Mohammad Fahmy

; There are many energy budget models and classifications of urban climate layers, field measurements, simulations and researches in the field of urban climatology that concerns about the mutual impact of climate and urban form. Although there is a magnificent progress in the field, but some few promising world wide projects (Oke, 2006), and some design studies and methodologies (Bitan, 1988), (Pearlmutter et al., 1999) and (Ali-Toudert and Mayer, 2007), the application for that knowledge still away from the urban form sensitive design, because they have been done from the physical, mathematical and meteorological points of view but haven't been investigated till now from the applied urban planning and design point of view specially at local scale of a neighborhood climate. The need is for all parties of the urban field as in real process, the scientific circle won't be closed without the architects, urban designers, planners, Econo-sociologists and psychologists' participation in the model. However this extensive paper is prepared to introduce this large field of knowledge about how to design urban fabric and patterns in accordance to climate aspects and its scales of application along with definitions concerning human thermal comfort in the field. Introduction: Briefing for literature and research approaches; Yet it is complex relations to investigate that of the climatology, meteorology, built form, with the microclimate scale of urban planning patterns, consequently how can we imagine solving that complexity of a local climatology scale to assess urban thermal comfort which has been illustrated to be certainly unachievable 100% from any single mean point of view without broadening the scope of research due to urban mobility of climate conditions. It is not only from physiology calculation of heat balance, not only from human thermal regulatory with metabolism and clothing adjustments, not only with the behavioral adjustments, not only by physical environmental adjustments and passive sensitive design, but with all of these techniques, methodologies, sequences and applications that have to apply specific interdisciplinary geometrized tools of Pysio-Psychological thermal comfort adaptation to form a fabric. Such a definition of model defines at the same time the objective of the great work in urban climatology-meteorology fields, from the microclimate scale to mesoscale.

Climate change and urban growth mean that many city residents will face thermally uncomfortable futures. Greater use of mechanical cooling is not reasonable solution; it will consume more energy, discharge more heat and carbon emissions and in turn affecting quality of urban life. Therefore, the microclimatic effects of an urban site in the fifth community in New Cairo is numerically assessed in the present day conditions and compared with the years 2020, 2050 and 2080 climate change scenarios which have been predicted using the morphing methodology. Simulations for the four climate condition sets were then carried out by the numerical model ENVI-met BETA5 which has the capability of representing almost all environmental and personal factors influencing a pedestrian. Comparisons took place for outdoor air temperature Ta and the pedestrian comfort levels in terms of the Predicted Mean Vote, PMV, at 1.2m above ground level. Eventually, an averaging methodology is used to describe the whole site conditions rather than at a single or few points. Results show that climate change conditions increased PMV and Ta values compared with present day. This indicates the need in the near future for a completely different urban forms rather the western dot fabric single family housing before the primary energy supply will not meet the demand in the Egyptian residential sector which means on the other hand that urban development, prosperity and quality of life will be affected.

In order to achieve outdoor thermal comfort in hot, arid zones it is necessary to have a clear understanding of the interactions between the prevailing climate and the urban form. Modern urban planning in Cairo does not use the vernacular urban principles or architectural forms, choosing instead a hybrid urban form between the Arab vernacular compact urban architecture and the western suburban dot pattern urban form could enhance the situation. This study investigated the microclimatic thermal behaviour of hybrid traditional and modern street canyon types of urban form in Cairo in order to establish an urban planning tool for passive cooling. Numerical simulations were performed, using both thermal and CFD software, for a hot summer's day in Cairo for different street canyon configurations including different canyon orientations to the prevailing wind and different canyon geometries. Initial results indicate that very dense urban layouts can have a beneficial impact upon outdoor thermal comfort but can, if incorrectly orientated, severely reduce the potential for any wind-driven cooling because of excessive wind sheltering. Some urban layout combinations of canyon geometry and orientation are suggested to provide satisfactory outdoor thermal comfort conditions at street level.

... [11] Fahmy, M., Urban form adaptation towards ... [12] Fahmy, M., A. Trabolsi, and S. Sharples, Dual stage simulations to study microclimate thermal effect on ... [25] Ali-Toudert, F. and H. Mayer, Numerical study on the effects of aspect ratio and orientation of an urban street canyon ...