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UCL Institute for Environmental Design and Engineering

ANTONIA VAVANOU DIALA NOUREDDINE OLIVER WELLS SPYROS EFTHYMIOPOULOS 1


TABLE OF CONTENTS 1. ARCHITECTURE AND DWELLING

4. CONCLUSIONS

1.1 Introduction and Site Analysis

3

4.1 Discussion

14

1.2 Climate Analysis

4

4.2 Limitations

14

1.3 Shoebox Analysis

5

4.3 State of the Art

14

1.4 Environmental Targets

6

1.5 Architectural Design

7

1.6 Initial Environmental Strategy

8

5. REFERENCES

15

6. APPENDICES 2. DOCUMENTATION

Appendix A: Shoebox Analysis

16

2.1 Energy Analysis

8-10

Appendix B: Architectural Drawings

17-30

2.2 Life Cycle Assessment

11

Appendix C: Environmental strategy

31-33

2.3 Solar Penetration Analysis

12

Appendix D: 3D Renders

34-41

Appendix E: Energy Analysis

42-56

Appendix F: Embodied Carbon/Energy Analysis

57-58

Appendix G: Solar Penetration Analysis

58-59

3. COMFORT AND CLIMATE COMPARISON 3.1 Effect of Climate on Design Proposal

13

3.2 Suggested Strategies

13

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1.1 INTRODUCTION AND SITE ANALYSIS The design of passive solar buildings contributes towards the optimization of buildings as systems that act as natural filters between the indoor and outdoor environments, while maximizing the utilization of solar energy (Athientis et al., 2002) . The aim of this project is to understand how energy consumption in domestic buildings can be minimized through appropriate building solar design and to use computer simulation for building optimization. The objective is to design a self-sufficient solar-powered house using a combination of architectural and environmental strategies. This report explores passive solar design strategies to achieve the demands for human comfort, good air quality, and to demonstrate an energy efficient home through the implementation of heating, cooling, humidity control and ventilation.

LOCATION The Mbeya region is situated in the Southern Highlands of Tanzania, Africa, at an altitude of 1700 metres above sea level with high peaks of 2,981 metres (PO-RALG, 2016). The site is located in Iwambi, near the city of Mbeya as seen in Figures 1 and 2, which sits at an 1627 metre altitude (Health Facility Registry, 2019).

SUNPATH Mbeya’s sun path varies throughout the year due to its close proximity to the equator. Figure 4 displays the sunpath diagram for the solstices and equinoxes in Mbeya. In the winter the sun's path moves slightly to the north and in the summer it move back to the south. Moreover, sunrise and sunset times in Tanzania do not differ much throughout the year. Figure 5 illustrates the sun movement from winter to summer, at midday. The sun is at a lower angle in winter (57°) compared to the high summer angle (75°). The diagram in Figure 6 displays the optimum solar orientation by taking into account the sun’s path and prevailing wind direction. It can be determined that the optimum solar orientation is North, because lower solar radiation is received and there is a low risk of overheating throughout the year. The worst orientation is towards the south, whereby a higher exposure to solar radiation exists and overheating risks.

Figure 3: Pollutant Levels comparison between CAQI and Iwambi, Mbeya. Source: Meteoblue, 2018.

AIR QUALITY The air quality index (AQI) data for Iwambi indicates good outdoor air quality due to its rural location. A one-week forecast of particulate matter (PM and desert dust) and Gases (Ozone) is displayed in Figure 3. This indicated low PM10 and ozone gas levels between 20-40 ug/m3 and PM2.5 levels below 10 ug/m3 (Meteoblue, 2018).

Figure 5: Solar angles

Figure 1: Location of Iwambi, Mbeya, Tanzania below the equatorial line.

Figure 2: Site location Source: Google Earth Maps

Figure 4: Sun path diagram with solstices and equinoxes for Mbeya, Tanzania. Source: Weather Tool

Figure 6: Diagram displaying optimum solar orientation Source: Weather Tool

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1.2 CLIMATE ANALYSIS

WIND

SUNSHINE AND CLOUD COVERAGE

MICROCLIMATE

The prevailing wind direction is mainly from the South East. Figure 7 shows the average wind speeds are in the 5-15 kph range, which according to the Beaufort scale tend to be between gentle and moderate (RMetS Editor, 2018). On average, a higher percentage of wind occurs during the winter season compared to the dryer summer months. Wind temperatures vary between 15-25 °C annually, as displayed in Figure 8.

The clearer parts of the year in Mbeya last for 6 months, beginning in April and ending in October. The average number of sunshine hours is between 7-10 hours. The cloudier part of the year begins around October and lasts for 6 months, ending in April. The average number of sunshine hours last between 4-7 hours.

There is minimal neighboring construction in the surrounding rural area, therefore wind speed is expected to be higher along with open and direct sun exposure. However, there is diversity in the geology, soil type, and vegetation in Mbeya. Apart from the cooling that abundant rainfall provides, it stimulates the fertile soils which have good drainage quality (Huang et al, 2017). This allows for thriving vegetation, such as dense trees which provide shading, creating a cool microclimate around the site’s surrounding.

PSYCHROMETRIC CHART

Figure 7: Average yearly wind frequency. Source: Weather Tool

Figure 10 shows the annual temperature and humidity variations in Mbeya. The average indoor temperature range for human comfort throughout the year is between 22-27°C. The findings from the psychrometric chart show that the design strategies to be considered include passive solar heating, thermal mass, exposed mass, and natural ventilation. Passive solar heating will help increase indoor temperature during winter, while natural ventilation will provide cooling during the warmer summer months. Thermal mass and exposed mass will both prevent excessive temperature and will reduce the risk of overheating.

Figure 8: Average annual wind temperatures. Source: Weather Tool

TEMPERATURE AND PRECIPIRTAION Mbeya has a subtropical highland climate with humid summers and dry winters. Figure 9 displays the average monthly climate data for the Mbeya region, which was used to define the seasons as shown in Table 1.

(a)

Table 1: Seasonal temperature averages. Source: Weather Tool Season

Month

Average Temp °C

Winter

May-Aug

20

Summer

Sep- Dec

27

Shoulder months

Jan-Apr

22

The large fluctuations between recorded high and low temperatures during the day and night are displayed in Figure 9(a). Mbeya also has a distinct wet season with a mean annual rainfall of 1,200mm which occurs for six months between November and April (PORALG, 2016).

(b)

(c)

HUMIDITY LEVELS Humidity levels are generally high due to Mbeya's subtropical climate. These levels tend to rise when there is more rainfall, particularly in the wet season. The monthly average percentages for relative humidity depicted in Figure 9 range between 55% to 78% throughout the year. 4

(d) Figure 9. (a) Annual temperature ranges in Mbeya (b) Number of days with precipitation (c) Hours of sunshine (d) Average relative humidity Sources: World Climate Guide (n.d.) and Weather Tool

Figure 10: Graphic Comfort Zone: Acceptable range of operative temperature and humidity. Source: Weather Tool


1.3 SHOEBOX ANALYSIS 0o 8.5 x 8.5

The shoebox modelling analysis was used to determine how design features and changes in the building envelope affected its energy performance and the indoor environment.

ASSUMPTIONS For the purposes of the early-design modelling, a shoebox with dimensions of 12.5m x 6m x 3m was produced. The materials used for the initial simulations are included in Appendix A. The temperature and natural light were used as the design variables during the analysis.

1. SHAPE

RESULTS

6 x 12

±30o

2. ORIENTATION

12 x 6

The outcome of the results are explained below, with each analysis graphically represented in Figure 11.

±45o

1. SHAPE

Orthogonal shape with longest sides facing south and north was found to be most appropriate for Mbeya. Large surface facing north for the collection of solar heat gains in winter period. East and West facades, have limited surface area and therefore less heating gains from sun during summer.

winter

roof

2. ORIENTATION

Optimum orientation was determined to be 0o at East – West orientation. Maximum heat gains occur during winter.

South 6. SHADING

3. ZONING

south

summer

East

3. ZONING

North area of the building has better thermal conditions during summer and winter. South area of the building is colder and darker during winter, but warmer during summer. 9. WINDOWS

4. POSITION & SIZE OF SUNROOM

5. SHADING

A double roof system was designed to protect the sunroom against overheating, especially during summer. A shading system on the south façade was implemented to minimize heat gains from the windows.

Light weight

east

Optimum position is the center of orthogonal shape to improve thermal comfort. Avoids largest heat gains in East and West orientation. Optimum size of each building volume was 4x6m to achieve high thermal performance.

West

North

4. SUNROOM POSITION

middle

7. THERMAL MASS

Medium weight Top Heavy weight

west

6. THERMAL MASS

High thermal mass construction materials reduced temperature fluctuations. The rate of heat transfer reduced with increased thermal mass.

6x6

External

7. TIMBER POSITION

Timber was used as a construction material but also increased the thermal performance of building elements. Optimum position of timber is external or between the walls to reduce temperature fluctuations. Placing the timber internally reduced the thermal mass.

5. SUNROOM SIZE

4x6

Internal

Middle

8. WINDOWS

Optimum position of windows was facing North to increase solar gains and daylight during winter. Windows facing South is the second option for increased heat gains but requires extra shading during summer. Windows facing East and West caused large heat gains which led to an overheating risk.

8. TIMBER POSITION

2x6

Figure 11: Breakdown of Shoebox iterations on IES

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1.4 ENVIRONMENTAL TARGETS

OCCUPANCY PATTERN

HUMIDITY LEVELS

This house is designed for a family of four, two professional adults, and two children. One of the two parents will work at home as a child-minder for 10 toddlers who are looked after in the house with the help of a grandmother who does not live there. The occupancy pattern shown in Table 2 remains constant throughout the year..

Based on EN 15251:2007 humidity levels within a building should be maintained between 25-60%. On the other hand ASHRAE Standard 55 (2017) implies that the upper limit for relative humidity should be 60% while no lower limit is indicated. However, extremely low humidity levels can cause irritations and were found to affect occupant wellbeing (ASHRAE HANDBOOK, 2017). As a result, the range from EN 15251:2007 was adopted for the purpose of this study.

