﻿Integration as the key to all-round cost reductions
Integrating the control of the various services in a building such as heating, lighting, air conditioning, ventilation etc., onto a single network is increasingly acknowledged as making possible a substantial reduction in energy consumption and the capital cost of controls compared with a number of standalone systems for each service.
Achieving these benefits requires the various sensors and controls to communicate using a single protocol, such as KNX — an open standard based on more than 15 years’ experience in the market and covered by the international standard ISO/IEC 14543-3.
Iain Gordon, president of the association KNX UK, tells us, ‘Studies reveal that networked home and building control based on KNX allows up to 50% energy savings.’ That level of savings implies that integrated systems, such, as KNX have an important role to play in reducing carbon emissions from buildings and complying with ever-more stringent Building Regulations.
In particular, Iain Gordon refers to research in Germany at Bremen University of Applied Sciences over four years which found that the use of KNX reduced energy consumption by 50% compared with ‘normal’ operation.
The project was the newly constructed Centre for Informatics & Media Technologies. This building has a specific energy consumption of 60 to 75 kWh/m2/a. Two identical classrooms were selected as test rooms. One was fitted with a conventional installation (‘normal’ operation) and the other with KNX controls for regulating heating and lighting (‘automation’ mode) and data collected over four years.
One important conclusion was that the extra investment in KNX bus control paid back its cost after just one year.
The control capabilities of KNX and its installation benefits are explained by Darren Burford, vice president of KNX UK and managing director of Andromeda Telematics. The benefits derive from there being one system for all networks — such as lighting control, blind/solar control, window control, natural and passive ventilation, HVAC, metering and energy management and monitoring systems. In addition, only one head-end PC is required.
Because the many manufacturers of KNX-compatible products around the world support the protocol and their products are tested for compatibility, no gateways are needed to achieve openness. Darren Burford summarises, ‘The integrated building is a building that has one control network performing many functions, all in harmony with each other.’
Various installation benefits immediately follow. There is no duplication of networks and equipment, leading to less cabling being needed and also less labour needed for installation. A single network and one systems integrator also ensures that there are clear lines of communication.
While KNX is much less widely used in the UK than in other countries, it is gaining market share, according to Eric Anderson of Siemens, which makes KNX compatible equipment. And several major projects in the UK more than bear comparison with KNX projects overseas.
Two major projects in China are the ‘Bird’s nest Olympic stadium and terminal 3 at Beijing Airport.
The entire lighting system of the Olympic stadium was controlled by KNX — including the lighting displays at the opening and closing ceremonies.
Terminal 3 at the airport includes more than 11 000 KNX devices to control, lighting, heating and air-conditioning systems and transmit error messages.
In Germany, the electrical building installation of the headquarters of German Telecom’s International Net Management Center is based on KNX to control shutters and provide constant light regulation in all the offices. In the foyer and control centre, dimmable lighting is managed through light scenes and presence detection.
Three substantial projects in the UK are Media City UK in Manchester, Terminal 5 at Heathrow Airport and Bridgewater Place in Leeds. However, let not these large projects belie the fact that KNX can be applied effectively to much smaller ones, for KNX is hugely scalable.
At Media City, NG Bailey awarded to EnTech the contract to provide the design and commissioning of KNX building-control solutions to three buildings, all of which will be occupied by the BBC.
Heathrow’s Terminal 5 is the largest KNX project in the UK and also the largest DALI lighting-control project in the UK. Designed, supplied and commissioned by Andromeda, the system controls the complete campus — including the main concourses, control tower, rail, energy centre and many other ancillary areas serving this huge terminal project.
At 33 storeys high, Bridgewater Place in Leeds is the tallest commercial building in Yorkshire. It is designed for multi-tenanted occupancy and incorporates lighting control using a KNX system supplied by Electrak International. The integrated package of KNX devices was sufficient to create 30 separate lines across 10 floors of the building for the Cat A fit-out.
While the traditional approach of lots of standalone systems might produce lower tender costs, Darren Burford believes that we must adopt the new way of working represented by system integration. To move forward, he urges that lifecycle costs and energy payback are fully considered — not just capital costs. There are also savings in installation time and costs to be gained from smart design. His firm advice is: ‘Do not be afraid to integrate systems.’