The first semester (Design + Research) project
Introduction This paper focuses on studying the classrooms indoor air quality of the preparatory year at King Abdulaziz University in Saudi Arabia. One of them is a classroom in an existing building in Jeddah that was taken as a research sample. the variables affecting the indoor air quality were measured and analyzed it by installing sensors to measure and record these variables in this classroom. After that research was done to determine the optimal range of these variables and compare them to check whether these results were within the optimal range of each variable or not. The results show that it is important to propose improvement measures to reduce CO2 concentrations and ensure thermal comfort. Users need to realize that the quality of the internal environment is important for their health, comfort and performance and efficiency.
INDOOR AIR QUALITY, "CASE STUDY"
MITIGATING CO2 CONCENTRATION IN CLASSROOMS USING ADJACENT CORRIDORS AND ATRIUMS
1. Research objective
5. Design Alternatives 5.2 Scenarios
Improve the indoor air quality of classrooms, by Mitigating CO2 concentration. Achieving guidelines to upgrade the quality of educational classrooms indoor spaces.
Management related (Schedule timeline)
Management related (Schedule timeline)
Management related (Schedule timeline)
3.1.1 A
3.1.1 A
01
3.1.1 A
02
03 Scenario 02 15 min. break
Current condition 10 min. break
CLASSROOM SCHEDULE SIMULATION DURING WORKDAY
CLASSROOM SCHEDULE PHYSICAL MEASUREMENT DURING WORKDAY
3. Research Method
10Min. 60Min.
3.1 Research factors
50Min.
01
02
3.1.1 Management related
Schedule timeline The current CO2 ratios, classroom occupancy times should be reconsidered by adjusting the sessions schedule of break timeline between classes, as break times reduce the Co2 concentration.
04
CLASS
10Min. 50Min.
05
CLASS
10Min. 50Min.
06
CLASS
07
BREAK
50Min.
50Min.
08
CLASS
15Min.
15Min.
10Min.
10Min.
50Min.
09
CLASS
60Min.
60Min.
10
01
OFF
CLASS
50Min.
50Min.
02
OFF
15Min. 50Min.
03
CLASS
15Min. 50Min.
04
CLASS
15Min. 50Min.
05
CLASS
CLASSROOM SCHEDULE SIMULATION DURING WORKDAY 15Min.
50Min.
06
CLASS
15Min.
07
BREAK
50Min.
50Min.
08
CLASS
09
CLASS
60Min.
10 OFF
CLASS
7:00
8:00
9:00
10:00
11:00
12:00
13:00
14:00
15:00
WORKDAY START
17:00
16:00
1600 ppm
1600 ppm
Space volume
1200 ppm
9:05
10:00
11:00
12:00
13:00
14:00
15:00
17:00
16:00
WORKDAY START
1800 ppm
1400 ppm
8:00
WORKDAY END
1800 ppm
3.1.2 C
5Min. 5Min. 50Min.
5Min. 50Min.
30Min.
50Min.
60Min.
01
02
03
04
05
06
04
08
09
04
08
09
10
OFF
CLASS
CLASS
BREAK
CLASS
BREAK
BREAK
CLASS
CLASS
BREAK
CLASS
CLASS
OFF
8:00
8:55
9:45
10:15
11:10
12:00 12:30
13:25
14:15 14:45
15:40
16:30
17:30
WORKDAY END
1000 ppm 800 ppm 600 ppm
400 ppm
400 ppm
200 ppm
0
5Min. 50Min.
30Min.
1200 ppm
600 ppm
200 ppm
5Min. 5Min. 50Min.
1400 ppm
800 ppm
400 ppm
5Min. 50Min.
30Min.
1600 ppm
1000 ppm
600 ppm
50Min.
1800 ppm
1200 ppm
800 ppm
50Min.
WORKDAY START
WORKDAY END
1400 ppm
1000 ppm
The size of the existing study spaces can be reviewed to be larger in size so that the space can accommodate higher oxygen ratios and less carbon dioxide.
7:00
5Min. 5Min.
5Min.
60Min.
7:00
3.1.2 Design related
3.1.1 A
10Min. 50Min.
03
CLASS
OFF
10Min. 50Min.
Scenario 03 5 min. break - 30 min. break
200 ppm
0
0
Scenario 01
Scenario 01
3.1.1 B
3.1.2 D
Occupants number
Mechanical systems
Co2 concentration can be reduced by reducing the number of students in the classroom, the large number of occupants in the indoor spaces increases the rates of Co2 concentration.
