Buildings are rapidly evolving as developers try to maximize their benefits, user expectations change, and climate change mitigation becomes urgent. So building automation systems are being upgraded to address these issues.
Changing expectations of buildings
Why the switch to smart buildings? Large capital investments in a new build project mean that the resulting space has to “work” as hard as possible over its lifetime to maximize profitability. With the rapidly changing nature of work, play, manufacturing, logistics, retail and care, buildings must be able to adapt to new circumstances. The coworking company (coworking) WeWork has demonstrated the principle by adapting 'old' buildings in the city center to create a flexible office space. Now the pandemic has taught us, in extremis, that exhibition halls can become hospitals, gyms, in turn, vaccination centers and our homes, our workplaces.
New buildings must be designed in such a way as to ensure that their physical space can be adapted in the fastest and most cost-effective way. They have to have an infrastructure. smart building flexible that can be quickly reconfigured to deliver power, lighting, HVAC, IT services and data networks wherever they are needed, no matter how the building itself is configured.
Buildings must also be rethought to minimize your climate footprint. Some of this can be achieved through stricter building codes, innovative materials, and new approaches: for example, using wireless connectivity instead of structured cabling to save raw materials like copper. Smart building strategies can also mitigate one of the biggest climate impacts of buildings: the way they are used. For example, combining occupancy detection with room-by-room climate and lighting control can prevent office spaces from heating, cooling, or lighting when not occupied.
Smart buildings are incorporating extensive surveillance and security measures with the aim of providing protection against a wide variety of threats. These measures may include IP security cameras, presence detectors and, since the pandemic, thermal imaging equipment at entrances to identify people with a fever. are also being introduced people counting systems, enabled by infrared sensors, to be able to count how many people are in a room at the same time.
These advances in technical infrastructure can help intelligent building management systems adjust HVAC parameters based on occupancy levels. They can also provide the raw data to understand the occupancy dynamics of a building – useful, for example, for tracking customer trends in retail spaces or optimizing staff distribution in many other contexts.
The pandemic has also taught us that buildings can have a major impact on our health. HVAC systems are being upgraded so that they can monitor and enhance air quality, using sensors to detect heat and humidity, as well as check the concentration of key gases such as oxygen, nitrogen and carbon dioxide.
La lighting is another critical aspect of smart building strategies. A properly designed system can “encourage” customers to buy more in stores, allow workers to focus longer in their offices, and help people enjoy their time in social spaces. One way to deliver such functional lighting is through intelligent systems, which can be controlled remotely to offer a wide variety of effects and quickly adapt to major changes, such as the reconfiguration of different spaces in the building.
There are at least two approaches to implementing such smart lighting networks: one provides independent power to the lights and then connects them to the building management system via a mesh network. Bluetooth (mesh) and the other uses Power over Ethernet (PoE) to provide power and control data to each light.
In another example of how the choice of connectivity strategies is becoming intertwined with the operation of buildings, some developers are considering the use of smart lighting to provide data links and functional lighting.
Li-Fi, enabled by modulating lighting LEDs at frequencies high enough to carry large amounts of valuable data without causing noticeable flicker, is considered by some to be an alternative to Wi-Fi. Some reports also claim that Li-Fi is more secure than Wi-Fi in certain use cases.
Wired connectivity standards
As smart buildings are expected to integrate many different types of functionality, they often use heterogeneous connectivity strategies brought from other disciplines. Many traditional facility management systems employ hierarchical connectivity, with a primary bus linking high-level controllers to each other, and then secondary buses providing connections to lower-level controllers, I/O devices, and user interfaces.
Devices “talk” to each other over open protocols such as BACnet or LonTalk, while physical connectivity is achieved in a variety of ways, including fiber optic, Fieldbus or traditional Ethernet links, RS232 and RS485 serial connections, or low-power, low-bandwidth wireless networks.
Advanced building management systems are migrating towards the use of IP as a unifying protocol for all communications. Communication is then provided in different forms such as fiber optics for the backbone of the building, traditional Ethernet with PoE options, and wireless options including Wi-Fi, Li-Fi, Bluetooth, Zigbee, and even 5G.
