BUILDING ON THE EDGE Climatic design guidelines for Emerging Cities - PowerPoint PPT Presentation

BUILDING ON THE EDGE Climatic design guidelines for Emerging Cities of EtEthiopia The case of Addis Ababa Fasika Sahlemariam Gebremeskel Project mentors Jochen Lam Matthias Rammig Final presentation slides June 25 2015 Stuttgart, Germany Picture for cover EiABC chair of Architectural design

BUILDING ON THE EDGE ME ETHIOPIA Äthiopien Graduated in Architecture from EiABC in 2012 Fasika Sahlemariam Gebremeskel www.eiabc.edu.et Architect from Ethiopia

Project overview BUILDING ON THE EDGE As climate is the major factor in the performance of the built environment, the project uses climate responsive design as a main tool to provide “Climatic design guideline” for rapidly expanding city of Addis Ababa BUILDING ON THE EDGE x 12 x 1970 Current Next 40 years Addis Ababa recent years area expansion and population growth rate

BUILDING ON THE EDGE Structure of the study The project uses analytic step-by-step, test and design test investigation and Documentation Design +Test methodology to come up with the guidelines. A Climatic design Climatic guidelines and construction Addis Ababa recommendations guidelines Climate for Addis Ababa B New design + C Thermal comfort Building on the Edge Choose building Design Proposal to be built at construction the city edge to show the materials Daylight application of the guideline Test existing construction prototypes

BUILDING ON THE EDGE Test Buildings These buildings were used 2010-11 2011-12 2012-13 because of their approach to alternative SUDU SECU SICU construction materials [ S ustainable U rban D welling U nit] [ S ustainable E merging C ity U nit] [ S ustainable I ncremental C ity U nit] Rammed earth construction straw panel and timber construction Combined precast concrete and timber construction www.eiabc.edu.et

BUILDING ON THE EDGE Climate Addis Ababa has a minimum seasonal fluctuation in 35 temperature as well as Total 30 radiation throughout the year Outdoor Air Temperature [°C] 25 The main challenge is the daily 20 temperature swing which can 15 reach up to 20 K in summer 10 months [Nov-Jan] . 5 0 jan feb mar apr may jun jul aug sep oct nov dec 35 250 30 200 191 186 25 181 Insolation [kWh/m²] 171 171 170 170 Temperature [°C] 167 20 150 142 140 126 119 15 100 10 50 5 0 0 jan Feb mar apr may jun jul aug sep oct nov dec jan feb mar apr may jun jul aug sep oct nov dec Annual average temperature fluctuation is less than 4 K Horizontal Insolation: 1934 kWh/m²/a Yearly Mean Outside Temperature 16.6 ° C Minimum fluctuation during the rainy season June- August Mean Outside Air Temperature [°C] Minimum Outside Temperature [°C] for full climate analysis please refer to Project Report Maximum Outside Temperature [°C] DAY = SUMMER NIGHT = WINTER

BUILDING ON THE EDGE Thermal simulation results [Summary] Hourly thermal simulation results of the first floor Operative temperature statstics Operative temperature statstics Operative temperature statstics First oor First oor First oor 4500 4500 4500 4000 4000 4000 3500 3500 3500 3000 3000 3000 Frequency [h] Frequency [h] Frequency [h] 2500 2500 2500 2105 1855 2000 2000 2000 1745 1448 1464 1500 1500 1312 1500 1193 1198 1174 1186 1064 1008 865 1002 959 901 1000 1000 1000 798 717 688 609 645 604 459 500 500 500 281 207 206 161 131 122 84 28 26 4 0 0 0 0 0 3 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 Operative temperature [° C ] Operative temperature [° C ] Operative temperature [ ° C ] Cold Cold Cold Average u value 2.16 W/m²K Average u value 0.99 W/m²K Average u value 0.83 W/m²K Comfortable Comfortable Comfortable Envelope window wall ratio 17 % Envelope window wall ratio 7.4 % Envelope window wall ratio 10 % Hot Hot Hot The 60 cm thick massive earth envelope uses its high thermal Although this building has the lowest win wall ratio Due to light weight construction especially the uninsulated metal mass to store the heat from the high radiation and reduces heat the effect of uninsulated roof meant that indoor temperatures roof exposed to maximum daily radiation and cold nights creates flow during the night to create a stable indoor temperature. were in the comfort limit for just above 60 % of the year. very high temperature above 30 ° C and over 1700 hrs below 18 °C. All boundary conditions and assumptions on the full report

