BUILDING SCIENCE 2 [BLD61303] PROJECT 1: Lighting and Acoustic Performance Evaluation and Design of __________________________________________________
L a n t e r n H o t e l GROUP MEMBERS: CHEAH TECK WEI NICOLE HOOI YI TIEN RICKY WONG YII TAN KAI CHONG TSANG HAO REN VICKY LEE WEI KEE
TUTOR : Mr. Edwin Chan
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T A B L E O F C O N T E N T
1.0
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 1.1 1.2
2.0 3.0
METHODOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 2.1
3.2
3.3
3.4
3.5
Introduction to lighting 3.1.1 Natural lighting 3.1.2 Artificial Lighting 3.1.3 Materials Precedent Study 3.2.1 Introduction 3.2.2 Analysis 3.2.3 Conclusion Site Lighting 3.3.1 Spatial Quality of Light – Natural Lighting 3.3.2 Spatial Quality of Light – Artificial Lighting 3.3.3 Tabulation of Data 3.3.4 Interpretation of Data Light Analysis 3.4.1 Reception/Cafeteria - Daylight Factor Calculation - Lumen Method - Room Index Calculation 3.4.2 Atrium - Daylight Factor Calculation - Lumen Method - Room Index Calculation 3.4.3 Staircase - Daylight Factor Calculation - Lumen Method - Room Index Calculation Conclusion of Lighting Evaluation in Lantern Hotel
ACOUSTIC STUDY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 4.1
4.2
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Sequence of working
LIGHTING STUDY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3.1
4.0
Aim and Objective Site Study 1.2.1 Introduction 1.2.2 Selection Criteria 1.2.3 Architectural Drawings 1.2.4 Zoning of Spaces
Introduction to acoustic 4.1.1 Literature Review 4.1.2 Architecture Acoustics 4.1.3 Material Absorbent Precedent Study
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4.3
4.4
4.5
4.2.1 Introduction 4.2.2 Analysis Site Acoustics 4.3.1 Outdoor Noise Sources 4.3.2 Indoor Noise Sources 4.3.3 Equipment Location 4.3.4 Equipment Specification 4.3.5 Data Tabulation and analysis Acoustic Analysis 4.4.1 Reverberation Time - Zone 1: Cafeteria Bar / Reception - Zone 2: Cafeteria Dining Area / Corridor (Atrium) - Zone 3: Room Type 1 - Zone 4: Room Type 2 - Zone 5: Room Type 3 4.4.2 Sound Intensity Level - Zone 1: Cafeteria Bar / Reception - Zone 2: Cafeteria Dining Area / Corridor (Atrium) - Zone 3: Room Type 1 - Zone 4: Room Type 2 - Zone 5: Room Type 3 - Zone 6: Corridor 4.4.3 Sound Reduction Index - Wall 1: Café Reception / Bar Area - Wall 2: Room Type 3 (Room with Fixed Glass) - Wall 3: Room Type 3 ( Room with Glass Box) Conclusion of Acoustic Evaluation in Lantern Hotel
BIBILOGRAPHY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .7 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 3
A B S T R A C T This report contains of our observation and data collection of lighting and acoustic performances of Lantern Hotel, Petaling Street.
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1.0 INTRODUCTION 1.1 Aim and Objective By observing and analyzing the lighting and acoustic performances in Lantern Hotel, we aim to have a better understanding on the characteristic of a space on how the design approaches affect the lighting and acoustic performances of the space, and how different types of lighting and different types of sound sources influence the performances and also user experience. We also provide suggestions for better lighting and acoustic quality in the case study space.
1.2 Site Study 1.2.1 Introduction of site In a stylish renovated four-storey old building, with an industrial-meets-tropical design touch, Lantern Hotel is a budget hotel located at the heart of ever busy Petaling street of China town in Kuala Lumpur. Lantern Hotel occupies the second, third and fourth floor of the building above an existing bank on the first floor. The hotel consists of 49 rooms such as glass box room, room with verandah and normal room, an atrium, a cafeteria and a deck. With its dark brown clay bricks facade design (Figure xx ) that aims to melt harmoniously with hustle and bustle of the surroundings, Lantern Hotel became one of the modern landmarks of the street.
Figure xx : Faรงade design of Lantern Hotel
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1.2.2 Selection criteria
Being surrounded by variety of activities happening in Petaling street, the sound of people bargain on the street market in front, hawkers cooking behind and vehicles moving nearby the street contribute to the study of acoustic of the hotel. The design of the facade and the atrium at the centre of the building layout allows natural lighting in the building , this has contributed to the study of natural lighting. Designed as such, most of the spaces of the hotel do not require artificial lighting during day time. However, during night time the hotel is fairly brighten up with dim artificial lighting due to the theme and essence of the concept of Lantern Hotel.
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Figure xx : Surrounding environment of Lantern Hotel
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1.2.3 Architectural Drawings
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1.2.4 Zoning of Spaces
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2.0 METHODOLOGY
2.1 Sequence of working
Precedent Studies Document and study precedent studies on lighting and acoustic analysis similar to hotel case study that we choose. Analyze and compare the data collected in conjunction with other criteria of lighting and acoustic design such as spaces, environment and location. Evaluation and critique on the existing building design based on selected precedent studies as reference.
Drawings Preparation
Plans, section and elevation drawings were drawn and prepared in AutoCAD. Grid lines were arranged 2 meters apart for data collection and analysis. Figure xx : second floor and fourth plan with 2m grids for data collection purposes
Site Visit Due to similarity of spatial arrangement across all the floors, we decided to scale down the area of research only on the 2nd and 4th floor which accomodate the main spaces such as reception, cafĂŠ and hotel rooms. Moreover 4th floor is furthest from street level but closer to the atrium which will affect the lighting and acoustic performances .
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Data Collection Lighting analysis was conducted using the Lux Meter, readings were taken at 2 meter intervals at different position of 1 meter and 1.5-meter height. On the other hand, acoustic level readings were recorded using a sound meter. We picked two significant rooms from each floor due to similar layout, differences can be identified through the position of hotel rooms where 2nd floor rooms with lanai faced the street while 4th floor room with and without glass box faced the internal courtyard. Figure xx : Lutron digital lux meter LX-101
Figure xx : Lutron digital sound meter
Tabulation of data and diagramming Light and sound contour diagram were prepared using Ecotect 2011 which provides better understanding towards concentration of noise and lightings for different hotel zones.
Calculations
Lighting analysis carried further through calculations using formulas for daylight factor, room index and illuminance level. On the other hand, acoustic level readings were analysed by using the formula of reverberation time and sound intensity level.
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3.0 LIGHTING STUDY
3.1 Introduction to Lighting 3. 1.1 Literature Review
Light is an energy manifesting itself as electromagnetic radiation. Visible light is an electromagnetic radiation with wavelength in the range of 400-700 nanometres (nm). It is visible to the human eye and is responsible for the sense of sight. Light helps humans to gain vision by using the human eye that has the ability to gain information through light entering the eye. Light illuminates an area, the more intense the light, the brighter the area becomes. 3.1.2 Architecture Lighting In architecture, lighting of an area is controlled to create an easy-to-see and amusing luminous environment for interior and exterior of buildings. Lighting affects a space psychologically, it can bring many benefits if utilise properly. In architecture, designers can use light to create circulation, navigation around a space, creating visual emphasis and most importantly, creating a comfortable environment for the human eye to perform. To investigate and review the lighting of an area, a photometer is need to measure the luminance unit known as, Lux. Different spaces require difference luminance, depending on the function of the space. For example, most office work can be comfortably done at 250 to 500 lux, while supermarket usually requires it to be at 750 to 1000 lux. This is ensure to create the perfect luminous environment for the users.