Table 2: Occupancy Schedule No

Name

Size

1

Living Room

18.35 m2

2

Solarium Toddlers

21.60 m2

13 m2

Occupancy Members

Operational Hours Weekdays Weekends

Use

Age groups

4

17:00-21:00 5 days per week

10:00-22:00 2 days per week

Rest area & visitors

10-100 years

12

9:00-17:00 5 days per week

10:00-18:00 2 days per week

Working area Childminding Dining room

0-100 years

4

07:00-9:00 17:00-21:00 5 days per week

10:00-11:00 13:00-14:00 18:00-19:00 2 days per week

Cooking Dining room

10-100 years

22:00-10:00 2 days per week

Sleeping Playing

10-12 years

22:00-10:00 2 days per week

Sleeping

35-45 years

-

-

3

Kitchen

4

Bedroom children

13.20

m2

2

21:00-7:00 5 days per week

5

Bedroom parents

18.35 m2

2

21:00-7:00 5 days per week

6

Ancillary Spaces

-

-

VENTILATION RATES & CO2 CONCENTRATION LEVELS Based on the EN 15251:2007, it was determined that the design should comply with targets set for a Class II building. As a result, ventilation rates should be provided to maintain CO2 concentration levels under 1000ppm for more than 95% of the occupied hours.

NOISE LEVELS For determining noise level limits, CIBSE GUIDE A was utilized as indicated in Table 4.

DAYLIGHT & LIGHTING LEVELS To ensure visual comfort was achieved within the house, BREEAM guidelines were used to determine the requirements for daylight factors. The requirements for lighting levels, displayed in Table 4 were determined using guidance from the Illuminating Engineering Society (IES), which outlines a minimum lux level to be achieved in different areas and types of houses.

COMFORT TEMPERATURE RANGE Mbeya has a mild subtropical climate which indicates the need to utilise an adaptive approach to specify the comfort criteria. The occupants cover a number of age groups which have different metabolic rates and activity levels. Clothing is another factor that affects an occupant’s comfort and wellbeing within a space. As a result, emphasis was placed on determining the most appropriate comfort conditions for the occupants of the house. The comfort temperature range throughout different seasons was determined by using two standards; ASHRAE Standard 55 (2017) and EN 15251:2007 as shown in Table 3 below. Table 3: Comfort Temperature Requirements Comfort Temperature range for Summer (oC)

Comfort Temperature range for Shoulder months (oC)

Standard

Comfort Temperature range for Winter (oC)

ASHRAE Standard 55 (2004)

20.5-25.5

22-27

21.5-26.5

EN 15251:2007

21.5-27.5

22.5-28.5

22-28

ASHRAE Standard 55 was considered as the most appropriate guide for determining the comfort temperature range, as it provides a lower range of temperatures with smaller deviations throughout the year. This allowed occupants that are sensitive to temperature changes, such as the grandmother, due to their metabolic rate (ASHRAE HANDBOOK), to not experience large temperature fluctuations. 6

Table 4: Other Environmental Targets

Noise (dbA)

BREEAM's Average Daylight Factor requirement

BREEAM's Average daylight illuminance in lux (averaged over entire space)

IES Standards Illumination Level (lux)

25 -60

35

1.2

30-100

50

Bedroom

25 -60

30

1.2

30-100

50

Kitchen

25 -60

45-50

1.5

30-100

150

Bathrooms

25 -60

-

1.2

30-100

100

Hallways and Landings

25 -60

-

1.2

30-100

150

Stairs

25 -60

-

1.2

30-100

100

Area Type

Relative Humidity Levels (%)

Living Room


1.5 ARCHITECTURAL DESIGN The architectural approach combined climate analysis, IES shoebox results, daylight analysis, and architectural principles, to make the building thermally comfortable for the occupants, aesthetically appealing, and memorable. The house includes: a living room, kitchen, two bedrooms, a nursery/working area, and ancillary spaces which have a total area – including walls and two floors – of 120.20m2 (Ground floor 70.40m2 and first floor 49.80m2). Refer to Appendix B and D for detailed architectural drawings and 3D renders.

Figure 12. Appropriate building shape and orientation

SHAPE & ORIENTATION The shoebox analysis found that an orthogonal shape, with large sides facing South was the ideal position to optimize the use of the sun (see Figure 12). To take advantage of this optimum position, the house is orientated with 0o deviation from the South. The house is arranged over two levels, ground and first to ensure that both the footprint and solar envelope limitations were adhered to.

Figure 13. Sunroom optimum position.

PRIVATE SPACES (first floor)

CONCEPT The main concept for this project is the sunroom nursery area. The house is organised around this meeting point, which is multifunctional and can be seen from all parts of the house (see Figure 14). The location is designed for the nursery so visual contact and attention can be given at all times. Moreover, this area can be used by the family during weekends for different activities through utilisation of other spaces (living room and kitchen). The sunroom is placed at the center of the orthogonal shape, shown in Figure 13, as it was found to be the most appropriate position from the shoebox analysis. The sunroom is double height and has a fully glazed façade on the north, giving that area and adjacent rooms a greater connection with the external environment and nature. The sunroom nursery area performs as a heat collector and distributor during winter and as a cooling mechanism during summer periods. It is a space with optimal thermal and natural lighting conditions for the toddlers during the day, as well as a pleasant environment and activity area for the family during evening and weekends.

Figure 14. Sunroom concept - 3D model view

BEDROOMS LIVING ROOM_KITCHEN

PUBLIC SPACES (ground floor) Figure 15. Architectural zoning sketches based on uses.

winter

summer

ZONING The house consists of two volumes which are connected by a bridge in the double height sunroom. Architectural zoning based on uses: Spaces that are predominantly used for occupants during the day are located on the ground floor (living room, kitchen, toddlers’ area) and spaces that are used predominantly during the night are based on the first floor (bedrooms) (Figure 15). Environmental zoning: From the shoebox and climate analysis, it was found that the north side of the building has better thermal conditions during both summer and winter periods. On the contrary, the south side is colder and darker during winter but receives increased thermal gains during summer. For these reasons, spaces that require, increased heating during winter and cooling during summer, are placed facing north (living room, toddlers’ area, kitchen, bedrooms). Ancillary spaces that are used less (staircases, bathrooms, storage and circulation areas) are placed towards the south, acting as buffer zones (Figure 16). The role of the buffer zone is to reduce the impact of changes in the external environment to the internal spaces, contribute towards energy savings and improve the indoor thermal environment (Andreadaki, 2006).

warm

cool

cool

warm

GROUND FLOOR

GROUND FLOOR

cool

warm cool

warm

DOUBLE ROOF CONCEPT The double roof system, with a 5% slope gradient, is introduced to mitigate overheating in the sunroom, control solar penetration, enable stack ventilation through the sunroom’s glazed roof, as well as protect the building during the rainy season .

FIRST FLOOR

FIRST FLOOR

Figure 16 . Environmental zoning according to sun path.

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1.6 ENVIRONMENTAL DESIGN

SUMMER

WINTER

INITIAL ENVIRONMENTAL STRATEGY The environmental design is based on the sunroom area, which positively contributes to the heat balance in winter due to the penetration of solar radiation. The sunroom is centrally located in the house where all other spaces to be in contact with it. The North façade and roof of sun room are fully glazed to increase solar gains during winter (Figure 18a). The South façade and floors are constructed with materials which have high thermal mass designed to store heat during the day and release it overnight (Figure 18a). Windows of adjacent spaces are kept open so heat can be transferred and stored in the rooms during the day (Figure 18b). At night, during winter months, all internal openings are closed to keep the heat trapped within each room (ex. Bedrooms). This reduces heat losses via the fully glazed façade and roof of the sun room (Figure 18b).

Figure 18a. Sunroom environmental operation during winter day/night

Figure 18b. House environmental operation during winter day/night

Figure 19a. Sunroom environmental operation during summer day/night

Figure 19b. House environmental operation during summer day/night

During both winter and summer months the sun room is protected from overheating by the double roof system which also enables stack ventilation (Figure 19a). During winter the ventilation rate is minimized to reduce heat losses whereas during summer both stack and cross ventilation strategies are used to avoid overheating and minimize humidity levels (Figure 19b). For the final environmental strategy, see Appendix C.

2. DOCUMENTATION 2.1 ENERGY ANALYSIS BASELINE MODEL For the purpose of this analysis, the IES VE software was used to simulate the performance of the building in Mbeya, Tanzania. Data regarding temperature, humidity levels, and CO2 concentration within the spaces were extracted and used to carry out an energy analysis.

2.1.1 MODEL ASSUMPTIONS Key assumptions made regarding the production of the model are outlined below: THERMAL ZONE DIVISION

The model was divided into nine thermal zones (see Appendix E) based on achieving criteria of optimal use and conditions of each space. VENTILATION STRATEGY

BUILDING MODEL GEOMETRY The baseline model was simulated as a free running building. With regards to the orientation and direction of the building the house entrance was selected to be north-facing. BUILDING CONSTRUCTION AND FABRIC In terms of materials, external walls consisted of mud bricks while the internal partitions consisted of timber board. Cast concrete was applied to the ground floor and roof elements, while the material of the first floor was timber. Details regarding the construction materials used for the building fabric are included in Appendix E. It is important to note the internal walls of the sunroom were designed and simulated as having the same construction elements as the external walls. This allowed the adjacent spaces to be protected against the high diurnal temperature fluctuations in the sunroom, caused by the low U-values of the glazing elements. 8

To achieve the indoor air quality requirements, the baseline’s model ventilation strategy utilized the stack effect driven by buoyancy and was the same for all seasons and spaces. External windows were used as inlets and the internal windows were open for air to escape through the openable sunroom glazed roof. For design calculations and ventilation requirements (see Appendix E) INTERNAL GAINS

Based on the occupancy pattern specified in Appendix E, occupancy profiles were created in IES VE to ensure that the internal heat gains originating from occupants were included. INFILTRATION RATE

An infiltration rate of 0.15 ach was selected in accordance with CIBSE GUIDE A and this parameter was kept constant while undertaking the design iterations.


2. DOCUMENTATION 2.1.2 RESULTS AND IMPLICATIONS | BASELINE MODEL CO2 levels under 1000ppm were maintained during 100% occupancy (see Appendix E). However, problems were identified relating to the inability to maintain indoor temperatures within the comfort zone, for more than 62% of the occupied hours (as indicated in Figure 20).

62%

Annual percent within thermal comfort for Baseline Model

Issues observed in the baseline model: - High temperatures & humidity levels within the sunroom all year-round. - High temperatures in parents' bedroom during summer months. - Low temperatures in kitchen, living room, and children's bedroom all yearround.

