A lack of land in big cities means engineers often have to build upwards. The more high-rise buildings there are, the more heat that ends up getting trapped between buildings. As a result, temperatures in urban areas tend to be higher on average than in rural areas.
This phenomenon, known as the urban heat island, is such a big problem that demand for air conditioning is expected to have tripled by 2050, according to the International Energy Agency. But air conditioning isn’t the greenest of solutions and, to provide the electricity to keep it running, it’s generally the case that fossil fuels will need to be burned.
So urban planners are providing more green spaces – studies have shown that they have a cooling effect. However, more still needs to be done to reduce the urban heat-island effect. The answer is a smarter way of designing and constructing buildings.
There has been an exponential increase in the use of Building Information Modelling (BIM) in the building services and construction industries over the best part of the last decade. The main benefit is that, once assets have been documented using BIM, the model and information are stored digitally and can then be shared with and accessed by stakeholders in a construction supply chain.
This means better collaboration and oversight of projects, and helps to improve the delivery of new builds and reduce potential faults, delays and associated costs.
However, BIM can be more than just about constructing buildings and infrastructure more quickly. When combined with augmented reality (AR), virtual reality (VR) and mixed reality (MX), the technologies have the potential to be transformative. For example, by uploading a BIM model into AR, VR or MX software, engineers can use immersive-reality goggles or headsets to walk through a building site with a digital overlay of the finished build in their field of vision, making it easier to identify any mechanical or structural issues.
So how could these technologies provide a creative solution to the urban heat-island problem?
Unseasonably warm temperatures in a city are often exacerbated by bitumen surfaces including car parks. Materials such as asphalt store heat during the day and release it at night. A combination of BIM and AR, VR and MX could be used to simulate scenarios that might help to reduce waste heat and, more importantly, mitigate the urban heat-island effect. These could include having cars parked underground or in garages instead of in outside car parks or on the streets.
Digital models could also be used to understand the structural feasibility of constructing car parks underneath new high-rise buildings. Engineers could visualise how a car park needs to be constructed without damaging any existing pipes or other critical assets.
Vision of the future
With digital information overlaid in their field of vision when wearing goggles or headsets, engineers could get a better understanding of the waste heat that is generated by high-rise buildings. They could, for instance, see how a system that captures waste heat, stores it elsewhere in the building and converts it into electricity could be designed and engineered so that it fits seamlessly into a building’s infrastructure without disturbing the urban ecosystem.
Most modern high-rise buildings are made from glass and steel, and, while glass is a poor conductor compared to metal, it does of course retain heat very well. As a result, modern buildings end up being hothouses and it means building and facility managers often need to keep air-conditioning units running around the clock to keep occupants cool.
If BIM is combined with AR, VR and MX successfully, the technologies have the potential to support engineers and other stakeholders in the construction supply chain to construct smarter buildings that are more sustainable and run more efficiently.
While the technologies won’t eliminate the urban heat-island effect, they would reduce the temperature inside and between buildings. Building managers won’t need to keep the air conditioning running all the time. And you’d feel cooler when walking around a big city.
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.