effect of colours on lighting efficiency in...

This work by ‘Rohini Singh’ is Part Fulfillment of the requirement for Masters’ Degree in Interior Design Program at CEPT University.Intellectual property of these remains with CEPT University and any content of this should not be copied in total or in part without prior written permission.

EFFECT OF COLOURS ON LIGHTING EFFICIENCY IN INTERIORSthesis presentation

Rohini SinghMasters’ in Interior Architecture and Design,Faculty of Design, CEPT University, Ahmedabad

July 08, 2009

2


presentation overview

introduction

problem description

literature review

methods and procedure

analysis

conclusion

research methodology

selection of tool

base case derivation

primary experiment

pilot study

analysis plan

primary analysis

example case

3


integral part of structures that contain them – usually buildings [1]

it is process of shaping the experience of interior space, through the manipulation of spatial volumeas well as surface treatment.’ [2]

a coordinated whole with architecture, function, and visual aspects unified

sensitive and conscious design to make material civilization harmonious, efficient and meaningful.

introduction I interior space I lighting I efficiency I colour

Theoretical Source: [1] Pile, John F. Color in interior design: McGraw-Hill Professional, 1997

[2] < http://www.ncku.edu.tw/~ives/ives/english/department/interior_space_design.htm>

Interior space

4


standards and legislatedenergy codes addresstheoretical approaches tobuilding systems such aslighting, HVAC, energymanagement, etc.

Interior design not onlydomain of interior designer oran architect but lightingdesigners, HVACconsultant, civil engineer, theelectrical engineers, etc.

Comprehensive lightingdesign - functional lightprovided, the energy consumedand aesthetics

architect

interior designer

lighting engineer

HVAC consultant

civil engineer

buildingowner

construction manager

facilities manager


Illustration Source: Obanye 2006)

5


Artificial lighting major energy consumptioncomponent especially office buildings.

To realize the full potential of energy efficientlighting, careful attention to many interactingvariables.

standards like IESNA have developedscientific bases for lighting ; consider andidentify color, daylight availability, glareand, light distribution as prime issues toperpetuate efficient interiors. lighting consumes 25 – 30% of energy in

commercial buildings, U.S. Department of Energy.

Office Buildings - largest components of

Commercial Building Electricity Use. [4]

In India lighting component about 15 – 18 % of the

total electricity. [5]


Theoretical Source: [4] E SOURCE: Lighting Technology Atlas, Ch. 4. 1994[5] <http://www.renewingindia.org/newsletters/bee/past/bee_june_09_06b.htm>

6


colour is one of the most dominant spatial elements

colours of an interior surface can absorb or reflect light and distribution of light from the lightsource.

Effect the efficiency of the luminaire’s distribution and consecutively the lighting efficiency of thespace.

one-third of the energy use of a lighting system depends upon the surrounding interiorfeatures, such as colour and reflectivity of room surfaces. [6]

colour decisions cannot be based only on aesthetics and artistry, knowledge and technicalexpertise are essential

relate colour preferences to efficiency of a space; contribute not only to visual experience but thevalue of the space.


Theoretical Source: [6] Lighting, Energy Star Building Manual: 8pp, 17th Sept. 2008

this very thought, idea or concept incites the research and it seeks to examine the effect ofSurface Colour on distribution of light from light source.

7


Interior Space

Light

Colour

Efficiency

lighting loads

energy consumption

harmony between

them is essential

colour and light

interior space element

colour and light

define space

application of

light: aesthetics and

function

conscious

designing

dominant

spatial element

8


introduction I problem description

energy efficiency is important butconsider visual comfort, health, etc.

understand the issues of quality andquantity of light

little consensus in terms of both theirenergy* performance and visual comfortconformity and its quantification

worth exploring the range of surfacereflectance for room surfaces, workplaneand partitions that are the most energyefficient and adhere to the visual balanceof the space.

aim: of the study is to determine the effect of Colour on Lighting Efficiency of Interior space while maintaining the visual comfort standards.

