METHODS TO IMPROVE INDOOR ENVIRONMENTAL QUALITY (IEQ) IN CLASSROOMS IN HOT CLIMATES. 05

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure BY: HAMED MOHAMMED AL-HALAWANI

instructor: Dr-Ing. Mohannad Bayoumi Advanced Design Studio (AR600) KAUARCH | LESS Studio Architecture and Planning Faculty

King Abdulaziz University

2019

CONTENT 1. Introduction 2. Research problem 3. Research objective 4. Literature review 4.1Related research 4.2 standard 5. Research Methods 5.1 Study framework

5.2 metrics 5.3 Sample selection 5.4 Field Measurement 5.5 Model building 5.2 metrics

3

6. Research sample analysis 6.1 West fasade 6.2 East fasade 6.3 Soth fasade 6.4 North fasade

6.5 Results

6.6 Recommendations 7. Design alternatives 7.1 alternatives geometry 7.2 West orientation analysis 7.3 East orientation analysis 7.4 Soth orientation analysis 7.5 North orientation analysis 7.6 Recommendations 8. Conclusion

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

1 INTRODUCTION

Through this study, which is concerned with studying the availability of daylight in the classrooms, and the level of visual comfort, by studying a classroom in Jeddah at King Abdulaziz University, finding solutions related to the windows geometry, and studying its impact on the level of daylight and comfort of the occupants, in aim to reach the appropriate design For windows in each orientation, by applying and testing a number of models using climate-based measures.

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

2. Research problem

-visual comfort in educational buildings is an important issue, since is directly related to the students' wellbeing and learning process, this research will evaluate the impact of the design of the educational building's .

-artificial lighting are Used as the main source of lighting in buildings With neglecting the exploitation of renewable resources in lighting.

-By observing a sample of a classroom at King Abdulaziz University, there is a lack of daylight and direct sunlight exposure , which reduces user comfort.

2.1 Research question For a certain orientation what are the criteria of window openings that help enhance high performance of daylighting of classroom?

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

3 . Research objective

-Increasing the student's visual perception quality by studying the level of daylight and visual comfort through studying direct sunlight -Evaluation performance of windows geometry for a classroom and design different alternatives of windows geometry -A number of recommendations will be proposed to improve visual comfort levels without requiring additional cooling loads that require for current WWR (23%).

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

4. Literature review 4.1 Related research Productivity A relationship between lighting systems and elementary school students' dental health, attendance, growth and development, vision, and academic achievement.

A Study into the Effects of Light on Children of Elementary School-Age A Case of Daylight Robbery.1992 Canada

by Hathaway, Warren E.; And Others

Productivity

Health

students with the most daylighting in their classrooms progressed 20% faster on math tests and 26% on reading tests in one year than those with the least. Similarly, students in classrooms with the largest window areas were found to progress 15% faster in math and 23% faster in reading than those with the least

-People have a natural attraction to daylight and tend to prefer daylit spaces to those that are artificially lit.

-Studies have shown that the use of natural light in buildings can have significant psychological and physiological effects on the health, well-being and performance of humans -Studies have also shown that exposure to natural light can have a beneficial impact on the occupant's health by decreasing the occurrence of headaches, seasonal affective disorder (SAD), eyestrain, stress etc.

Daylighting in Schools An Investigation into the Relationship Between Daylighting and Human Performance .1999 USA

by HESCHONG MAHONE GROUP

Health -natural light can reduce psychological sadness related to the seasonal affective disorder and enhance productivity.

-aylighting also has the advantages of full spectrum lighting and related health benefits.

Design and analysis of an active daylight harvesting system for building 2018

by Xiujie Li a, Yeyan Wei b, Junbin Zhang a, Peng Jin a

An active sunlight redirection system for daylight enhancement beyond the perimeter zone 2016

by Antonis Kontadakis a, *, Aris Tsangrassoulis a, L. Doulos b, F. Topalis b

energy saving

Daylight control

-Thus, the adoption of daylight harvesting systems is an essential strategy in order to considerably reduce lighting energy consumption and peak electric loads. These systems offer the potential to reduce the electricity used, from 20% to 60% in optimal conditions

-Users adjust the traditional blinds to prevent glare and heat, but once the blinds are closed, we will cut off the optical connection to the outer bore and the blinds will remain closed even after the glare is gone.