BUILDING ON THE EDGE Daylight simulation results Daylight simulation showing the average value of the both floors target Values [refer to full report] DF > 3 % DA 300 lux fully occupied schedule Win wall ratio 20.5 % Win wall ratio 6.2 % Win wall ratio 6.2 % Average daylight factor 3.6 Average daylight factor 0.7 Average daylight factor 1.8 Average daylight autonomy 82 % Average daylight autonomy 40 % Average daylight autonomy 69 % Flexible opening size and position Small opening size in which location Semi-flexible opening size with Determined by load-bearing modular over 2 m roof overhang on all sides straw board panel With overall win wall ratio of 20 % with out any This building has the lowest win wall ratio of 6.2 % in Here the main factor was the roof overhang of 2 m on all shading or overhangs ,the building achieved which the north and south facades are completely closed. sides reduced the daylight values below the target value 3.6 % daylight factor more than the target value and also This added with the roof overhang on all sides reduced the to 1.8 daylight factor . 300 lux illumination for more than 82 % of the daylight Daylight factor to only 0.7 , less than 30 % of the target value. hours in Addis Ababa. All boundary conditions and assumptions on the full report

SUMMARY Selection of building technology Out of the test buildings Structure Envelope Interior structure these materials were chosen for further study ? Precast concterte Rammed earth Agro- stone [Compressed fiber board] New block [efficient lateral and vertical load ] [Thermal Mass] [ Light weight and mass production ] Example building for Fast and minimize waste High thermal capacity Fast construction Building on the edge Guideline Design flexibility Flexible opening Light weight [35 kg /m²] for 10 cm board Local knowhow Low embodied energy Reduce load on bearing structure Local codes are available Durability Finish ready Separating the building envelope Ideal due to the property to store Modular in construction and from the structure gives flexibility thermal energy and allowing light weight for reduction of dead load on to design the envelope flexible opening for daylight bearing structure .

BUILDING ON THE EDGE Thermal design guidelines Due to the minor seasonal fluctuation of the outdoor Passive heating Passive cooling temperature these passive Direct morning sun access and afternoon shading Natural ventilation strategies are tested to be Heating loads can be With average outdoor applicable throughout the year North covered by direct solar gain temperature between 15-20° 0 1000 h 338 23 900 h >0.5 m/s and thermal mass throughout the year, 800 h >3.5 m/s 315 45 700 h >6.5 m/s 600 h >9.5 m/s natural ventilation can be used 500 h >12.5 m/s 293 400 h 68 300 h for passive cooling 200 h W N 100 h West 270 90 East 0 h 248 113 225 135 Course of sun in Dec 21 Major wind East to West 203 158 with position of the sun at 2 pm 180 South S E Course of sun in June 21 Available Wind Data: 8760 [h] height: 10 m; wind velocity profile exponent: 0.22 Degree Value Marks The Middle Of The Angle Interval with position of the sun at 2 pm Massing and orientation Openings for solar gain Buildings with high internal load Buildings with Low internal load Perspective Section maximize ventilation minimize excessive north Optional horizontal Minimum shading overhang for June rate heat loss angle required south Horizontal overhang for Dec angle and west Top and west vertical shading . shading required Full access to the east for morning cross ventilation Stack ventilation sun access W E W E east Heat gain Low windows for direct in convention Internal movable shading sun in the morning for exposing for glare maximum internal thermal mass Internal thermal to radiation mass Heat out west Compact design with East west orientation to allow Movable external External movable shading shading for glare and reduced air speed efficient cross ventilation for glare and heat rejection direct heat gain in the afternoon on external thermal mass Full explanation on the full report