* here and later in the study ,by energy performance it implies its lighting energy performance

Benefits high

Benefits low

Things we want to recommend

Design intervention

occurs naturally

Requires a lot attention

Things we must discourage

Visual comfort

Efficiency

9


Research objectives:

study quantitative aspect of Colour, its reflectance and its ability

analyze the relationship between surface colour reflectance

validate the performance of different reflectance combinations of the room surfaces by verifyingagainst the optimal visual comfort requirements

identify the Colours schemes those prove feasible within the premises of the study.

Scope and limitations :

analysis would take into account only artificially lit areas i.e. non-daylight areas

Model derived from typical layout of Open Plan Offices of Ahmedabad, India.

Luminosity performance and parameters conforms to lighting standards such asIESNA, CIBSE, etc.All manual calculations and simulations done using algorithms established on diffuse reflectancebehaviour The study is confined to matte finished surfaces only

introduction I problem description

10


literature review I summary

value property of colour arises from relative luminance of asurface or light.

grey value of colour alone can be presumed to calibrate theluminous character of light.

Mary C. Miller surface colour can augment or negate thedistribution of light.

Andreas Zimmermann longer people are exposed to avisual environment better the surfaces to be defined, especiallyoffices.

lighting standards and codes emphasize : colour of the room surfaces, Surface reflectance, andresultant inter-reflection of light in room influences functioning and appraisal of lighting systems.

ASHRAE/IESNA Standard 90.1-1999 User’s Manual surface reflectances of 80% forceilings, 50% for walls, and 20% for floors to be used in daylighting calculations. [7]

Theoretical Source: [7] ANSI/ASHRAE/IESNA Standard 90.1 – 2001: Energy Standard for Buildings Except Low-Rise Residential Buildings.

11


5th LRO Symposium on Light & Human Health, Nov 2002 and BRANZ report ‘Colours andReflectances of room surfaces are part of the lighting system.’

Leyla Dokuzer Ozturk; Architectural Science Review 2003, differences in luminance of asurface are perceived as light stains and they decline room visual quality.

The CIBSE Code for interior Lighting (1994) maintain the visual balance within a space

G. R. Newsham, D. M. Sander suggests optimum luminance, reflectance values. E.g. fordesktop illuminance, a reduction of 10% will occur if: workstation reflectance is decreased from 50%to 20% and ceiling reflectance is decreased by around 10%

literature review I summary

12


methods and procedure I research methodology

Hypothesissurface colour effects distribution of light

Literature study

derive base case from variable Wall:Floor:Ceiling

analysis

Final analysis

conclusion

13


methods and procedure I research methodology I detail

Base Case Model Building information Design variables

Building gross area

Building depth, length, height

Interior arrangement

Room surface characteristics i.e. reflectance of W, F, C, Wo and P

Lighting design variables

Lumnaire and its arrangement

Lighting levels

Installed power density

Required performance parameters

Literature Study Data collection Survey of parameters involved

14


ExperimentComputer Simulation

DIALux Input to DIALux Variation on

reflectance of

W:F:COutput from DIALux

Analysis

Visual comfort assessment

of output data from

simulation

Manual calculations

Filter the ones that confirm

the comfort standards

Required parameters

Calculated parameters

from simulation output

Simulate the ones that confirm

for performance parameters Wo

and P

Output data from DIALux

Lighting power density

assessment

Manual calculations

Filter the ones that confirm

the comfort standards

Required parameters

Calculated parameters

from simulation output

Final selected cases

15


Final Analysis Identify grey tones

corresponding to reflectance

of W,F, C, Wo and P of final

selected cases

Identify colours

corresponding to grey tones

Munsell 9 step grey scale

Conclusion Interior Colour scheme

recommendation for W, F, C , Wo

and P

16


methods and procedure I simulation tool

DIALux, Version 4.6.2 – light planning program

ability to look at variables like reflectancequantities, photometric quantities and lighting load

integrated raytracing module.

Lighting design with colour filters and materials andsurface textures

calculate lighting of surfaces, provide technicallighting data for room and surface of an object andconsumption data for lamps.

photometric files like IES, EULUMDAT or CIBSE canbe imported

compliant with DIN 18599 and tested againstinternational standards (CIE 171:2006).

Theoretical Source: <http://www.dialux>

Building Description

Import luminaire data

running DIALux lighting design program

lighting calculation for room surfaces

connected lighting

load and maintained illuminace calculation

Modify properties

of room surfaces.