-A new controller for office spaces with venetian blinds has been developed to explicitly address both daylight maximization and glare control

An active sunlight redirection system for daylight enhancement beyond the perimeter zone 2016

by Antonis Kontadakis a, *, Aris Tsangrassoulis a, L. Doulos b, F. Topalis b

A daylight optimized simulation-based shading controller for venetian blinds 2017 Angelina Katsifaraki, Bruno Bueno , Tilmann E. Kuhn

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

4. Literature review 4.1 Related research Visual perception The Relative Visual Performance (RVP) model to enable a normally sighted person to practece deferant activites in suggested livil of illumenance. where the visual conditions are represented by just three factors: • Target size, being the angular size of the detail to be seen, measured in microsteradians (μsr).

• Luminance contrast of the detail against its background.

• Retinal illuminance for the observer, measured in trolands, which provides an indication of the level of the stimulus to the retinal photoreceptors.

energy saving Traditional building consumes 40% of the energy in developed countries, whilst the lighting consumes up to 40% electricity in commercial and residential buildings -daylight harvesting alone can achieve a minimum energy savings of 10% Design and analysis of an active daylight harvesting system for building 2018

by Xiujie Li a, Yeyan Wei b, Junbin Zhang a, Peng Jin a

WFR -The research also studied window wall ratio (WWR) , 24 alternative were analysed based on window shape.

-an optimal range of WFR, 15–24%, was presented which also controls glare and overheat. The study also indicated how window shape and size affected the average DF and uniformity simultaneously, Evaluation of Daylight regulations in buildings using daylight factor analysis method by radiance 2018

LIGHTING BY DESIGN

By Christopher Cuttle , Architectural Press , 2003

classroom geometries -Daylight Factor (DF) and the Daylight Autonomy (DA), showed that room and window geometries have high influence on daylight harvesting maximization.

- DIVA software was used to simulate daylight.

-square and rectangular classroom geometries have been tested with no remarkable differences.

-thire is a relationship between windows geometry and energy consumption.

Room and window geometry influence for daylight harvesting maximization Effects on

Window screens -artificial lights account for 19% of electricity consumption which is equivalent to 6% of CO2 emissions - A second solar screen is installed, the illuminance level varies between 175 and 200 Lux, and the heat flow is reduced between 36.1% and 52.5%, depending on the misalignment of the screens holes. In term of illuminance, solar screens with down misaligned holes show the best performance, Double solar screens for window to control sunlight in Kuwait Esam M. Alawadhi

sunlight redirection -paper proposes a sunlight redirection system that uses a number of movable mirrors, installed on a light shelf and capable of tracking the sun. Reflected sunlight is projected towards a specified, fixed target area on the ceiling -The results indicate an increase of 99%, in the daylighting levels in the secondary (non-daylit) area during the summer solstice and a reduction of 21%, during the winter solstice.

An active sunlight redirection system for daylight enhancement beyond the perimeter zone 2016 Antonis Kontadakis a, *, Aris Tsangrassoulis a, L. Doulos b, F. Topalis b

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

4. Literature review 4.1 Related research daylight metrec - the DF persists as the dominant evaluation metric because of its inherent simplicity rather than its realism.

- UDI gives an indication of the propensity for high levels of illumination that are associated with discomfort and solar gains, by depinding on human factors, rather than the single threshold value which is designed specifically for energy calculations.

-It has also been observed that people tend to tolerate much lower illuminance levels of daylight than artificial light, particularly in diminishing daylight conditions at the end of the day, such as continuing to read at daylight levels as low as 50 lx Useful daylight illuminances: A replacement for daylight factors

By Azza Nabil, John Mardaljevic

daylight metrec -annual Daylight Glare Probability (DGP) are the metrics used to evaluate daylight availability and visual comfort.

-experiments were carried out using the Rhino/Grasshopper/DIVA simulation environment.

-complex venetian blinds systems based on multiple-curved sections was generate.

A comparison of two light-redirecting fenestration systems using a modified modeling technique for Radiance 3-phase method simulations 2018 Luis Santosa, , AntĂłnio LeitĂŁob, Luisa Caldasc

daylight metrec - Different daylight and glare metrics developed over the past years, are categorized into two groups; static and dynamic. Static (point in time illuminance based) daylight metrics (e.g., DF) have been replaced with more advanced dynamic (climatebased daylight modelling, known as CBDM) metrics (e.g., DA, UDI, sDA300/50%) in the last few years.