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3.2 Precedent Study 3.2.1 Introduction Baia Bursa Hotel, Turkey The Baia Bursa Hotel is one of the establishments of the Sรถnmez Industry holding A.ล . It is located in the city centre of Bursa. As a luxurious hotel in the city, Baia Bursa Hotel comes with luxurious rooms in various choices, bars, restaurants, spa, swimming pool, meeting and conference room that is designed offering an unparalleled experience of elegant, contemporary luxury with highly attentive personal service. The interior of the hotel adapts a calm and tranquil ambient with a modern approach to the design.
Figure xx : Baia Bursa Hotel exterior
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3.2.2 Analysis
The hotel lobby is a space that serves an important function as it is the first impression for the hotel guest when they first enter the hotel building. The guest enters the main lobby through a vestibule and make their way to the front desk and check in area. The hotel lobby is designed to create an inviting feeling by using transparent glass panel that introduces light into the lobby. The selection of material of the hotel lobby is more towards a brownish scheme that gives a more relaxing feeling. More than that, the hotel lobby designed with simplicity comes in prior as heavy ornamentation does not feel as comfortable and relaxing. Activities | Tasks: - Check in/check out at Reception area - VDTs at the front desk for employees - Lounge areas for reading and waiting.
The hotel lobby uses glass panel at the entrance and vestibule to promote light diffuse into the lobby hall during daytime. (As shown in Figure xx) This has effectively lighten up the space and also given the guest a sense of openness. During night time, the lobby is only lighten up by using artificial light source such as accent light (purple) and pendant light(white) hence the whole lobby space is in a dim light condition. This is specially designed to create a relaxing feeling for the guest in the lobby. The red box represents the direct light created by the pendant light that focused on the decoration on the center of the lobby. (As shown in Figure xx)
Figure xx : Baia Bursa Hotel lobby
Figure xx : Table light at lobby of Baia Bursa Hotel lobby
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The reception area, restaurant and bar area are also decorated by accent lighting and pendant lights. Due to the function of reception area, more pendant lights are used to create more direct light towards the table for guest’s visibility while checking in or out. (As shown in Figure xx) The hotel lobby restaurant and bar whereas functioning more towards a relaxing and comfortable space needed lesser lighting, hence more accent lighting are used compared to direct lighting to create the relaxing ambience. (As shown in Figure xx) The guest lounge is a space for the guest to have a seat while waiting, rest and read. On the wall of the lounge is decorated by using art pieces with down lights, creating an accent while lighting up the art piece. (As shown in Figure xx)
Figure xx : Table light at lobby of Baia Bursa Hotel lobby
3.2.3 Conclusion
The Baia Bursa hotel has a dimmer brightness level within the lobby; however it makes up for it with a relaxing feel to the general space. There is a accent lighting element in the center of the lobby created by using direct lighting on a piece of decoration, it acts as the major lighting fixture within the space and adds to the aesthetics of the lobby, there are also task lighting elements above the reception area. Accent lighting methods are used to wall wash and light up pieces of artwork. The wall colors and color renderings of the lighting elements create a harmony between the design and the general lighting of the space. The circulation of this lobby may be undefined; however the main areas within the lobby are accented as a point interest. Overall the consideration of lighting design of has been focused on at a certain level.
Figure xx : Lobby restaurant and bar of Baia Bursa Hotel lobby
Figure xx : Guest lounge of Baia Bursa Hotel lobby
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3.3 Site Lighting 3.3.1 Spatial Quality of Light – Natural Lighting Lantern Hotel relies heavily on natural lighting to lit up the space during the day . In order to allow more light into the building, Lantern Hotel features an acrylic roof above the triple volume atrium (As shown in Figure xx), allowing sunlight to penetrates and light up most of the public spaces especially the atrium that provides seats for guests. (As shown in Figure xx & xx ) The design of triple volume atrium that allows penetration of sunlight is sufficient to lit up the whole building throughout the four floors. The rooms on the floors above are mostly lit up by sunlight as well through windows or glass box design. (As shown in Figure xx)
Figure xx : Arcylic roof above atrium
Figure xx : Glass box design of rooms above
Figure xx : Seats providd for guests at atrium
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To further increase the penetration of natural light into the building, the faรงade is designed as porous bricks facade to allow natural light to enter through the gaps in between the bricks from both sides of the building, the building does not merely depend on the natural light entering from the atrium at the core of the building . (As shown in Figure xx). However, the faรงade of Lantern Hotel is not entirely designed as porous bricks. Some parts of the faรงade are of louvers shutter windows to control the amount of light entering the building by opening or closing the louvers windows. (As shown in Figure xx) The natural light covered most part of the public area .This passive design strategy is functional and aesthetical as well, fitting well with the concept of the building.
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The passive design strategy not only light up the public areas, some of the hotel rooms of Lantern Hotel can also be lit only by natural sunlight during the day. Rooms attached to the facade, have a room created similarly as a balcony but more enclosed (As shown in Figure xx and xx). The balcony has louvers windows that allow hotel guests to open or close the window based on the desired environment they want in the room. Meanwhile rooms isolated in the middle of 3rd and 4th floor not attached to the faรงade but instead have corridors as buffer, are designed to have glass boxes or fixed windows facing the atrium that captures natural light into the room.
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3.3.3 Spatial Quality of Light – Artificial Lighting Despite the good utilization of natural lighting, it could not cover all building areas even during the day, since some places are meant to be enclosed thus natural light is not sufficient in those areas. ( As shown in Figrue xx) This is why artificial lighting is essential. Logically, places that natural light can’t enter require the use of artificial lighting, normally the inner part of the building.
Despite the good utilization of natural lighting, it could not cover all building areas because some spaces are meant to be enclosed thus natural light is not sufficient in some areas. This is why artificial lighting is essential in these areas. Spaces that natural light can’t enter require the use of artificial lighting to light up the space, normally the inner part of the building. In Lantern hotel, all the rooms,inner corridor, toilet, and stairs require the use of artificial lighting. The artificial lightings in Lantern hotel are mostly used for safety purpose during the day at spaces such as stairs and inner corridor .
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With such reliance to the natural light, the brightness of the building drop drastically during the night. Artificial lighting is used to rectify this problem. Instead of ambient lightings which provide general lighting, Lantern Hotel uses all accent lightings which are dim and warm yellow or orange. (As shown in Figure xx) The different lightings of Lantern Hotel at night are more for ambient and atmosphere . This is also used to match the concept of the building, a lantern hotel, thus a lot of lights can be found enclosed in a hollow object, similarly to a lantern. During the night, when the interior is brighter than exterior, the building will seem as in it is glowing, like a lantern.
