Integrated Building Management System
Published on : Monday 09-08-2021
Rushil Srivastava presents an overview of an integrated Building Management Systems with web-based access.
This article provides an overview on the iBMS project background work, aim, challenge, future trends, a basis for the future. We have chosen HVAC (Heating, Ventilation and Air Conditioning) system in this article and described how the conventional system can be transformed to an energy efficient and Smart system adopting the Internet/Intranet to develop integrated Building Management Systems (iBMS) This paper also addresses two technical issues: the Web-based access and the integration of BMS. These should be addressed for accessing BMS remotely via the internet, integrating control networks using the internet protocols and infrastructures, and using the internet for building management. An internet-enabled system that integrates building has been developed and tested.
Market analysis
India is a growing nation and its real estate market is expected to reach the size of US$ 1 trillion by the year 2030. According to the Ministry of Commerce & Industry, Govt of India; from July 2020 to December 2020 as shown in Figures 1 and 2, the commercial buildings in the top eight cities saw 22.2 million square feet of sales, while new completions totalled 17.2 million square feet. In the second half of the year 2020, the Information Technology (IT/ITeS) sector dominated with a 41% share, followed by the BSFI and Manufacturing sectors with 16% each, and Other Services and Co-working sectors with 17% and 10%, respectively. At 5.7 million square feet, the manufacturing sector accounts for 24% of office space leasing in 2020. Between Pune, Chennai, and Delhi NCR, SMEs and electronic component makers rented the most, followed by auto sector leasing in Chennai, Ahmedabad, and Pune. The 3PL, e-commerce, and retail categories, respectively, accounted for 34%, 26%, and 9% of all office space rentals. The office category drew 71% of all PE investments in real estate in Q4 FY21, followed by retail (15%), residential (7%), and warehousing (7%).
With this high demand in office spaces, there is a lot of scope for Integrated Building Management System. iBMS uses interlinked networks to control and monitor every aspect of the building including energy efficiency. As per statistics 40% of world’s energy consumption is in buildings and a stunning 50% of this can be saved by optimising the energy consumption with Smart integrated Building Management System.
Opportunities for business
Some of the systems mentioned in Figure 3 are to monitor and control various building services facilitating building operation and maintenance. This also provides user level visualisation, remote monitoring and control and MIS data. These systems may be deployed in industrial infrastructures such as factories, in enterprise buildings, malls, residential communities, etc., as well. Apart from HVAC, water, waste management, IT infrastructure, etc., they are also connected to security systems like access control, CCTV, intrusion prevention systems, etc. The current technology of building automation systems far exceeds what we have seen in the past with the introduction of latest technologies like IoT, Cloud, and Artificial Intelligence. We can see the full scope of an integrated building management system in Figure 3.
Process
HVAC systems are one of the key systems of building mechanical systems that offer inhabitants with thermal comfort and good quality indoor air. According to numerous zones, location, and distribution, HVAC systems can be divided into central and local systems. Heating, ventilation, and cooling or air-conditioning equipment are the three main components of the HVAC system. Central HVAC systems are installed away from the building and conditioned air flows through a delivery ducting in a central equipment room system. All-air, air-water, and all-water systems are included in central HVAC systems. A general HVAC system is shown below in Figure 4.
As it can be observed in the figure above, there are two types of air coming inside the air handling unit of an HVAC system, one is the return air, it is the air from inside the building and will be having a high CO2 level and the other one is the outdoor air also known as fresh air, which comes from outside the building and have a lesser CO2 content as compared to that of return air. The two types of air will get mixed in the mixing section and then move on to the filter, there are two types of filters that are placed in the system, i.e., pre filter and fine filter. Pre filter removes all the dust particles and fine filter removes any viruses greater than 10 microns. Thereafter air goes to the cooling coil where the temperature of the air is cooled. After cooling the air, the air is supplied to the building as supply air.
SMART control system
This process needs regular monitoring and controlling of the temperature, CO2 levels, humidity, etc., and hence automating these systems for better and more efficient use is essential. The use of a programmable logic controller (PLC) is essential for such applications. It can help in both monitoring and controlling the system. Due to the large size of the infrastructures, remote Input/Output modules or ‘remote I/O’ which refers to an I/O module that is physically separated from the control PLC are used for the controlling and monitoring through PLC. An adaptor module connected to the controller backplane in the PLC rack will allow a remote I/O module to communicate with the PLC. The I/O modules take data from several sensors like CO2 sensors, temperature sensors, humidity sensors, etc. There are various network protocols that are used to transfer this data to the controller however PROFINET is one such reliable and commonly used protocol. PROFINET operates in the real-time channel for such applications which means that it skips 3 layers out of 7 as shown in Figure 5. This helps in reducing latency and jitter and transfers the signals at a speed of 100mbps.
Once the data reaches the controller, according to the logic designed and downloaded to the controller, the data is computed and further transferred to the workstation where it can be controlled and monitored using an HMI. There is another way to check the parameters of the building, it can be done using a web client which will enable the user to monitor the system from anywhere using any device like phone, tablet or laptop. OPC UA can be used for wireless communication. Majority of the controllers have an in-built OPC server which can send the data to the various OPC clients. The network hierarchy is as shown in Figure 6.
As it can be observed that the data from the sensors and actuators will first come to the controller via PROFINET and from there they will be transferred to the clients. OPC UA, short for Open Platform Communication Unified Architecture, is the main successor to classic OPC, and one of its main advantages is that it is platform independent, allowing it to be easily integrated with Windows, Linux, Mac, Android, and other platforms. This is important in the manufacturing industry, where machines and systems are frequently running on different platforms. It also simplifies things by combining all of the different protocols into a single definition. Other significant benefits include the ease with which OPC UA may be deployed, the security of data interchange, the flexibility to handle outdated systems as well as existing infrastructure, and scalability.
Conclusion
Aiming to meet the energy, Safety and environmental objectives, SMART building automation for achieving cost-effective energy savings and corresponding greenhouse gas emissions reduction is the need of the hour. The iBMS project driven by the increasing demands for energy efficiency, better controllability and ease in operation in the buildings sector are gradually becoming an integral part of the Building Management System. While the energy sector, the commercial buildings, are moving towards a digitalisation, SMART building systems are expected to play a substantial role in attaining a smooth and effective transition.
Rushil Srivastava, is a student of RV College of Engineering, Bengaluru. The author acknowledges the role of Dr Rachana S Akki, Assistant Professor, RV College of Engineering, Bengaluru, under whose guidance this article was written.