Figure 20. Percentage of time within the thermal comfort zone during occupancy, baseline model

2.1.3 MODEL ITERATIVE ANALYSIS

Ventilation Strategies:

-Winter / Shoulder months The ventilation of the ground floor was based on inlets in the sunroom. Internal windows in the living room and kitchen were suggested to be 5% open during occupied hours while external windows were shut. This strategy utilized the temperature difference between the sunroom and all adjacent spaces, causing mass transfer due to convection phenomena (Bergman et al., 2014). Consequently, airflow between the spaces in the lower ground was utilized to provide both ventilation and an even distribution of temperature. First floor ventilation used external windows as inlets and internal as outlets (sunroom stack effect), and the rates were maintained to low levels to avoid heat losses and a CO2 concentration above target limits. -Summer To mitigate overheating during summer in the sunroom, a higher ventilation rate was proposed and that was achieved by increasing the openable area of the sunroom’s windows. For the kitchen and living room, cross-flow ventilation was applied as an efficient measure to cool down these two spaces. The first floor follows the ventilation strategy applied during winter/shoulder months but with higher ventilation rates. Results from the first iteration set have shown a noticeable increase of 14% of the percentage of time during occupancy when temperature remains within the target limits. Humidity levels maintained within the target range for an additional 2% of the occupied hours, while CO2 levels stayed under 1000ppm for over 95% of the time (see Appendix E). In total the building was improved by 14% from the 1st iteration (Figure 22).

82%

Annual percent within thermal comfort for 2nd iteration

Figure 22. Percentage of time within the thermal comfort zone during occupancy, 2nd iteration

There are 3 sets of iterations related to ventilation, fabric and shading. 1) VENTILATION STRATEGIES AND PASSIVE COOLING SET OVERHEATING AND LOW TEMPERATURES MITIGATION

68%

Annual percent within thermal comfort for 1st iteration

89%

Annual percent within thermal comfort for 3nd iteration

3rd iteration: High Thermal Mass and U-value improvements Following the high diurnal temperature differences observed in Mbeya’s climate, the temperature within the building fluctuates throughout the day (see Appendix E). To address the problem, materials with high thermal mass were proposed to replace the existing building elements. Materials with high thermal mass, are considered to be very important for the regulation of temperature within a building (Reardon, 2013).

1st iteration: Adjustment of Windows Openable Area To achieve better thermal conditions for the spaces that suffered from low temperatures, ventilation rates were decreased to the point where CO2 levels were maintained under 1000 ppm for more than 95% of the occupied hours. On the other hand, to ensure lower temperatures in the sunroom, an increased ventilation rate was introduced. To achieve this result, the proportion of openable glazing area increased in the sunroom and decreased in the other thermal zones (see Appendix E). The extracted data from the simulation indicated a 9.7% increase of the time where temperature in all spaces were within the defined limits (Figure 21). The outcome of this developed design resulted in further ventilation strategies being implemented to reduce the energy consumption and improve the thermal comfort of occupants. 2nd iteration: Implementation of alternative ventilation strategy and ventilation rates In contrary to the baseline model ventilation strategy which was constant year round, three different ventilation strategies for the different seasons (summer, winter and shoulder months) were implemented to provide a uniform thermal environment.

2) FABRIC IMPROVEMENTS SET BALANCE THERMAL CONDITIONS

Figure 21. Percentage of time within the thermal comfort zone during occupancy, 1st iteration

-Walls Construction: Timber as insulator The low embodied carbon and high thermal capacity of rammed earth were the main reasons for selecting this material over mud bricks (baseline model). However, its high thermal conductivity can lead to a high U-value of the internal and external walls. Due to material limitations for this project, the solution was to apply timber board (200mm) as an insulator material in the middle of the rammed earth wall. This addition ensures lower U-values for external and internal sunroom walls (see Appendix E). The position of timber in the middle of the construction was selected to take advantage of improved insulation and a higher thermal mass.

Figure 23. Percentage of time within the thermal comfort zone during occupancy, 3rd iteration

Findings by Najafian (2012) and Wang et al. (2017) also indicate that insulating a wall externally decreases the rate of heat transfer and is appropriate for climates where high diurnal temperature differences occur. 9


2. DOCUMENTATION -Glazing To reduce heat losses through the glazing elements, 12 mm clear float glass was used to replace the 6 mm glass that was used for the baseline model. Having clear float glass allows sunlight to be transmitted into the building while the increase of its thickness led to a 17.5% reduction of the U-value.

Moreover, an increase of 20% in the percentage of time when indoor temperature was kept within the comfort zone was achieved. Modifying the construction elements was the next most effective strategy, resulting in a 7% increase in improvement levels when compared to the 2nd iteration. Installing shading systems contributed the least, despite its necessity to control daylight penetration.

Based on the results of the 3rd iteration, provided in Appendix E, the changes in fabric constructions proved to be beneficial for achieving temperatures within the target range across the year. Humidity levels were also maintained within the target limits for a longer time than in the iteration where light thermal mass materials was used. The annual percent within the thermal comfort levels was found to be 89% (Figure 23).

90%

Annual percent within thermal comfort for 4th Iteration-Final

3) SHADING SET MITIGATION OF OVERHEATING AND EXCESSIVE SUNLIGHT EXPOSURE

Comparing the indoor temperature data between the baseline and the final model, it can be stated that uniformity and stability of the thermal environment has been achieved (see Appendix E). Despite the fact that the indoor temperature results have been provided for the worst case scenarios (hottest and coldest days of the year), small temperature deviations were observed.

2.1.5 ENERGY REQUIREMENTS | FINAL MODEL The total load required to meet the demand of the house is 6280 kWh/yr. Table XX shows the load broken down into requirements for heating, cooling and other appliances. The heating and cooling loads have been calculated using IES modeling. To determine the loads of other appliances in the house, both data from CIBSE Guide A and manufactures were used alongside a usage schedule. A full breakdown of these loads are presented in Appendix E.

4th Final iteration: External Shading systems applied Shading was considered to be a key strategy for the iterative process. External horizontal louvers in the north façade of the sunroom were beneficial for decreasing the overheating problem in the sunroom during winter. The fins of the roof were also rotated from vertical position to an angle of 45o preventing the sunroom overheating, due to excessive exposure to sunlight. Results of the 4th-final iteration have shown a 38.73% increase in the sunrooms conditions while the percentage of occupied hours annually when the target temperature range was achieved in the building increased by 28% (Figure 24).

Figure 24. Percentage of time within the thermal comfort zone during occupancy, 4rh iteration

The strategy employed to meet this load was to have all equipment run from electricity produced by a photovoltaic array located on the service plot. The array consisted of 16 panels, each rated at 300 Watt, giving a total system size of 4.8 kWp. To calculate the energy generated, it was assumed the panels receive on average, four hours of full sunlight per day, thus this system generates 7000 kWh/yr.

2.1.4 OVERALL MODEL ANALYSIS

Table 5. Energy Requirements of the Final Model

62% Baseline Model

20%

82%

7%

Ventilation Strategy

89% Fabric Improvements

1%

90% Shading Systems Final Model

28% total improvement Figure 25. Iteration process improvements

To provide comfortable thermal conditions for occupants in this project, three main variables must be controlled: Temperature, humidity, and CO2 levels. By implementing appropriate ventilation strategies, passive solar controls, and modifying construction elements, internal temperature control was achieved for 90% of occupied hours. CO2 concentration levels were also kept below 1000 ppm, indicating sufficient ventilation in the building at the time. However, with Mbeya’s humid climate, humidity control poses a serious challenge and implementing ventilation strategies alone is not sufficient. As displayed in Figure 25, implementing a ventilation strategy as a first measure does improve thermal performance significantly. 10

Source

Load (kWh/year)

Space Heating (kWh) Space Cooling (kWh) Other Appliances (kWh) Total

2,777.1 649.4 2,850.28 6,276.78


In this study, the principles of the Life Cycle Assessment ( were used to evaluate the embodied carbon and energy of the house. This was based on BS EN 15978 2011 the European Standard for the assessment of environmental performance of buildings The building life cycle is broken down into four sections shown below in Figure 26. The embodied carbon impact of the house is represented within the first two stages of the cycle product and the construction process. The building use and end of life stage are not in the scope of this report, and therefore will not be considered during this analysis.

The building elements with the largest embodied carbon were the external wall, roof, and ground floor, as shown by Figure 28. Using natural building materials such as rammed earth reduced the embodied carbon of the external wall due to not requiring energy intensive extraction or manufacturing techniques. This material will also be sources locally so transportation cost are low and it can be recycled at the end of the building life. Embodied Carbon (kgCO2/m2)

2.2 LIFE CYCLE ASSESSMENT

60.00 50.00 40.00 30.00 20.00

10.00 0.00 External Internal Wall Partitions

Ground First Floor Floor

Roof

Second Roof

Windows

Building Element Figure 28. Building Element Embodied Carbon m2 Floor Area

Figure 26. Building Assessment Information. Source: Moncaster et al., 2013

All data for this analysis has been collected using the Bath Inventory of Carbon and Energy ( Database (Hammond Jones, 2011). The database uses cradle to gate boundary conditions, which were adopted for this study. A limitation to this database is that all data is from secondary resources which can have variable boundary conditions, therefore not all of the data will meet the ICE’s boundary conditions (Hammond Jones, 2011) .

2.2.2 EMBODIED ENERGY The embodied energy of the entire house was 250 GJ which was up to 24% lower than when traditional building materials, such as bricks, were used for the external walls. The external wall and roof elements both had the largest embodied energy of the constructions.

14%

External Wall 35%

2.2.1 EMBODIED CARBON The overall embodied carbon was calculated for a total of three design iterations, with the final iteration having a total embodied carbon of 230 kgCO2/m2 The final design had a 41% reduction in embodied carbon when compared to the first iteration, with each iteration shown in Figure 27. This graph highlights that the second iteration had the lowest embodied, however during the energy analysis it was discovered that this construction did not stratify the environmental targets outlined in this report Therefore, new constructions had to be designed to achieve the environmental targets which had increased embodied carbon but this was offset by reduced heating and cooling loads by meeting the targets The calculations for each iteration are shown in Appendix F.

Embodied Carbon

500.00 400.00 300.00 200.00

13%

Internal Partitions Ground Floor First Floor Roof

1% 24%

9%

Second Roof Windows

5%

Figure 29. Building Element Embodied Energy

2.2.3 IMPROVEMENTS AND LIMITATIONS Further improvements to reduce the embodied carbon of the building would need to focus on the external wall and roof elements. An alternative material, which provides the same thermal performance but reduced embodied carbon, would be needed to replace the timber board which is the highest emitting material in both constructions. It is however, difficult to predict the exact embodied carbon of the timber due to the lack of studies and high element of natural variation which increases the risk of these results being inaccurate (Hammond & Jones, 2011).