Update feedback

Surface calculation

surface wise calculation

calculation result

export to file

simplified diagram of DIALUX program structure

17


methods and procedure I basecase model I input data

open plan office of typical workstation unitarrangement -non-daylight zone

BP ERGO Ltd. Ahmedabad modular system.

net office space taken 66% of the gross i.e. 1800sq.m. [8]

Model Parameter ValueRoom length [m] 68.4mRoom depth [m] 26.3mCeiling height [m] 3.50m

area allowance per person is taken11sq.m

1.2 m high (3DZOOM) partition - 4-unitcluster workstation of 13 sq.m approx.

Workstation height -750mm.

Theoretical Source: [8] DeChiara, Panero, & Zelnik. Time-Saver Standards for Interior Design and Space Planning. New York, NY: McGraw Hill, 1991

18


methods and procedure I basecase model I input data

linear fluorescent ‘TL’5- delivers right colour rendering-low glare mirror optics luminaires

Interior illumination maintained at 300 lux.

Parameter Value Luminaire Philips TBS600 1xTL5-

28W/840 HF D7 Lamps 278 x TL5-28W Luminous flux 2600 lm Luminaire Wattage 32.0 W Light loss factor 0.8 Total installed lighting power [W]

8896

Mounting Height 3.0 m

19


methods and procedure I basecase model I views

DIALux rendered image showing the office workstation andluminaire arrangement

a typical 4-Unit modular cluster from the derived office layout

20


methods and procedure I pilot study I exercise 1Relationship between: Reflectance, Luminance, Illuminance and Uniformity .

0

10

20

30

40

50

60

70

80

90

Reflectance value [%]

Case 10

Case 9

Case 8

Case 7

Case 6

Case 5

Case 4

Case 3

Case 2

Case 1

Inferences: steep increase after 70% reflectance; 90% being maximum luminance values i.e. gradual increase till 70% but steep increase from 80%-90% reflectance Uniformity for workplane is gradual except for reflectance 30-40% is constant.

0

200

400

600

800

case 1

(0%)

case 2

(10%)

case 3

(20%)

case 4

(30%)

case 5

(40%)

case 6

(50%)

case 7

(60%)

case 8

(70%)

case 9

(80%)

case

10

(90%)

Con

nec

ted

Load

W/m

2/1

00L

ux

Cases

Workplane

average …

0

0.1

0.2

0.3

0.4

0.5

case 1

(0%)

case 2

(10%)

case 3

(20%)

case 4

(30%)

case 5

(40%)

case 6

(50%)

case 7

(60%)

case 8

(70%)

case 9

(80%)

case

10

(90%)

rati

o

Cases

Uniformity

Workplane Ceiling Floor

21


methods and procedure I pilot study I exercise 2Quantification of the energy performance

lighting loads i.e. the connected load (here) for all the cases is obtained from the simulation result

Inferences: with the increase in reflectance theConnected Load decreases.

load for Case.1 is found to be 57.81W/m²/100 lx and for Case.10 is 1.31W/m²/100 lx.

Conclusion:

marked difference between lightingenergy performance with eachincrease in reflectance values. impliesa space with higher reflectance wouldhave less connected load and viceversa.

57.81

26.46

16.7811.94 8.95 6.82 5.18 5.09 3.76 1.31

0

10

20

30

40

50

60

70

case 1 (0%)

case 2 (10%)

case 3 (20%)

case 4 (30%)

case 5 (40%)

case 6 (50%)

case 7 (60%)

case 8 (70%)

case 9 (80%)

case 10 (90%)

Co

nn

ecte

d L

oad

W/m

2/1

00

Lux

Cases

Load

Load

Specific Connected Load In terms of W/m²/100 lx

Reflectancecase 1 (0%)

case 2 (10%)

case 3 (20%)

case 4 (30%)

case 5 (40%)

case 6 (50%)

case 7 (60%)

case 8 (70%)

case 9 (80%)

case 10 (90%)

Load 57.81 26.46 16.78 11.94 8.95 6.82 5.18 5.09 3.76 1.31

22


methods and procedure I analysis plan I basecase

Base case is derived by finding outthe most ‘Operable Range’

‘Operable Range’ – variation on setof W: F: C reflectance combinations

lighting system were kept constantand room did not contain anyfurniture.

