KNX UK believes that during the operational life-cycle of a building, efficient energy usage can only be achieved properly if it is continually optimised with demand based BACS (Building Automation & Control System[s]) coupled with continual monitoring and adjustment of energy saving measures. With this approach, energy consumption can typically be reduced by up to 30%, based on BS EN 15232 and the energy savings that can achieved when going from a C Class to an A Class building and the thermal savings based on an office application.
According to the European Union Directive for Energy performance of Buildings, the energy performance of a building means the amount of energy actually consumed to meet a building’s different needs for heating, hot water heating, cooling, ventilation, lighting and auxiliary energy. The European Union mandated CEN (European Committee for Standardisation) has standardised calculation methods in order to improve energy savings within CEN TC247. This has been approved to BS EN 15232 – 2012 Energy Performance of Buildings – Impact of Building Automation, Controls & Building Management. The BCIA, other companies and organisations are lobbying for a greater awareness of this Standard and the benefits it can bring building users in terms of energy savings.
In BS EN 15232-2012, BACS energy performance Class A covers a building with automatic high energy performance building automation & control systems, TBM (Technical Building Management Systems) and include integrated individual room control, including demand control. Class B includes buildings with advanced building automation and control systems and TBM; Class C buildings have a standard building automation and control system only whilst Class D buildings have no energy efficient building automation and control system.
Different efficiency factors are also laid out for different types of buildings from offices, lecture halls and hotels, through to shopping centres, schools, restaurants, hospitals, industrial facilities and wholesale centres amongst others. Whilst all of these types of premises are recognised as having the potential to save energy, they are treated separately due to the way that they may be used, hours of occupancy and so on.
KNX UK fully supports the use of demand led BACS to achieve Class A energy performance. It recognises too that the monitoring and analysis of building services’ performance is essential so that operational parameters can be continuously adapted and any additional measures can be decided upon.
So why does KNX provide the optimum approach to achieving Class A energy performance? In the traditional approach to building controls, it has not been uncommon for installations to be carried out by a number of different companies with many different sets of components. With the KNX open protocol system there is no need for different standalone separate systems. Linking lighting control, façade control, ventilation systems, underfloor heating and radiator zone control and smart metering altogether on the same bus network, allows them to share information about the space being controlled and provide the most energy efficient solution.
A key factor is that the building control system should be able to evolve and change as the building’s usage also changes over time. KNX intelligent building control systems are designed to cater for the changing needs of the building and offer suitable upgrade paths and expansion capability for the future. KNX certified products are guaranteed to be completely interoperable between different manufacturers.
KNX controls are an integral part of The Crystal, a Sustainable Cities Initiative by Siemens. The building was designed to achieve top scores on the international assessments for energy-efficient buildings, including BREEAM (Building Research Establishment Environmental Assessment Method).
The Crystal uses solar power, ground source heat pumps and energy-efficient LED lighting. An indication of the energy efficiency of the building is that total electrical consumption is 1467 Mwh/year and that predicted average consumption is 212 kWh/m2/year, which highlights the fact that this building is designed to use less electrical energy and generate less CO2 than any equivalent building.
KNX intelligent building controls are used for a range of control functions as part of the Building Management System architecture. KNX sits alongside and operates seamlessly with other protocols used within the BMS system including BACnet and Modbus. This underlines the ability of KNX to be linked to other “best in class protocols” in order to maximise energy performance and help to achieve Class A building performance. It is also important to note that KNX can be linked to any manufacturer’s building control system.
KNX applications include air handling units, fans, room controls, windows and roof vents. It also provides demand controlled lighting levels within individual rooms through passive infra-red detectors as well as controlling the blinds – all though wall mounted controllers. KNX was the ideal choice for The Crystal as it allowed multiple disciplines to be easily linked, reducing the installation costs and ensuring interoperability.
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