Intelligent Buildings and Building Automation

Introduction

Modern buildings are now built with intelligence. Building automation (BA) systems play a crucial role in monitoring these sophisticated buildings. Monitoring and automatic control of building services systems are important to ensure that the design objectives are met in operation with least human interference.

The concept of intelligent building (IB) has attained importance over the years. This article touches upon briefly the philosophies behind these systems. Though it is difficult to formulate a unique conception of IBs, there is no single definition is available worldwide. However, the approaches to defining an IB can be grouped into three categories as listed below:

• Performance- based definitions;
• Service- based definitions;
• System- based definitions.

Performance- Based Definitions

Performance-based definitions define IBs by stating what performances a building should have. A typical performance-based IB definition may be a building created to give its users the most efficient environment; at the same time, the building utilizes and manages resources efficiently and minimizes the life costs of hardware and facilities.

Another example of a performance- based definition is that given by the Intelligent Building Institute (IBI) in the United States, which states that an IB provides a highly efficient, comfortable and convenient environment by satisfying four fundamental demands: structure, system, service and management, and optimizing their interrelationship.

Performance- based IB definitions emphasize building performance and the demands of users rather than the technologies or systems provided. According to this category of definition, owners and developers of buildings need to understand correctly what kind of buildings they want and also how to satisfy continuously the increasing demands of users. Energy and environmental performances of buildings are certainly among the important issues of an IB. An intelligent building should also adapt itself quickly in response to internal and external conditions, and to meet the changing demands of users.

Services- Based Definitions

Service-based definitions describe IBs from the viewpoint of services and/or quality of services provided by buildings. According to ‘Japanese Intelligent Building Institute-JIBI’, an IB is a building with the service functions of communication, office automation and building automation, and is convenient for intelligent activities. Services to users are emphasized. The key issues of IBs in Japan focus on the following four services aspects:

• Serving as a locus for receiving and transmitting information and supporting efficient management;
• Ensuring satisfaction and convenience of persons working inside;
• Rationalization of building management to provide more attractive administrative services at lower cost;
• Fast, flexible and economical responses to the changing sociological environment, diverse and complex working demands and active business strategies.

System- based definitions

System-based IB definitions describe IBs by directly addressing the technologies and technology systems that IBs should include. A typical system- based IB definition is the one suggested in the Chinese IB Design Standard (GB/ T50314–2000), which states that IBs provide building automation, office automation and communication network systems, and an optimal composition integrates the structure, system, service and management, providing the building with high efficiency, comfort, convenience and safety to users.

Intelligent Reality 

In the context of the modern building environment, it is obvious that intelligent buildings have to co-exist with advanced information technology (IT) systems. But having only technology systems is not enough to make a building an intelligent one. Furthermore, the technology systems should be correctly configured and properly integrated with each other and with the building facilities. The system functions should be appropriately customized to meet user requirements and to provide the expected performance of intelligent buildings.

Finally, the technology systems, including their integration and interoperation, should be properly commissioned and maintained to ensure they function as expected. Besides the system hardware and software, the application software, including that for facility automation and control, optimization and management, should be customized and commissioned appropriately. A building may have technology systems, but if they are not working correctly it will not make the building intelligent in reality. Instead, the technology systems may create headaches for operators and users. Intelligent Buildings involve multi-industrial system engineering and require the right combination of architecture, structure, environment, building services, information technology, automation and facility management. In addition, IBs are also strongly related to economic and cultural aspects.

Intelligent Architecture and Structure

Successful implementation of advanced technologies including information technology is the main feature of intelligent buildings and these systems have to be integrated in the building design from conceptual stage. Keeping ‘Performance’ as the key objective, buildings have to be designed considering the role of several key elements such as-the hardware facilities, building façades and materials etc.