Scenario 02
Scenario 01
Redistribute the air inside the building during the working hours, by adding extensions linking the indoor public spaces in the building with classrooms to increase the control of the distribution of CO2 ratios. Management related (Occupants number)
Design related (Space volume)
3.1.1 B
3.1.2 C
C C 3.1.2
02
01
01
Design related (Space volume) Atrium zone 3 Space volume: 5,484.8 m
3.2 Methodology Floor area 4420m Solid and unventilated area 1346m2 Free ventileted area 3047m2 Classrooms area 1700m2
Discussion
Management variables
Students performance
Schedule
1600 1.06 m
1200
53
54
47
Atr. 36
zone 17
Atr. 24
zone 16
7:00
02
12:00
50Min.
50Min.
07
BREAK
10Min.
10Min. 50Min.
06
CLASS
11:00
10Min. 50Min.
05
CLASS
10:00
10Min. 50Min.
04
CLASS
9:00
10Min. 50Min.
03
CLASS
8:00
10Min. 50Min.
08
CLASS
13:00
14:00
60Min.
09
CLASS
10 OFF
CLASS
15:00
16:00
Classroom zone Space volume: 205.5 m3
17:00
WORKDAY END
WORKDAY START
ppm
600
44
46
ppm
32
zone 04
52
51
400 ppm
1.06 m
01
zone 19
zone 07
1.06 m
800
45
50Min.
OFF
ppm
1000
zone 15
Results
50
zone 11
zone 01
Conclusion and Recommendations
49
48
ppm
Scenarios
zone 02
200 ppm
0
42
All free spaces 3047m2 100% Classrooms area 1820m2 55.80% Corridors area 1346m2 44.20%
Students: 30 - Area: 68.5
Atrium
Current condition 01
41
40
zone 09
39
38
33
34
zone 18
43 35
33%
37
67%
Atrium zone
Total Mixed Volume Classroom Volume Allocated volume from corridors and atrium for each classroom
Corridor zone
Classroom zone
Scenario 02
Mechanical
Design variables
Research sample
57.5%
55
zone 08 zone 14
42.5%
zone 05
Suggested alternatives
Space volume
60Min.
56
zone 06
ppm
7.50 m
Aimed condition
31
9.14 m
Scenarios
Measurement
CORRIDORS SCHEDULE
10Min.
ppm
Space efficiency
Current situation Corridors and atriums
30
Occupants
Corridors zone Space volume: 1346 m3
HOURS DURING WORKDAY
1400
Current condition
Space volume: 2742.4m3 All vertical space: 5,484.8m3
2
According to the standard, the student number was reduced to 30 students in the classroom, we can notice a slight decrease in the CO2concentration level by 12.5%.
Evaluate
Scenario 03
Observations
Analyze
Findings
4. Case Analysis 4.1 Research sample
9.14 m
1.06 m
Classroom building 535 King Abdulaziz university Space volume: 205.5 m³
Design related (Space volume)
Design related (Space volume)
Design related (Space volume)
3.1.2 C
3.1.2 C Atrium 03
3.1.2 C
We observe a decrease in the concentration of CO it reach 2 882.48 ppm at its highest concentration point.
Comparing and analyize
02
1.06 m
7.50 m
We observe a decrease in the concentration CO it reach 946.23 2 ppm at its highest concentration point. Corridors zone Space volume: 51.77 m3PEAK
1.06 m
Classroom zone Space volume: 210 m3
New classroom zone Space volume: 313.65 m3
1400 ppm
1200
1000 ppm
800 ppm
1000
800 ppm 800
600 ppm
600 ppm
400 ppm
600
400 ppm
200 ppm
200 ppm
0
MEASUREMENT TOOL SPOT HEIGHT 1.10 m
1400
1200 ppm
1000 ppm
Atrium zone Space volume: 52.67 m3
Scenario 02
1400 ppm
1200 ppm
PLAN
Classroom 53
PEAK 882.48 ppm 10:20 am.
946.23 ppm 10:20 am.
400
Corridor
0
CALIBRATION
200
0
SCENARIO 01
7:00 7:20 7:40 8:00 8:20 8:40 9:00 9:20 9:4010:0010:2010:4011:0011:2011:4012:0012:2012:4013:0013:2013:4014:0014:2014:4015:0015:2015:4016:0016:2016:40
CALIBRATION
SCENARIO 01
SCENARIO 02
�ΔϠγϠγ
CALIBRATION
�ΔϠγϠγ
�ΔϠγϠγ
SCENARIO 01
�ΔϠγϠγ
CLASSROOM 53
ZONE 1
3.00 m
SECTION
4.2 Measurement and Simulation tools Design related (Mechanical system)
Design related (Mechanical system)
3.1.2 D
3.1.2 D
3.1.2 3.1.2 D 9.14 m
01
02
02 9.14 m
CLASSROOM SCHEDULE HOURS DURING WORKDAY
1.06 m
7.50 m
IDA ICE
1.06 m
7:00
10Min.
10Min.
10Min.
10Min.
10Min.
10Min.
60Min.
50Min.
50Min.
50Min.
50Min.
50Min.
50Min.
50Min.
