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Project ReportOn

DIALUX BASED INTERIOR LIGHTING DESIGN AND MATLAB

COMPUTATION

Project Report Submitted in partial fulfillment of the requirements for the degree of Bachelor of Technology from West Bengal University of

Technology

ByPranab Biswas Roll No - 08176016023Kartik Samanta Roll No - 08176016043Rahul Biswas Roll No - 08176016057Dipankar Roy Roll No - 08176016046

Under the Guidance of Prof.- Ms. Deblina Sabui (Assistant Professor, Dept of E.E)

Department of Electrical Engineering.Hooghly Engineering & Technology College

Hooghly, West Bengal

2011-2012

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Certificate of Recommendation

It is hereby recommended to consider the project report entitled “ DIALUX BASED INTERIOR LIGHTING DESIGN AND MATLAB

COMPUTATION’’ submitted by

Pranab Biswas Roll No - 08176016023Kartik Samanta Roll No - 08176016043Rahul Biswas Roll No - 08176016057Dipankar Roy Roll No - 08176016046

for partial fulfillment of the requirements for the award of the degree of Bachelor of Technology in Electrical Engineering from West Bengal University of Technology.

--------------------- ---------------------------------

Prof. Ms. Deblina Sabui Prof. D. M. Kar(Assistant Professor ) ( Head of the Department ) Project Guide (i

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Certificate of Approval

It is hereby approved the project report entitled "( DIALUX BASED INTERIOR LIGHTING DESIGN AND MATLAB COMPUTATION’’)" submitted

by Pranab Biswas Roll No - 08176016023Kartik Samanta Roll No - 08176016043Rahul Biswas Roll No - 08176016057Dipankar Roy Roll No - 08176016046

for partial fulfillment of the requirements for the award of the degree of Bachelor of Technology in Electrical Engineering from West Bengal University Of Technology.

Board of Examiners

---------------------------

-----------------------------

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------------------------------- (ii)

Contents

CHAPTER NO. TOPIC PAGE NUMBER

1 Definition

2 Case Study One

3 Case Study One

4 Case study three

5 Matlab Computation

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(iii)List of the Figure

.

SERIAL NO.

TOPIC PAGE NUMBER

1 RELATION BETWEEN DIFFERENT LIGHTING PARAMETERS

2 INVERSE SQUARE LAW3 LUMEN METHOD OF LIGHT CALCULATION4 SPACE: HEIGHT RATIO (SHR)5 DIALux Light Wizard6 DIALux 4.4 project [WORKSTATION 3D ]

8 DIALux 4.4 project [FLOOR PLANE VIEW ]

9 Luminaire diagram

10

11

12

isolux plot

mountaing plot

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List of the Tables

1. OFFICE WORK PLACE AREA / Photometric Results

2. OFFICE CONFERANCE ROOM/Photometric Results

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ACKNOWLEDGEMENT

We would like to articulate our deep gratitude to our project guide Ms. Deblina Sabui who has always been source of motivation and firm support for carrying out the project. We express our gratitude to Prof D. M. Kar, Professor and Head of the Department, Electrical Engineering for his invaluable suggestion and constant encouragement all through the work. We would also like to convey our sincerest gratitude and indebtedness to all other faculty members and staff of Department of Electrical Engineering , HETC, who bestowed their great effort and guidance at appropriate times without which it would have been difficult on our project work.An assemblage of this nature could never have been attempted with our reference to and inspiration from the works of others whose details are mentioned on reference section. We acknowledge our indebtedness to all of them. Further, we would like to express our feeling towards our parents and God who directly or indirectly encourage and motivated us during this dissertation.

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Abstract

The Project investigates the energy efficient technology as an artificial lighting source for office buildings. Light is a form of Electromagnetic energy radiated from a body which is capable of being perceived by the human eye. The sensation of light result from a flow of energy into the eye and the light will appear to vary if the rate of this flow of energy varies.An effective strategy to reduce the lighting power density in offices while maintaining high quality lighting can have huge energy savings potential for commercial office space. Task/ Ambient light optimizes lighting power density through a reduction in overhead lighting level supplemented by bringing personal task light to the workspace.A lighting system based on uniformly placed CFL, T5 are in a ceiling is designed with respect to requirements for lighting comfort on the workplaces in typical office buildings. Now a days it is possible to model rooms with luminaires and accommodated with daylight calculations by Lighting software and simulate the illuminance behavior. Furthermore controlling strategies with automatic switches sensors, timer, etc are implemented, which make it possible to calculate the efficiency of the lighting planning design. The controlling strategies in Light Calc are made with focus on individual control to obtain three set goals. First equally distributed illuminance in the room, then high illuminance in the work places and lower surroundings illuminance finally daylight control.All strategies are implemented and tested by simulations in an office model. All luminaire are controlled individually and the solution of optimized via a wanted illuminance value. Result show that by applying individual light control saves energy, especially when combined with daylight.After obtaining the complete model and programming of lighting design in the 3D system. The model is simulated using MATLAB.