-The correlation between UDI 300e3000 (50%) and sDA 300 lux (50%) simulations and overall occupant satisfaction toward the visual environment is high enough to support the adoption of climate-based simulations. availability and visual comfort in classrooms 2019 AZahra S. Zomorodian, Mohammad Tahsildoost*

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

4. Literature review 4.2 standard Educational Buildings standards (EUROPEAN STANDARD

-illuminance level : Useful daylight illuminances 1. Are within the range defined as useful (i.e. 100–2000 lx); 2. Fall short of the useful range (i.e. less than 100 lx); 3. Exceed the useful range (i.e. greater than 2000 lx).

Characteristic visual tasks

Illuminance Illuminance category

(CIBSE 1994)

(lux)

(IESNA 2000)

30

A Public spaces

Confined to movement and casual seeing without perception of detail.

50

B Simple orientation for short visits

Movement and casual seeing with only limited perception of detail.

100

C Working spaces where simple visual tasks are performed

Involving some risk to people, equipment or product.

Requiring some perception of detail

150

Moderately easy: i.e. large detail, high contrast

300

D Performance of visual tasks of high contrast and large size

Moderately difficult: i.e. moderate size, may be of low contrast. Colour judgement may be required.

500

E Performance of visual tasks of high contrast and small size, or low contrast and large size

200

Difficult: details to be seen are 750 small and of low contrast.

Colour judgements may be important.

Very difficult: very small details which may be of very low contrast. Accurate colour judgements required.

1000

Extremely difficult: details are extremely small and of low contrast. Optical aids may be

1500

F Performance of visual tasks of low contrast and small size

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

4. Literature review 4.2 standard illuminance and visual tasks -Spatial Daylight Autonomy (sDA300/50%) is a metric indicating whether the quality of daylight in interior spaces is sufficient. It is defined as the percentage of analysis area that receives more than 300 lux for 50% of the analysis period.

To achieve LEED 4, not only sDA300/50%>55 should be passed, but also glare should be controlled, considering the Annual Sunlight Exposure (ASE), which is a metric for controlling high illuminance levels on workplace due to direct sunlight is defined as the percentage of the space that has direct sunlight (i.e. 1000 lux and above) for more than 250 h of occupation. A maximum 10% ASE is considered acceptable in LEED v4. It should be noted that ASE is not a glare metric. It is a proxy for discomfort (both thermal and visual)

LEED daylight credits version

threshold

LEED v2 2004

75% area minimum 2% daylight factor

LEED v3 2008

75% area between 25 and 500 fc (270e5400 lux)

LEED v3 2009

75% area between 10 and 500 fc (108e5400 lux)

LEED v4 2013

-Op�on:1, sDA300/50%>55% and ASE 1000/250 h < 10% -Op�on: 2, 75% area between 300 and 3000 lux -90% area between 300 and 3000 lux

Time

points

NA

1

September 21 at 9 a.m. and 3 p.m. 1

Annual September 21 at 9 a.m. and 3 p.m.

1

2-3 1

Type of interior, task or activity

Em lx

Classrooms, tutorial rooms

300

Classroom for evening classes and adults education

500

Lecture hall

500

Black board

500

Demonstration table Art rooms Art rooms in art schools Technical drawing rooms Practical rooms and laboratories Handicraft rooms Teaching workshop Music practice rooms Computer practice rooms (menu driven) Language laboratory Preparation rooms and workshops Entrance halls Circulation areas, corridors Stairs Student common rooms and assembly halls Teachers rooms Library: bookshelves Library: reading areas Stock rooms for teaching materials

500 500 750 750 500 500 500 300 300

Remarks Lighting should be controllable Lighting should be controllable Lighting should be controllable Prevent specular reflections In lecture halls 750 lx.

TCP ≥ 5000 K.

DSE-work: see 4.11.