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4.0 ACOUSTIC STUDY 4.1 Introduction to Acoustic 4.1.1 Literature Review Acoustics is the science of sound. It deals with the study of all mechanical waves in gases, liquids and solids. Sound can be defined as vibration in an elastic medium which are gases, liquids and gasses or air, water and any physical objects that still return to its normal state after being deflected. Sound can be reflected, absorbed, transmitted and diffracted. Sound and noise are two distinctive terms that people most of the time treat as the same. However, sound is desirable whereas noise is unwanted sound. Even though noise is not desirable but some noise could be beneficial too such as fire alarms and music. Other than that, it also has effect to communication and performance which interrupt occupants’ activities and cause problem if it is not being controlled.
4.1.2 Architecture Acoustic
Architecture acoustic is the science of controlling sound in a space which might include the design of spaces, structures and mechanical systems that meet the hearing needs for instance concert halls, classrooms and etc. Building acoustics is vital in attaining sound quality that is appropriate for a space. Pleasing sound quality and safe sound level are very important for creating suitable mood and safety in a space but it is hard to be achieved without proper design effort. The acoustic mood created in a space is highly affected by the buffer from the building exterior outdoor noise and building interior design and indoor noise.
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4.2 Precedent Study 4.2.1 Introduction Best Western Eurohotel
Best Western Eurohotel is a three-star hotel with facilities such as a cafeteria, covered swimming pool, restaurant, fitness gym and conference hall located in the central area of city of Baia Mare, Maremures, Romania. The building was built in 1964 hosted for the headquarters of a computer centre. Between 2004 and 2005, the building was consolidated and refurbished. They had extended horizontally and vertically for some new units of facilities. As a hotel located in the center of the city, the key acoustic challenge of the hotel is to provide sufficient acoustic absorption at the faรงade of the hotel that absorbs the noise from the outside streets and hotel rooms. Acoustic measurements were performed in the hotel to check the insulation levels of partition walls and of the faรงade at airborne noise and of the floors to the impact noise. The acoustic level affects the experience of the users in the hotel. There are a few key acoustic factors which is: a. Room Insulation b. Airborne Noise Level c. Impact Sound Levels
Figure xx : Exterior of Best Western Eurohotel
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4.2.2 Analysis Determination of Airborne Noise Level in Current Floors To determine the Airborne Noise Level in the hotel rooms, frequency intervals between 20 and 20,000 Hz are used. The partition walls of the hotel from the first and second floor are made of 12cm thickness of full brick masonry and 3cm thick of lime cement mortar on both side, with dimensions of 5.45m length and 3.00m height. Figure xx : Detail of partition wall at the st nd 1 and 2 floor
Figure xx : Dimensions of the partition wall
Two hotel rooms, room 104 and 105 are chosen to be measured. The noise level of surrounding spaces such as the reception, central hall from the first floor of hotel, neighbouring rooms are measured from a height of 1.30m as they affect the noise level inside the room as well.
Figure xx : Rooms 104 and 105 from the first floor
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The in situ sound attenuation indices, were determined according to the norms related to sound protection with relationship ( ) where: L1, L2 are noise levels in the emission space, respectively in the reception space, [dB]; S – the wall surface, [m2]; A – the equivalent absorption area, in the receptive room, [m2]. The Reverberation time, T is measured and calculated using the formula where: V is the volume of the room, [m3]; A – the equivalent absorption area, [m2]
The surface of the partition wall between the emission room and the receptive room is S = 5.50 × 3.00 = 16.50 m2 and the volume of the receptive room is V = 48.91 m3.The rating of airborne sound was done according to existent standards. The airborne sound reduction index for the partition wall, noted 'w R , is defined with the method presented in the standards, by comparing the curve of the acoustic damping coefficients ( ) ' i R f , obtained in 1/3 octave bands over the range 100 Hz to 3,150 Hz and the reference (calibrated) curve of the sound damping coefficients . The curve ( ) ' i R f and the reference (calibrated) curve are presented. Figure xx : The curve of the acoustic damping coeffecients R(f) and the reference curve
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The method through which the two curves are compared consists in displacing the reference curve (calibrated curve) with 1 dB steps, versus the measured and calculated curve, ( ) ' i R f , until the sum of the negative deviations reaches the highest value, but does not exceed 32.0. The deviation is seen as negative, at a certain frequency, if the measured or calculated value is lower than the reference value. Only negative deviations are considered. If the movement follows the mentioned procedure, the value of the reference curve, expressed in dB at 500 Hz, is 'w R . In our case we have According to Norms related to sound protection the admissible value of the airborne sound reduction index for the inner partition walls in a hotel is 51 dB. It yields that Therefore the wall does not ensures the insulation against the airborne sound. A comparison of the curves of acoustic attenuation indices, ( ) ' i R f , with the curve Cz 30 was also made. This comparison is given in the normatives as the admitted limit of the inner airborne sound in dwelling rooms or sleeping rooms in a hotel (Fig. 7).
Figure xx : Noise levels compared with admissible noise curve limits Cz30
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Comparing the noise level in room 105 with the reference curve Cz 30, one notices that, at higher frequencies (250, 500, 1,000, 2,000, 4,000, 8,000 Hz), the admitted values are exceeded by 0.98, 3.32, 0.89, 3.25, 7.81 and, respectively, 8.77 dB. Conclusion As a conclusion, from the point of view of the acoustic measurements, the partition wall between rooms 104 and 105 do not provide the sound insulation level required. This means that measures should be installed for additional sound insulation. A rehabilitation solution, from an acoustic point of view would have been the plating of the initial wall with a metallic skeleton, mineral wool of minimum 5 cm thickness, inserted in the metallic skeleton and over the profiles gypsum plaster plates, on both sides of the existing wall. Impact Sound level in the Rooms Impact sound level in one of the main key factor that affects the acoustic level in a room . In the study of this hotel, the impact sound level of the room’s floor is measured by using frequency intervals between 20Hz to 20,000Hz. An impact hammer is used to measure the 12cm thick reinforced concrete with 3cm thick fire-free-wall-to-wall carpet.
Figure xx : Current floor floring The rating of impact sound is calculated using the formula:
L= sound level in the reception room.(room 105) (dB) A = equivalent area for acoustic absorption in the reception space (m2) A0= Calculated function of the reverberation time measured in room 105 – equivalent area of reference for acoustic absorption (a0 = 10m2)
Figure xx : Rating index
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The curve of the normalized levels, Ln(f), which corresponds to the constructive unit made up of the reinforced concrete + flooring, was calculated with relationship (4); the curve Ln(f) was compared to the reference curve from Fig. 14 and Table 3. A reference flooring is taken (12 cm thick reinforced concrete flooring), where the values of the normalised impact noise, Ln,r,o , and the impact sound insulation index, Ln,r,o,w = 78 dB, are known. The reference curve is displaced up and down so that the sum of detrimental deviations nears as much as possible to the value of 32 dB, but does not exceed it; the impact sound insulation index (Ln,r,w) represents the value found at 500 Hz on the reference curve (moved with 2 dB), to overlap curve Ln(f). The index regarding the improvement of the impact sound insulation (ΔLw) for the single reinforced concrete flooring is calculated with the relationship In our case we have ΔLw = 78 – 62 = 16 dB. According to Norms related to sound protection, the condition for a flooring to provide impact sound insulation is given by
Conclusion Calculations show, by comparing curve Ln(f) with the reference curve, that the floor between rooms 105 and 205 provides the necessary impact sound insulation, at minimum level. In brief, considering measurements, the impact sound insulation of the flooring needs not improvement.