The variations as per the generalrecommendations by standards –set175 cases.

175 cases simulated to determinetheir lighting loads

Room surface Range*

30 – 70%

20 – 70%

40 – 90%

Wall

Floor

Ceiling

*range for reflectance values as

per standards

W20 F20 C20 - 90

F30 C20 - 90

F40 C20 - 90

…..

W30 F20 C20 - 90

F30 C20 - 90

F40 C20 - 90

…..

W40 F20 C20 - 90

F30 C20 - 90

F40 C20 - 90

…..

…..

….. W70 F20 C20 - 90

F30 C20 - 90

F40 C20 - 90

…..

175 W:F:C cases

23


methods and procedure I analysis plan I primary experiment Variation on reflectances of Workplane andthe Partitions for selected 9 Base Cases andsimulation is carried out

model includes furniture layout that is theworkstations

24 simulation sub-cases (trials) for each ofthe 9 Base Cases

216 cases [24x9] results compared to visualcomfort standards.

Criteria for Visual Comfort Standard

Criteria Luminous variable

< 2.5 Ratio of Illuminance of Wo : P

< 5:1 Ratio of max. and min Illuminance of Wo

≥ 0.5 Ratio of Illuminance of W: Wo

≥ 0.8 Ratio between min. and avg. Illuminance of Wo : W< 5:1 Ratio between max. and min. Illuminance

< 1.0 and > 0.5 Contrast Rendition Factor (CRF)

reflectance value for walls should be 50-70%, floor 20 – 40% and for ceiling 60 – 80%.

S.No. W:F:C cases

reflectance[%]

1 70:40:80

2 60:40:803 50:40:80

4 70:30:805 50:30:80

6 50:20:80

7 60:20:708 50:30:60

9 50:20:60

Workplane Partition

30– 80% 40 – 70%

24


Final result: Selection of the best model cases:

lighting power density is estimated for all the selected cases. ECBC recommends a Lighting powerdensity of 11.8 W/m2 for Open Plan Offices

Lighting installation power density W/m2 = [Average installed maintained illuminance(lm/m2)] /[equipment efficacy (lm/W)]

methods and procedure I analysis plan I primary experiment

25


methods and procedure I analysis map

Basecase Simulation

Variation on performance parameter W:F:C

175 Cases

9 Base Cases

Confirming recommendation by standards CIBSE for preferred W:F:C reflectance

Simulation

Variation on performance parameter Wo : P

216 Cases [ 9 x 24]

Output data form simulation

Visual comfort assessment

49 Cases Lighting power density assessment

Manual calculations

Manual calculations

26


analysis I basecase analysisBase case derivation analysis: Analysis for base case derivation is dealt in two parts:

Understanding of the behavioral pattern of the cases:

W30 F20 C20 - 90

F30 C20 - 90

F40 C20 - 90

…..

30% Constant Wall Reflectance

W40 F20 C20 - 90

F30 C20 - 90

F40 C20 - 90

…..


W50 F20 C20 - 90

F30 C20 - 90

F40 C20 - 90

…..


0.00

0.50

1.00

1.50

2.00

2.50

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35Co

nn

ecte

d lo

ad W

/m2

/10

0lu

x

Cases


27


analysis I basecase analysis

Inference:highest difference for the case of Ceilings and least difference for Walls.For 30% constant reflectance, ceiling takes up the maximum loads.For 40% constant reflectance, both ceilings and floor take up the maximum loads.For 50% constant reflectance, all three parameters perform same and have nearly same load values.But as the reflectances increase, the decrease in load values is more in case of ceilings.