Intelligent architecture

Intelligent architecture refers to built forms whose integrated systems are capable of anticipating and responding to phenomena, whether internal or external, that affect the performance of the building and its occupants. Intelligent architecture relates to three distinct areas of concern:

• Intelligent design;
• Appropriate use of intelligent technology;
• Intelligent use and maintenance of buildings.

Intelligent design- requires that the building design responds to humanistic, cultural and contextual issues; that it exhibits simultaneous concern for economic, political and global issues; and that it produces an artificial enclosure which exists in harmony with nature. Existing in harmony with nature includes responding to the physical laws of nature and the proper use of natural resources.

Intelligent technology- the mere availability of a large variety of smart materials and intelligent technologies often results in their use in inappropriate situations. Integrating intelligent technologies with an intelligent built form that responds to the inherent cultural preferences of the occupants is a central theme in intelligent architecture. As an example, in areas where people place a high premium on operable windows for conservation of electricity, the most appropriate and efficient air- conditioning strategy for a building may be the use of thermal mass and night- time free cooling instead of a high- tech air- conditioning system. In other cases, the use of carefully selected electric lighting and environmental control strategies may be more appropriate.

Maintenance of buildings-truly intelligent architecture incorporates intelligent facility management (FM) processes. For a design to be intelligent it must take into consideration the life cycle of a building and its various systems and components. Although an intelligent building may be complex, it should be fundamentally simple to operate, be energy and resource efficient, and easy to maintain, upgrade, modify and recycle.

Materials and equipment that require complex maintenance and unhealthy cleaning agents, and building components that must be treated as hazardous waste in the recycling process (e.g. mercury in light- bulbs) would not be used in a fully developed intelligent architecture.

Intelligent Building Façades

Intelligent Building Facades - Al Bahar Towers, Abu Dhabi, UAE

The character of the building envelope will be affected dramatically by the development of intelligent buildings. Façades designed to integrate a host of emerging technologies will have an inherent ‘intelligence’ and be able to respond automatically, or through human intervention, to contextual conditions and individual needs. In the modern context, intelligent façades can:

• Be centrally controlled while still providing the occupant with manual control facility.
• Change their thermo-physical properties such as thermal resistance, transmittance, absorptance, permeability, etc;
• Modify their interior and exterior colour and/or texture; function as communicating media façades with video and voice capabilities;
• Change optical properties and allow the creation of patterned glazing, providing the opportunity for dynamic shading and remote light control.

The development of the intelligent and responsive façade necessitates the redefinition of the terms ‘window’ and ‘wall’. With the introduction of new glazing and wall assemblies, what is ‘transparent’ may become ‘opaque’ with the flick of a switch. Central controls for intelligent façades will respond to climatic conditions by transforming the building envelope to optimize heating and cooling loads, daylight utilization, natural ventilation, and so on. Intelligent façades will transport daylight deep into a building’s interior and allow the occupants to determine the degree of luminous, acoustical and thermal comfort required along with the degree of visual and acoustical privacy provided by the enclosure. Additionally, we can now imagine interior partitions that will allow the occupants to transform the aesthetic quality of their working environment whenever and however they choose.

The idea of the intelligent or smart system, originally applied to electrical, mechanical and aerospace systems, recently has been extended to include civil structures as advances in sensing, networking and new materials have made continuous monitoring and control of structural functions a realizable goal. By definition, the intelligent structure has the capability to identify its status and optimally adapt its function in response to stimuli.

Facilities Management vs. Intelligent Buildings

Building Management Functions

Facility Management-FM, is the practice of coordinating the physical workplace with the people and work of the organization; it integrates the principles of business administration, architecture and the behavioural and engineering sciences. The definition is often simplified to mean that facility managers integrate the people of an organization with its purpose (work) and place (facilities).