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IntroductionIn this thesis modern lighting technology is investigated to provide artificial lighting in office buildings. This is done in order to achieve lower energy consumption, good light distribution and color rendering along with individual control for the best possible lighting scenarios for each desired task. Here this new technology is used to design a better solution than conventional artificial lighting especially due to the longer life time of T5s and lower annual costs in electricity. The lighting system is designed to represent the required standards and comfort level of office work environment along with individual control to gain the best possible office environment with uniformly placed T5s in the ceiling. The idea is to control the output level in an energy efficient way, such as keeping a desired light level at the work stations while regulating the rest down to a minimum. Therefore a system with individual control unit each lamp is needed. Implementing this design gives the benefit of creating a complete system with individual control of the lamps by controlling the desired light level with and without daylight present. In this thesis the lighting system is implemented by means of simulations in the MATLAB program and designed by DIALUX. In additions to the program so that the photometric data from a lamp can be imported and a mathematical model of combined daylight and T5 illumination can be calculated with the controlling strategy mentioned above. This method is a valuable tool in designing and running light installations with energy saving as a main goal. This solution can be recommended as an energy effective combination with the new T5 technology, Individual control and daylight.

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Chapter 1 Definitions

LUMEN :

Luminous flux or luminous power is the measure of the power of light source. It differs from radiant flux, the measure of the total power of light emitted, in that luminous flux is adjusted to reflect the varying sensitivity of the human eye to different wavelengths of light. The unit of luminous flux is the lumen (lm). One lumen is defined as the luminous flux of light produced by a light source that emits one candela of luminous intensity over a solid angle of one steradian. In other systems of units, luminous flux may have units of power.

LUMINOUS INTENSITY:

Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd), an SI base unit.

ILLUMINANCE:

Illuminance is the total luminous flux incident on a surface, per unit area. It is a measure of the intensity of the incident light, wavelength-weighted by the luminosity function to correlate with human brightness perception. Similarly, luminous emittance is the luminous flux per unit area emitted from a surface. Luminous emittance is also known as luminous existence.

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In SI derived units these are measured in lux (lx) or lumens per square metre (cd·sr·m−2). In the CGS system, the unit of illuminance is the photo, which is equal to 10,000 lux. The foot-candle is a non-metric unit of illuminance that is used in photography.

Illuminance was formerly often called brightness, but this leads to confusion with other uses of the word. "Brightness" should never be used for quantitative description, but only for no quantitative references to physiological sensations and perceptions of light.

LUMINANCE:

Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The SI unit for

Definitions

luminance is candela per square metre (cd/m2). A non-SI term for the same unit is the "nit". The CGS unit of luminance is the stilb, which is equal to one candela per square centimeter or 10 kcd/m2.

RELATION BETWEEN DIFFERENT LIGHTING PARAMETERS

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LIGHT OUTPUT RATIO (LOR):

The ratio of the light output of a luminaire to the light output of the lamps without a luminaire.

LOAD FACTOR:

The ratio of energy consumed by a controlled lighting installation to the energy which would have been consumed without controls, over a period of time.

Definitions

LAMP LUMEN MAINTENANCE FACTOR (LLMF):

The proportion of light output of a lamp, after a specified number of hours operation, to the initial light output of the lamp.

LAMP SURVIVAL FACTOR (LSF):

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The % of lamps still operating in an installation after a specified number of hours operation.

LIGHT LOSS FACTOR (LLF):

This term has been replaced by maintenance factor in the 1994 CIBSE Guide. Previously LLF and MF differed in that the latter took no account of the lamp lumen maintenance factor (LLMF). In the 1994 Guide, maintenance factor takes LLMF into account.

LUMINAIRE MAINTENANCE FACTOR (LMF):

The ratio of light output after a specified period of time to initial light output of the luminaire. This takes account of dirt and dust reducing the light output of the luminaire.