0

0.5

1

1.5

2

2.5

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35Co

nn

ecte

d lo

ad W

/m2

/10

0lu

x

Cases

30% Constant Floor Reflectance

1.40

1.50

1.60

1.70

1.80

1.90

2.00

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25Co

nn

ecte

d lo

ad W

/m2

/10

0lu

x

Cases

30% Constant Ceiling Reflectance

28


analysis I primary analysis I example case

Case – W70: F40: C80

70%

80%

40%

Workplane Isoline

and Isolux diagram

Surface r [%] Eav [lx] Emax[lx] Lavg [cd/m²]

Floor 40 345 447 44

Ceiling 80 126 336 32

Walls 70 151 364 35

29


analysis I primary analysis I example caseprimary analysis: case model is simulated byexperimentation is done by varying the reflectance of theWorkplane and Partitions.24 simulations are to be done for the each of the case.

Wo P

1 30 40

2 30 50

3 30 60

4 30 70

5 40 40

6 40 50

7 40 60

8 40 70

9 50 40

10 50 50

11 50 60

12 50 70

13 60 40

14 60 50

15 60 60

16 60 70

17 70 40

18 70 50

19 70 60

20 70 70

21 80 40

22 80 50

23 80 60

24 80 70

Reflectance [%]

Cases

Range of reflectance

Workplane Partition

30 40

40 50

50 60

60 70

70

80

30



Of these cases, as per output data the Eav, Emin, Emax for Workplane, partition, wall and ceiling are examined.

Case Reflectance Wo

Reflectance P

Eav Wo [lux]

Eav P [lux]

Eav W [lux]

Eav C [lux]

Emax Wo [lux]

Emin Wo [lux]

1 30 40 253 128.1 68 52 378 174

2 30 50 259 131.9 74 60 384 177

3 30 60 265 137.4 81 68 393 183

4 30 70 273 144.8 88 77 403 185

5 40 40 255 131.6 70 56 383 175

6 40 50 261 136.2 77 64 390 181

7 40 60 267 140.1 83 72 396 186

8 40 70 275 148.2 91 81 404 188

9 50 40 257 136.8 73 60 390 180

10 50 50 263 145.1 79 68 397 185

11 50 60 270 148.3 86 76 401 187

12 50 70 278 155.5 94 86 411 189

13 60 40 259 143.1 75 64 397 183

14 60 50 265 148.9 81 72 402 183

15 60 60 272 154.2 88 80 407 189

16 60 70 281 160.7 94 91 414 194

17 70 40 261 147.1 77 66 401 182

18 70 50 267 151.0 84 76 406 188

19 70 60 274 161.7 91 85 415 190

20 70 70 283 169.2 100 96 422 194

21 80 40 263 153.2 80 71 409 183

22 80 50 270 160.6 86 80 414 189

23 80 60 277 168.1 94 89 422 193

24 80 70 286 178.5 103 101 432 219

31


analysis I primary analysis I example caseVisual comfort assessment:

Criteria 2

Ratio of Illuminance of Wo : P < 2.5

1 30 40 253 128.1 0.2

2 30 50 259 131.9 0.2

3 30 60 265 137.4 0.2

4 30 70 273 144.8 0.3

5 40 40 255 131.6 0.2

6 40 50 261 136.2 0.2

7 40 60 267 140.1 0.2

8 40 70 275 148.2 0.3

9 50 40 257 136.8 0.2

10 50 50 263 145.1 0.2

11 50 60 270 148.3 0.2

12 50 70 278 155.5 0.3

13 60 40 259 143.1 0.2

14 60 50 265 148.9 0.2

15 60 60 272 154.2 0.2

16 60 70 281 160.7 0.2

17 70 40 261 147.1 0.2

18 70 50 267 151.0 0.2

19 70 60 274 161.7 0.2

20 70 70 283 169.2 0.2

21 80 40 263 153.2 0.2

22 80 50 270 160.6 0.2

23 80 60 277 168.1 0.2

24 80 70 286 178.5 0.2

Eav Wo/

Eav P

Luminous

variable

Case Wo P Eav Wo

[lux]

Eav P [lux]