The International Council for Research and Innovation in Building and Construction (CIB) Working Commission on Facilities Management and Maintenance summarized the scope of facilities management in the following categories:

• Financial management-This refers to the investment issues including: sale and purchase, rental return, rebuild or renovation, etc.
• Space management-This includes space utilization, interior design, fit- out and relocation, etc.
• Operational management-This refers to the maintenance management and refurbishment and  lease and property management including building enclosure, building services, building environment and building grounds.
• Behavioural management-This refers to the users of the building, including users’ perceptions, the satisfaction of the occupants and participation of users, etc.

Intelligent building and facilities management are closely connected. The scope of facilities management defined by FM professionals often includes significant parts of IB hardware facilities and functions. On the other hand, the contents of intelligent buildings defined by IB professionals often include significant FM elements. This situation reflects the fact that definitions of both terminologies cover a very wide scope and different points of view. In fact, modern IB systems are complex and powerful systems offering various functions for building control and management. The IB system is a preferred platform for supporting various tasks of building facilities management. At the same time, the success of implementing FM functions in IB systems makes intelligent building more attractive. IB systems as complex facilities to be managed actually create business opportunities for FM.

Conclusion IB systems

Energy Management Functions

The integration of IB components and subsystems has been the trend of IB technology development. Integration is essential for most functions of IB systems, such as automatic monitoring and management, and building performance optimization and diagnosis. Function integration increases the flexibility and possibilities of intelligent management of buildings. The integration of the automation and control systems is the basis for function integration. Digital technology plays a very important role in the integration as systems that consist of traditional technologies have many constraints in terms of information exchange and integration. The microprocessor, providing amazing power in computation, and in transmitting and processing information, is the key element of digital systems and the key element of IB and BA systems.

Modern IB systems have been becoming very large in terms of system scale and complex in terms of hardware and software system configurations, while their functions and capacities have been increasing progressively. System reliability is an important issue. Utilizing a decentralized network or a decentralized local area network (LAN) is the key to solving the system reliability issue and simplifying IB networks. Distributed intelligence is a major philosophical solution to ensure the reliability of such complex IB and BA systems. ‘Integrated but independent’ is one of the most essential concerns in the development and configuration of IB and BA systems.

Building Automation

Building automation system (BAS) is used to refer to a wide range of computerized building control systems, from special- purpose controllers, to standalone remote stations, to larger systems including central computer stations and printers. As discussed earlier, BAS is one of the major intelligent building systems. A Building Automation System comprises several subsystems which are connected in various ways to form a complete system. The system has to be designed and engineered around the building itself to serve the services systems for which it is intended. Consequently, although the component parts used may be identical, no two systems are the same, unless they are applied to identical buildings with identical services and identical uses. 

Building services include HVAC systems, electrical systems, lighting systems, fire systems and security systems and lift systems. In industrial buildings they may also include the compressed air, steam and hot water systems used for the manufacturing process. A BAS may be used to monitor, control and manage all or just some of these services. There are good reasons and ultimate objectives in investing considerable sums of money in this way. These will vary, depending on the use of the building and the way the building is managed as well as the relationship between the value of the end product and the cost of operating the building. It may also depend on the level of sophistication of the building services and their capital cost.

Building Management Functions

A building automation system is the high- technology tool or platform that expands and enhances the capabilities of those responsible for operations of a building. To better understand the potential impacts of a BAS, it may be helpful to look at the needs of the building operation and management which a BAS addresses. Typical functions provided by building automation systems include:

• Installation- management and control functions;
• Energy- management functions;
• Risk- management functions;
• Information- processing functions;
• Facility- management functions;
• Performance monitoring and diagnosis;
• Maintenance management.

Installation- Management and Control Functions 

Control functions of a BAS can be divided into two categories: local control (or installation- management and control) functions and supervisory control (or energy- management) functions. Local control functions are the basic control and automation that allow the building services systems to operate properly and provide adequate services. Local control functions can be further subdivided into two groups: sequencing control and process control.