100.00 0.00 1

2

Design Iterations

3

Figure 27. Overall Embodied Carbon per m2 floor area

The main limitation of this embodied carbon analysis is that only the cradle-to-gate figures are considered which do not include any transport to site or other construction processes. To improve the validity of the study a second source could be used to cross check the embodied carbon and energy figures from the Bath ICE Database. 11


2. DOCUMENTATION 2.3 SOLAR PENETRATION ANALYSIS Appropriate amounts of sunlight exposure reduces the dependence on artificial lighting, which increases energy consumption; however, excessive sunlight can cause glare and unwanted visual contrast which can significantly affect occupants health and comfort. A solar penetration analysis was performed by carrying out daylight factor ( simulations using FlucsDL on IESVE 2018 at a working plane height of 0.7 m, while taking into account the key building features of the space (see Appendix G). The solstice dates occurring in winter and summer (June 21 and December 22 were chosen to assess the performance of the working spaces on a clear sunny day at 12 00 pm. The results for both the base and final models are displayed in Table 7 below. The performances are set against the criteria outlined by BREEAM. Table 6: Daylight Factor results for the baseline and final model Area

Minimum Daylight Factor(%) (BREEAM)

Baseline Model Results

Final Model Results

Summer

Winter

Summer

Winter

Min-max (%)

Min-max (%)

Min-max (%)

Min-max (%)

Kitchen

1.5

1. Counter area: 0 2. Dining area: 2-8

Counter area: 0 Dining area: 2

Counter area:6 Dining area:2-6

Counter area: 6 Dining area: 2-8

Living Room Sunroom Stairs

1.2 1.2 1.2

2-8 28-58 12-29

2-5 50-80 15-40

5-7 12-20 24-44

5-7 12-20 12-22

Parent’s Bedroom

1.2

Office area: 0 Bedroom: 2-8

Office area: 0 Bedroom: 2-8

Office area: 7-15 Bedroom: 5-7

2-7

Children’s Bedroom

1.2

2-10

0-10

2-5

2-5

BASELINE MODEL PERFORMANCE By assessing the baseline model’s simulations (see Appendix G) it was found that a variety of spaces had either very high or low illuminance levels which can result in an increased risk of glare and overheating. The sunroom experienced high DF levels 28-58% in summer and 50-80% in winter), indicating over illumination predominantly caused by the single glazed northern façade feeding direct and diffused light into the space. The kitchen and both parent’s and children’s bedrooms had a DF between 0 and 10% which highlighted that areas of these spaces were substantially underlit. The underlit spaces included key working areas such as the kitchen counter and parent’s bedroom office. Moreover, high DF levels were observed in the staircase area 24-44% in summer and 12-22% in winter) due to the placement of the skylight above. IMPROVEMENT STRATEGIES To resolve the issues found in the base model, four strategies were implemented: • The fins on the roof were rotated by 45° to face West to protect the sunroom from direct sunlight exposure. • External louvres were added to provide shading for the sunroom and to reduce the high DF levels in the winter. • Internal venetian blinds were added on all glazed openings, which reduces the risk glare caused by direct sunlight through the windows. • Windows were added on the west façade of the kitchen and a skylight was placed over the parents’ bedroom office to provide sufficient lighting levels over these working spaces. FINAL MODEL PERFORMANCE As seen in Figure 30 the results in the final model displayed adequate daylight factor levels within each of the working spaces, whereby lighting levels were controlled and well-distributed, signifying a rare need for artificial lighting during the day. The DF levels in the sunroom were reduced to 12-29% (equivalent to 1000-2200 lux), providing a more comfortable area with access to sunlight for the occupants. The rooms that included underlit working spaces now have access to adequate daylight with overall DF levels ranging from 2-7%. By adding the venetian blinds to control., other areas have achieved DF levels between. Overall, these developments satisfy the BREEAM daylight factor criteria for all working spaces. One unresolved issue would be the overexposure experienced by the staircase area during summer. A good measure would be to provide a shading device. 12

Figure 30: Daylight factor simulations for final model. Source IESVE (FlucsDL)


3. COMFORT AND CLIMATE COMPARISON 3.1 EFFECT OF CLIMATE ON DESING PROPOSAL

3.2 SUGGESTED STRATEGIES

MODEL SIMULATION IN NIAMEY, NIGER To investigate whether the strategies used to provide thermal comfort in Mbeya can be useful to provide a good indoor environment while being in different climates, the design was simulated using weather data for Niamey, Niger. The simulation was performed keeping the same orientation for the building and the same properties for its fabric.

The building was designed based on the principles of bioclimatic architecture. The design aimed to provide comfortable conditions for occupants in the climate of Mbeya. As a result the strategies followed have proven to not be suitable for an extremely hot and semi arid climate. However, change of orientation, modification of the fabrics constructions and implementation of different environmental strategies could provide comfortable and healthy conditions for the occupants even in such environments.

CLIMATE OF NIAMEY Capital of Niger, Niamey, has an extremely hot and semi-arid climate. In reference to the Weather Tool, temperatures are high all year round indicating that no discrete seasons can be pointed. However, the different average temperature between the months of March-June (33oC) and JulyFebruary (29.7oC), lead to the selection of two different comfort zones for the indoor environment. ENVIRONMENTAL TARGETS Considering ASHRAE adaptive approach standard table 313123 has been created including the comfort temperature ranges for the two sets of months along with relative humidity and CO2 concentration targets . Table 7: Comfort conditions for Niamey, Niger Hot Season

Cool Season

RH

CO2 concentration

25.5-30.5 oC

24.5-29.5 oC

25-60%

<1000 ppm

SIMULATION RESULTS From the simulation made, the suggested comfort temperatures couldn't be maintained. Only in 7% of the occupied hours indoor temperatures remained within the target zones. Relative humidity was maintained for (44%) of the occupied hours while CO2 concentration was maintained bellow 1000ppm for more than 95% of the time. It is important to mention that in contrast to the high humidity levels observed in the case of Mbeya, relative humidity levels in Niamey remained under 25% for most of the remaining time (see Appendix E).

ORIENTATION For the case of Niamey, change of the orientation of the building can improve the performance of the design. In reference to the Weather Tool, the best orientation to minimize solar thermal heat gains throughout the year is north-east. For this reason, the large facades can get the minimum energy which corresponds to an annual value of 0.25 kWh/m2. BUILDING FABRIC Taking into account the high diurnal temperature differences of Niameyâ&#x20AC;&#x2122;s climate, high thermal mass materials can be utilized to provide small temperature deviations throughout the day. Furthermore due to the high outdoor temperatures observed, the glazing features of the sunroom can be replaced by opaque elements to provide further temperature stability and uniformity within the spaces. Glazing elements can also be replaced by others with low g-value, blocking high sunlight transmittance that can lead in overheating problems.

VENTILATION Implementing a change in ventilation strategy from stack effect to crossflow ventilation all year round can provide more cooling throughout the year if appropriate window operation schedules are considered. EVAPORATIVE COOLING To provide both cooling and humidification evaporative cooling was thought to be an appropriate strategy to be followed. For the strategy to be implemented, a pond is suggested to be placed in the sunroom. Taking advantage of the air movement due to crossflow ventilation and the hot temperatures observed in Niameyâ&#x20AC;&#x2122;s climate, evaporative cooling can be accomplished.

Figure 31:View of Niamey, Niger. Source: Google images

13


4. CONCLUSIONS 4.1 DISCUSSION

4.2 LIMITATIONS

This project has been produced to showcase how a self-sufficient solar powered house can be designed. The design has been based on the principles of bioclimatic design for the area of Mbeya, which through climate analysis, it was established to be subtropical with high humidity levels, large diurnal temperature fluctuations, and a rainy season.

This study identified limitations and assumptions which could potentially influence the results of the analysis. 1. Material limitations for this project included using only single-glazed windows and no use of insulation materials. 2. The double-roof system could not be appropriately modeled on IES, creating a void between the first and second roof. To avoid this intermediate area being considered as an internal space, windows were placed and were simulated to be open all-year long to achieve external temperature conditions. 3. The Solar Penetration Analysis assessed the results obtained on the winter and summer solstices at mid-day only. Simulations and analysis of solar penetration for the whole year were not covered, thus limiting the analysis of the building’s solar performance. 4. Limited sources and studies on Mbeya’s climate to assess content. 5. Limited data to calculate the embodied carbon analysis from existing databases. Some materials were not included and were difficult to find.

The design needed to be suitable for the local climate, occupants, and sustainability. The challenge of this was to design a building which was adjustable, to maximise its performance throughout the year in Mbeya’s climate. The sustainability of the designed was optimised by balancing the materials, carbon footprint, and thermal comfort performance. The architectural design included a sunroom which needed to be analysed to assess its performance in a subtropical climate. Taking thermal comfort in to consideration, people tend to adapt to their environment, which is why we used different thermal standards during the year. In general, people who live in warmer climates can tolerate higher temperatures. For this reason, the environmental strategy setout the thermal temperature conditions, ranging between 20.5-27°C, which was dependent on the season. To achieve these targets throughout the house, stack ventilation, high thermal mass materials and shading devices were employed as strategies. These strategies coherently worked together to allow the house to remain within the comfort targets an average of 90% of the time. This was achieved despite the challenge of a highly glazed sunroom designed as a nursery area.

4.3 STATE OF THE ART The main challenge of this project was not only to design and construct a fully self-sufficient solarpowered house but to also implement pioneering solutions and to improve the state-of-the-art, all while applying passive design strategies to a house in the subtropics.

An innovative feature of this house is the flexible ventilation strategy that utilized three different strategies for each season, as it is uncommon for a house to adjust its ventilation strategy according to the external environment’s temperature and seasons. Most houses nowadays employ the same ventilation strategy throughout the year, and in some cases, there is an absence of one. Natural ventilation was innovatively achieved by means of two main design features, the sunroom which was used as a main outlet (stack effect) and the orientation of the inclined double roof system- which was placed against the prevailing wind direction in order to apply stack effect effectively. Moreover, the materials used for the wall construction is another innovative feature. Timber was utilized as an insulation material and was combined with rammed earth, which acquired great results in terms of thermal performance. This allowed for the all external walls and internal partitions to be locally sourced and be made of 100% natural materials. This report hopes to serve as a learning tool that provides an insight into the processes and methods that can potentially aid in advancing the state-of-the-art in passive solar design. It also hopes to enable future designs to build upon the lessons that were gathered and up the bar in the delivery of high performing passive design buildings.