Criteria 3

Ratio of max. and min Illuminance of Wo< 5:1

1 30 40 378 174 2.2

2 30 50 384 177 2.2

3 30 60 393 183 2.1

4 30 70 403 185 2.2

5 40 40 383 175 2.2

6 40 50 390 181 2.2

7 40 60 396 186 2.1

8 40 70 404 188 2.1

9 50 40 390 180 2.2

10 50 50 397 185 2.1

11 50 60 401 187 2.1

12 50 70 411 189 2.2

13 60 40 397 183 2.2

14 60 50 402 183 2.2

15 60 60 407 189 2.2

16 60 70 414 194 2.1

17 70 40 401 182 2.2

18 70 50 406 188 2.2

19 70 60 415 190 2.2

20 70 70 422 194 2.2

21 80 40 409 183 2.2

22 80 50 414 189 2.2

23 80 60 422 193 2.2

24 80 70 432 219 2.0

Emax Wo/

Emin Wo

Luminous

variable

Case Wo P Emax Wo

[lux]

Emin Wo

[lux]

Criteria

4

Ratio of Illuminance of C: Wo 0.3 - 0.8

1 30 40 253 52 0.2

2 30 50 259 60 0.2

3 30 60 265 68 0.3

4 30 70 273 77 0.3

5 40 40 255 56 0.2

6 40 50 261 64 0.2

7 40 60 267 72 0.3

8 40 70 275 81 0.3

9 50 40 257 60 0.2

10 50 50 263 68 0.3

11 50 60 270 76 0.3

12 50 70 278 86 0.3

13 60 40 259 64 0.2

14 60 50 265 72 0.3

15 60 60 272 80 0.3

16 60 70 281 91 0.3

17 70 40 261 66 0.3

18 70 50 267 76 0.3

19 70 60 274 85 0.3

20 70 70 283 96 0.3

21 80 40 263 71 0.3

22 80 50 270 80 0.3

23 80 60 277 89 0.3

24 80 70 286 101 0.4

Eav C/

Eav Wo

Luminous

variable

Case Wo P Eav Wo

[lux]

Eav C

[lux]

32


analysis I primary analysis I example caseVisual comfort assessment:

Criteria 5

Ratio between min and avg. Illuminance of Workplane: Wall ≥ 0.8

1 30 40 254 174 0.7 57 46 0.8 1.2

2 30 50 260 178 0.7 76 51 0.7 1.0

3 30 60 267 184 0.7 83 55 0.7 1.0

4 30 70 276 193 0.7 90 60 0.7 1.0

5 40 40 257 174 0.7 72 48 0.7 1.0

6 40 50 262 182 0.7 78 52 0.7 1.0

7 40 60 269 187 0.7 85 57 0.7 1.0

8 40 70 277 189 0.7 93 66 0.7 1.0

9 50 40 259 180 0.7 74 51 0.7 1.0

10 50 50 264 185 0.7 81 55 0.7 1.0

11 50 60 271 189 0.7 88 61 0.7 1.0

12 50 70 279 190 0.7 96 70 0.7 0.9

13 60 40 260 183 0.7 77 53 0.7 1.0

14 60 50 268 185 0.7 83 59 0.7 1.0

15 60 60 274 187 0.7 91 63 0.7 1.0

16 60 70 282 194 0.7 99 73 0.7 0.9

17 70 40 260 186 0.7 79 55 0.7 1.0

18 70 50 267 184 0.7 83 57 0.7 1.0

19 70 60 274 187 0.7 91 63 0.7 1.0

20 70 70 282 194 0.7 99 73 0.7 0.9

21 80 40 265 184 0.7 81 56 0.7 1.0

22 80 50 271 189 0.7 88 61 0.7 1.0

23 80 60 279 194 0.7 96 68 0.7 1.0

24 80 70 288 220 0.8 106 80 0.8 1.0

Emin

Wo/ Eav

Eav W

[lux]

Emin W

[lux]

Emin W/

Eav WRatio

Emin Wo

[lux]

Luminous variable

Case Wo

reflectanc

P

reflectanc

Eav Wo

[lux]

Criteria

6

Contrast Rendition Factor (CRF) < 1.0 and > 0.5

1 30 40 24 16.4 0.4

2 30 50 25 21.9 0.1

3 30 60 26 26.8 (0.1)

4 30 70 26 31.9 (0.2)