ROOM INDEX:

This takes account of room proportions and height of the luminaire above the working plane. It is used to determine the Utilisation factor.

L x W R.I. = ---------------- (L + W) HmwhereL = LengthW = WidthHm = Height of luminaire above working plane.

MAINTENANCE FACTOR (MF):

The ratio of illuminance at the end of the maintenance period to the initial illuminance.MF = LSF x LLMF x LMF x RSMF.

Basic Definitions of Light

ROOM SURFACE MAINTENANCE FACTOR (RSMF):

The proportion of illuminance at the end of the maintenance period to the initial illuminance taking account of the reduction in room reflectance because of dirt and dust. It is separate to LMF and LLMF.

SPACE TO HEIGHT RATIO (SHR):

The ratio of: Distance between luminaire centers, in a regular square array of luminaires, divided by their height above the working plane.

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UTILISATION FACTOR (UF):

Proportion of light reaching working plane to light output of lamps. It depends on room index, room reflectance’s and type of luminaire used.

LAWS OF ILLUMINATION OR LUMINANCE

INVERSE SQUARE LAW : The area illuminated by the point light source increases in proportion to the square of the distance. It follows that the average illuminance would decrease by the same ratio.

IE = ---- d2

where d = the distance between the source and the object.

Basic Definitions of Light

LAMBERT’s COSINE LAW : When light does not fall normally on a surface, the area illuminated increases reducing the average illuminance by the same ratio. The Fig. shows light from a distant source striking surfaces AB and BC. The rays of incident light may be taken as parallel.

AB---- = Cos θBCwhere θ = The angle between the incident light and the normal to the surface BC. Therefore the average illuminance on a surface is given by the general formula:

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I Cos θΕ = −−−−− d2

LUMEN METHOD OF LIGHT CALCULATION

This method is most suitable for interior lighting design , where a high proportion of light on the working plane is reflected by internal surfaces. For external applications or where the reflectance of the surfaces is unknown or may not be relied upon (emergency lighting schemes), a utilisation factor for zero reflectance may be used. The lumen method, sometimes called the luminous flux

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Definitions

method of calculation, is normally used to calculate the average illuminance on working planes, or to calculate the number of luminaires required to provide a specified average illuminance in rooms. The following formula is used:

N (n . φ) . MF . UFE = -------------------- Aor

E x AN = ----------------- Mf . UF . (φ . n)

Where:N = Number of luminaires requiredE = Maintained Illuminance (lux)φ = Initial lamp output (lumens)n = Number of lamps in luminaireMF = Maintenance factorUF = Utilisation factorA = Area of room (m2)

UTILISATION FACTOR:

Lumens received on W.P.UF = --------------------------------- Lumens output of luminaires

Utilisation factor takes account of theloss of light due to absorption on roomsurfaces. It depends on 3 factors:

1. Type of Luminaire: A luminaire with a concentrated light output directed onthe working plane will have a higher UFthan a luminaire with a dispersed light output.2. Room index. This takes account ofthe length (L) and width (W) of the roomand the height of the luminaires abovethe working plane (Hm).

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Definitions

L x WR.I. = ------------ (L + W) Hm

2. Reflectances of Room Surfaces.

Bright coolers with high reflectance’sresult in a higher UF. A high utilisationfactor will mean fewer lamps are neededresulting in a more efficient energy usageand a lower capital cost.

SPACE: HEIGHT RATIO (SHR): This is the ratio of space betweenluminaires (S) to their height above theworking plane (Hm).Manufacturers will specify arecommended SHR for each of theirluminaires. Ensuring that luminairesare spaced within the recommendedvalue will mean an acceptable variationin illuminance across the workingplane. This is expressed in terms of theUniformity Ratio (see definitions).

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CHAPTER 2 Case Study One PART I: Workstation Lighting DesignThis project will gives us a quick interior lighting layout. With the help of this wizard it is possible to complete lighting design and simply. We will also be able to run full lighting calculation in lux and produce professional quality reports. Double click on the DIALux light icon on our computer. After starting , we are welcomed by a startup window (see Figure 1). To move to the next window click on next

Figure 1.Step 1.Enter Project InformationIn the Project Information Window(See Figure2),we can enter the data about our project . this information will appear later in our printour reports.

