IDENTIFY AND MITIGATE URBAN HEAT ISLAND
Due to the increase in the number of inhabitants and global temperature in cities and the rapid spread of urban pollution due to transport, it has become necessary to take into account the bioclimatic aspect of managing cities.
At ECOTEN our team of designers, engineers and consultants are working on various aspects of built environment and its sustainability. Our activities range from the building scale to the city scale. Among other activities, we concentrate on urban comfort and the problem of urban heat islands.
Urban heat island is characterized by higher temperatures in cities as compared to the surrounding areas, notably because of their material constitution and human activities.
This problem is becoming urgent due to number of inhabitants in city which is increasing and due to the global warming. Heat waves will be multiply, causing more discomfort, health risk and power consumption.
We create thermal map from Earth observation satellites data. It displays over an all city the temperature gradients prevailing. It allow to identify the hot and cold regions of a city :
→ Cold ones are suitable for vulnerable people facilities, as kindergarten and retirement house.
→ Hot are not, and should be renovated with urban heat island mitigation purpose.
Our clients are municipalities which are looking for an easy way to visualize temperature in their territory, in order to inform urban development decisions. We provide city thermal maps in hight definition.
With the help of specific technical tools, we can evaluate the impact of an urban design on the thermo-aeraulic comfort on that area or region, it's capacity to reduce urban heat island and the energy consumption of the buildings. For this we model the urban design in 3-D by taking into account parameters such as materials used, presence of vegetation, presence of water bodies, weather conditions of the site. There are several quantitative results which can be obtained from this model that are useful to address numerous urban issues.
Buildings Energy Consumption
A closed urban environment and the building design have a significant role to play in energy consumption of a building. In summer, depending on the uses of building, the electricity consumption due to air conditioning is a serious issue. By modeling the urban site, we can calculate the cooling needs of buildings and propose energy efficient building design.
A good design requires the reduction of urban heat islands and improvement of comfort level in public areas. With our simulations, we can evaluate several criterion such as air temperature, wind speed, humidity, solar radiation period used to study comfort of the urban environment. We can also calculate the universal thermal comfort index.
Wind Speeds Control
Newly constructed buildings in urban areas may result in the development of excess wind velocities. With our wind-analysis studies which we obtain from our model of a given urban neighborhood, we can evaluate the wind flow between buildings in that area. We can also calculate and obtain the average and maximum wind velocities flowing in that area.
For developing an urban area, there are several designs which can be used. For each design, we can model and quantify the contribution of comfort and energy consumption. We can determine which designs or scenarios are more effective in terms of energy and comfort and also for the mitigation of urban heat islands. There are several strategies that we can employ in order to do this: White (Clear surface) Green (presence of vegetation) and blue (presence of water bodies). In the graph below , we can see that the temperature of the street is 2.5 °C more in the case with the presence of trees than the case with it’s absence.
The Intergovernmental Panel for Climate Change (IPCC) published a report on global warming. The report contains many scenarios for the evolution of global temperature during the 21th century. With the information provided in this report, we can estimate the consequent impact of climate change on a given area.
For operating the simulations of urban micro-climate, we use the calculation engine of Solene-Microclimat. It has been developed by the research laboratory for urbanism in Nantes, France called "Centre de Recherche Nantais Architectures Urbanités" for over 10 years. It's most important characteristic is that it combines thermo-radiative model, computational fluid dynamics modes and thermal model of buildings and hence it is a powerful tool for analysis of urban micro-climate.
Our service is configured and applicable for many types of clients.
- City Officials and Urban Planners – Allows to create better living conditions for citizens through improved zoning, urban planning, and building design regulations. It is a tool for mitigating the urban heat island effect.
- Electricity Producers – Allows better load forecasting, peak reduction and costs savings. Decreases costs for smart grid development.
- Architect and Urbanist Agencies – Adds values to your project. Highlight their impact on the outdoor areas comfort and energy conservation.
- Engineering Offices – Takes into account the urban environment for energy dynamic simulations. Perform CFD calculation in urban area.