5 40 40 33 16.7 0.5

6 40 50 33 21.9 0.4

7 40 60 34 27.0 0.2

8 40 70 35 33.0 0.1

9 50 40 41 16.8 0.7

10 50 50 42 22.1 0.5

11 50 60 43 28.0 0.4

12 50 70 44 34.3 0.3

13 60 40 50 17.3 0.7

14 60 50 51 22.1 0.6

15 60 60 52 28.6 0.5

16 60 70 54 35.4 0.4

17 70 40 58 18.5 0.7

18 70 50 60 24.3 0.7

19 70 60 61 30.4 0.6

20 70 70 63 37.1 0.4

21 80 40 68 19.0 0.8

22 80 50 69 24.8 0.7

23 80 60 71 32.4 0.6

24 80 70 73 40.1 0.5

CRFLavg P

[cd/m²]

Luminous

variable

Case Wo

reflectanc

e

P

reflectanc

e

Lavg Wo

[cd/m²]

33


Lighting power density assessment:


Installed lighting power density assessment

Case Wo P Eav Wo [lx]

Eav W [lx]

Eav C [lx]

Eav F [lx]

Eav P [lx]

Eav for design

approach [lm/m2]

Design maintained illuminance

[lm/m2]

Equipment efficacy

Illumination Moderating

factor

Eav maintained

Light Power

Density

Connected load

1 0.5 0.4 259 75 64 171 132.2 14.024 25 1.176 0.54 13.54 11.51 2.06

2 0.6 0.4 261 77 66 172 142.9 14.378 25 1.176 0.55 13.77 11.80 2.04

3 0.7 0.4 264 80 70 175 147.2 14.724 25 1.176 0.56 13.94 11.86 2.02

4 0.7 0.5 270 87 79 181 150.1 15.342 25 1.176 0.57 14.21 12.08 1.97

5 0.8 0.4 266 83 74 176 154.3 15.066 25 1.176 0.57 14.16 12.04 2.01

6 0.8 0.5 273 90.0 83 183 167.1 15.922 25 1.176 0.58 14.58 12.40 1.96

34


analysis I primary analysis I final cases

S.No. W F C Wo P Connected Load LPD

1 70 40 80 60 40 2.04 11.80

2 70 40 80 70 40 2.02 11.85

3 70 30 80 70 40 2.06 11.80

4 70 30 80 80 40 2.05 11.83

5 60 40 80 60 50 2.05 11.80

6 60 40 80 70 40 2.03 11.88

7 60 40 80 80 40 2.02 11.89

8 60 20 70 70 50 2.10 11.80

9 60 20 70 80 40 2.13 11.80

10 50 40 80 60 40 2.06 11.80

11 50 30 80 60 40 2.05 11.84

12 50 30 80 70 40 2.08 11.71

13 50 30 80 70 50 2.04 11.80

14 50 30 80 80 40 2.07 11.84

15 50 30 60 70 50 2.11 11.80

16 50 20 80 70 40 2.17 11.72

17 50 20 80 70 50 2.14 11.85

18 50 20 80 80 40 2.16 11.87

19 50 20 60 70 40 2.17 11.79

20 50 20 60 80 40 2.16 11.89

35


conclusion I inferences

ceilings take up the maximum load if it is of low reflectance i.e. of dark colour.

medium reflectance value surface or mid- grey tones, all three surfaces perform in asimilar manner.

ceilings with higher reflectances take up least loads. desirable to have low reflectivefloors, medium reflective walls and high reflective ceilings.

Visual comfort assessment:

workplane reflectance ranging between 50-70% and in case of partitions 40-50%reflectance confirm visual standards.

it is desirable in terms of visual balance to have higher reflectance for workplane ascompared to the partition.

36



1.9

1.95

2

2.05

2.1

2.15

2.2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Co

nn

cete

d L

oad

W/m

2/1

00

lux

Cases

Final cases

Connected Load value W/m2/100lux

max. min. avg.

2.17 2.02 2.09

S.No Reflectance [lux]

W F C Wo P

1 70 40 80 60 40

2 70 40 80 70 40

3 70 30 80 70 40

4 70 30 80 80 40

5 60 40 80 60 50

6 60 40 80 70 40

7 60 40 80 80 40

8 60 20 70 70 50

9 60 20 70 80 40

10 50 40 80 60 40

11 50 30 80 60 40

12 50 30 80 70 40

13 50 30 80 70 50

14 50 30 80 80 40

15 50 30 60 70 50

16 50 20 80 70 40

17 50 20 80 70 50

18 50 20 80 80 40

19 50 20 60 70 40

20 50 20 60 80 40

37


60

40

80

80

40

0 20 40 60 80 100

W

F

C

Wo

P

Reflectance [%]

Case 7

Connected Load value W/m2/100lux

max. min. avg.