Sequencing control defines the order and conditions associated with bringing equipment online or moving it offline. The typical sequencing control in building systems includes chiller- sequencing control, pump- sequencing control, fan- sequencing control and lighting on/off control, among others. Process control is used to adjust the control variables to achieve well- defined process objectives in spite of disturbances, using measurements of state and/ or disturbance variables. Examples of typical process control in buildings are temperature control, air and water flow rate control and static pressure control.

Energy- Management Functions

For most BAS installations, savings brought about by improved energy management provide the economic justification for the purchase of the systems. The ways in which a BAS makes energy savings can be broadly grouped into two categories. The first is the savings which result through starting and stopping plants according to correct or optimal timing. The second is the savings which result through running plants in energy- efficient conditions, typically by setting the set- points of the local process controls at correct or optimal levels.

There is no better means of saving energy than that of turning off the energy- using equipment. Of course, you cannot turn off equipment that is needed constantly; we need to be able to turn off equipment without compromising the quality of services or the indoor environment. There are two approaches for starting and stopping equipment in an energy- efficient manner. They are called ‘scheduled’ and ‘optimized’ start/stop. In scheduled start/ stop, the HVAC equipment, lights and so on are turned on or off according to a combination of the clock and calendar. With an optimized start/stop program, the BAS assesses the existing conditions, anticipates conditions for the next several hours and decides when to start and stop the systems so that environmental conditions are provided during the complete building occupancy period with minimum energy use.

The control settings of the local controllers might be optimal and energy efficient when certain subsystems or certain subsystem performance criteria are considered. Supervisory control, often named optimal control, seeks to minimize or maximize a real function by systematically choosing the values of variables within allowed ranges. In the control of HVAC systems, for example, supervisory control aims at seeking the minimum energy input or operating cost to provide satisfactory indoor comfort and a healthy environment, taking into account the ever- changing indoor and outdoor conditions as well as the characteristics of HVAC systems. Compared to local control, supervisory control allows overall consideration of the system- level characteristics and interactions among all components and their associated variables.

Risk- Management Functions

In the same way that a BAS detects temperature and humidity conditions, it can also be used to detect fire or the presence of smoke. Fire safety integrated into BAS provides a greater degree of personnel safety than using two independent systems. The BAS is able, automatically, to close fire doors, close some air dampers and open others, start some fans and stop others and pressurize some parts of building with respect to others. This can help prevent the spread of fire and perhaps, more importantly, reduce the spread of smoke.

With the security system incorporated into the BAS, it almost always provides greater security and therefore reduces risk. Detection of someone trying to gain unauthorized entry is commonly by sensors on doors and windows. From the information reported to the central computer, the security officers can be made aware, not only that an intruder is present or is trying to gain entry, but also the intruder’s location within the building. Access control differs from security monitoring since as the name suggests it is actually controlling who has access to a building or certain parts of a building.

Information- Processing Functions

Performing an economic evaluation of a large BAS is not a trivial assignment, nor can it be absolutely precise. The basic data needed for the economic evaluation is the cost of the BAS and the economic benefits that can be derived from the BAS. It is likely that the initial cost of the BAS can be estimated more accurately than the annual savings from energy conservation and other improvements. Although prediction of dollar savings attributable to energy conservation features and building management features is difficult, powerful systems provide energy monitoring and graph/table reporting, making estimation easier. 

Engineers can directly access actual plant operating conditions through BAS to monitor energy use and energy cost, to carry out energy audits or to check performance using computer simulation techniques. With the support of BAS, a financial report can be produced with much less effort.

Facility- Management Functions

Security and Safety Control Systems

As discussed earlier, facilities management can have very broad definitions. FM professionals often consider almost all BAS functions as part of FM functions, and BASs are the systems used to achieve FM functions. Intelligent buildings need facilities management to define requirements, justify investment and deliver benefits. At the same time, facilities managers need intelligent buildings to control building performance, manage distributed services, adapt rapidly to changing requirements and provide crucial management information. From this point of view, the basis of facilities management is to ensure all the service equipment works properly. But from the viewpoint of building services engineers, FM functions mostly refer to the use of building spaces and facilities, including the economic effectiveness and financial aspects.