300 500 200 100 150 200 300 200 500 100

Sports halls, gymnasiums, swimming pools (general use)

300

School canteens Kitchen

200 500

For more specific activities, the requirements of EN 12193 shall be used

2

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

Sample identification

5. Research Methods 5.1 Study framework

Building a simulation model Field measurements model Calibration Current situation Analysis

ASE Analysis NORTH

sDA300/50% & UDI Analysis

EAST

WEST

SOUTH

result Recommendations for the current situation

window geometry Alternatives Type 1

Type 2

Type 3

Type 4

Type 5

Type 6 output

Type 7

Type 8

Type 9

Type 10

Type 11

Type 12

evaluation by sDA300/50% & UDI & ASE Determine the best alternative Recommendations Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

5. Research Methods 5.2 metrics Daylight metrics

(climatebased daylight modelling CBDM)

analyzing due to different condition of sky and its repetition during the year

Sky conditions change according to clouds,

Dynamic

Static

(climatebased daylight modelling CBDM)

(point in time illuminance based)

dust ,fog and sun path

DA Sky conditions in Jeddah

DF

sDA 300/50% UDI ASE DGP

ASE

ASE Annual Sunlight Exposure

WWR

WWR Window to Wall Ratio

WFR

WFR Window to Floor Ratio

DA

Daylight Autonomy

CBDM

climate-based daylight modelling

SDA

Spatial Daylight Autonomy

UDI

Useful Daylight Illuminance

DGP

Daylight Glare Probability

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

5. Research Methods 5.3 Sample selection

Ceiling height = 3 m Capacity = 35 students Area = 69 square meters WFR = 7.5 % WWR = 23 % Number of windows = 3 Window area = 1.72 m2

Photos of western classroom

Eleva�on of selected classroom

7.5 m

1.069 m

9.2 m Satellite image of 535 building

Plan

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

5. Research Methods 5.4 Field Measurement

Build the model and define the measurement points

Clean windows to get full window performance

2

4

Record the measurements and time

6

1

3

5

7

Survey work

Determine the measurement points on the field

Install the device on the measuring points and adjust its horizontal

Data entry and model calibration

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

5. Research Methods 5.4 Field Measurement Measurement result 29/Oct 13:30 PM - 14:00 PM

10:30 AM - 11:00 AM

250

169

117

94

76

68

644

446

278

202

149

125

242

170

116

91

78

70

639

415

265

199

150

133

290

178

127

89

79

76

804

445

295

212

162

142

724

448

302

202

155

135

854

432

260

198

153

134

LUX 500

245

167

124

98

76

76

248

176

115

93

76

75

375 250 125 0

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

5. Research Methods 5.5 Model building Parameters Materials properties

Simulation parameters

-ab ambient bounces

-ar ambient resolu�on

descrip�on Set the number of ambient bounces to N. This is the maximum number of diffuse bounces computed by the indirect calcula�on. A value of zero implies no indirect calcula�on.

Set the ambient resolu�on to res. This number will determine the maximum density of ambient values used in interpola�on.

Error will start to increase on surfaces spaced closer than the scene size divided by the ambient resolu�on. The maximum ambient value density is the scene size �mes the ambient accuracy (see the -aa op�on below) divided by the ambient resolu�on.

daylight

7

Building element

Surface op�cal proper�es

Value (%)

Window Double clear glazing

Visible Transmission (VT)

55

Ceiling

80

Internal wall

70

Reflectance %

Floor

40 30

Furniture

50

100

L

ambient parameter

lux 2000 1800 1600

Set the number of ambient divisions to N. The error -ad in the Monte Carlo calcula�on of indirect 1500 illuminance will be inversely propor�onal to ambient divisions the square root of this number. A value of zero implies no indirect calcula�on.

1200 1000 800 600 400

ambient sampling

Set the number of ambient super-samples to N. Super-samples are applied only to the ambient divisions which show a significant change.

20

-aa ambient accuracy

stores calculated ambient values in a file for re-use in subsequent simula�ons

0.1

-as

1400

200 0 10

9

8

7 6 5 4 Distance from the window ab = 2

ab = 4

ab = 6

3

2 ab = 8

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

1

5. Research Methods 5.5 Model building simulation

13:30 PM - 14:00 PM

10:30 AM - 11:00 AM

LUX 500 375 250 125 0 Climate data

SAU_MK_Jeddah-Abdulaziz.Intl.AP.410240

occupancy

2869 houres / year (7:00AM - 5:00PM) weekdays

glazing proper�es Window Double glazing

Visible Transmission (VT) %

55 %

Material proper�es

-

Ceiling (flat)

80

Internal wall (white)

Reflectance %

70

Floor (Polished granite)

