Realising the benefits of integrated building services
Services that can interact with one another offer the potential for buildings that are more comfortable and use less energy. Jeremy Aston examines the advantages of integrated building-services solutions.
Improving the efficiency of the buildings we occupy is a growing challenge. Legislation, the need for flexibility in a building’s use and technical demands are presenting new goals for those who design, build and maintain commercial and residential properties of all sizes.
The increasing automation of building services such as lighting, HVAC, access control, façade management with solar tracking, metering and audio-visual systems is in full swing. Much of this has been driven by demands to be energy efficient, with the new CRC EES (CRC Energy Efficiency Scheme) being a typical example. Associated with this is the need to be able to monitor and measure the effectiveness of building services.
To date, more often than not, the approach has been on a ‘silo’ basis, with each distinct service taking care of itself. There has only been a nod towards integration taking place when monitoring the building through a single building management system (BMS). This approach, whilst a step in the right direction, has issues. For example, it is entirely possible for systems to work against one another. Automation is not integration and it is easy to have a building that is simply not ‘joined up’. The key is the ability to provide truly integrated solutions (a joined-up building) where systems no longer operate in isolation. To achieve this, open platforms provide solutions (examples include KNX and DALI and M-Bus).
The concept of KNX open-protocol integrated building control opposes the traditional approach of many stand-alone separate systems, and refers to a bus system based around global standards for home and building (EN 50090, EN 13321-1 and ISO/IEC 14543). It is not manufacturer specific and uses one software tool, which is available to everyone, for programming.
This intelligent building technology is all about integrating control applications and allowing them to operate together. It shares information about the space being controlled, and the savings that can be made are considerable.
Consider, for example, a small office where lighting control, air conditioning, perimeter low-level heating and automatic blind control and are all controlled by a single KNX bus network and work together rather than independently or against one another. Their operational integration will clearly save on energy consumption by ensuring they work only when needed, so energy is consumed only when required. Extend this scenario across real estate with many additional operational building services functions and the potential for savings is vast.
DALI allows each light fitting to be controlled flexibly, offering dimming and comprehensive feedback on the state of the lamp. M-Bus is used for metering and is easily integrated to provide accurate and meaningful management information.
A joined-up building will allow heating on if a window is open or a room is unoccupied. A joined-up building does not just monitor the natural light available and use less artificial light near windows to maintain a constant brightness level — it can also activate louvres or blinds to reflect natural light into the room when the Sun is shining directly onto the window.
An example of this harmonious use of technology is at One Hyde Park, a prestigious development of over 80 apartments in central London. A blind-control system monitors the level of solar radiation across each façade and lowers blinds to prevent solar gain heating rooms. This is in turn ensures that the cooling systems in the apartments are not activated, preventing needless energy usage and increasing comfort for residents.
At Terminal 5, Heathrow, a KNX DALI system for monitoring and controlling lighting includes site-wide communication over the common IP data network. Over 150 000 DALI luminaires are connected, controlled and monitored — including emergency-lighting testing and monitoring. KNX also performs the energy monitoring of the lighting loads in accordance with Part L of the Building Regulations.
The system was developed to optimise energy efficiency and includes daylight-linked constant light control, presence detection, time scheduling of loads and intelligent lighting control with dimming — along with the monitoring of lifts, escalators, disabled toilet alarms and plant.
Any building can become joined up with fully integrated services. For example, just a few hundred pounds per room would enable a joined up school to integrate lighting, heating, blinds, audio-visual hardware and more. If a room is not occupied, the projector would be switched off, lighting turned off, heating lowered and the resultant reduction in energy usage measured — with as little human intervention as desired. Each room could be easily monitored and controlled — potentially remotely.
Jeremy Aston is managing director of KNX UK Association systems integrator Reality Logic.
Copies of the KNX Consultants Guide can be downloaded from www.knxuk.org