A. In this example ,enter the following data:Project: Office lighting designRoom: workstation in office building Surface condition: Clean surface

Nature of work :computer working Age of worker :22-40 Average lux level -500lux Selected lamp – 18 Watt T5 Selected luminaire- philips made TBS300/418, MIRROR-M5

B. On the right side of this window , we should already see the name ,company name, etc. that we entered during the configuration of DIALux. We can change any of this data as necessary

C. Click the Next Button when finished(see Figure 3)

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Case Study One

Figure 2

. Figure 3

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Case Study One

Step 2.Enter Room Dimensions, Reflectance ValuesThe next window is for Data Input (see Figure 3) where we specify the room geometry on the left hand side. We can also change the reflectance values used for the ceiling, walls and floor as necessary.For this project, we will create a room

a) Enter the following data:Length (a):10.00mWidth (b):7.00mHeight: 3.00m

b) For Reflectance Factor, Light Loss Factor, And work plane enter the following data:Ceiling: 80% Walls: 50% Ground: 68% Light Loss Factor: 0.80Work Plane Height: 0.560m

c) On the right side of this window, click on the Catalogs button to open up the luminaire database .We chose TBS300/418,MIRROR-C6 Luminaire. Click Next when finished.

Step3. Luminaire detaila) No luminaires-12 Piecesb) Type of luminaire- 6TBS300/418,MIRROR-M1 & PHILIPS SOLID STATE

LIGHTING c) Reflector used -MIRROR-M5d) Lamp used – 4 X 18 watt T5 , e) Luminaire Luminous Flux: 5200 lm f) Luminaire Wattage: 95.1 W g) Fitting: 4 x TRULITE 18W (Correction Factor 1.000).

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Case Study One

Step 4.Calculation and Results a) In the Calculation and Results window. A Under calculation parameters, enter 500

lux.Use the drop down menu to change the Luminaire Mounting to surface mounted.Click the Calculate icon and the program will start the point by point calculations.b) Once the calculations are finished, the Light Wizard will display the results in a

figure of isolux lines and a table of lux values for the work plane (see Figure4)c) Click the Calculate icon and the program will start the point by point calculations

d) Once the calculations are finished, the Light Wizard will display the results in a figure of isolux lines and a table of lux values for the work plane (see Figure 4).

e) .Click Next to continue to Step 4

Figure 4

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Case Study One

Step 5. Print Report and Export to DIALux.In the Result Output window you have the option to print the results or save them in electronic format as a PDF file

a) Click on the Save as DIALux Project button to save our project for further analysis.

b) Click next and then click finish to close the program.

Figure5. Results Output Window

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Case Study One

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Case Study One

PART II. Continuation of Project – workstation in office

This project will build upon the workstation in office room completed in Project #1.we will learn how to add objects, move luminaires around and add additional calculation grids.Double click on the DIALux icon on your desktop - or click Start -> All Programs -> DIALux. we will be welcomed by a startup window (see Figure 6).

Figure 6

Step 1. Open projectClick on the Open Project icon, and navigate to where you saved the “interior office lighting project” and click Open to load the project (see Figure 13)

Figure 7

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Case Study One

Step 2. Add Objects to the Project A. Open the project. B. Under Project Manager, click the Floor Plan icon

C. When click the floor plane icon we get workstation in floor palne view(see

figure 8)

Figure 8You can also change the objects’ location/properties in the Room View. Once an object has been inserted into a room, its context menu can also be accessed with a right click (see Figure 9).

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Case Study One

Step 3. Add office furniture and office accessories:

a. Under the project manager, click on the object icon.(see figure 10)

Figure 10

b. Click on furniture points and extract it.c. Then click the need things and drag over to the plane view.(see figure 11)

Figure 11

d. When the office accessories (table, chair, door, computer, dustbin etc.) drag over to the plane view it is looking like figure 12.

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Case Study One

PART III: Run Calculations and View Results

a. Under the main menu, click on Output and Start Calculations. When the Calculation window opens, make sure to place a check in the box next to Include Luminaires in Calculations and then click OK .

Figure 13

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Case Study One

b. View and Print Output: Under Project Manager, click the Output tab. Here we have many options on the type of reports to send to the client. In this example, place a check in the boxes next to: Project Cover, Summary, Input Protocol, Luminaires.