4.3 Site Acoustic
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4.3.1 Outdoor Noise Sources Located in the heart of Petaling Street Market which is a popular tourist attraction spot, Lantern Hotel has its own challenges in overcoming the noise level produced by the street. The market vibrant lifestyle attracting large crowds especially at night create certain noise level which is higher as sound travels upwards and eventually become weaker. (As shown in Figure xx) The porous bricks faรงade of Lantern Hotel facing towards the market has minimal effect in reducing noise level within the buildings as gaps are designed in between the bricks faรงade which easily allows the direct transmission of noise. Thus, most of the spaces within the building are affected by outdoor noise produced on the street .
Figure xx : Section showing outdoor noise source
Figure xx : Plan showing outdoor street noise source at second floor
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4.3.2 Indoor Noise Sources
Figure xx : Section showing indoor noise sources Indoor Noise sources in Lantern Hotel are speakers, air circulators and human activities. As shown in Figure xx, indoor noise level is higher on the second floor and gradually decreases as it travels upwards to third and fourth floor. Second floor has the highest noise level compared to other above as second floor comprises of primary public spaces such as reception, cafeteria, floors terrace and atrium that provide seats for guests. Thus, speakers, air circulators and human activities occur more on the second floor compared to floors above where the hotel rooms are allocated.
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Figure xx : Plans showing noise of human activiites
Apart from outdoor human activities in Petaling street, human activities in the building are also one of the main factors that contribute to the high noise decibel reading especially during peak hour. However, some of the hotel rooms are fairly affected by the indoor human activities. On the second floor, primary human activities mainly occur in spaces that are nearer to the outdoor , reception, cafeteria and outdoor deck. These spaces are mainly where light refreshments are provided for hotel guests. However, secondary activities mainly occur at the atrium where seats are provided. On the fourth floor, there are less human activities compared to second floor as fourth floor mainly comprises of hotel rooms. The two mini lounge areas are where the primary human activities occur. ( As shown in Figure xx )
Figure xx : Human activiites at cafeteria, reception,and atrium
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Figure xx : Second floor plan showing positions of speakers
The speakers are placed at the reception area and the sound is transmitted throughout the cafeteria and corridor as well as the open deck. The sound of music is either being directed, reflected or refracted depending on the reflectance of material surface. The purpose of placing speakers at the reception area is to create a welcoming atmosphere when guests walk in. The music emitted in the direction of terrace is being blocked by the stairs and thus, another speaker is placed at the open deck. The speakers only blare during the peak hour to liven up the mood when hotel guests are spending their night at the terrace drinking and hanging out.
Figure xx : Speakers placed at terrace
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Figure xx : Plans showing position of ventilitators
Lantern Hotel promotes natural ventilation by using porous bricks faรงade to allow smooth flow of outside air into the building. However, air circulators like ceiling fans and air conditioners are still used in Lantern Hotel to further improve human thermal comfort being in this context that has hot and humid weather most of the time. Corridors are ventilated using ceiling fans to minimize energy consumption and promote energy efficiency in the building by using less air-conditioner. Ceiling fans are only switched on during the peak period when the space has more users. Along the corridor, ceiling fans installed clatter against steel service piping running along ceilings (As shown in Figure xx ), it causes the production of unwanted noise along the corridor. Only the reception and cafeteria are cooled using ceiling cassette air conditioner (As shown in Figure xx ) to provide guests a pleasant welcoming space. Thus,the air conditioner is used from day to night. This has contributed to the higher decibel reading of the area during both non-peak hour and peak hour. Air conditioners are also used in all the hotel rooms where there are less natural ventilation allowed.
Figure xx : Ceiling fans installed against service pipes at the corridor
Figure xx : A row of ceiling fans at the Atrium
Figure xx : Ceiling cassette air conditioner at the Cafeteria
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4.3.3 Equipment Location BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 33
4.3.4 Equipment Specification
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4.3.5 Data Collection and analysis
› Figure xx : Acoustic performance of atrium/cafeteria during non- peak hour › Figure xx : Acoustic performance of atrium/cafeteria during peak hour
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Based on the two diagrams above, atrium has lower decibel reading compared to cafeteria during both peak period and non-peak period. The decibel reading gradually increases from the back of the space to the front of the space due to the location of Petaling street market where the front is facing directly to it. However, at the atrium decibel reading is lower as the atrium is in between two rows of rooms on both sides to cater their guests, thus outside noise source can be hardly detected unless there are movements of guests and contribution of equipment noise – ceiling fan during peak period. During non-peak period, decibel reading is highest at E3, reception of Lantern Hotel . The production of workers’ noise during non-peak hour contribute to the high decibel reading at point E3. Electrical appliances such as fans and coffee grinder are not switched on and being used during non-peak hour thus the overall decibel reading is lower due to the decrease in noise contribution of interior noise source. During peak period, the noise level is highest at point E3 and F5 , reception of Lantern Hotel and mini bar at the cafeteria. Outdoor noise and indoor noise sources both contribute to the overall high decibel reading of the atrium and cafeteria. The area becomes merrier as the night approaches because of night market at Petaling street and the blaring music from the speakers placed at the outdoor deck to liven up the mood of the hotel at night when guests start to return from outside.
36 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
Figure xx : Acoustic performance of corridor during non- peak hour
Figure xx : Acoustic performance of corridor during peak hour
BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 37
Based on the two diagrams above, the corridor on the fourth floor of Lantern Hotel receive less noise from the outside compared to atrium and cafeteria on the second floor. The high decibel reading is contributed by outdoor noise source due to the direct sound transmission through the porous bricks façade and indoor noise source – ventilation equipment. Decible reading is higher at the locations of electrical fans also where the fenestrations of the façade are. Decibel reading is constantly high starting from point O10 because of the outdoor noise produced from the kitchen of the food court behind Lantern Hotel. The decibel reading for both peak and non-peak period are similar in pattern but different in decibel reading values. Thus, the overall noise level of the corridor is constant during peak and non-peak hours and less affected due to the higher floor level compared to atrium and cafeteria also less human movements on the higher floor level where the rooms are located.
38 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
Figure xx : Acoustic performance of room type 2&3 during non- peak hour
Figure xx : Acoustic performance of room type 2&3 during peak hour
BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 39
Based on the two diagrams above, rooms facing the outside has higher decibel reading than rooms facing the corridor inside as rooms outside receive more outdoor noise source. The rooms should have low noise level in order to provide guests a comfortable environment to rest. Therefore, the corridor acts as a buffer of the rooms facing outside from the outdoor noise. The decibel reading of the corridor in figure xx and xx are relatively higher than the decibel readings of corridor above. Similar to the decibel reading of corridor, the pattern of decibel reading for rooms are the same but different in decibel reading value. The room has the overall lowest decibel reading compared to the other two studied space – atrium & cafeteria due to the arrangement of plan as strategy to reduce noise level in the rooms. Some of the rooms of room type 2 are not affected at all, however all of the rooms of room type 3 are affected by outdoor noise as the decibel reading is higher when points are near to the outside compared to points near the atrium.