40

Furniture

50

Space between simula�on points

1.25* 1.3 meters

simula�on points hight

0.76 meters

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

5. Research Methods 5.5 Model building Calibration simulation

29/Oct

Measurement

10:30 AM - 11:00 AM

29/Oct

10:30 AM - 11:00 AM

1.1 Measurement of study cases

LUX 500 375 250

250

169

117

94

76

68

242

170

116

91

78

70

290

178

127

89

79

76

245

167

124

98

76

76

248

176

115

93

76

75

125 0 300 250

simulation measurements error rate

mean lux 126.6 129 1.8604651

200 150

simula�on measurements

lux

100 50 0 6

5

4

3

2

Distance from the window

1

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

6. Research sample analysis 6.1 West fasade current situation daylighted space area (percentage)

W current (Daylight distribu�on)

100

DA 300/50% of Occupied Hours % 100

90

75

40

50

20

25

0

80 70 60 50 30 10 1

2

0 Climate data

SAU_MK_Jeddah-Abdulaziz.Intl.AP.410240

occupancy

2869 houres / year (7:00AM - 5:00PM) weekdays

glazing proper�es Window Double glazing

Visible Transmission (VT) %

55 %

Material proper�es

-

Ceiling (flat)

80

Internal wall (white)

Reflectance %

70

3

4

5

6

Distance from the window

7

8

9

10

sDA300/50% WEST

daylighted space area (percentage) 60

floor area%

50 40

Floor (Polished granite)

40

30

Furniture

50

20

Space between simula�on points

1.25* 1.3 meters

10

simula�on points hight

0.76 meters

0

sDA300lux/50% UDI100-2000 ASH

sDA300lux/50%

UDI100-2000

ASH

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

6. Research sample analysis 6.2 East fasade current situation daylighted space area (percentage)

sDA300/50% EAST

100

90

DA 300/50% of Occupied Hours % 100

80

75

30

50

10

70 60 50 40 20 0 1

25

2

SAU_MK_Jeddah-Abdulaziz.Intl.AP.410240

occupancy

2869 houres / year (7:00AM - 5:00PM) weekdays 55 %

daylighted space area (percentage) 60

Material proper�es

-

50

Ceiling (flat)

80

glazing proper�es Window Double glazing

Internal wall (white)

Visible Transmission (VT) %

Reflectance %

70

Floor (Polished granite)

40

Furniture

50

4

5

6

7

Distance from the window

8

9

10

sDA300/50% EAST

0 Climate data

3

floor area%

40 sDA300lux/50%

30

UDI100-2000

20

Space between simula�on points

1.25* 1.3 meters

10

simula�on points hight

0.76 meters

0

ASH

sDA300lux/50%

UDI100-2000

ASH

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

6. Research sample analysis 6.3 South fasade current situation daylighted space area (percentage)

DA 300/50% of Occupied Hours % 100

sDA300/50% SOUTH

100 90 80 70 60 50 40 30 20 10 0

75

1

2

3

4

5

6

7

Distance from the window

8

9

10

sDA300/50% SOUTH

50 25 0 Climate data

SAU_MK_Jeddah-Abdulaziz.Intl.AP.410240

occupancy

2869 houres / year (7:00AM - 5:00PM) weekdays

glazing proper�es

Visible Transmission (VT) %

daylighted space area (percentage) 80

55 %

70

Material proper�es

-

60

Ceiling (flat)

80

50

70

40

Floor (Polished granite)

40

30

Furniture

50

20

Window Double glazing

Internal wall (white)

Reflectance %

Space between simula�on points

1.25* 1.3 meters

simula�on points hight

0.76 meters

floor area%

sDA300lux/50% UDI100-2000 ASH

10 0 sDA300lux/50%

UDI100-2000

ASH

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

6. Research sample analysis 6.4 North facade current situation

daylighted space area (percentage)

sDA300/50% NORTH

100 90 80 70 60

DA 300/50% of Occupied Hours % 100

50 40 30 20 10 0 1

75

2

3

4

5

6

Distance from the window

7

8

9

10

sDA300/50% NORTH

50 25 0

Climate data

SAU_MK_Jeddah-Abdulaziz.Intl.AP.410240

occupancy

2869 houres / year (7:00AM - 5:00PM) weekdays

glazing proper�es Window Double glazing

Visible Transmission (VT) %

55 %

Material proper�es

-

Ceiling (flat)

