Network Communications News (NCN) August 2016 - Page 31

intelligent buildings S P E C I A L F E AT U R E any building to choose and implement an appropriate tried and tested BEMS strategy, helping reduce its carbon footprint, provide improved working environments as well as one that will work into the future easily reflecting changes and variations in the buildings usage. This means that services such as HVAC and lighting are only used when required. Parameters for ensuring a steady temperature can be programmed into the BEMS to ensure the building stays within certain performance parameters. But ultimately, the building operates for and in response to the requirements of occupants. Data needs Carlo Gavazzi’s Dupline 2-wire bus system simplifies field level wiring. However, controls technology is changing and extending the possibilities of what can be achieved. The technology also means that the building occupant can be the focus of the BEMS, which can save energy while also providing better comfort levels established on a demand control based system. Control solutions Fortunately the market continues to develop innovative and energy saving control solutions which provide greater visibility and performance tracking. This makes it easier for occupants of As buildings and building services equipment become more advanced, the functionality is also becoming more complex. The demand for detailed information on building performance means that collecting and delivering that data is crucial – and relies on the communications networks of the BEMS, which in turn rely on good quality wiring. It may not be something that building managers consider too closely, but smart wiring systems can make all the difference in terms of capital cost and long term efficiency. Communications networks are used extensively in building management systems at the automation and management levels. These are often known as the primary levels of a BEMS network. Devices further down the network, at the device level, such as sensors, and I/O modules including indicators and actuators, would traditionally require separate wiring runs to link them to primary level. This means that if a project plan includes a high number of these devices spread over a wide area, then the wiring costs using the traditional approach can be high. This may result in a compromise to the design of the system, with field devices omitted because it is considered too costly to include them. And so the BEMS cannot offer the functionality that the designer has in mind. Smart wiring Crucially, building managers should think about smart wiring systems, more importance on this could make all the difference in terms of capital cost and long term efficiency. However, the very latest wiring technologies and techniques overcome this problem. For example, a 2-wire bus system can link field devices together, without the requirement to connect each separate sensor or actuator back to the primary level of the building management system. Essentially, this creates decentralised sensors and I/O modules, giving much greater flexibility on the distribution of devices without the costs of extra wiring. There are also sensors for CO2, temperature and humidity that can now be powered from the bus. This further reduces the need for wiring to power the devices. Also, a 2-wire bus cable can be run from sensor to sensor, collecting all the measured values. Each sensor does not have to be individually wired back to the main controller. Forward thinking manufacturers are leading the way on creating more potential for a single-system approach. For example, Carlo Gavazzi now offers a DALI gateway from its Dupline wiring system, making it possible to integrate HVAC with lighting applications. The current industry approach to contracting means that lighting is specified as ‘electrical’ and HVAC as ‘mechanical’. This creates a false message that the two have to be controlled separately – an expensive and unnecessary approach. By putting the ‘system’ firmly at the heart of building management, designers and installers will deliver all-round better buildings. The market continues to develop innovative and energy saving control solutions. 31 30-31 Intelligent Buildings – Carlo Gavazzi.indd 31 02/08/2016 12:11