Smart buildings and automation in smart cities
January 22, 2020
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By Gregory Miller
Currently, around 55 per cent of the world’s 7.7 billion inhabitants live in urban areas. According to the United Nations, by 2050, this figure will rise to 68 per cent, adding another 2.5 billion people to our towns and cities.[i] Sustainable cities will therefore not only have to deal with problems like congestion, air pollution and energy insecurity, but also the added stresses and strains of many more inhabitants.
Perhaps the answer to these problems lies in smart building automation – the use of advanced technology which encompasses energy, comfort and security solutions, and combines it with maximizing resource efficiency.
In countries like Canada or the United States, buildings account for around 40 per cent of total energy use.[ii] If you consider the energy also required for their construction, this represents a level of energy use which is unsustainable–and a key driver of climate change.
Automation of ‘smart buildings’ offers a way of reducing this burden by cutting energy demand. So-called ‘near zero power buildings’ use load aggregation, smart appliance control and the exploitation of thermal inertia to drastically improve building energy performance.
Technology monitors the operation of the building, detects inefficient behaviour and achieves significant energy savings through the optimized use of lighting, heating and cooling.
One of the key aspects of building automation systems is that they can be retrofitted, lowering the need for energy-intensive new construction. A retrofit façade system is perhaps one of the most cost-effective of these methods – it deals with insulation, control of daylight and comfort levels, all cost-effective methods of improving building energy efficiency.
In a project in Bilbao, Spain,[iii] two buildings – one a residential building, and one an office building – were given smart façades. It proved how smart design can be applied successfully to existing buildings. The lighting, shutters and windows were all optimized to reduce cooling and heating demand (by 63 per cent in the office building, in the case of cooling). The results for the residential house were also impressive: new exterior shutters and windows, using control algorithms, reduced heating and lighting demand by 13 and 58 per cent, respectively.[iv]
Comfort and cost savings
Automated building systems can thus increase comfort and save the occupant money. And in the case of an office space especially, it can create happier and more productive workers. Smart buildings automatically react to climatic changes, maximizing solar gains and minimizing heat loss. Also, they can help to protect against fatigue, theft, data loss and pollution.
The secret is the integration of different technologies and a constant exchange of information. Currently, office buildings simply don’t react – lights may stay on, computers may be left on standby, windows may remain open, and so on. This is not how it should be.
A recent study out of Ottawa, Ont.,[v] revealed that nearly half of all office buildings (those they investigated) had completely ineffective after-hours energy-saving measures. In all of them, the cooling change point temperature was lower than the heating change point temperature – leading to buildings that were sometimes warm when there was absolutely no need.
The study applied inverse modelling techniques to the problem by training the change point models with outdoor temperature data, wind speed, horizontal solar irradiance and binary work hours. The result is not just the ability of systems like these to improve heating and cooling efficiency, but also to improve ventilation performance, thermal conductance, air infiltration and the efficiency of lighting and appliances.
Safety and security
Automation systems can continuously monitor security and fire protection systems, customizing these solutions to the needs of individuals or companies. At construction phase, automation can reduce worker risk through integrated ‘human-in-the-loop physical systems’ (HiLCPS) which can proactively foresee higher-risk episodes and prevent accidents (e.g. during mega construction projects like stadium or airport builds).
In Hong Kong, in a study of one of the largest construction companies,[vi] smart construction methods were shown to already be shaping the city landscape. The company is using AI chatbot for recording accidents, smart concrete sensors, drone photogrammetry, 3-D printing, virtual reality and wearable robotics.
In Brazil, a country with one of the highest rates of worker fatalities, automated safety systems at construction sites are already improving safety records by quickly identifying hazards and monitoring use of protective equipment.[vii]
Automation also ensures that the fire protection system works in conjunction with ventilation control, door opening and closing, access control systems and lighting, which is connected to the alarm system. In other words, safety is optimized and the constructor can provide greater security, minimize worker risk and improve on-site accountability.
Within an intelligent construction site, workers may be biometrically recognized, ensuring no trespassing. If there is a fire or major incident, the evacuation and extinction systems are systematically activated, and the air supply at the fire source can be shut down.
A voice evacuation system can then guide all workers in immediate danger to a safe place outside the building by illuminating the escape routes. The access control opens all the doors of the escape route and closes those that lead to the fire source. Cameras supervise the evacuation and a central alarm station provides the fire department with information to fight the fire in the best possible way.
Long-term energy savings
In the same way that automation can aid construction safety and performance, it can also boost the long-term energy efficiency of buildings.
Heating and cooling uses between 18 and 73 per cent of a building’s total energy.[viii] Therefore, methods which use optimization algorithms, like Model Predictive Control (MPC), take command of the heating and cooling, and have the potential to significantly improve HVAC design and performance.
In a recent study by Jorissen at the Arenberg Doctoral School,[ix] the benefits of MPC were made clear: it was shown to use 82 per cent less electrical energy than a state-of-the-art rule-based controller (i.e. thermostatic control) at comparable thermal comfort levels.
Clearly, city landscapes are slowly changing. Buildings are integral to how smart and how sustainable they ultimately become.
Gregory Miller is a writer with DO Supply who covers robotics, artificial intelligence and automation. When not writing, he enjoys hiking, rock climbing and opining about the virtues of coffee.
[iii] This project is being funded by the EU’s Horizon 2020 research and innovation programme. See: https://iopscience.iop.org/article/10.1088/1755-1315/225/1/012034/pd
[iv] Figures are taken from the study: https://iopscience.iop.org/article/10.1088/1755-1315/225/1/012034/pdf
[v] This was a study of the Detection and interpretation of anomalies in building energy use through inverse modelling. See: https://www.tandfonline.com/doi/full/10.1080/23744731.2019.1565550?scroll=top&needAccess=true
[vi] This was a study carried out by Rita Yi Man Li. See: https://link.springer.com/chapter/10.1007/978-981-13-5761-9_9
[vii] RFID automated systems have been studied in Brazil and proven to be efficient in identifying and locating CPE and mapping worker behaviour in relation to risk of falling. See: Alqahtani, A. Y. et al. (2019) Responsible Manufacturing: Issues Pertaining to Sustainability. CRC Press.
[viii] See: Ürge-Vorsatz, D. et al. (2015) ‘Heating and cooling energy trends and drivers in buildings’, Renewable and Sustainable Energy Reviews, 41, pp. 85–98. doi: 10.1016/j.rser.2014.08.039.