Figure 14

c. Luminaire image :

TBS300/418,MIRROR-M5

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Case Study One

OFFICE WORK PLACE AREA /Summary:------------------------------------------------------------------------------------------------------------

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Case Study One

OFFICE WORK PLACE AREA / Photometric Results:------------------------------------------------------------------------------------------------------------

Total Luminous Flux: 124800 lmTotal Load: 2282.4 WLight loss factor: 0.80

Surface Average Illuminances [lx] Reflection factor [%]

Average luminance [cd/m²]

direct indirect total

Workplane 278 160 438 / /

Floor 179 131 310 15 15

Ceiling 0 201 201 80 51

Wall 1 126 152 278 82 73

Wall 2 125125

178146

304270

8282

7971

Wall 3

Wall 4 103 142 245 46 36

Table 1

Chapter 3

Case Study TwoPROBLEM PRESENTATIONS TWOPART I: Conference Lighting Design

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This is the project will gives us a quick interior conference lighting layout. With the help of this wizard it is possible to complete lighting design and simply. We will also be able to run full lighting calculation in lux and produce professional quality reports. Double click on the DIALux light icon on our computer same as the previous project one. After starting, we are welcomed by a startup window (see Figure 15). To move to the next window click on next

Figure 15Step 1.Enter Project InformationIn the Project Information Window,we can enter the data about our project . this information will appear later in our printour reports.

a) In this example ,enter the following data:i. Project: Office lighting design

ii. Room: conference in office building iii. Surface condition: Clean surfaceiv. Nature of work : conference, meeting v. Age of worker : 22-40

vi. Average lux level -400luxvii. Selected lamp – 18 Watt T5 and LED 1 WATT

viii. Selected luminaire- 6TBS300/418,MIRROR-M1 and Philips solid state lighting

b) On the right side of this window, we should already see the name ,company name, etc. that we entered during the configuration of DIALux. We can change any of this data as necessary.

Case Study Two

c) Click the Next Button when finished(same as the project one).

Step 2.Enter Room Dimensions, Reflectance Values

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The next window is for Data Input where we specify the room geometry on the left hand side. we can also change the reflectance values used for the ceiling , walls and floor as necessary.For this project, we will create a room,

a) Enter the following data:Length(a):15.00mWidth (b) :10.00mHeight: 3.00m

b) For Reflectance Factor, Light Loss Factor, And work plane enter the following data:

Ceiling: 80% Walls: 50% Ground: 68% Light Loss Factor: 0.80Work Plane Height: 0.560m

c) On the right side of this window, click on the Catalogs button to

open up the luminaire database .We chose TBS300/418,MIRROR-C6 Luminaire and Philips solid state lighting.

d) Click Next when finished.

Step3. Luminaire detail

a) No luminaires-12 Piecesb) Type of luminaire- 6TBS300/418,MIRROR-M1 & PHILIPS SOLID STATE

LIGHTING c) Reflector used -MIRROR-M5d) Lamp used – 4 X 18 watt T5 , 1 WATT LEDe) Luminaire Luminous Flux: 5200 lm & 441 lmf) Luminaire Wattage: 95.1 W & 14.7 w g) Fitting: 4 x TRULITE 18W (Correction Factor 1.000)

Case Study Two

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Figure 16: 6TBS300/418,MIRROR-M1 Figure 17: PHILIPS SOLID STATE LIGHTING

a. When the conference room accessories (table, chair, door, computer, dustbin etc.) drag over to the plane view it is looking like figure 12 and its 3D view look like figure 19.

Figure 18

Case Study Two

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Figure 19

Step 4: PART III: Run Calculations and View Results

a) Under the main menu, click on Output and Start Calculations. When the Calculation window opens, make sure to place a check in the box next to Include Luminaires in Calculations and then click OK.

b) View and Print Output: Under Project Manager, click the Output tab. Here we have many options on the type of reports to send to the client. In this example, place a check in the boxes next to: Project Cover, Summary, Input Protocol, Luminaires.

