Realising the intelligent building
Darren Burford explores the vital role of compatible connectivity in making possible the truly integrated building — and the installation and operational benefits.
Designed for integration — the benefits of integrating building systems are fully exploited in the redevelopment of St Pancras station in London using the capabilities of KNX (formerly EIB).
The phrase ‘intelligent buildings’ is now commonly applied to commercial or residential accommodation where owners and managers have complete control over the everyday working or living environment. It covers heating, ventilation, air conditioning and lighting — but it can go beyond these basics to provide control over the operation of blinds, appliances, windows, security systems, metering and many other functions. This is all achievable through the simple system for intelligent electrical installation networking known as KNX (formerly EIB). As part of a KNX installation, the bus cable combines devices and systems within a building, whereas previously they functioned separately from one another. New functions can be added to this network quite simply by simply looping the bus cable to the new device. As it is low voltage, there is no need for potentially expensive and disruptive encasement — so KNX is easily expandable to encompass additional functionally at a later date. Expandable
KNX is an open, gradually expandable and consistently user-orientated system. The system is prepared for coming generations of systems and building-service devices. The products of hundreds of worldwide well-known manufacturers are KNX compatible, making installation a safe investment for the future. Every manufacturer’s product works with the products of every other KNX manufacturer and there are no integration issues, so there are no hidden engineering costs. Indeed KNX is the world’s first open and platform-independent standard for home and building control, approved as a European Standard EN 50090 and worldwide standard ISO/ IEC 14543. Because KNX is a distributed system, sensors and devices can be mixed and matched to provide any degree of functionality required. It is in fact almost Lego for building controls — with imagination as the only limit. Sensors such as motion detectors and thermostats send impulses over a transmission medium to so-called actuators which then activate or deactivate the lights or the heating system, for example. These sensors and actuators can be programmed and linked as desired. It is easy for occupants to manipulate the functions of the KNX system using familiar switches, the telephone or a remote computer. Investment return on each KNX device is highly geared, as each product on the bus, such as a movement detector, can not only switch lighting as in conventional installations but can also set back heating when a room is empty and provide security information regarding movement on a head-end PC graphic. A KNX system can also act as an ‘electronic watchdog’ overnight in any building, deterring crime. Motion detectors, break-glass sensors and electronic shutter control can be connected to an alarm system or emergency call circuit. If there are suspicious noises outside, a panic button can be pressed, and the lights will go on and the shutters open. Alarm conditions can be conveyed by e-mail or SMS and to a mobile telephone. In unoccupied buildings, at weekends or during holidays, the presence of people can be simulated by, for example, time-controlled lights in different rooms. KNX can automatically open the blinds in the morning — every day at a different time, if desired — and close them at night. Climate control is vital in office buildings, and a brightness sensor can detect if blinds are closed. At the same time, heating and ventilation can be regulated separately in each room via temperature sensors. During the winter, when warmth and light make an even greater contribution to the comfort that a building provides, KNX technology regulates climate and lighting for each room in accordance with the outdoor temperature and daylight levels. Energy conservation
KNX can also make an important contribution to energy conservation. If a window is opened, the window contact sends a signal to the individual room regulator. The radiator valve then closes to the frost-protection setting so that heat does not escape outdoors. The intelligent heating management of KNX can also provide reliable protection against frost damage when the building is unoccupied. In the evening, lighting variations can be programmed to specific requirements by pressing a button. In an office, this may mean turning off or dimming lights in certain unoccupied or semi-occupied rooms. Energy management is also promoted, as KNX can switch on power-hungry devices automatically when electricity is cheapest. As well as operating appliances, KNX can monitor windows and skylights. Typically, a rain sensor controls their automatic closing in the event of inclement weather. Information can be made available on mobile devices such as PDAs. This is achieved through the development of technical facilities-management software that features open interface technology which effectively integrates all technical disciplines within a building such as electrical apparatus, heating, ventilating, air conditioning and security. The software also integrates open standards in building automation into the world of communication technologies. All the information gathered can be sent by SMS, e-mail or fax and also has Internet functionality as well as database connectivity to display results. It is therefore particularly attractive for the facilities management of remote sites. Whether the aim is to create a workstation to control all these facilities or simply to control the functions of a particular building, this software provides the solution. Bus systems are changing as a result of more demanding customer requirements and because of technological advances. The demands made by the end users are increasing for a number of reasons — such as a greater need to protect investment and the desire to expand the capability of the bus at a later date without having to refer to the original supplier. Simpler integration
At the same time, suppliers of KNX systems can offer more favourably priced solutions and simpler integration of third-party products. Vendor independence guarantees interoperability without the need for costly gateways. Indeed, as bus systems become more standardised, the engineering behind them also becomes more straightforward and more cost effective. This standardisation in Europe has taken a major step forward with KNX as the world’s first open and platform independent standard for building comfort, bringing together BACnet, Profibus, EIB, Batibus, EHS and LonTalk protocols. KNX based systems can be installed by a systems integrator which is a member of the Konnex UK Association. Installation costs are low, particularly as there is less cable to install compared to a conventional installation. Also, because of the high level of integration and functionality there is only one twisted pair to install, which can result in up to a 60% reduction in cable requirements. Not only is building intelligence a technology of today, it is also a technology that is evolving rapidly — with KNX technology at the forefront of the evolution gaining fast widespread acceptance. Konnex UK brings together KNX manufacturers and suppliers, who can offer products to the UK market, and systems integrators with experience in all types of commercial and domestic organisation. Darren Burford is vice president of Konnex UK, PO Box 4082, Bracknell, Berks RG42 9EQ.