Figure 32: Exterior 3d render of the house | North elevation

14


5. REFERENCES American Society of Heating, Refrigerating Air-Conditioning Engineers & ASHRAE, 2017. 2017 ASHRAE handbook : fundamentals. SI. Andreadaki, E. (2006). Bioclimatic Design, Environment and Sustainability. 1st ed. Thessaloniki, Greece: University Studio Press. ANSI/ASHRAE (2017) Standard 55: 2017, Thermal Environmental Conditions for Human Occupancy. ASHRAE, Atlanta

Reardon, C. (2013) ‘Thermal mass’, Your Home, p. 178-. doi: 10.3901/JME.2009.03.010.

RMetS Editor. (2019). The Beaufort Scale: Measuring Wind Speed. [online]. Available at: https://www.rmets.org/resource/beaufort-scale. (Accessed: 11 February 2019). World Climate Guide (n.d.). Mbeya climate guide, Tanzania. [online]. Available at: http://www.worldclimateguide.co.uk/guides/tanzania/mbeya/ (Accessed: 12 February 2019). Waters, J. R. (2003) Energy conservation in buildings: a guide to Part L of the Building regulations, Blackwell. doi: 10.1002/9780470773802.ch15.

Athienitis et al. (2002). Thermal analysis and design of passive solar buildings /A.K. Athienitis and M. Santamouris., London: James & James. BSI (2007) BS EN 15251: 2007: Indoor environmental parameters for design and assessment of energy performance of buildings- addressing indoor air quality, thermal environment, lighting and acoustics (London: British Standards Institution). Hammond, G. & Jones, C., 2011. Inventory of Carbon & Energy (ICE), Bath: Bath University. Health Facility Registry. (2019). Iwambi. [online]. Available at: https:// hfr-portal.ucchosting.co.tz/index.php?r=facilities/view&facility_id=102031-2 (Accessed: 11 February 2019). Hoyt Tyler, Schiavon Stefano, Piccioli Alberto, Cheung Toby, Moon Dustin, and Steinfeld Kyle, 2017, CBE Thermal Comfort Tool. Center for the Built Environment, University of California Berkeley, http://comfort.cbe.berkeley.edu/ Huang et al. (2017). Urban Planning Study For Tanzania- Impact And Effectiveness of Urban Planning on City Spatial Development. World Bank Group. Makenya, A. R. & and Nguluma, H. M. (2007) ‘Optimization of Building Materials and Designs towards Sustainable Building Construction in Urban Tanzania’, pp. 2083–2093. doi: 10.21275/ART20174369. Meteoblue (2019). Air quality and pollen forecast for Iwambi. Available https://www.meteoblue.com/en/weather/forecast/airquality/iwambi_tanzania_11005363 (Accessed: 11 February 2019).

at:

Moncaster, Alice & Soulti, Eleni & G, Mubarak & K, Symons. (2013). Retrofitting solid wall buildings: energy and carbon costs and savings. Najafian, M. (2012) ‘The Effect of Orientation on Optimum Insulation Position in the Wall of a Building with Natural Ventilation in Hot and Dry Climate’, Internal Journal for Advanced Design and Manufacturing Technology, 5(3). Nicol, F., Humphreys, M. and Roaf, S. (2012) Adaptive thermal comfort: Principles and practice, Adaptive Thermal Comfort: Principles and Practice. doi: 10.4324/9780203123010. PO-RALG. (2016). Environmental and Social Impact Assessment for Proposed Additional Investment Sub-Projects in Mbeya, Mbeya City Council.

Figure 33: Exterior 3d render of the house | South elevation

15


6. APPENDICES APPENDIX A: SHOEBOX ANALYSIS Table A.1: Construction materials used for shoebox simulations

Construction Lightweight External Wall

Mediumweight External Wall

Heavyweight External Wall

Heavyweight External Wall (External Insulated) Heavyweight External Wall (Internal Insulated)

Heavyweight External Wall (Insulated)

Heavyweight External Wall (Less Insulated)

16

Construction Materials (Outer to inner) 50mm Concrete Block (Light), 50mm Cavity, 50mm Timber, 50mm Concrete (Light) 100mm Concrete Block (Mediumweight), 50mm Cavity, 70mm Timber, 100mm Concrete Block (Mediumweight) 100mm Concrete Block (Heavyweight), 50mm Cavity, 115 mm Timber, 100mm Concrete Block (Heavyweight) 15 mm Timber, 50mm Cavity, 200mm Concrete Block (Heavyweight) 200mm Concrete Block (Heavyweight), 50mm Cavity, 115 mm Timber 100mm Concrete Block (Heavyweight), 50mm Cavity, 200 mm Timber, 100mm Concrete Block (Heavyweight) 100mm Concrete Block (Heavyweight), 50mm Cavity, 50 mm Timber, 100mm Concrete Block (Heavyweight)

Total Thickness (mm)

U-value (W/m²K)

g-value

Thermal Mass

200

0.85

-

Lightweight

320

0.85

-

Mediumweight

365

0.85

-

Heavyweight

0.85

-

Heavyweight

0.85

-

Heavyweight

450

0.6

-

Heavyweight

300

0.6

-

Heavyweight

365

365

Windows

6mm Clear Float Glass

6

5.70

0.82

-

Ground Floor

150mm Cast Concrete, 20mm Plaster, 30mm Concrete Tiles

200

0.22

-

Mediumweight

Roof

30mm Clay Tile, 20mm Plaster, 150mm Timber , 150mm Cast Concrete, 30mm Clay Tile

380

1.68

-

Very Lightweight


APPENDIX B: ARCHITECTURAL DRAWINGS

17


APPENDIX B: ARCHITECTURAL DRAWINGS

18


19


APPENDIX B: ARCHITECTURAL DRAWINGS

20


21


APPENDIX B: ARCHITECTURAL DRAWINGS

22


23


APPENDIX B: ARCHITECTURAL DRAWINGS

24


25


APPENDIX B: ARCHITECTURAL DRAWINGS

26


27


28


29


APPENDIX B: ARCHITECTURAL DRAWINGS

30


APPENDIX C: ENVIRONMENTAL STRATEGY

31


APPENDIX C: ENVIRONMENTAL STRATEGY

32


33


APPENDIX D: 3D RENDERS

Exterior 3D render | North Elevation

34


Exterior 3D render | South Elevation

35


APPENDIX D: 3D RENDERS

Interior 3D render | Sunroom - Nursery Area

36


Interior 3D render | Sunroom â&#x20AC;&#x201C; Nursery Area | North view

37


APPENDIX D: 3D RENDERS

Interior 3D render | Sunroom - Nursery Area | Top view

38


Interior 3D render | Sunroom â&#x20AC;&#x201C; First floor | Bridge view

39


APPENDIX D: 3D RENDERS

Exterior 3D render | South Elevation | Night view

40


Exterior 3D render | North Elevation | Night view

41


APPENDIX E: ENERGY ANALYSIS

Table E1: Baseline model construction materials

Construction

External Wall Internal Partitions

Ground Floor First Floor Roof Second Roof Glass Windows

Construction Materials (Outer to inner) 300mm Mud Brick 100mm Timber Board 150mm Cast Concrete 150mm Timber Board 150mm Cast Concrete 6mm Clear Float Glass 6mm Clear Float Glass

Table E3: Baseline model internal heat gains (Values used: Chapter 6 CIBSE GUIDE A)

Total Thickness (mm)

U-value (W/m²K)

g-value

Thermal Mass

300

1.76

-

Mediumweight

Sensible

100

1.16

-

Very Lightweight

150

0.22

-

Mediumweight

150

0.90

-

150

1.68

-

6

5.70

0.82

6

5.70

0.82

Very Lightweight Very Lightweight

Space Applied

Hours per day applied

During Occupancy hours *

Latent

People

81

45

Sunroom, Living room, Kitchen, Parents Bedroom, Childrens Bedroom

Refrigerator

352

-

Kitchen

24

Freezer

323

-

Kitchen

24

Oven

234

-

Kitchen

0.5

-

Table E2: Baseline model occupancy pattern used in IES

42

Total, sensible and latent heat emission (for dry bulb tempterature of 22oC) [W]

Spaces

Occupants During Weekdays

Occupants During Weekends

Occupancy During Weekdays

Occupancy During Weekends

Sunroom

12

12

9:00-17:00 5 days per week

10:00-18:00 2 days per week

Kitchen

2

2

7:00-9:00 17:00-21:00 5 days per week

10:00-22:00 2 days per week

Living Room

2

1

7:00-9:00 17:00-21:00 5 days per week

10:00-22:00 2 days per week

Parents Bedroom

2

2

21:00-7:00 5 days per week

22:00-10:00 2 days per week

Children Bedroom

2

2

21:00-7:00 5 days per week

22:00-9:00 2 days per week


Ventilation Requirements- Baseline Model According to British Standard BS EN 15251:2007, the airflow required for sufficient ventilation of a space is given by the following equation: đ?&#x2019;&#x2019;tot = đ?&#x2019;? â&#x2C6;&#x2122; đ?&#x2019;&#x2019;p + đ?&#x2018;¨ â&#x2C6;&#x2122; đ?&#x2019;&#x2019;B Where: đ?&#x2018;&#x17E;tot ----total ventilation rate needed for a space, [l/s] n ----number of the occupantsm đ?&#x2018;&#x17E;p --- ventilation rate needed per person, [l/s], A --- room floor area [m2] qB ---ventilation rate for emissions from building, l/s, ô&#x20AC;Źś Taking into account that the designed building is considered to be very low polluting and it belongs in category II, the ventilation rate per person is 7 l/s and the ventilation rate for the building emissions is 0.35 l/s as indicated in BS EN 15251:2007 Table B.3.

