Adaptive Control System: Singapore Office Building 2021

Adaptive Control System: Singapore Office Building 2021
Fatimah Al-Ameen
University of Melbourne

Energy consumption in the infrastructure sector continues to increase with population and economic growth around the world. While the Greenhouse Gas emission (GHG) in Singapore doubled by 2020, Singapore has committed to reducing GHG emissions by 7- 11%. The building sector holds a great account in GHG with 14% and almost 50% of the country’s electricity use (“building-energy-efficiency-r-and-d-roadmap,” 2020).

Solving the cooling problem is the key to reduce the energy-intensive load in buildings and decrease carbon emissions.

As a tropical country, Singapore spends the majority of its Energy (60%) on cooling the buildings. As a result, the use of air conditioning per person is greater than any country in Southeast Asia and is projected to go higher by 2030 (Singapore, 2018). Thus, solving the cooling problem is the key to reduce the energy-intensive load in buildings and decrease carbon emissions (Fernandez, 2018).

Energy efficiency improvements were observed as a result of technology adoption in best-in-class buildings (GM Platinum as a proxy) from 8% in a short time up to 40% in the long time frame (“building-energy-efficiency-r-and-d-roadmap,” 2020). Both “Adaptive controls based upon occupancy” and “Self-adapting distributed system” were in the top 4 technologies used in green buildings in Singapore in 2020.

What is Adaptive Control System?

The use of the Building Management system has been adapted into most commercial buildings. It enables centralized monitoring, control, and management of services. The adaptive control technology is the advanced technology that utilizes the integrated sensors into its model predictive system and operates accordingly. In the case of an Office building, we propose a Self-adapting distributed air-con system that integrates the technology to optimize the indoor air temperature and intake of fresh air based on indoor activities (SGBC, 2021). The device is embedded with a novel algorithm that is designed to instantly conceive data from occupancy patterns and behaviours to generate an inverse model of the heat transfer in each area (Gunay, 2016).

Adaptive Control System

Figure 1, schematic of Adaptive system (Gunay, 2016)

 

Where Adaptive Control System used?

In 2020 Keppel Land was awarded $1.8 million by the Building and Construction Authority in Singapore (BCA) under Green Buildings Innovation Cluster to implement technologies to achieve super low energy (Fernandez, 2018). Keppel Bay Tower became a leader in optimizing this technology and achieved a reduction of 22% in annual energy consumption. Keppel piloted energy-efficient technologies including adaptive control systems into the existing building and promoted a new way of adopting sustainability within the existing condition. It was later certified as Singapore’s first Green mark platinum (zero Energy) commercial building (Teh, 2020).

How Adaptive Control System is relevant?

As part of a national plan, Singapore has committed itself to oblige the new standard of producing “Super Low Energy” buildings. Developers are encouraged to take the lead in using innovative technologies for making highly efficient buildings. Office buildings were specially tasked to lower their energy rate by 60% of 2005 levels (Fernandez, 2018). The SLE challenge helps the owners to take the lead in emerging energy efficiency technology and sustainability and to play as a role model for future developments (Teh, 2020).

In warm and humid climate, ventilation plays an effective role in improving air quality and cooling the temperature. However, cooling systems consume 40 to 50 per cent of a building’s energy and produce large quantities of the greenhouse gases that drive climate change. The Self-Adapting distributing system controls the fresh air intake to maximize the air quality and works in parallel with a highly efficient air-conditioning system to achieve the best outcome. It would not reduce the quality of the cooling and the comfort temperature instead; it saves energy from reducing the excessive energy load and leakage.

Office building accommodates different types of people in different sitting modes from conventional open plan office space to intimate and enclosed meeting rooms. Air- conditioning control systems in offices, as well as other civic buildings, often plan for the hottest day and highest comfort range to satisfy all users. Data shows, cooling rate exceeds the required range for about 40% and would not turn down when is not needed (sg, 2020). While all the areas require access to cooling, ventilation and fresh air, some spaces have lower demands due to less intensive activity. Also, operating hours of office buildings is typical and predictable during a day and a year however, there are some exceptions for after hour or a seasonal peak time usage. The adaptive control system of distribution air-conditioning takes into consideration the indoor activity as well as outside air conditions to manage the distribution of air conditioning based on demand.

Opportunities of Adaptive Control System:

One great advantage of this system for offices is that it can easily be adopted into old technologies. There are many office buildings that still use a century-old air conditioning system that expends most of the energy in the industry. By executing this system in those buildings, the city’s energy consumption rate reduces significantly.

The algorithm within the device undertakes a learning process from collecting occupancy patterns in real-time using a small number of sensors in different zones. Then the information collected and generated into the model will automatically determine the amount of infused fresh air and cooling it requires to maintain a comfortable air temperature within the space (Gunay, 2016). Repetition of the patterns and temperature variation is tested over a year to underpin the most efficient air distribution rhythm with minimum energy waste. This system has proven to reduce the space cooling loads and offer significant energy savings potential if used and developed further (“building-energy-efficiency-r-and-d-roadmap,” 2020).

There are few studies that show the positive outcomes of using adaptive control technology in different building types and how Indoor air quality was positively affected. A recent study of implementing a similar control system suggested a high satisfactory rate in performance and temperature within the internal space and draws a connection to the improved learning ability in the tested school case study (Georgios & Petros, 2020). Keppel Bay Tower also evaluated a 10% reduction in air-conditioning energy usage as well as better thermal comfort. Occupants also noted a more pleasant indoor environment quality within the building (SGBC, 2021).

Challenges of Adaptive Control System:

Although this system can be adopted with any old version of the air distributing system and is scalable to accommodate all building sizes, the energy rate reduction is limited in accordance with the host air-con system. Thus, high-rate energy reduction would be applicable if high-efficiency air conditioning would be used. Nevertheless, further developments and studies been conducted on this system and is predicted to provide significant energy savings and cost-effective solution.

Also, the use of this smart technologies requires technical maintenance and regular observation and updates to function purposefully within the system.

Adaptive Control System

Figure 2, the control laboratory for maintenance (Gunay, 2016)

 

Future prospect of Adaptive Control System:

The use of adaptive technologies has been in trend for many years. There are many experimental models and algorithms for different users and functions. These experimental models have helped this technology to retrofit, restore and develop to make more effective provisions. As a result, It is well proven within the industry and green rating buildings in a way that was amongst the top 4 technologies been used in Singapore within the last year.

As a result of continuous research and experimental examinations on this system, there seems to be an indefinite path towards its future. Because of the idea of adapting and correlating the human experience and existing condition with the operating system, this technology would be always popular. It might get upgraded or adjusted in the future to be able to remain relevant within the industry.

Conclusion:

People spend 90% of their time indoors and indoor climate control impacts our economics and environmental system by using 35% of energy use. (Stazi, Naspi, Ulpiani, Di Perna, & Buildings, 2017). The sensor-based technology detects the algorithms of occupant’s activity and indoor climate and presents a model for the most effective and efficient air-distributing and fresh air intake.
It prioritizes human comfort and wellbeing in a small indoor space as well as on a massive planet. Scientists have discovered a solution to take care of the ecological system by minimizing energy waste and promoting the best indoor air quality.

Adaptive Control System

Figure 3, Example of implementing the adaptive control sensors within different zones for different air distributing intake (Gunay, 2016).

 

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