01
02
03
04
05
06
07
08
OFF
OFF
Specific for measure CO2 concentration in air, temperature and relative humidity
1.06 m
1.06 m
Scenario 02 (Corridors and atriums) 15 min. break
10Min.
temperature and relative humidity
Design related (Mechanical system)
8:00
OFF
9:00
OFF
10:00
OFF
11:00
ON
12:00
OFF
13:00
14:00
09
10 OFF
OFF
15:00
17:00
16:00
CORRIDOR
PLAN
PLAN
TEMPERATURE CLASSROM ANALYSIS 0C TEMPERATURE(C) O
RELATIVE HUMIDITY (%)
O
70%
26C
68%
25 C
66%
24 C
64%
23 C
62%
22 C
60%
21 C
58%
2
zone 06
49
48 47
45 44
46
zone 11
50
53
Atr. 36
zone 04
41
40
54 zone 17
Atr. 24
32
52
zone 02
42
55
zone 08
zone 16 zone 19
zone 18
zone 07
RELATIVE HUMIDITY CLASSROM ANALYSIS
The basic concept of reducing the CO2 concentration in the interior spaces is to replace the air in the contaminated space with unpolluted air, but the problem is that if the indoor air is replaced by the air from outdoor the internal temperature will increase which affects the thermal comfort of the occupants.
56
zone 15
Since there are low users densities in some of the internal spaces such as the corridors and atriums, the problem can be avoided by using the air switch between the spaces are usually occupied only for short times (breaktimes period) and spaces with high intensity of use (as the classrooms). This will achieve the goal of reducing CO2 pollution without increasing electrical energy consumption by conditioning outdoor air.
Scenario 01
31
zone 01
4.3 Measurement analysis
30
zone 05
Using the simulation software, all the spaces on one of the building floors will be opened to each other to verify the effectiveness of the proposed solution.
WORKDAY END
zone 14
WORKDAY START
60Min.
50Min.
OFF
Applying the proposed solution idea by using the simulation program
1.06 m
SIMULATION
1.06 m
MEASUREMENT
51
zone 09
39
38
33
43
34
35
37
O
O
O
O
0 :0
DAY TIME
COMFORT TEMPERATURE
O
17
17
:0
0
O
DAY TIME
RELATIVE HUMIDITY HIGHEST LEVEL STANDARD
RELATIVE HUMIDITY (%)
TEMPERATURE(C)
Psychrometric chart
CLASS OFF
Absolute humidity (kg/kg) Relativ e humidity (%) 100
90
80
70
60
50
40 0.0550
The two most important variables affecting the thermal comfort in the classroom temperature and relative humidity. The data average readings were shown on the Psychrometric chart to determine whether the results were within the range of thermal comfort zone or not.
30
0.0500
40
0.0450
0.0350
Observations
0.0300
As shown the in the diagram, data avearge is placed in the comfort zone.
30 0.0250
COMFORT ZONE DATA AVERAGE
0.0200
25
Max. 2000 ppm
02
Min. 400 ppm
Max. 2000 ppm
5
10
15
20
25
30
35
40
45
50
55
60
65
Wet bulb temperature Comfort zone
We notice the highest value of CO2 concentration levels in educational spaces reach 2008 ppm.
32
52
zone 02
42
41
40
39
51
zone 09
38
33
34
zone 19
zone 18
43 35
37
49
48 47
45 44
46
zone 11
50
53
Atr. 36
zone 04
52
zone 02
42
41
40
39
zone 17
Atr. 24
32
54
51
zone 09
38
33
34
zone 16 zone 19
zone 18
43 35
37
30
31
56
zone 06
49
48 47
45 44
46
zone 11
50
53
Atr. 36
zone 04
32
41
40
39
54 zone 17
Atr. 24
52
zone 02
42
55
zone 08
51
zone 09
38
33
34
End 12:00 am.
CO2 CONCENTRATION (ppm)
1400 ppm
6. Recommendations
1200 ppm
1000 ppm
The charts show a high increase in CO2 concentrations in the working day due to the classroom is full by students. Consequently, the carbon dioxide emissions due to students congestion increase to a concentration level of 1270 ppm, which causes complaints of drowsiness and poor air.
800 ppm
In
600 ppm
conclusion, the following recommendations are presented based on the above research, study and analysis:
400 ppm
200 ppm
0 ppm
17 :0 0
Observations
DAY TIME
CLASS OFF
CO2 STANDARD
WORKDAY CO2 LEVEL
The Department of Architecture (KAUARCH) Faculty of Architecture and Planning King Abdulaziz University
1- Taking into account during the design that the Spaces should be designed with dimensions and sizes commensurate with their uses. 2- Changing the scheduling of students ’sessions times and break times. 3- Reducing the number of students in the single educational space, in proportion to its size. 4- Improving the mechanical systems of building conditioning and ventilation to allow more fresh air to enter the air conditioning cycle. 5- Adding windows between the interior spaces of the building that allows air exchange between educational spaces and general corridor spaces when the indoor air quality decreases to reduce energy waste when opening the external windows.