Baseline Model Stack Effect Calculations

According to AM 10, the areas of the openings are calculated by the following formula,

Where: Î&#x201D;đ?&#x2018;?ô&#x20AC;Źś ---pressure difference between NPL and external air, Pa Î&#x201D;đ?&#x153;&#x152;ô&#x20AC;Źś ---density difference between internal and external air, 0.01208 kg â&#x2C6;&#x2122; đ?&#x2018;&#x161;ô&#x20AC;Źś ô&#x20AC;Źś g ---gravitational acceleration, 9.81 m â&#x2C6;&#x2122; đ?&#x2018; ô&#x20AC;Źś ô&#x20AC;Źś đ?&#x2018;§ô&#x20AC;Źś --height of Neutral Point Level

Where: đ??´ô&#x20AC;Źś ---openable area of windows, [m2]ô&#x20AC;Źś đ?&#x2018;&#x17E;ô&#x20AC;Źś ---ventilation rates, [đ?&#x2018;&#x161;3 /đ?&#x2018; ]ô&#x20AC;Źś ô&#x20AC;Źś đ??śô&#x20AC;Źś ---discharge coefficient, 0.61 đ?&#x2018;&#x2020;ô&#x20AC;Źś --- S = +1 for flow entering the space and S = â&#x20AC;&#x201C;1 for flow leaving the space đ?&#x153;&#x152;ô&#x20AC;Źś ---reference density, 1.2 kg â&#x2C6;&#x2122; đ?&#x2018;&#x161;ô&#x20AC;Źś ô&#x20AC;Źś

Table E4: Data and results from AM 10 calculations for baseline model Space

No of opening

Area (m2)

Persons

Ventilation Requirement( m3 /đ?&#x2018; )

Height of window (m)

Î&#x201D;pi (Pa)

Effective area (m2)

Percentage of opening

Sun room

2

24

12

92.4

1.25

0.42

0.18

2%

Living Room

3

24

2

22.4

1.1

0.44

0.04

2%

Kitchen

1

24

2

22.4

1.15

0.43

0.04

3%

Parents Bedroom

7

24

2

22.4

3.6

0.14

0.08

6%

Childrens Bedroom

8

24

2

22.4

3.8

0.12

0.08

8%

Stack

11

137.2

0.2

0.02

1.13

9%

Where: Î&#x201D;đ?&#x2018;?ô&#x20AC;Źś ---pressure difference between windows and external air, Pa đ?&#x2018;§ô&#x20AC;Źś ---height of windows, m

43


APPENDIX E: ENERGY ANALYSIS

44


100%

100%

88% 80%

80%

76%

80%

62%

62%

61%

84%

73%

40%

37%

35%

41%

27% 20%

33%

3%

1%

1%

20%

0%

11%

0%

3%

2% Kitchen

Living Room Cold conditions

Sunroom

32% 22%

9% 3%

1%

39%

40%

19%

58%

56%

60% 38%

67%

67%

60%

Parents Bedroom

Comfortable Temperatures

Childrens bedroom

Stairs

2%

Parents Bedroom

Childrens bedroom

1%

0% Kitchen

Living Room

Sunroom

Overheating Cold conditions

Figure E1: Percentage of time during occupancy (shoulder months) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

100%

5%

1%

Comfortable Temperatures

Stairs

Overheating

Figure E4: Percentage of time during occupancy (annually) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

100% 81%

80% 60%

57%

80%

66%

65% 55% 45%

43%

65%

53% 47% 33%

40%

1%

Parents Bedroom

Childrens bedroom

0%

0% Kitchen

Living Room

Sunroom

36%

40% 2%

2%

Comfortable Temperatures

37%

40%

58% 42%

23% 20%

Stairs 0% Sunroom

Cold conditions

60% 48%52%

33%

20% 0%

64%

60%

17% 0%

77%

Kitchen

Living Room

Childrens bedroom

Parents Bedroom

Stairs

Overheating 25<RH<60

Figure E2: Percentage of time during occupancy (winter) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

RH>60

Figure E5: Percentage of time during occupancy (annually) indicating comfortable and uncomfortable humidity levels

100% 84% 80%

82%

72%

67%

66%

83%

100%

100% 80%

60%

80%

62%

60% 40%

40% 28%

28%

26%

20%

20% 6%

7%

0%

6%

10%

16%

13% 4%

60% 24%

47%

53%

40% 13%

0%

20% 0%

25<RH<60

3%

RH>60

0% Kitchen

Living Room

Cold conditions

Sunroom

Parents Bedroom

Comfortable Temperatures

Childrens bedroom

Stairs

Overheating

Figure E3: Percentage of time during occupancy (summer) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

Figure E6: Percentage of time during occupancy (annually) indicating cold conditions, comfortable temperatures and overheating

Figure E7: Percentage of time during occupancy (annually) indicating comfortable and uncomfortable humidity levels

45


APPENDIX E: ENERGY ANALYSIS 1st ITERATION: ADJUSTMENT OF WINDOWS OPENABLE AREA

2nd ITERATION: IMPLEMENTATION OF ALTERNATIVE VENTILATION STRATEGY AND VENTILATION RATES

Table E6: Operation schedule of openings

Table E8: Operation schedule of openings

Space

No of Window

Operation Time During Weekdays

Operation Time During Weekends

Space

No of Window

Operation Time During Weekdays

Operation Time During Weekends

Sunroom

2

9:00-17:00 5 days per week

10:00-18:00 2 days per week

Sunroom

2

9:00-17:00 5 days per week

10:00-18:00 2 days per week

Kitchen

1

7:00-9:00 17:00-21:00 5 days per week

10:00-22:00 2 days per week

Kitchen

1

7:00-9:00 17:00-21:00 5 days per week

10:00-22:00 2 days per week

Living Room

3

7:00-9:00 17:00-21:00 5 days per week

10:00-22:00 2 days per week

Living Room

3

7:00-9:00 17:00-21:00 5 days per week

10:00-22:00 2 days per week

Parents Bedroom

8

21:00-7:00 5 days per week

22:00-10:00 2 days per week

Parents Bedroom

8

21:00-7:00 5 days per week

22:00-10:00 2 days per week

Children Bedroom

7

21:00-7:00 5 days per week

22:00-9:00 2 days per week

Children Bedroom

7

21:00-7:00 5 days per week

22:00-9:00 2 days per week

Internal Living room-Kitchen

4,5

All Day Long

All Day Long

4,5

Internal Bedrooms

Internal Living room-Kitchen

10:00-22:00 5 days per week

10

7:00-9:00 17:00-21:00 5 days per week

Internal Bedrooms

10

All Day Long

All Day Long

Stack

11

Stack

11

All Day Long

All Day Long

All Day Long All Day Long

All Day Long All Day Long

Table E9: Openable area percentage

Table E7: Openable area percentage

Space

46

No of Window

Space

No of Window

Openable area percentage during Shoulder Months

Openable area percentage during Shoulder Months Winter

Openable area percentage during Shoulder Months Summer

Sunroom

2

11.0%

9.4%

26%

Kitchen

1

0.0%

0.0%

9%

Living Room

3

0.0%

0.0%

15%

Parents Bedroom

8

4.6%

4.6%

6.5%

Children Bedroom

7

5.6%

5.6%

8%

Internal Living roomKitchen

4,5

5.0%

5.0%

0%

Internal Bedrooms

10

100.0%

100.0%

100%

Stack

11

21%

17.64%

49%

Openable area percentage

Sunroom

2

3.7%

Kitchen

1

1.6%

Living Room

3

1.1%

Parents Bedroom

8

3%

Children Bedroom

7

3.8%

Internal Living roomKitchen

4,5

100%

Internal Bedrooms

10

100.0%

Stack

11

15%


1st Iteration Results 100%

100%

91%

80% 67%

86%

87%

82%

69%

75% 65%

63%

60%

82%

80% 55%

60%

49%49%

42% 40%

32%

40%

28%

20% 3%

1%

3%

4%

1%

32% 24%

18%

13% 5%

35%

15%

20% 3%

2%

0%

0%

3%

1%

0% Kitchen

Living Room

Sunroom

Cold conditions

Parents Bedroom

Childrens bedroom

Comfortable Temperatures

Stairs

Kitchen

Overheating

100%

Sunroom

Comfortable Temperatures

Stairs

Overheating

73%

80%

62%

60%

60% 52% 48%

Childrens bedroom

100% 74%

50%50%

Parents Bedroom

Figure E11: Percentage of time during occupancy (annualy) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

87%

80%

Living Room

Cold conditions

Figure E8: Percentage of time during occupancy (shoulder months) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

60%

7%

6%

3%

56%

54%

42%

40%

40%

38%

40%

44%

57% 43%

48%52%

55% 45%

Parents Bedroom

Stairs

27%

20% 25%

20% 0%

0%

10%

4%

0% Sunroom

3%

2%

Parents Bedroom

Childrens bedroom

Kitchen

Living Room

0%

Childrens bedroom

0% Kitchen

Living Room

Cold conditions

Sunroom

Comfortable Temperatures

Stairs

25<RH<60

RH>60

Figure E12: Percentage of time during occupancy (annualy) indicating comfortable and uncomfortable humidity levels

Overheating

Figure E9: Percentage of time during occupancy (winter)indicating cold conditions, comfortable temperatures and overheating for every conditioned space

100% 84% 80%

72%

87%

87%

80%

64% 60% 35%

40% 22%

20% 7% 1%

2%

Sunroom

Parents Bedroom

8%

6%

80%

69%

60%

60%

40%

40%

20%

14%

20% 6%

100%

100%

73%

19%

12%

Living Room

Cold conditions

20%

4%

0%

0% 25<RH<60

Comfortable Temperatures

52%

10%

0% Kitchen

48%

Childrens bedroom

RH>60

Stairs

Overheating

Figure E10: Percentage of time during occupancy (summer) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

Figure E13: Percentage of time during occupancy (annualy) indicating cold conditions, comfortable temperatures and overheating

Figure E14: Percentage of time during occupancy (annually) indicating comfortable and uncomfortable humidity levels

47


APPENDIX E: ENERGY ANALYSIS (2nd Iteration Results) 100% 87%

91% 83%

80%

92%

89%

100% 84%

88%

90%

86%

81%

80%

69%

63% 60%

60%

40%

40%

28%

22% 20%

10% 3%

8%

9%

9%

6%

20%

10% 3%

2%

Parents Bedroom

Childrens bedroom

4%

11% 5%

5%

0%

10%

9%

9%

11%

8%

5%

3%

Parents Bedroom

Childrens bedroom

4%

6%

0% Kitchen

Living Room

Cold conditions

Sunroom

Comfortable Temperatures

Stairs

Overheating

100% 80%

81%

Living Room

Cold conditions

Figure E15: Percentage of time during occupancy (shoulder months) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

87%

Kitchen

91%

Sunroom

Comfortable Temperatures

Stairs

Overheating

Figure E18: Percentage of time during occupancy (annualy) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

100%

81%

80%

80% 64%

61%

55%

52% 48%

45%

53% 47%

39%

36%

40%

40%

61% 54% 46%

60%

60%

27% 20%

19%

17%

18%

13%

10% 3%

1%

Parents Bedroom

Childrens bedroom

1%

0%

20%

8% 1%

0%

0% Kitchen

Living Room

Cold conditions

Sunroom

Comfortable Temperatures

Sunroom

Stairs

83% 80%

85%

88%

Living Room 25<RH<60

Overheating

Figure E16: Percentage of time during occupancy (winter)indicating cold conditions, comfortable temperatures and overheating for every conditioned space