40 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
Figure xx : Acoustic performance of room type 1 during non- peak hour Figure xx : Acoustic performance of room type 1 during peak hour
BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 41
Based on the two diagrams above, Room type 1 is greatly affected by both the indoor noise sources and outdoor noise. Compared to decibel readings of Room type 2&3 (As shown in Figure xx and xx), Room type 1 located on the second floor has higher decibel readings. As the room layout of Room type 1 has lanai or verandah that is attached to the faรงade. This has made the room to be directly connected to the outside through the verandah when the louvered window is opened. Thus, the decibel reading of verandah is higher compared to room space during non-peak hour. During peak hour, the decibel readings in the room are constantly high because of the outdoor activities of Petaling street also the indoor human activities occur at the atrium when hotel guests return to the hotel at night contribute to the high decibel reading of the room.
42 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
4.4 Acoustic Analysis 4.4.1 Reverberation Time Reverberation Time (RT) at 500 Hz The reverberation time of a space refers to the time taken for sound energy to dissipate. Reverberation in an enclosed space is made up multiple ‘echoes’ or ‘reflections’. Reverberation time is calculated to determine how well a space can function for its intended use and to analyse if the absorption coefficient of the material is efficient enough within a space. In fact, different material has different acoustic absorption coefficient in different frequencies. Acoustical absorption of materials in 500 Hz frequency are taken as reference to calculate reverberation time. Table below shows the total sound absorption at 500 Hz during peak and non-peak hour. The reverberation time of a room is linked to the the surfaces that enclose it and the volume of the room by the Sabine equation: A = đ?‘şđ?&#x;? đ?’‚đ?&#x;? + đ?‘şđ?&#x;? đ?’‚đ?&#x;? + đ?‘şđ?&#x;‘ đ?’‚đ?&#x;‘ + đ?‘şđ?&#x;’ đ?’‚đ?&#x;’ + â‹Ż . đ?‘şđ?’? đ?’‚đ?’? S= Surface area of material, A = Absorption Coefficient of Material
RT
=
��� �
T = Reverberation Time in seconds = 0.16 V = Volume of Space, A = Total Room Absorption Internal Space Private Office Open Plan Office Secondary School Classroom Hotel Rooms Coffee bar Atrium Restaurant
Reverberation Time, s 0.6 â&#x20AC;&#x201C; 0.8 0.8 â&#x20AC;&#x201C; 1.2 < 0.8 0.4 â&#x20AC;&#x201C; 0.6 < 1.0 1.5 -2.0 0.8 - 1.2
Recommended Reverberation Time for Indicative Spaces Source: http://clarkesaunders.com/reverberation-time
BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 43
i.
Zoning of Spaces The reverberation time of main interior spaces of Lantern Hotel is calculated. The spaces include: Zone 1 Cafeteria Bar & Reception Zone 2 Cafeteria Dining Area//Corridor (Atrium) Zone 3 Room Type 1 (Room facing outside at 2nd Floor) Zone 4 Room Type 2 (Room facing outside at 4th Floor) Zone 5 Room Type 3 (Room facing inside at 4th Floor)
ii.
Volume of main interior spaces, V = Zone 1 + Zone 2 + Zone 3 +Zone 4 + Zone 5 = 114.4 m3 + 710.66 m3 + 62.72 m3 + 26.4 m3+ 34.88 m3 = 949.06 m3
44 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
Zone 1 Calculation: Cafeteria Bar & Reception
Building Element Ceiling Wall
Surface Material, Color & Description White Plaster Standard Brickwork Painted Plaster Surface on Masonry Wall Slate Chalkboard Light Walnut Parquet fixed on concrete Smooth Polished Concrete Light Walnut Timber Shutter Polished Concrete Light Walnut Plywood Plank Counter & Surface Metal Stool Porous Brick Counter Stand
Area (m2) 41.4 7.6 42.8 10.95 33.6 7.8 11.7 5.5 20.6 0.75 4.95 41.4
Absorption Coefficient 0.02 0.03 0.02 0.11 0.07 0.02 0.03 0.02 0.07 0.14 0.03 0.01
Sa 0.828 0.228 0.856 1.2045 2.352 0.156 0.351 0.11 1.442 0.105 0.1485 0.414 6.842
Human Total Absorption (Peak Hour)
7
0.42 per person
2.8 9.642
Human Total Absorption (Non-Peak Hour)
2
0.42 per person
0.84 7.682
Floor Window Furniture
Air Total Material Absorption Value
Non-Peak Hour
Peak Hour RT
=
=
!.!" ! ! !
!.!" ! !!".! !.!"#
!.!" ! !
RT
=
=
!
!.!" ! !!".! !.!"#
= 2.38 s = 1.89 s The reverberation time for Zone 1 in 500 Hz of absorption is 1.89 s and 2.38 s during peak and non-peak hour respectively when the timber shutters are shut. According to the standard comfort of reverberation time for restaurants is less than 1.0 s. The reverberation time of the case study on 500 Hz has exceeded this standard range. This space with longer reverberation time shows that the noises within the space created by the coffee machines which will affect the level of comfort of guests when dining in that particular area. However, the problem is solved when the timber shutter windows are open so that the reverberation time within the space is lower.
BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 45
Zone 2 Calculation: Cafeteria Dining Area//Corridor (Atrium)
Building Element Ceiling Wall
Surface Material Acrylic Skylight Standard Brickwork Concrete Block painted white Porous Concrete Block Floor Light Walnut Parquet fixed on concrete Beam White Plaster Concrete Furniture Light Walnut Timber Chairs and Tables Total Material Absorption Value
Area 66.9 5.54 356.4 2.49 66.9 24.78 0.9
Absorption Coefficient 0.02 0.03 0.06 0.05 0.07 0.02 0.07
Sa 1.338 0.1662 21.384 0.1245 4.683 0.4956 0.063 28.2543
Human Total Absorption (Peak Hour)
8
0.42 per person
3.36 31.6143
Human Total Absorption (Non-Peak Hour)
2
0.42 per person
0.84 29.0943
Peak Hour RT
=
=
Non-Peak Hour
!.!" ! ! !
!.!" !"#$.!! !".!"#$
!.!" ! !
RT
=
=
!
!.!" ! !"#.!! !".!"#$
= 3.59 s = 3.91 s The reverberation time for Zone 2 in 500 Hz of absorption is 3.59s and 3.91s during peak and non-peak hour respectively. According to the standard comfort of reverberation time for atrium is between 1.5-2.0s. The reverberation time of the case study on 500 Hz has exceeded this standard range. This space with longer reverberation time shows that the noises within the space causes build-up noise level within the dining area itself as well as creating loud noise source to the adjacent hotel rooms along the corridor which will affect the level of comfort of guests. The prolongation of the sound in that space is caused by continued multiple reflections and dispersion of sound at the corners of the beams across the atrium.
46 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
Zone 3 Calculation: Room Type 1 (Room facing outside at 2nd Floor) Building Element Ceiling Floor
Surface Material Cement Board Ceiling Terrazzo Tiles Porous Brick Wall Painted Concrete Block Standard Brickwork Solid Timber Door Light Walnut Timber Shutter
Wall Door Window Human Air Total Absorption, A
RT
=
=
!.!" ! ! !