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Case Study Two OFFICE CONFERANCE PLACE AREA /Summary:

------------------------------------------------------------------------------------------------------------

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Case Study Two

OFFICE CONFERANCE ROOM/Photometric Results-----------------------------------------------------------------------------------------------------------

Total Luminous Flux: 21214 lmTotal Load: 395.9 WLight loss factor: 0.80Boundary Zone: 0.000 m

Surface Average Illuminances [lx] Reflection factor [%]

Average luminance [cd/m²]

direct indirect total

Workplane 83 32 115 / /

Floor 61 34 95 26 7.86

Ceiling 0.00 45 45 80 11

Wall 1 13 35 49 76 12

Wall 2 4619

3839

8459

7676

2014

Wall 3

Wall 4 24 34 59 76 14

Table 2

CHAPTER 4

Case Study ThreeMATLAB COMPUTATION

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Step 1. We are create a matlab programming for interior office conference room, see in below

%Direct Hoz.illuminance computation on Hoz.working plane %From single Luminaire placed at center of a room with dimension of 15m x 10m. %Mounting ht = 4m %Assigning of Input variablesxL=7.5; yL=5; hm=4;i=1;j=1;ESUM=0;N=0; Emin=5000;Emax=0;%..............................% Grid Point coordinate selectionfor xg=0.25:0.25:14.75 for yg=9.75:-0.25:0.25%............................. % Direct Contribution from source at a Grid point % NP: distance between nadir point(N) and grid point(P) NP=sqrt((xL-xg)^2+(yL-yg)^2); gama=atan(NP/hm); I=500*(1+2*(cos(gama))); Ep=(I*(cos(gama))^3)/(hm^2); %...................... %Saving Grid-specific illuminance at 2-D array E(i,j)=Ep; %...................... %Cumulative Sum of Illuminance values and Number of grid points(N) ESUM=ESUM+Ep;N=N+1; %.............................. %Finding out Emin and Emax if (Ep < Emin) Emin=Ep; elseif (Ep > Emax)

Case study three

Emax=Ep; end %.................

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i=i+1; end j=j+1; i=1;end %Uniformity of illuminance calculationEavg=ESUM/NU1=Emin/Eavg;U2=Emin/Emax;%................................%Plotting of Isolux contour and Mountain Plotxg=0.25:0.25:14.75;yg=9.75:-0.25:0.25;[XG,YG]=meshgrid(xg,yg);v=Emax*[0.90,0.80,0.70,0.60,0.50,0.40,0.30];[C,h]=contour(XG,YG,E,v);clabel(C,h);axis([0.25,14.75,0.25,9.75]);saveas(gcf,'ISOLUXplot1.fig')pausesurf(XG,YG,E);saveas(gcf,'MOUNTAINplot1.fig')%............................

Step 2. Output result and diagramwe have get illumination average value office conference room in matlab Output file.Eavg =26.1105We have also get isolux plot figure form matlab output (Figure20 ) and also mountaing plot figure form matlab output (figure 21).

Case study three

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Figure 20

Figure 21 -:CONCLUSION:-

The project has been done by us during one year and try to overcast the view of interior lighting design .This project gives us a lot of knowledge about light, it’s

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properties and indoor lighting design technique for different place in different work .The project built help of DIALUX software which based on preparing for lighting design.

→The DIALUX software can be established, how much light needed to the right place for right work at right time.

→This type of lighting design modern efficient technique which can reduce the power loss, so that technique was saving the energy from the bad worst. Here this technique is used to build to working station and try to highlight the proper use of light.

→ Here calculate the value of the various thing like flux, candela, lumens etc by using the DIALUX 4 Version.

→ Here use the MATLAB software which is one of the suitable and easier process for calculate of different essential lighting properties and also represent the ISOLUX diagram which gives to us known to different phenomena about light and its interior lighting design.

At last, it is a true thatT5s have proven to be extremely effective due to their long lifespan and increased efficiency. However, T5 fluorescent bulbs have performed significantly better in multiple studies that are critical to commercial and residential usage ,it is important to consider crucial factors such as heat dissipation, the CRI rating, efficacy, overall cost, and lifespan of bulbs.

Bibliography

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[1] Author B.L. Theraja & A. K. Theraja ; “Utilizaton of Electrical Energy’

[2]Author Rajput ;Dhanpat company pvt ltd in ‘Energy conservation & Utilisation’

[3] Energy crisishttp://en.wikipedia.org/wiki/Energy_crisis

[4] illuminationfundhttp://www.opticalres.com/lt/illuminationfund.pdf

[5] tutorial-dialux.pdf http://gitalistia.files.wordpress.com/2008/12/tutorial-dialux.pdf

[7] Interior lighting design StudentsGuidhttp://eleceng.dit.ie/kkelly/Lighting/Interior%20lighting%20design

%20%20%20%20%20%20Students%20Guide.pdf)

[8] surface-contourhttp://www.math.neu.edu/~braverman/Teaching/Fall2000/surface-contour.pdf

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