100%

Kitchen

Parents Bedroom

Stairs

RH>60

Figure E19: Percentage of time during occupancy (annualy) indicating comfortable and uncomfortable humidity levels

86%

78%

100%

100% 82%

59%

60%

34%

40% 18%

20%

12% 5%

4%

7%

7%

8%

13% 6%

6%

1%

80%

80%

60%

60%

40%

40%

20%

9%

9%

0%

0% Kitchen

Living Room

Cold conditions

48

Childrens bedroom

Sunroom

Parents Bedroom

Comfortable Temperatures

Childrens bedroom

49%

51%

25<RH<60

RH>60

20% 0%

Stairs

Overheating

Figure E17: Percentage of time during occupancy (summer) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

Figure E20: Percentage of time during occupancy (annualy) indicating cold conditions, comfortable temperatures and overheating

Figure E21: Percentage of time during occupancy (annualy) indicating comfortable and uncomfortable humidity levels


3rd Iteration Results 100%

97%

98%

80%

99%

98%

100%

100%

92%

97%

91%

96%

97%

80%

72%

65% 60%

60%

40%

40%

28%

22% 20%

20%

3%

0%

1%

1%

7%

1%

0%

2%

1%

0%

5%

0%

0% Living Room

Cold conditions

Sunroom

Parents Bedroom

Comfortable Temperatures

Childrens bedroom

Stairs

Kitchen

Overheating

89%

98%

91%

97%

7%

2%

1%

1%

3%

1%

3%

Sunroom

Parents Bedroom

Childrens bedroom

Comfortable Temperatures

Stairs

Overheating

Figure E25: Percentage of time during occupancy (annualy) indicating cold conditions, comfortable temperatures and overheating for every conditioned space 100%

98%

80%

80%

66% 63%

60%

60%

40%

40%

53% 47%

51%50%

50%50%

52% 48%

51%49%

Kitchen

Living Room

Childrens bedroom

Parents Bedroom

Stairs

34%

28% 20%

11%

9% 0%

9% 1%

0%

1%

1%

2%

2%

0%

0%

0% Kitchen

Living Room

Cold conditions

Sunroom

Parents Bedroom

Comfortable Temperatures

Childrens bedroom

Stairs

Sunroom

Overheating

25<RH<60

Figure E23: Percentage of time during occupancy (winter) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

100%

Living Room

Cold conditions

Figure E22: Percentage of time during occupancy (shoulder months) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

20%

6%

0% Kitchen

100%

4%

3%

94%

90%

93%

Figure E26: Percentage of time during occupancy (annualy) indicating comfortable and uncomfortable humidity levels

92%

84%

100%

60% 60% 35%

8% 2%

1%

80%

80%

60%

60%

40%

40%

20%

16%

20%

6%

3%

Sunroom

Parents Bedroom

4%

3%

8%

7% 0%

0%

100%

89%

80%

40%

8%

0%

0% Kitchen

Living Room

Cold conditions

Comfortable Temperatures

RH>60

Childrens bedroom

52%

48%

20% 0% 25<RH<60

RH>60

Stairs

Overheating

Figure E24: Percentage of time during occupancy (summer) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

Figure E27: Percentage of time during occupancy (annualy) indicating cold conditions, comfortable temperatures and overheating

Figure E28: Percentage of time during occupancy (annualy) indicating comfortable and uncomfortable humidity levels

49


APPENDIX E: ENERGY ANALYSIS (4th Iteration Results â&#x20AC;&#x201C; Final Model) 100%

97%

98%

97%

97%

100%

100%

91%

97%

93%

93%

92%

90%

74%

80%

80%

71%

70% 60%

60%

50% 40%

40%

30% 17%

20% 10%

3%

9% 0%

2%

3%

0%

18%

20% 3%

0%

0%

0%

6%

0%

0%

3%

5%

11% 3%

6%

6%

1%

1%

2%

1%

0% Kitchen

Living Room

Cold conditions

Sunroom

Parents Bedroom

Childrens bedroom

Comfortable Temperatures

Stairs

Kitchen

Living Room

Cold conditions

Overheating

Sunroom

Parents Bedroom

Childrens bedroom

Comfortable Temperatures

Stairs

Overheating

Figure E32: Percentage of time during occupancy (annually) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

Figure E29: Percentage of time during occupancy (shoulder months) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

70% 100%

87%

94%

88%

87%

60%

86%

50%

74%

80%

40% 60% 30% 40% 20%

20% 19%

13%

13% 0%

7% 0%

10%

14%

12%

0%

6% 0%

0%

Parents Bedroom

Childrens bedroom

0%

Sunroom

0% Kitchen

Living Room

Sunroom

Cold conditions

Comfortable Temperatures

90%

94%

91%

Living Room

Stairs 25<RH<60

Overheating

97%

Stairs

RH>60

100%

90%

80% 64% 60%

80%

80%

60%

60%

40%

40%

54% 46%

30% 20%

20%

8% 2%

8% 2%

7%

4%

2%

1%

3%

0%

2%

6%

4%

0%

Kitchen

Living Room

Cold conditions

Sunroom

Parents Bedroom

Comfortable Temperatures

Childrens bedroom

20% 0% 25<RH<60

0%

50

Parents Bedroom

98% 100%

40%

Childrens bedroom

Figure E33: Percentage of time during occupancy (annually) indicating comfortable and uncomfortable humidity levels

Figure E30: Percentage of time during occupancy (winter)indicating cold conditions, comfortable temperatures and overheating for every conditioned space 100%

Kitchen

RH>60

Stairs

Overheating

Figure E31: Percentage of time during occupancy (summer) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

Figure E34: Percentage of time during occupancy (annually) indicating cold conditions, comfortable temperatures and overheating

Figure E35: Percentage of time during occupancy (annually) indicating comfortable and uncomfortable humidity levels


Climate Comparison Niamey, Niger 99%

100%

99%

99%

100%

100%

100%

100%

93%

90% 80%

80%

70% 60%

60%

50% 40%

40%

30% 20% 10%

20% 0% 1%

0% 1%

0% 1%

0% 0%

0% 0%

Sunroom

Parents Bedroom

Childrens bedroom

0% Kitchen

Living Room

Cold conditions

Comfortable Temperatures

7%

0% 0% Stairs

Overheating

Figure E36: Percentage of time during occupancy (hot season) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

0% 0% Cold conditions

Comfortable Temperatures

Overheating

Figure E39: Percentage of time during occupancy (annually) indicating cold conditions, comfortable temperatures and overheating 100.0%

100%

89%

89%

87%

80%

80.0%

88%

85%

80%

60.0%

60%

40.0%

40% 20%

13% 1%

20.0%

19% 11% 0%

10% 1%

15%

12%

1%

0%

Parents Bedroom

Childrens bedroom

0%

0.0%

0% Kitchen

Living Room

Cold conditions

Sunroom

Comfortable Temperatures

Kitchen

Stairs

Living Room

Sunroom

RH<25.00

Overheating

Figure E37: Percentage of time during occupancy (cool season)indicating cold conditions, comfortable temperatures and overheating for every conditioned space

Parents Bedroom

25<RH<60

Childrens bedroom

Stairs

RH>60

Figure E40: Percentage of time during occupancy (annually) indicating comfortable and uncomfortable humidity levels 60.00%

100%

94%

94%

93%

94%

92%

90%

45.56% 80%

44.00%

40.00% 60% 40% 20.00% 20% 7% 0%

0%

6%

1%

6%

10%

8%

1%

0%

Parents Bedroom

Childrens bedroom

0%

10.41%

6%

0% Kitchen

Living Room

Sunroom

Stairs 0.00% RH<25.00

Cold conditions

Comfortable Temperatures

25<RH<60

RH>60

Overheating

Figure E38: Percentage of time during occupancy (Annual) indicating cold conditions, comfortable temperatures and overheating for every conditioned space

Figure E41: Percentage of time during occupancy (annually) indicating comfortable and uncomfortable humidity levels

51


APPENDIX E: ENERGY ANALYSIS (CO2 Concentration for all iterations) Table E10: Percentage of time during occupancy when CO2 < 1000ppm Sun room Baseline Model Configuratio n of Ventilation Rates Implementat ion of Alternative Ventilation Strategies

Kitchen

Living Room

Childrens bedroom

Parents Bedroom

Stairs

99.9%

100.0%

100.0%

100.0%

99.8%

100.0%

100.0%

100.0%

100.0%

99.9%

98.2%

100.0%

Final Model(Shading application)

90%

Fabric Modifications

89%

Implementation of Alternative Ventilation Strategies

100.0%

99.3%

98.8%

93.9%

97.0%

82%

99.6%

Configuration of Ventilation Rates

Fabric Modification s

100.0%

98.7%

97.3%

97.1%

97.7%

98.2%

Final Model (Shading application)

100.0%

98.6%

97.1%

95.3%

96.2%

97.6%

Final Model in Niamey

100.00%

97.60%

97.00%

97.00%

93.45%

96.70%

68%

Baseline Model

62%

0%

20%

40%

60%

80%

Figure E42: Percentage of time within comfort temperature range (annually)

52

100%


Energy Balance during the year BASELINE MODEL

FINAL MODEL

11 February

February 11 30

30

Comfort range 21.5-26.5oC

25 20

Comfort range 21.5-26.5oC

20 15

10

10

5

5

0

0

0.5

24:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00

Temperature Within House

Outdoor Temperature

Figure E43: Comparison of temperature within baseline model and outdoor temperature for typical day of shoulder months

0.7

0.6

0.4

24:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00

15

Temperature Within House

0.8

25

0.3 0.2

Outdoor Temperature

0.1

Figure E45: Comparison of temperature within baseline model and outdoor temperature for typical day of shoulder months

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 01-31 01-28 01-31 01-30 01-31 01-30 01-31 01-31 01-30 01-31 01-30 01-31

July 14

July 14

25

Comfort range 20.5-25.5oC

20

Figure E48: Heating energy demand for the final model during the year

25

Comfort range 20.5-25.5oC

20 15

15

10

10

5

5

0

Temperature Within House

0.25

24:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00

0:30 1:30 2:30 3:30 4:30 5:30 6:30 7:30 8:30 9:30 10:30 11:30 12:30 13:30 14:30 15:30 16:30 17:30 18:30 19:30 20:30 21:30 22:30 23:30