Feras Essam Balkhi Supervisor: Dr-Ing. Mohannad Bayoumi
zone 18
43 35
CO2 Concentration Starting PEAK 9:50 am. 1270 ppm 10:30 am.
zone 16 zone 19
zone 07
0
zone 04
zone 17
Atr. 24
zone 16
Scenario 04 Space CO2 30 799.3 31 794.1 32 788.6 33 798 34 798.3 35 798.3 37 798.3 38 793.7 39 793.7 40 793.7 41 793.7 42 804.2 43 805 44 797.3 45 854.2 46 826.7 47 826.7 48 880.8 49 795 50 787.2 51 798.1 52 791.1 53 797.2 54 795.1 55 806.2 56 800.8 Zone 01 795.4 Zone 02 802.2 Zone 04 751.6 Zone 05 829.1 Zone 06 807.7 Zone 07 964.5 Zone 08 908.5 Zone 09 869.6 Zone 10 793 Zone 11 747.2 Zone 14 988.4 Zone 15 1015 Zone 17 1024 Zone 16 1088 Zone 18 1009 Zone 19 965.1 Atr. 24 750 Atr. 36 735.6
Max. 2000 ppm
zone 15
Relative humidity
-5
Atr. 36
54
55
zone 08
When applying the idea in the simulation program to an entire floor of the building and opening the spaces to each other according to the following variables data (the maximum capacity of the educational spaces - the timing and duration of break times equal 15 minutes between each two sessions) after that if we add some mechanical solutions (As an example CO2 sensors & VAV HVAC systems) the results are shown as follows
Min. 400 ppm
zone 01
-10
44
46
53
zone 06
02 03
zone 05
Absolute humidity
-15
45
50
56
zone 07
-20
47
zone 11
31
zone 15
0.0000
49
48
55
zone 08
30
zone 01
Observation
-5 -10
zone 06
We notice a decrease in the highest value of the CO2 concentration in educational spaces from 2008 ppm to 1509 ppm, and this is a good improvement. Looking at the average values of CO2 concentration levels in educational spaces, we find that it's generally decreased by 13.2%.
Scenario 02 Space CO2 30 1150 31 1277 32 1182 33 1317 34 1318 35 1318 37 1318 38 1300 39 1299 40 1299 41 1299 42 1418 43 1419 44 1287 45 1509 46 1459 47 1459 48 1414 49 1274 50 1147 51 1303 52 1200 53 1208 54 1290 55 1402 56 1297 Zone 01 974 Zone 02 1064 Zone 04 981 Zone 05 1123 Zone 06 1037 Zone 07 1087 Zone 08 1087 Zone 09 1109 Zone 10 1092 Zone 11 953.8 Zone 14 1088 Zone 15 1127 Zone 17 1193 Zone 16 1113 Zone 18 1111 Zone 19 1056 Atr. 24 961.4 Atr. 36 945.2
zone 05
0
Wet bulb temperature (°C)
56
zone 07
0.0050
31
zone 15
10 5
30
zone 01
0.0100
15
When entering the variables into the simulation program for an entire floor of the building based on the following data (the maximum capacity of the educational spaces - the timing and duration of the break times is equal to 15 minutes between every two sessions) the results appear as follows.
Observation
zone 05
Temperature: 22.25 C Relative humidity: 66.5%
Current condition
Scenario 01 Space CO2 30 1455 31 1455 32 1446 33 1455 34 1455 35 1455 37 1455 38 1455 39 1455 40 1455 41 1455 42 1513 43 1513 44 1455 45 1840 46 1653 47 1653 48 2008 49 1455 50 1455 51 1455 52 1455 53 1455 54 1455 55 1513 56 1455 Zone 01 796.6 Zone 02 796.7 Zone 04 727.9 Zone 05 846.4 Zone 06 804.2 Zone 07 978.4 Zone 08 933.2 Zone 09 922.8 Zone 10 805.7 Zone 11 729.8 Zone 14 979.4 Zone 15 1006 Zone 17 1076 Zone 16 1017 Zone 18 1015 Zone 19 965.3 Atr. 24 732.1 Atr. 36 706.3
CO2 concentration
3.1.2 D
CO2 concentration
zone 14
20 o
Dry bulb temperature
Min. 400 ppm
zone 14
0.0150
-25
3.1.2 D
CO2 concentration
zone 14
10
-40 -35 -30 Dry bulb temperature (°C)
Design related (Mechanical system)
0.0400
20
Data taken 13.OCT.2019
3.1.2 D
01 35
Data average
Design related (Mechanical system)
Design related (Mechanical system)
37