Area 25.2 25.2 4.32 45.4 16.9 1.8 11.1 6 25.2
Absorption Coefficient 0.04 0.01 0.03 0.06 0.03 0.06 0.03 0.42 per person 0.01
Sa 1.008 0.252 0.1296 2.724 0.507 0.108 0.333 2.52 0.252 7.8336
!.!" ! !".!" !.!""#
= 1.28 s The reverberation time for Zone 3 which is the worker rest room, in 500 Hz of absorption is 1.28s. According to the standard comfort of reverberation time is between 0.4 - 0.6s. The reverberation time of the case study on 500 Hz has exceeded this standard range. This space with longer reverberation time shows that both the noises within the space and noise intrusion from external street creates loud noise source to the adjacent hotel rooms along the corridor which will affect the level of comfort of guests. Zone 4 Calculation: Room Type 2 (Room facing outside at 4th Floor) Building Element Ceiling Floor Wall Door Window Human Air Total Absorption, A
!.!" ! !
RT
=
=
= 1.18 s
!
Surface Material Cement Board Ceiling Terrazzo Tiles Painted Concrete Block Solid Timber Door 6mm Glass
Area 8.25 8.25 34.96 1.8 2.45 2 8.25
Absorption Coefficient 0.04 0.015 0.06 0.06 0.04 0.42 per person 0.01
Sa 0.33 0.12375 2.0976 0.108 0.098 0.84 0.0825 3.58185
!.!" ! !".! !.!"#$
BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 47
Zone 5 :Calculation: Room Type 3 (Room facing inside at 4th Floor) Building Element Ceiling Floor
Surface Material Cement Board Ceiling Terrazzo Tiles Painted Concrete Block 6 mm Glass Solid Timber Door Ordinary window glass
Wall Door Glass box Human Air Total Absorption, A
RT
=
=
!.!" ! ! !
Area 10.9 10.9 42.56 9.288 1.8 9.288 2 10.9
Absorption Coefficient 0.04 0.015 0.06 0.04 0.06 0.04 0.42 per person 0.01
Sa 0.436 0.1635 2.5536 0.37152 0.108 0.37152 0.82 0.109 4.56162
!.!" ! !".!! !.!"#"$
= 1.22 s The reverberation time for Zone 4 and 5 which is room with window and room with reverberation glass box, in 500 Hz of absorption is 1.18s and 1.22. According to the standard comfort of reverberation time is between 0.4 - 0.6s. The reverberation time of the case study on 500 Hz has exceeded this standard range. The build-up noise level within the room can be reduced by implementing surface treatment like using carpet for floors etc.
48 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
4.4.1 Sound Intensity Level (SIL) Intensity is defined as the sound power per unit area. The usual context is the measurement of sound intensity in the air at a listener's location. The basic units are watts/m2 or watts/cm2. SPL/SIL = 10 log10
đ??&#x2C6;
đ?&#x2018;°đ?&#x2019;&#x201C;đ?&#x2019;&#x2020;đ?&#x2019;&#x2021;
-2
, where SIL = Sound Intensity Level, Iref = 1 x 10
Zone 1 Calculation: Cafeteria Bar & Reception Non-peak Hour: Reading 1 = 75 dB SIL
= 10 log10
75 dB
= 10 log10
log-1 7.5 I! Reading 2
=
!!
!!
!!"# !! ! ! !"!!"
! ! !"!!"
= (3.162 x 107) x (1x 10-12) = 3.162 x 10-5 = 65 dB
SIL
= 10 log10
65 dB
= 10 log10 !!
!!
!!"# !! ! ! !"!!"
log-1 7.5
=
I!
= (3.162 x 106) x (1x 10-12) = 3.162 x 10-6
! ! !"!!"
Sum of all the points, I 1+ 2 + n = (3.162 x 10-5) + (3.162x 10-6) + (n) (Provided n = I! value at remaining points = 3.478 x 10-5+ n Combined SIL = 10 log10
!!"!#$
= 10 log10
!!"# !.!"# ! !"!! !! ! ! !"!!"
Following calculation included in the table provided below
BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 49
Peak Hour: Reading 1 SIL
= 10 log10
81 dB
= 10 log10
log-1 8.1 I! Reading 2
= 81 dB
=
!!
!!
!!"# !! ! ! !"!!"
! ! !"!!"
= (1.259 x 108) x (1x 10-12) = 1.259 x 10-4 = 72 dB
SIL
= 10 log10
72 dB
= 10 log10 !!
!!
!!"# !! ! ! !"!!"
log-1 7.2
=
I!
= (1.584 x 107) x (1x 10-12) = 1.584 x 10-5
! ! !"!!"
Total Intensities, I TOTAL = (1.259 x 10-4) + (1.584x 10-5) +n (Provided n = I! value at remaining points) = 1.4174 x 10-4 + n !!"!#$
Combined SPL
= 10 log10
= 10 log10
!!"# !.!"#! ! !"!! !! ! ! !"!!"
Following calculation included in the table provided below
50 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
Cafeteria (Non Peak) Sound Intensity I value (dB) 75 3.16 x10-5 67 5.01 x10-6 68 6.31 x10-6 69 7.94 x10-6 69 7.94 x10-6 66 3.98 x10-6 65 3.16 x10-6 66 3.98 x10-6 Total 7.01 x10-5 Combined SPL 78.45 dB
Cafeteria (Peak) Sound Intensity(dB) I value 1.26 x10-4 2.51 x10-5 2.00 x10-5 2.51 x10-5 3.98 x10-5 6.31 x10-5 3.98 x10-4 1.58 x10-5 7.13 x10-5
81 74 73 74 76 78 86 72 Total
Combined SPL
88.53 dB
The average sound intensity level at the cafeteria is the highest because it’s located at the entrance of the hotel. The main noise sources are generally contributed by visitors and workers. On the other hand, the sound intensity level fluctuate around 70dB to 80dB during the operation hours of the sound system and coffee machine installed at the reception/cafeteria area. However during non-peak hours, noise level remains highest among other spaces in lantern hotel. This is due to the application of perforated façade and operable window which would likely to allow transmittance of noise from the busy street market and AHU across the street. Perforated façade and operable window may provide aesthetic but results in poor sound insulation properties of the space.
BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 51
Zone 2 Calculation : Cafeteria Dining Area // Corridor (Atrium) Atrium (Non Peak) Sound Intensity (Db) 66 62 56 55 52 52 51 52 51 51 56 58 Total Combined SPL
I value 3.98 x10-6 1.58 x10-6 3.98 x10-7 3.16 x10-7 1.58 x10-7 1.58 x10-7 1.25 x10-7 1.58 x10-7 1.25 x10-7 1.25 x10-7 7.13 x10-6 6.31 x10-7 1.49 x10-5 71.73 dB
Atrium (Peak) Sound Intensity (Db) 72 78 62 61 58 58 57 58 57 57 62 64 Total Combined SPL
I value 1.58 x10-5 6.31 x10-5 1.58 x10-6 1.26 x10-6 6.30 x10-7 6.30 x10-7 5.01 x10-7 6.31 x10-7 5.01 x10-7 5.01 x10-7 1.58 x10-6 2.51 x10-6 8.93 x10-5 79.51 dB
The average sound intensity level is generally higher at the central atrium because it’s the heart of the hotel and holds most of the public activities during the peak hour. However, the noise level still remains around 71dB during non-peak hours, noise level was generally contributed from the street level due to openness of the perforated façade and operable louvered windows. Masking noise generated from the air conditioner creates a sound barrier, allowed the street noises to be hardly noticeable. The application of masking noise improves acoustic experience, allowed the user to appreciate the spaces without disruption from external noise. ‘
52 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
Zone 3 Calculation: Room Type 1 (Room facing outside at 2nd Floor) Room Type 1 (Non peak) Room Type 1(Peak) Sound Intensity (dB) I Value Sound Intensity (dB) I Value 62 1.58 x10-6 65 3.16 x10-6 60 1.00 x10-6 65 3.16 x10-6 65 3.16 x10-6 68 6.31 x10-6 -6 63 2.00 x10 65 3.16 x10-6 60 1.00 x10-7 64 2.51 x10-6 65 3.16 x10-6 68 6.31 x10-6 50 1.00 x10-7 55 3.16 x10-7 51 1.26 x10-7 54 2.51 x10-7 -7 55 3.16 x10 58 6.31 x10-7 50 1.00 x10-7 55 3.16 x10-7 50 1.00 x10-7 55 3.16 x10-7 55 3.16 x10-7 59 7.94 x10-7 Total 1.30 x10-5 Total 2.72 x10-5 Combined SPL 71.13 dB Combined SPL 74.35 dB Zone 4 Calculation: Room Type 2 (Room facing outside at 4th Floor) Room Type 2 (Non peak) Sound Intensity (dB) I Value 46 3.98 x10-7 40 1.00 x10-8 45 3.16 x10-8 40 1.00 x10-8 43 2.00 x10-8 45 3.16 x10-8 43 2.00 x10-8 46 3.98 x10-8 43 2.00 x10-8 45 3.16 x10-8 46 3.98 x10-8 45 3.16 x10-8 46 3.98 x10-8 44 2.51 x10-8 Total 3.97 x10-7 Combined SPL 55.91dB
Room Type 2 (Peak) Sound Intensity (dB) I Value 51 1.26 x10-7 47 5.01 x10-8 50 1.00 x10-7 47 5.01 x10-8 45 3.16 x10-8 50 1.00 x10-7 45 3.16 x10-8 50 1.00 x10-7 46 3.98 x10-8 52 1.58 x10-7 46 3.98 x10-8 51 1.26 x10-7 53 2.00 x10-7 49 7.94 x10-7 Total 1.23 10-6 Combined SPL 60.91dB
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Zone 5 :Calculation: Room Type 3 (Room facing inside at 4th Floor) Room Type 3 (Non peak) Sound Intensity 38 6.31 x10-7 43 2.00 x10-8 38 6.31 x10-7 45 3.16 x10-8 43 2.00 x10-8 45 3.16 x10-8 43 2.00 x10-8 46 3.98 x10-8 43 2.00 x10-8 45 3.16 x10-8 46 3.98 x10-8 45 3.16 x10-8 46 3.98 x10-8 44 2.51 x10-8 3.63 x10-7 Combined SPL 55.60dB Corridor (Non Peak) Sound Intensity (dB) 49 50 48 51 51
r)
I Value 7.94 x10-7 1.00 x10-7 6.31 x10-7 1.25 x10-7 1.26 x10-7
Room Type 3 (Peak) Sound intensity 51 1.25 x10-7 47 5.01 x10-8 50 1.00 x10-7 47 5.01 x10-8 45 3.16 x10-8 50 1.00 x10-7 45 3.16 x10-8 50 1.00 x10-7 46 3.98 x10-8 52 1.58 x10-7 46 3.98 x10-8 51 1.25 x10-7 53 2.00 x10-7 49 7.94 x10-8 1.23 x10-6 Combined SPL 60.90dB Corridor (Peak) Sound Intensity (dB) 59 62 59 60 63
I Value 7.94 x10-7 1.58 x10-7 7.94 x10-7 1.00 x10-6 2.00 x10-6
Zon e 6 : Corr idor ( 4th Floo
54 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
53 2.00 x10-7 61 1.26 x10-6 -7 -6 54 2.51 x10 61 1.26 x10 -7 -6 55 3.16 x10 65 3.16 x10 55 3.16 x10-7 65 3.16 x10-6 53 2.00 x10-7 63 2.00 x10-6 -7 -6 56 3.98 x10 65 3.16 x10 -7 -6 58 6.31 x10 66 3.98 x10 54 2.51 x10-7 63 2.00 x10-6 -7 -6 56 3.98 x10 66 3.98 x10 -7 -6 56 3.98 x10 66 3.98 x10 54 2.51 x10-7 64 2.51 x10-6 -7 53 2.00 x10 63 zone and sound barrier 2.00 x10-7 towards Corridor reduces noise level as it provides a buffering -7 -6 58 The results 6.31 x10 3.16 x10 the hotel rooms. shown in the table 65 indicates significant lower sound -7 -6 7.94 x10 65 type 3 due to 3.16 x10 intensity level 59 recorded in Room type 2 and Room the presence of -6 -6 60 1.00 x10 67 5.01 x10 corridor. On the other hand, the results shown that Room type 1 receive higher noise Total 6.73 x10-6 Total 5.00 x10-5 level from the street market, which is believed to be transmitted directly from the street through street facing balcony in Room type 1. Combined SIL 68.28dB Combined SIL 76.99 dB
Other than that, manipulating distance between noise sources plays an important role in reducing noise level. The tabulated data proves that corridor, room 2 and 3 located at the 4th floor of the hotel typically receive less noise when itâ&#x20AC;&#x2122;s further apart from the street. Generally the position and layout of the room ominously affects the acoustic quality of the room.
BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 55
4.4.3 Sound Transmission Loss (TL) Sound Transmission Loss (TL) analysis is conducted to analyse the reduction of sound from external space to the internal space. For this case study, the transmission loss or reduction in decibels (dB) is determined as sound waves passed through a particular material of different wall surfaces of the cafĂŠ and its corridor area at second floor. Calculation of transmission loss on materials is based on the formulae as stated below: SRI = TL = 10 log10
đ?&#x;?
đ?&#x2018;ťđ?&#x2019;&#x201A;đ?&#x2019;&#x2014;
,
Where, Tav = Average transmission coefficient of materials SRIn = 10 log10
Tav =
đ?&#x2018;ťđ?&#x2019;?đ?&#x2019;&#x2022;đ?&#x2019;&#x201A;đ?&#x2019;? đ?&#x2018;şđ?&#x2019;&#x2013;đ?&#x2019;&#x201C;đ?&#x2019;&#x2021;đ?&#x2019;&#x201A;đ?&#x2019;&#x201E;đ?&#x2019;&#x2020; đ?&#x2018;¨đ?&#x2019;&#x201C;đ?&#x2019;&#x2020;đ?&#x2019;&#x201A;
Building Component Wall 1 Wall 2 Wall 3 Wall 4 Wall 5
,
đ?&#x2018;ťđ?&#x2019;? (đ?&#x2018;şđ?&#x;? đ?&#x2019;&#x2122; đ?&#x2018;ťđ?&#x2019;&#x201E;đ?&#x;? ) ! (đ?&#x2018;şđ?&#x;? đ?&#x2019;&#x2122; đ?&#x2018;ťđ?&#x2019;&#x201E;đ?&#x;? ) ! â&#x20AC;Ś.(đ?&#x2018;şđ?&#x2019;? đ?&#x2019;&#x2122; đ?&#x2018;ťđ?&#x2019;&#x201E;đ?&#x2019;? )
Where, Sn = Surface Area of Material Tcn = Transmission Coefficient of Material
đ?&#x;?