80

Internal wall (white)

Reflectance %

70

Floor (Polished granite)

40

Furniture

50

Space between simula�on points

1.25* 1.3 meters

simula�on points hight

0.76 meters

daylighted space area (percentage) 50 45 40 35 30 25 20 15 10 5 0

sDA300lux/50%

floor area%

sDA300lux/50% UDI100-2000 ASH

UDI100-2000

ASH

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

6. Research sample analysis 6.5 Results daylighted space area (percentage)

daylighted space area (percentage)

sDA300lux/50%

UDI100-2000

80

25

70

20

60 50

15 sDA300lux/50%

10

40

UDI100-2000

30 20

5

10 0

0 W

E

S

W

N

E

S

sDA300/50%

% 100

ASE

ASE > 250 h (area %)

90 80

16

70

14

60

12

50

N

10

40 30

8

20

6

10

ASE

4

0 1

2

3

4 5 6 7 Distance from the window

8

sDA300/50% WEST

sDA300/50% EAST

sDA300/50% SOUTH

sDA300/50% NORTH

9

10

2 0 W

E

S

N

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

6. Research sample analysis 6.6 Recommendations Daylight avalibility Recommendations North orientation: - The results showed that there is no exposure to sunlight on the northern side, so the window size can be changed to address the lack of daylight or change the type of window glass, and 80% transparency with U value = 1 W/(m2k) was tested and the and the value of sDA300 increased from 8 to 18%.

South orientation: -Sunlight Exposure is low, with high daylight up to the rest of the orientations, so it is advised to design this fasade as classrooms to provide more daylight.

- Test different windows geometry. glass transparent = 55%

glass transparent = 80%

East and West orientation: - Test different windows geometry.

- Increase WFR with consideration the balance between the amount of lighting gained and the amount of additional expected energy loads.

- Artificial lighting design on more than one level, to complement with daylight, to achieve energy saving.

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

6. Research sample analysis 6.6 Recommendations Sun exposure

N

ASE

ASE > 250 h (area %)

16 14 12 10 8

ASE

6

Summer Solstice 21 June

4 2 0 W

equinox 21 Mar 21 Sep

W 18

7

17

E

S

N

E

8 16

9 15

14

13

12

Winter solstice 21 Dec

S

11

10

Recommendations South orientation: - sun exposure for long hours during the day, sun with large angles that can be treated architecturally with sun-breakers. Horizontal breakers of 15 cm have been experimented with a wall depth of 69 cm, which reducing ASE to 0%.

East and West orientation - The orientations are exposed to the sun at a narrow angle that is difficult to handle architecturally, but it can be treated administratively by occupying the classrooms in the eastern orientation from 12 o'clock until sunset, and applying this to the western orientation from seven o'clock to twelve.

- Change the polished floor to reduce the sun's reflection on the floor and the use of rough materials.

- Change the place of the blackboard from north to south of the classroom to avoid exposure to sunlight and improve the student's visual perception, and conditions of vision for the teacher

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

7. Design alternatives 7.1 alternatives geometry -All alternatives are designed with the same WWR and WFR to neutralize all other factors and to know the most effective wendow geometry.

Ceiling height = 3 m Capacity = 35 students Area = 69 square meters WFR = 7.5 % WWR = 23 %

Climate data

SAU_MK_Jeddah-Abdulaziz.Intl.AP.410240

occupancy

2869 houres / year (7:00AM - 5:00PM) weekdays

glazing proper�es Window Double glazing

Visible Transmission (VT) %

model 2

model 4

model 5

model 7

model 8

model 10

model 11

model 3

model 6

55 %

Material proper�es

-

Ceiling (flat)

80

Internal wall (white)

model 1

Reflectance %

70

Floor (Polished granite)

40

Furniture

50

Space between simula�on points

1.25* 1.3 meters

simula�on points hight

0.76 meters

model 9

model 12

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

7. Design alternatives 7.2 West orientation analysis Results

model 1

model 2

model 4

model 5

model 7

model 8

model 3

model 6

model 9

DA 300/50% of Occupied Hours % 100 75 50 25

model 10

model 11

model 12

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

0

7. Design alternatives

daylighted space area (percentage)

DA300lux/50% (floor area %) (west)

