Introduction : Urban Heat Island

Transcription

1 MITIGATING URBAN HEAT ISLAND EFFECT BY URBAN DESIGN FORMS AND MATERIALS Julen BOUYER, Marjore MUSY, Yuan Huang, Khaled ATHAMENA 5th Urban Research Symposum June 28-30, 2009, Marselle zdzda Introducton : Urban Heat Island Urbanzaton -Urban Ub form, densty -Materals -Heat load - Urban Heat Island effect - Heat waves - Health - Excess death rate Energy consumpton for buldngs Comfort requrements Albedo - Radatve effects Rugosty - convectve effects Vegetaton and water - evapostanspraton effects 1

2 Introducton : Indcators Urban form Materals and use Basc Physcal phenomenon Complex phenomenon Indcator smplfed measure that combnes part of the nfluent parameter to allow us to compare ther effect one the complex Introducton : Our approach Develop models to represent and understand complex phenomenon Physcs based models Valdaton of ndcators Indcator Propose smple ndcators that allow us to predct urban plannng performance Charactersaton of urban forms Typology Classfy urban form 2

3 1 - Urban form and energy Urban Form Classfcaton Indcators to compare performances Energy consumpton of buldngs 1 - Urban form and energy Urban Form Generc bult form Pattern Sngle buldng Street Pavlon, Slab, Terrace Scale Terrace-court, Pavlon-court, court shape rato : S/V man façade orentaton glazng rato rato of sde : L x /L y Aspect Rato H/W Street Orentaton plot rato, ste coverage Floor space ndex (FSI) shape rato: S/V grd azmuth : δ total surface area number of floors n sky vew factor base block dmenson L=L y buldng depth rato l=l x /L y drectonal aspect rato H/W x & H/W y drectonal street wdth rato w=w x /W y Indcator 3

4 Albedo Urban form (solar access, nter-reflectons) Sun poston Materals and arrangement H W Doulos, L.; Santamours, M. & Lvada, I. Passve coolng of outdoor urban spaces. The role of materals Solar Energy, 2004, 77, Plane and solated surface energy reflected 1- energy absorbed albedo ncdent energy ncdent energy Rough surface albedo energy reflectedto the sky ncdent energy after nter-reflectons 1- energy absorbed ncdent energy 4

5 Calculaton procedure wth Solene Drect ncdent energy, reflectons -> albedo 2 Radatve smulaton 1 Model Meshed surfaces + Materals radatve characterstcs Applcaton to Lyon Confluence Project 1 Materals revew Example of block A North 5

6 Applcaton to Lyon Confluence Project The dffe ren t bloc ks N orth Bl oc A Sout h Bl oc A N orth Bl oc B Sout h Bl oc B C bloc k Lyon conf lu ence Gar den cty Sm ulat on date Gl ob al Ene rgy nc den t (KWh) Ene rgy Solar Abso rbed (KWh) Albedo C B South B North A South A North Lyon Confluence Phase 1 Garden cty - The more a surface see the sky, the more t partcpates to the albedo - The bgger the materal s albedo s, the more the surface partcpates to the albedo Albedo ndcator ncludng materals albedo and SVF A S S 6

7 3 - Mcroclmatc smulaton Modellng Smulaton tool 3 - Mcroclmatc smulaton Results (Mcroclmatc varables) Ar température dfference (T smul T meteo) wnter, 14h Convectve exchange coeffcent (hc) wnter, 14h 7

8 3 - Mcroclmatc smulaton Results (Energy consumpton of buldngs) In wnter 3 - Mcroclmatc smulaton Results (Energy consumpton of buldngs) In summer 8

9 Concluson Study 1 : Possblty to classfy urban fabrcs by the mean of morphologcal ndcators Study 2 : Development of a morpho-physcal p ndcator able to evaluate qucly solar mplcaton n the UHI Study 3 : Development of a fne tool able to treat mcroclmatc scale Future work : Methodologes to go from one scale to another Valdaton Desgn strateges 9