.1: Yoga mats and fitness gym balls.
Moreover, although there is a partition wall between zone 1 and zone 2, the sound reduction index of the partition does not really reflect the sound intensity level and sound transmission between the two zones because the partition wall does not really enclose and separate the two zones as there are gaps before and after the wall. The transmission of sound is affected by the open concept planning of the gym as the sound is usually diffused into the reception area. The same thing happened to the partition between zone 1 and zone 3, zone 1 and zone 4, zone 2 and zone 4, zone 2 and zone 5 where the partition wall contains a numbers of windows and a door. Some of the windows are often kept opened and there is a gap left by the automated glass doors, allowing sound to diffuse inter-zones, thus the transmission of sound is affected.
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4.10 Recommendations It can be summarized that the overall acoustic performance in the gym is not satisfying based on the calculations during peak and non-peak hours. As a gym where noise is generated from the activities and the equipment, several features of the design could be modified in order to improve the acoustic performance and quality of the space. For example, the painting and the finishing of the wall and floor and the amount of the soft elements with higher absorption coefficient. A layer of acoustical painting should be performed while fabric wrapped wall panels should be installed at places where applicable. Ceiling wise, baffles are one of the effective and low cost measures to actually assist in reducing reflective or reverberating noise, hence reducing airborne sound. On the other hand, acoustic banners which are effective sound absorbers could be installed flush to the roof deck to reduce sound intensity levels in harsh acoustical environment like gym. Installation of all these materials could help in reducing the reverberation time to the optimum level while sound intensity levels are reduced simultaneously to create a more peaceful environment, increasing speech intelligibility, communication efficiency and quality of sound systems.
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