7.2 West orientation analysis Results

25 20 15 10 5 0

Model 1

Model 2

Model 3

DA300lux/50% (floor area %) (west)

daylighted space area (percentage)

Model 4

Model 5

Model 6

Model 7

Model 8

Model 9

UDI 100-2000 (floor area %) (west)

90 80 70 60 50 40 30 20 10 0

UDI 100-2000 (floor area %) (west)

ASE > 250 h (area %)

ASE (floor area %) (west)

20 15 10 Model 10

Model 11

Model 12

5 0

ASE (floor area %) (west)

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

7. Design alternatives 7.2 West orientation analysis Recommendations Recommendations - It was shown the results of all alternatives with the clarification of the alternatives that have achieved less than ASE average.

-Model 9 achieved sDA300/50%, up to 58.3 % more than the current design, and an 13.5 % increase in UDI.

sDA300/50% daylighted space area

windows opening performance (West)

34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0

model 9

59, 21 59,19 58, 18 63, 16 54, 13 73, 14 58, 12 52, 12

79, 18 model 12

76, 14

model 11

21, 0 0

10

20

30

79, 0 40

50

60

70

UDI 100 - 2000 daylighted space area (percentage)

80

90

100

alternatives that have achieved less than ASE average

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

7. Design alternatives 7.3 East orientation analysis Results

model 1

model 2

model 4

model 5

model 7

model 8

model 3

model 6

model 9

DA 300/50% of Occupied Hours % 100 75 50 25

model 10

model 11

model 12

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

0

7. Design alternatives

daylighted space area (percentage)

7.3 East orientation analysis Results

DA300lux/50% (floor area %) (East)

25 20 15 10 5

Model 1

Model 2

Model 3

0

daylighted space area (percentage) Model 4

Model 7

Model 5

Model 6

Model 8

Model 9

DA300lux/50% (floor area %) (East)

UDI 100-2000 (floor area %) (East)

90 80 70 60 50 40 30 20 10 0

UDI 100-2000 (floor area %) (East)

ASE > 250 h (area %)

ASE (floor area %) (East)

25 20 15

Model 10

Model 11

Model 12

10 5 0

�ΔϠγϠγ

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

7. Design alternatives 7.3 East orientation analysis Recommendations Recommendations - It was shown the results of all alternatives with the clarification of the alternatives that have achieved less than ASE average.

-Model 3 achieved sDA300/50%, up to 50 % more than the current design, and an 54.9 % increase in UDI.

windows opening performance (East)

34 32 30 28 26 24 22 20 18 sDA300/50% 16 daylighted space area 14 12 10 8 6 4 2 0

model 3

61, 20 61, 18 79, 18 64, 17 74, 16

45, 17

model 7

68, 14 51, 12 54, 11

49, 12

model 2

22, 0 0

10

20

30

72, 0 40

50

60

UDI 100 - 2000 daylighted space area (percentage)

70

80

90

alternatives that have achieved less than ASE average

100

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

7. Design alternatives 7.4 South orientation analysis Results

model 1

model 2

model 4

model 5

model 7

model 8

model 3

model 6

model 9

DA 300/50% of Occupied Hours % 100 75 50 25

model 10

model 11

model 12

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

0

7. Design alternatives

daylighted space area (percentage)

DA300lux/50% (floor area %) (South)

7.4 South orientation analysis Results

Model 1

Model 2

35 30 25 20 15 10 5 0

Model 3

DA300lux/50% (floor area %) (South)

daylighted space area (percentage)

UDI 100-2000 (floor area %) (South)

120

Model 4

Model 5

Model 6

100 80 60 40 20 0

Model 7

Model 8

Model 9

UDI 100-2000 (floor area %) (South)

ASE > 250 h (area %)

ASE (floor area %) (South)

10 8 6

Model 10

Model 11

Model 12

4 2 0

ASE (floor area %) (South)

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

7. Design alternatives 7.4 South orientation analysis Recommendations Recommendations - It was shown the results of all alternatives with the clarification of the alternatives that have achieved less than ASE average.

