Each year with the crossing of seasonal thresholds, the summers in the cities are getting worse. Due to the constant hive of human activity, skyscrapers hindering the flow of wind and dark surfaces soaking up the heat; it is constantly warming up. The heat island effect refers to these higher temperatures that are seen in and around the city as compared to its neighboring countryside. Additionally, with global warming and climate change, the city-dwellers problems are only going to get worse. Major metropolises must decide to transform themselves to stay cool, even if it may mean from the ground up.
One of the most operative solutions is to design and construct buildings that consume less energy and use ecological materials. Even though the latest technological expansions especially BIM Architectural Services make this objective more realistic, tangible results will still take time. Below we highlight three other ways in which cities can cool down.
1. The Juxtaposition of Black and White
Chromatics states that the hues of black absorb heat, and yet a lot of our current infrastructure utilizes black. This is primarily seen in road construction and rooftops. Roads use materials like concrete and asphalt as it is waterproof, ductile, and easy to apply. However, it not just retains heat but also releases that heat during the cooler times of the day. This means around the clock hot weather.
White on rooftops and concrete can on the other hand reflect about 50% more light and be thus used to reduce the temperature. Authorities in Los Angeles have launched a “cool pavements pilot project” where the roads are being painted over with a white asphalt emulsion and per mile, tests have recorded a drop of 5.6 degree Celsius. The success of this project has been followed by Chicago, Seattle and New York is going a step further by painting many of its rooftops in light-colored coatings. On top of cooling the city the ancillary benefit is that when the rooftops absorb less heat and the interiors of the buildings are cooler.
2. Plant More Trees
Don’t let the city become a concrete jungle because a mature tree holds 400 gallons of water in its trunk and foliage and can cool their surroundings by 2 degrees. With a dearth of space, planners need to become more creative in where and how they will plant more trees. One successful approach has been to make the rooftops into urban gardens. This was done successfully by the Chicago city hall, which in 2001 installed a green roof in a bid to tackle the city’s growing temperatures. When the area around the city hall was mapped with thermal cameras the temperature was found to be 21 degrees’ Celsius lower than its surroundings. In 2010 Toronto passed legislation requiring green roofs on new construction over 2000 sq. meters in size. San Francisco and Denver followed in their footsteps in 2016 and 2017 respectively bypassing the same legislation. Newer projects trying to adopt this into their buildings especially for high rises need to take into account many considerations. Here, Virtual 3D Modeling can be extremely useful especially MEP BIM Services, as they take into account the ducts, air-cooling conditions, and heating systems that would be required to measure the effect of rooftop gardens on the internal temperatures of the building.
Architects are also now using this concept and incorporating whole trees into buildings. Milan’s ‘Bosco Verticale’ contains hundreds of trees and plants across different levels. This is no simple feat as it requires extensive testing and may face many additional costs. Here, also BIM can be helpful as it prioritizes cost-effectiveness and greater control during the operations phase. With BIM the designers can take into consideration the position of the sun, weather conditions, etc. and determine how different materials will react together. Also by the use of simulation, the designers can also monitor the final product’s reaction to the environment and carry out quantifiable impact calculations of the building.
3. Create a Windy City
For every megalopolis on Earth, the landscape and topography are relatively absolute. However, Masdar City in Abu Dhabi has been made as a testing lab for how better city planning can result in cooler cities. No cars are allowed in the city and the buildings are thus located closer together. This creates a shade for the streets and walkways protecting them from the intense desert sun. Even though the project has largely been inundated by issues, it still shows results by being up to 15 degrees cooler than its surroundings.
Though not all cities can be this drastically changed there are a few changes that could be adapted to counter the heat island effect. Germany’s Stuttgart is a live example of this. It is geographically located in a valley where the heat and smog get trapped, added to it there is extreme pollution generated from Germany’s booming automotive industry. Urban Planners needed to find some solution before the city suffocated on itself. They are now fighting to prevent the construction of very large buildings which could prevent airflows, and by creating a number of ventilation corridors throughout the city. These are wide, tree-fringed roads that help the flow of clean, cool air from the hills into the city at night. Though, the same solution might not work for every city as it’s very much subject to weather conditions and geography it might still urge other cities to find their own solution.
The Smart City planning approach is no longer just an option, it has to be the way of life. The facts currently stand at 55% of our population living in cities even though they just occupy 2% of our total land area. The number is steadily rising and expected to hit 68% in 2040. Cities will have to adapt to not just accommodate the growing population but to simply remain livable. The above changes may seem like a lot of hassle for a small reward but on a larger scale they will end up making an immense difference.
Hands holding clear green meadow with sun battery -DepositPhotos