2.17 2.02 2.09

50

20

80

70

40

0 20 40 60 80 100

W

F

C

Wo

P

Reflectance [%]

Case 16


50

20

60

70

40

0 20 40 60 80

W

F

C

Wo

P

Reflectance [%]

Case 19

50

20

80

80

40

0 20 40 60 80 100

W

F

C

Wo

P

Reflectance [%]

Case 18

60

20

70

70

50

0 20 40 60 80

W

F

C

Wo

P

Reflectance [%]

Case 8

50

30

80

70

40

0 20 40 60 80 100

W

F

C

Wo

P

Reflectance [%]

Case 12

38


conclusion I inferences I grey tones

1- W70_F40_C80_Wo60_P40

2- W70_F40_C80_Wo70_P40

3- W70_F30_C80_Wo70_P40

4- W70_F30_C80_Wo80_P40

5- W60_F40_C80_Wo60_P50

6- W60_F40_C80_Wo70_P40

7- W60_F40_C80_Wo80_P40

8- W60_F20_C70_Wo70_P50

9- W60_F20_C70_Wo80_P40

10- W50_F40_C80_Wo60_P40

11- W50_F30_C80_Wo60_P40

12- W50_F30_C80_Wo70_P40

13- W50_F30_C80_Wo70_P50

14- W50_F30_C80_Wo80_P40

15- W50_F30_C60_Wo70_P50

16- W50_F20_C80_Wo70_P40

17- W50_F20_C80_Wo70_P50

18- W50_F20_C80_Wo80_P40

19- W50_F20_C60_Wo70_P40

20- W70_F20_C60_Wo80_P40

min. load max. load avg. load

39


conclusion I colour scheme

40


conclusion I inferences I colour templateW70_F40_C80_Wo60_P40 W70_F40_C80_Wo70_P40

W70_F30_C80_Wo70_P40 W70_F30_C80_Wo80_P40

W60_F40_C80_Wo60_P50 W60_F40_C80_Wo70_P40

W60_F40_C80_Wo80_P40 W60_F20_C70_Wo70_P50

W60_F20_C70_Wo80_P40 W50_F40_C80_Wo60_P40

Load - 2.04 Load - 2.02

Load - 2.06 Load - 2.05

Load - 2.05 Load - 2.03

Load - 2.02 Load - 2.10

Load - 2.13 Load - 2.06

41


conclusion I inferences I colour templateW50_F30_C80_Wo60_P40 W50_F30_C80_Wo70_P40

W50_F30_C80_Wo70_P50 W50_F30_C80_Wo80_P40

W50_F30_C60_Wo70_P50 W50_F20_C80_Wo70_P40

W50_F20_C80_Wo70_P50 W50_F20_C80_Wo80_P40

W50_F20_C60_Wo70_P40 W70_F20_C60_Wo80_P40

Load - 2.05 Load - 2.08

Load - 2.04 Load - 2.07

Load - 2.11 Load - 2.17

Load - 2.14 Load - 2.16

Load - 2.17 Load - 2.16

42


conclusion I inferences I summary

The significance of the derived predicted colour schemes is that they were derived from theoreticalassumptions and then were quantified and thus verified to construct an empirical investigation.

Most importantly, a rational method for assessing visual comfort and lighting efficiency of an interiorspace through surface colour variance was sought to examine.

Thence, this study reinforces the message that interior and lighting design criteria for spaces which do not take into account the effect of the Colour and

its reflectance property are likely to be flawed.

Colours, especially interior surface colours are still often derided as the realm of the “decorator”.[8]

Rather it should be a designer’s call to control the luminous environment to intelligently specify the relationship between lighting and building surfaces

reflected distribution and hence interior colours.

Theoretical Source: [8] <http://www.archmedia.com.au/aa/aaissue.php?article=5&issueid=200207&typeon=>

effect of colours on lighting efficiency in...

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