-Model 4 achieved sDA300/50%, up to 39 % more than the current design, and an 40.3 % increase in UDI.

windows opening performance (south)

34 32 30 28 26 24 22 20 18 sDA300/50% 16 daylighted 14 space area 12 10 8 6 4 2 0

76, 32 71, 30

100, 33 89, 32 94, 32 100, 29

model 4

70, 27 67, 23 69, 21

90, 21

100, 23 model 5

50, 8

0

20

40

60

80

UDI 100 - 2000 daylighted space area (percentage)

100

model 9

alternatives that have achieved less than ASE average

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

7. Design alternatives 7.5 North orientation analysis Results

model 1

model 2

model 4

model 5

model 7

model 8

model 3

model 6

model 9

DA 300/50% of Occupied Hours % 100 75 50 25

model 10

model 11

model 12

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

0

7. Design alternatives 7.5 North orientation analysis Results

daylighted space area (percentage)

DA300lux/50% (floor area %) (North)

20 15 10 5

Model 1

Model 2

Model 3

0

daylighted space area (percentage)

DA300lux/50% (floor area %) (North)

UDI 100-2000 (floor area %) (North)

Model 4

Model 5

Model 6

Model 7

Model 8

Model 9

80 70 60 50 40 30 20 10 0

UDI 100-2000 (floor area %) (North)

ASE > 250 h (area %)

ASE (floor area %) (North)

1 0.8 0.6 0.4 Model 10

Model 11

Model 12

0.2 0

ASE (floor area %) (North)

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

7. Design alternatives 7.5 North orientation analysis Recommendations Recommendations - It was shown the results of all alternatives with the clarification of the alternatives that have achieved less than ASE average.

-Model 5 achieved sDA300/50%, up to 112.5% more than the current design, and an 31.8% increase in UDI.

windows opening performance (North)

34 32 30 28 26 24 22 20 18 sDA300/50% 16 daylighted space area 14 12 10 8 6 4 2 0

model 5

model 3

58, 19 53, 17 58, 16

68, 17 66, 12

43, 12 44, 8 50, 9 47, 7 60, 7 17, 0 0

10

20

model 9

66, 0 30

40

50

60

70

UDI 100 - 2000 daylighted space area (percentage)

80

90

100

alternatives that have achieved less than ASE average

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure

8. Conclusion By analyzing the performance of existing windows and proposed alternatives in all building orientations, it is possible to improve daylight conditions and visual comfort through the following: - For each orientation there are specific conditions that require different designs for window geometry, analyzes showed high differences between the performance of the same window in different interfaces.

-The three criteria that were used to evaluate daylight in the study proved to be effective. They accurately described the performance of windows even with the unification of their areas and the properties of their materials.

- Fore North orientation the architectural designer can use proposed models and evaluate them according to the standards that have been applied, to develop a special model to suit the specificity of the building.

- Fore North orientation the results showed that there is no exposure to sunlight on the northern side, so the window size can be changed to address the lack of daylight or change the type of window glass, and 80% transparency with U value = 1 W/(m2k) was tested and the and the value of sDA300 increased from 8 to 18%.

-Model 5 achieved sDA300/50%, up to 112.5% more than the current design, and an 31.8% increase in UDI. Although Model 5 showed better results than the current window by more than twice as much, the level of daylight is still

-For East and West orientation they are exposed to direct sun light at a narrow angle that is difficult to handle architecturally, but it can be treated administratively by occupying the classrooms in the eastern orientation from 12 o'clock until sunset, and applying this to the western orientation from seven o'clock to twelve.

- For East , West and south orientation , it is recommended to change the polished floor to reduce the sun's reflection on the floor and the use of rough materials.

- For East and West orientation it is recommended to change the place of the blackboard from north to south of the classroom to avoid exposure to sunlight and improve the student's visual perception, and conditions of vision for the teacher.

-For South orientation sunlight Exposure is low, with high daylight up to the rest of the orientations, so it is advised to design this fasade as classrooms to provide more daylight.

-Sunbreaks and reflectors can be installed on the southern faรงade because the sun's angle is large and reaches 45 degrees in the winter solstice, which is less valuable.

- for West orientation Model 9 achieved sDA300/50%, up to 58.3 % more than the current design, and an 13.5 % increase in UDI. - For East orientation Model 3 achieved sDA300/50%, up to 50 % more than the current design, and an 54.9 % increase in UDI. - For South Model 4 achieved sDA300/50%, up to 39 % more than the current design, and an 40.3 % increase in UDI.

Daylight performance analysis and enhancement of classrooms windows to maintain visual comfort levels and avoid direct sunlight exposure