Intelligent buildings usually imply facilities management via building automation systems. Therefore, the facilities management of intelligent buildings requires the combination of an integrated BAS and the traditional information management system. Facility owners and managers require large amounts of data of various types for quality and efficient management. Typically, this information, such as management data of utilities, energy, maintenance, space, tenant and environmental compliance, is available and recorded on various computers or control stations.

In practice, most of the facilities management systems are still single information management systems. They cannot retrieve data from integrated building automation systems, which are a huge data source. Future computer aided facilities and maintenance management systems should provide more convenient and efficient management tools and exploit fully the advantage of integrated building automation systems in intelligent buildings.

Security and Safety Control Systems 

Architects and engineers aim to find cost- effective solutions addressing the security and safety concerns of employers, employees, customers and other users of buildings, which not only comply with government regulations, but also provide enhanced protection. Some of the systems under this category include;

• Closed circuit television (CCTV) systems;
• Access control systems;
• Burglar alarm systems;
• Fire alarm systems.

CCTV Systems

CCTV systems are implemented and integrated in safety and security applications to provide remote ‘eyes’ for security operators by providing live- action displays from a distance and/or to keep a video record of the spaces under monitoring. With today’s labour costs, CCTV is a cost- effective means for expanding security and safety control. Certainly, the main objective of CCTV systems should not be to record ‘thieves’, but rather to prevent theft. There are two basic categories of CCTV systems: analogue CCTV systems and digital CCTV systems (or IP surveillance systems).

Access- Control Systems

Access - Control Systems

Access control is the ability to permit or deny the use of a particular resource by a particular entity. Physical access by a person is controlled on the basis of authorization, payment and the like. In physical security, the term access control refers to the practice of restricting entrance to a property, a building or room to authorized persons. Physical access control can be achieved through mechanical means such as locks and keys, or through technological means such as advanced access- control systems. Access control in this chapter is concerned only with physical access control.

Locks and keys have been used to control access to buildings and rooms for hundreds if not thousands of years. Today, the traditional key- based lock is still the most popular means used for access control of buildings, rooms and even commercial spaces. However, electric (or electronic) locks are commonly used nowadays to provide more effective or more secure access control. Electric locks are sometimes standalone with an electronic control panel mounted directly on the lock. More often electric locks are connected to an access- control system. Access- control locks are also designed in different forms to suit different applications such as to control access to public transportation, car parks, and construction sites and even for immigration control.

Fire Alarm Systems

Fire Alarm Systems

The function of fire alarm systems is to detect the presence of unwanted fire in the protected spaces by monitoring environmental changes associated with combustion. Fire alarm systems may be activated automatically, manually or usually both. The purpose of using fire alarm systems is to notify people to evacuate in the event of a fire or other emergency, to call the fire protection department for emergency aid, and to activate other associated systems to control the spread of fire and smoke. It is worth noting that the fire alarm system is an essential measure but not the only measure for the fire safety of a building in terms of both regulations and reality. Concerning fire alarm systems, it is critical to properly select and place the detectors according to the layout and use of spaces. This section discusses the basic components and the typical configurations of fire alarm systems.

Burglar Alarm Systems

The use of burglar alarm systems (or intrusion- detection systems) is to detect unwanted attempts in accessing a space or object. The main functions of burglar alarm systems can be divided into three categories including: perimeter protection, area/space protection and object/spot protection. Various sensing devices of very different mechanisms are available for detection at different situations. Intrusion- detection systems also often refer to the systems for protecting computers or other information systems from unwanted access. However, this chapter is only concerned with the detection of unwanted physical access to protected spaces or objects.

References:

• Smart Building Systems by James Sinopoli
• Intelligent Buildings and Building Automation by Shengwie