Building Element Material Surface Area, S (m2) 5 windows Timber 8.4 Unfinished Brick Wall 100mm Brick 8.6 Plastered Brick Wall Plastered Brick 63.7 4 Solid Timber Doors Timber 7.2 2 Timber Shutter Windows Timber 4.5 Unfinished Brick Wall 100mm Brick 19.1 Concrete Block Wall Painted White Paint 57.6 8 Solid Timber Doors Timber 14.4 Concrete Block Wall Painted White Paint 44.6 6 Solid Timber Doors Timber 10.8
SRI (dB) 10 39 58 37 10 39 45 37 45 37
Transmission Coefficient (T) 0.1 1.259 đ?&#x2018;Ľ 10 )* 1.585 đ?&#x2018;Ľ 10 )1.995 đ?&#x2018;Ľ 10 )* 0.1 1.259 đ?&#x2018;Ľ 10 )* 3.162 đ?&#x2018;Ľ 10 )2 1.995 đ?&#x2018;Ľ 10 )* 3.162 đ?&#x2018;Ľ 10 )2 1.995 đ?&#x2018;Ľ 10 )*
Sn x Tcn 8.4 đ?&#x2018;Ľ 10)1 1.082 đ?&#x2018;Ľ 10 ), 1.009 đ?&#x2018;Ľ 10 )* 1.436 đ?&#x2018;Ľ 10 ), 4.5 đ?&#x2018;Ľ 10)1 2.405 đ?&#x2018;Ľ 10 ), 1.537 đ?&#x2018;Ľ 10 ), 2.872 đ?&#x2018;Ľ 10 ), 1.410 đ?&#x2018;Ľ 10 ), 2.155 đ?&#x2018;Ľ 10 ),
56 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
Wall 1 Overall Sound Energy Transmission Coefficient (Café Reception & Bar Area) Windows Unfinished Brick Wall 100mm ! ! SRI = 10 log10 ! SRI = 10 log10 ! SRI Brick = 39 SRI Timber = 10 ! ! 39 = 10 log10 ! 10 = 10 log10 !
!
log-1 1 = ! Transmission Coefficient of Timber, TTimber = 0.1 Average Transmission Coefficient of Materials Tav
= =
!.! ! !.! ! !.!"# ! !"!! ! !.! !.!!!.! !.!"!(!.!"# ! !"!! )
=
!.!"#
!"
Overall SRI of Wall 1 SRI
!"
= 4.947 x 10!!
!
log-1 3.9 = ! Transmission Coefficient of Brick, TBrick -4 = 1.259 x 10
= 10 log10
!!"
SRI Wall 1
= 10 log10
= 13dB
BS8233 Guidance Noise Levels
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BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 57
Standard Internal Noise Control for Hotel Bar & Reception Required Transmission Coefficient
Daytime – 30 dB to 45 dB Night Time – 25 dB to 35 dB Daytime: 40
!
= 10 log10 ! !
log-1 4 = ! = 1 x 10-4 Night Time: ! 30 = 10 l og10 ! !
log-1 3 = ! = 1 x 10-3 Table shows Comparison with Standard Noise Rating (NR) Value and required TL
Noise Level in reception and coffee bar of Lantern Hotel after transmission loss: Street Noise Overall TL of wall Noticeable Noise Peak Hour 83 dB 13 dB 70 dB Non-peak Hour 78 dB 13 dB 65 dB As shown in the calculation above, wall 1 experienced only 13 dB overall transmission loss where 65dB to 70 dB is the noticeable noise within the cafeteria. It exceeds the standard noise rating value (40dB during day time and 30 dB during night time) of a reception and coffee bar as well as its required transmission coefficient. Thus the SRI/TL of the hotel rooms is not efficient enough to maintain the human comfort level due to its perforated brick facade.
58 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
Wall 2 Overall Sound Energy Transmission Coefficient for Room Type 3 (Room with Fixed Glass) Fixed Window Concrete Blockwall Painted White ! ! SRI = 10 log10 ! SRI = 10 log10 ! SRI Brick = 35 SRI Timber = 10 ! ! 35 = 10 log10 ! 45 = 10 log10 !
!
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log-1 4.5 = ! Transmission Coefficient of Timber, TTimber = 3.16 x 10-5 Average Transmission Coefficient of Materials
log-1 3.5 = ! Transmission Coefficient of Brick, TBrick -4 = 3.16 x 10 Overall SRI of Wall 1
Tav
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SRI
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= 10 log10
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SRI Wall 1
= 10 log10
= 40.2 dB
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BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 59
Wall 3 Overall Sound Energy Transmission Coefficient for Room Type 3 (Room with Glass Box) Concrete Blockwall Painted White Fixed Glass Wall ! ! SRI = 10 log10 ! SRI = 10 log10 ! SRI Brick = 35 SRI Timber = 10 ! ! 35 = 10 log10 ! 45 = 10 log10 !
!
!
log-1 4.5 = ! Transmission Coefficient of Timber, TTimber = 3.16 x 10-5 Average Transmission Coefficient of Materials
log-1 3.5 = ! Transmission Coefficient of Brick, TBrick -4 = 3.16 x 10
Tav
=
SRI
=
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Overall SRI of Wall 1
SRI Wall 1
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= 10 log10
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= 10 log10
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= 36.38 dB = 2.3 x đ?&#x;?đ?&#x;&#x17D; Standard Internal Noise Control for Hotel Rooms Standard Internal Noise Control for Hotel Daytime â&#x20AC;&#x201C; 25 dB Rooms Night Time â&#x20AC;&#x201C; 20 dB Required Transmission Coefficient Daytime: ! 25 = 10 log10 !
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log-1 2.5 = ! = 3.1622 x 10-3 Night Time: ! 20 = 10 log10 ! !
log-1 2 = ! = 1 x 10-2
60 BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL
Noise Level in hotel rooms of Lantern Hotel after transmission loss: Room with Fixed Glass Noise from Atrium Overall TL of wall Noticeable Noise Peak Hour 60 dB 36.38 dB 23.62 dB Non-peak Hour 51 dB 36.38 dB 14.62 dB Room with Glass Box Noise from Atrium Overall TL of wall Peak Hour 60 dB 40.2 dB Non-peak Hour 51 dB 40.2 dB
Noticeable Noise 19.8 dB 10.8 dB
As shown in the table above, wall 2 at 3 walls experienced 36 to 40 dB overall transmission loss for hotel rooms where 10 to 24 dB are the noticeable noise within the hotel rooms However, it does not exceed the standard noise rating value (25 dB during day time and 20 dB during night time) of a hotel room as well as its required transmission coefficient. Thus the SRI/TL of the hotel rooms meet the requirement of an appropriate internal noise level for a hotel to maintain the human comfort level.
BLD 61303 BUILDING SCIENCE 2 LIGHTING & ACOUSTIC PERFORMANCE LANTERN HOTEL 61