0

Temperature Within House

Outdoor Temperature

0.2

Outdoor Temperature 0.15

Figure E44: Comparison of temperature within baseline model and outdoor temperature for coldest day of winter

Figure E46: Comparison of temperature within baseline model and outdoor temperature for coldest day of winter 0.1

October 11

0:30 1:30 2:30 3:30 4:30 5:30 6:30 7:30 8:30 9:30 10:30 11:30 12:30 13:30 14:30 15:30 16:30 17:30 18:30 19:30 20:30 21:30 22:30 23:30

Comfort range 22-27oC

Temperature

Outdoor Temperature

Figure E45: Comparison of temperature within baseline model and outdoor temperature for hottest day of summer

35 30 25 20 15 10 5 0

0

Comfort range 22-27oC

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 01-31 01-28 01-31 01-30 01-31 01-30 01-31 01-31 01-30 01-31 01-30 01-31

Figure E49: Cooling energy demand for the final model during the year

24:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00

35 30 25 20 15 10 5 0

0.05

October 11

Temperature Within House

Outdoor Temperature

Figure E47: Comparison of temperature within baseline model and outdoor temperature for hottest day of summer

53


APPENDIX E: ENERGY ANALYSIS (Temperature fluctuations, conditioned spaces, Baseline Model)

Figure E50 : Annual outdoor temperature (red line) in comparison to indoor temperature of Kitchen (blue line)

Figure E51: Annual outdoor temperature (red line) in comparison to indoor temperature of Living Room (blue line)

54

Figure E52: Annual outdoor temperature (red line) in comparison to indoor temperature of Sunroom (blue line)

Figure E53: Annual outdoor temperature (red line) in comparison to indoor temperature of Parents Bedroom (blue line)

Figure E54: Annual outdoor temperature (red line) in comparison to indoor temperature of Childrenâ&#x20AC;&#x2122;s Bedroom (blue line)


Temperature fluctuations, conditioned spaces, Final Model

Figure E55: Annual outdoor temperature (red line) in comparison to indoor temperature of Kitchen (blue line)

Figure E56: Annual outdoor temperature (red line) in comparison to indoor temperature of Living Room (blue line)

Figure E58: Annual outdoor temperature (red line) in comparison to indoor temperature of Parents Bedroom (blue line)

Figure E59: Annual outdoor temperature (red line) in comparison to indoor temperature of Childrenâ&#x20AC;&#x2122;s Bedroom (blue line)

Figure E57: Annual outdoor temperature (red line) in comparison to indoor temperature of Sunroom (blue line)

55


APPENDIX E: ENERGY ANALYSIS (PVs Installation)

56


APPENDIX F: EMBODIED CARBON/ENERGY ANALYSIS Table F1: Breakdown of Embodied Carbon/ Energy: 1st Iteration

Surface Area (m2)

Volume (m3)

Density (kg/m3)

Weight (kg)

Embodied Carbon (kgCO2/kg)

Overall Embodied Emboided Embodied Carbon Per m2 Energy (MJ/kg) Carbon (kgCO2) Floor Area

Overall Embodied Energy (GJ)

Overall Embodied Energy Per m2 Floor Area

Building Element

Materials

Thickness (m)

External Wall

Brick Timber Board Brick

0.10 0.20 0.10

155.12 155.12 155.12

15.51 31.02 15.51

1750.00 480.00 1750.00

27146.00 14891.52 27146.00

0.24 0.20 0.24

6515.04 2978.30 6515.04

90.49 41.37 90.49

3.00 4.50 3.00

81.44 67.01 81.44

1.13 0.93 1.13

Internal Partitions

Brick

0.10

41.50

4.15

1750.00

7262.50

0.24

1743.00

24.21

3.00

21.79

0.30

Cast Concrete (Dense) Plaster Concrete tiles Timber Board Cast Concrete (Dense) Clay Titles Plaster Timber board Cast Concrete (lightweight) Clear Glass Timber fins Clear Glass

0.15 0.02 0.03 0.03 0.12 0.03 0.02 0.15 0.15 0.01 0.03 0.01

72.00 72.00 72.00 48.00 48.00 72.00 72.00 72.00 72.00 72.00 0.05 76.60

10.80 1.44 2.16 1.44 5.76 2.16 1.44 10.80 10.80 0.43 0.05 0.46

2000.00 1200.00 2100.00 480.00 2000.00 1900.00 1200.00 480.00 750.00 2500.00 480.00 2500.00

21600.00 1728.00 4536.00 691.20 11520.00 4104.00 1728.00 5184.00 8100.00 1080.00 25.92 1149.00

0.11 0.12 0.11 0.20 0.11 0.45 0.12 0.20 0.09 0.86 0.20 0.86

2419.20 207.36 508.03 138.24 1290.24 1846.80 207.36 1036.80 753.30 928.80 5.18 988.14

33.60 2.88 7.06 1.92 17.92 25.65 2.88 14.40 10.46 12.90 0.07 13.72

0.82 1.80 0.82 4.50 0.82 6.50 1.80 4.50 0.82 15.00 4.50 15.00

17.71 3.11 3.72 3.11 9.45 26.68 3.11 23.33 6.64 16.20 0.12 17.24

0.25 0.04 0.05 0.04 0.13 0.37 0.04 0.32 0.09 0.23 0.00 0.24

Ground Floor

First Floor

Roof

Second Roof Windows

Table F2: Breakdown of Embodied Carbon/ Energy: 2st Iteration

Building Element

Embodied Carbon (kgCO2/kg)

Overall Embodied Emboided Embodied Carbon Per m2 Energy (MJ/kg) Carbon (kgCO2) Floor Area

Overall Embodied Energy (GJ)

Overall Embodied Energy Per m2 Floor Area 0.60

Materials

Thickness (m)

Surface Area (m2)

Mud Brick

0.30

155.12

46.54

1750.00

81438.00

0.03

2785.18

38.68

0.53

43.41

Timber Board

0.10

41.50

4.15

480.00

1992.00

0.20

398.40

5.53

4.50

8.96

Ground Floor

Cast Concrete (Dense)

0.15

72.00

10.80

2000.00

21600.00

0.11

2419.20

33.60

0.82

17.71

First Floor

Timber Board

0.15

48.00

7.20

480.00

3456.00

0.20

691.20

9.60

4.50

15.55

0.22

Roof

Cast Concrete (lightweight)

0.15

72.00

10.80

750.00

8100.00

0.09

753.30

10.46

0.82

6.64

0.09

Clear Glass

0.01

72.00

0.43

2500.00

1080.00

0.86

928.80

12.90

15.00

16.20

0.23

Timber fins

0.03

0.05

0.05

480.00

25.92

0.20

5.18

0.07

4.50

0.12

0.00

Clear Glass

0.01

76.60

0.46

2500.00

1149.00

0.86

988.14

13.72

15.00

17.24

0.24

External Wall Internal Partitions

3

3

Volume (m ) Density (kg/m ) Weight (kg)

0.12 0.25

Second Roof Windows

57


APPENDIX F: EMBODIED CARBON/ENERGY ANALYSIS Table F3: Breakdown of Embodied Carbon/ Energy: Final Model

Building Element

Embodied Carbon (kgCO2/kg)

Overall Embodied Emboided Embodied Carbon Per m2 Energy (MJ/kg) Carbon (kgCO2) Floor Area

Overall Embodied Energy (GJ)

Overall Embodied Energy Per m2 Floor Area

Materials

Thickness (m)

Surface Area (m2)

Rammed Earth

0.10

155.12

15.51

1460.00

22647.52

0.02

520.89

7.23

0.45

10.19

0.14

Timber Board

0.20

155.12

31.02

480.00

14891.52

0.20

2978.30

41.37

4.50

67.01

0.93

Rammed Earth

0.10

155.12

15.51

1460.00

22647.52

0.02

520.89

7.23

0.45

10.19

0.14

Internal Partitions

Rammed Earth

0.10

41.50

4.15

1460.00

6059.00

0.02

139.36

1.94

0.45

2.73

Ground Floor

Cast Concrete (Dense)

0.20

72.00

14.40

2000.00

28800.00

0.11

3225.60

44.80

0.82

23.62

Timber Board

0.03

48.00

1.44

480.00

691.20

0.20

138.24

1.92

4.50

3.11

0.04

Cast Concrete (Dense)

0.12

48.00

5.76

2000.00

11520.00

0.11

1290.24

17.92

0.82

9.45

0.13

Clay Titles

0.03

72.00

2.16

1900.00

4104.00

0.45

1846.80

25.65

6.50

26.68

0.37

Plaster

0.02

72.00

1.44

1200.00

1728.00

0.12

207.36

2.88

1.80

3.11

0.04

Timber board

0.15

72.00

10.80

480.00

5184.00

0.20

1036.80

14.40

4.50

23.33

0.32

Cast Concrete (lightweight)

0.15

72.00

10.80

750.00

8100.00

0.09

753.30

10.46

0.82

6.64

0.09

Clear Glass

0.01

72.00

0.86

2500.00

2160.00

0.86

1857.60

25.80

15.00

32.40

0.45

Timber fins

0.03

0.05

0.05

480.00

25.92

0.20

5.18

0.07

4.50

0.12

0.00

Clear Glass

0.01

76.60

0.92

2500.00

2298.00

0.86

1976.28

27.45

15.00

34.47

0.48

External Wall

3

3

Volume (m ) Density (kg/m ) Weight (kg)

0.04 0.33

First Floor

Roof

Second Roof Windows

APPENDIX G: SOLAR PENETRATION ANALYSIS

Table G1: Internal surface properties: Inputs on IESVE (FlucsDL)

58

Component

Material

Reflectance value (%)

External Walls

Rammed Earth

43

Internal Walls and partitions

Rammed earth w/ timber frames

43

Floor

Grey Matte Concrete

45

Ceiling

Exposed concrete- matte finish

45

Glazing

Clear glass

-

Window frames

Timber

35

Door

Timber

35


Baseline Model Analysis: Daylight Factor Table F3: Breakdown of Embodied Carbon/ Energy: Final Model

59


UCL 2018-2019

Profile for Antonia Vavanou

Passive Solar Design | UCL Msc Built Environment: Environmental Design and Engineering  

The aim of this project is to design a self-sufficient solar powered house using a combination of architectural and environmental strategies...

Passive Solar Design | UCL Msc Built Environment: Environmental Design and Engineering  

The aim of this project is to design a self-sufficient solar powered house using a combination of architectural and environmental strategies...

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