An emerging connectivity option is Single-pair Ethernet (PES), a “shortcut” version of traditional Ethernet that uses a single twisted pair for data transmission and has miniaturized connectors. SPE offers a denser, faster, easier to install, and more affordable connectivity alternative to traditional Ethernet. SPE is defined in the standard amendment IEEE 802.3cg-2019 and specifies a transmission of 10 Mbit/s at distances of up to 1000 meters (10Base-T1L). Signals for that standard will need conversion to connect to 10/100/1000Base-T networks.
The SPE standard is supported by emerging cable, connector, and channel performance specifications. The new SPE connector, defined in IEC 63171-1, resembles the LC connector used for fiber optics and is also known as 'Copper LC'. It will also be possible to supply up to 50 W over SPE, although the approach used is not compatible with current PoE infrastructure. Work is also underway to define how SPE should be used in structured cabling installations, allowing it to play a larger role in smart building infrastructure in the future.
Wireless connectivity
The various building services are introducing many different protocols to enable wireless connectivity in their facilities. For example, the capabilities of Bluetooth Low Energy Mesh Network facilitate the creation of wireless networks and following the best practices among the low-cost sensors installed in an intelligent building. And Bluetooth beaconing capabilities, meanwhile, can also be used to deliver highly localized data services to building occupants.
In addition, multiple low-power wireless LAN technologies can be employed, such as Zigbee, to provide functionality improvements in the building.
As with wired connectivity, while sticking to a single standard would be desirable, in practice, smart buildings will likely need to implement multiple low-power WAN standards to support the use of a wide variety of features such as sensors, lighting, and controls. local.
A key standard when it comes to wireless connectivity in smart buildings will be IEEE802.11ax, commonly known as Wi-Fi 6. It uses the same frequencies and channel structure as previous Wi-Fi standards, but with more sophisticated modulation schemes to support higher data rates over the same amount of radio spectrum. Wi-Fi 6 employs a technique multipath called as MIMO (multiple input multiple output) multi-user to allow each access point to handle eight concurrent users, double that of Wi-Fi 5. And the techniques beam-forming will help extend the reach of each router. Support for a technique called "target wake time" will make it possible for Wi-Fi 6 routers to "warn" devices when to "wake up" and when to "go to sleep" in order to minimize their power consumption. As a side effect, having fewer devices polling the router will help reduce radio interference and increase overall throughput.
This combination of features will make it easier for smart building designers to provide high-bandwidth connectivity to transient multi-user populations in crowded locations from fewer routers. It will also make wireless connectivity a more capable option for semi-permanent infrastructure such as security cameras.
At the top of the wireless connectivity stack, in terms of capacity and complexity, is the mobile standard. 5G. It is a widely developed mobile communications standard that offers higher bandwidth and lower latency and supports more devices per unit area served than previous mobile standards. It also includes two low-energy, data-rate communications protocols that are formulated to support IoT devices. The promise in 5G is that many smart building connectivity needs could, in theory, use working equipment. under the umbrella of a single general standard.
5G deployment in buildings involves installing multiple 5G signal repeaters or a distributed antenna system that connects back to a centralized 5G base station. Users will have to decide whether they want to deploy a private 5G network or simply bring a third-party operator's network indoors. Propagation issues, especially with millimeter wave bands licensed for 5G in places like the United States, will also make it important to do proper radio planning to minimize interference between colocated wireless networks and maximize service for each user.
Conclusion
The premise of smart buildings is that, with the right communications, sensing and actuation infrastructure, they will transform from useful places to stay out of the elements into sophisticated “machines for living”. Of course, this idealized vision would be made possible by cutting-edge technology and a single heterogeneous connectivity backbone.
In reality, today's smart buildings have evolved from the not-so-smart buildings of the past, so their functionality and connectivity will be implemented with a mix of new and existing technologies. Therefore, connectivity planning in this context will have much more to do with ensuring peaceful coexistence between multiple standards than choosing the right approach to work from scratch.
This article has been published in the latest edition of the magazine AVNET “Focus”. If you have any questions about sensors for building automation, please contact our team of technical specialists from the AVNET website.
Article written by martin kenan, technical director of Avnet Abacus
