Ethernet-Based Low Voltage Lighting Drives Intelligent Buildings

1. Intelligent Buildings Concept
The intelligent building concept helps connect multiple devices, people, and processes to drive new user experiences and better business outcomes by converging multiple, disparate building networks, systems and services via a secure and intelligent network platform. Such systems help unlock new experiences and efficiencies whilst lowering building operating costs over the typical 50 year lifetime of a building.

• Transformative user experience: Different building systems, such as lighting, heating, air conditioning, IP, VoiP, as well as physical security and access control, can now easily and securely work together. They can adapt to users’ needs in real time to make spaces work better for individuals, groups, functions, and teams, e.g. heating and cooling systems can be dynamically adapted in indoor spaces based on real-time occupancy. In addition, smart systems can significantly improve the productivity, safety, and comfort of building occupants.

• Lower-cost, more efficient building and tenant services: The intelligent building lowers the cost of building systems installation, operation, and management through unified communications and centralized control of global facilities. It breaks through silos of independently operated building systems to make it easier to automate all building services.

• New business insights: Through digitisation, it now becomes possible to put sensor data into huge databases that can be analysed using neural networks and artificial intelligence to gain deeper insight into how employees, customers, and guests are using indoor spaces, allowing improved business decisions to be made about use of valuable real estate such as room, floor and building occupancy.

2. Ethernet-Based Low Voltage Lighting

Low voltage LED lighting is playing an increasingly important role within Intelligent Buildings, driven by the adoption of Category 6A Ethernet cabling to luminaires.

Low voltage lighting marks a new era and new opportunities for the cabling industry, as lighting projects involving hundreds and thousands of luminaires and sensors can only be deployed viably and reliably using wired solutions.

2.1. Why LED Lighting for Intelligent Buildings?
LED luminaires offer three compelling reasons for inclusion in the intelligent building:
1. They consume less electricity.
2. They generate less heat.
3. They are 100% dimmable.

Additional advantages of low voltage LED lighting include:
• Enhanced optical wireless networking: The recent development of optical LiFi networks, can theoretically achieve speeds of up to 226Gbps. LiFi networking also transcends many of the limitations associated with WiFi networks, such as limited bandwidth and potential carcinogenic effects.
• Long life Luminaires: LED luminaires have a long life, typically 50,000 hours and centralised LED drivers drastically reduce maintenance costs.
• Reduced Energy Consumption: The reduction in the amount of energy used for lighting can directly impact the reduction of HVAC costs. For every three watts reduced in lighting, there is a corresponding one watt reduction in HVAC load.
• Health & Safety: Low voltage, smart lighting provides significant health and safety benefits, allowing easy maintenance and office reconfiguration. Advanced emergency evacuation wayfinding uses LED luminaires to flash and change colour to aid employees to locate the nearest and safest exit route.

2.2. Creating new User Experiences via Lighting Services
With an IP backbone linking multiple building systems in a smart, connected architecture, future lighting systems will improve safety, comfort, productivity and business deliverables. New services can be offered by low voltage, digital lighting solutions, including:
• Highly personalized workspaces: Many organisations are using ‘hot-desking’ or ‘hotelling’ to create temporary reserved work spaces. Employees can customize light in their reserved spaces. A smart, connected workspace can even automatically carry over an employee’s pre-set IP phone preferences and automatically log them into collaboration tools. In shared spaces, the same digital architecture supports multiple functional working zones that can easily change to suit a new employee, team, or task.

• Human-centric, healthier lighting: Users will be able to control lighting intensity and colour temperature in every work space, alongside other factors to adapt to the needs of occupants. Circadian rhythm lighting can increase productivity up to 16 percent, aid patient recovery in hospitals and improve learning in schools.

• Getting people to destinations faster: Digital lighting solutions can be integrated with digital signage and wayfinding applications that automatically connect with employees’ and visitors’ personal devices. Employees can quickly find a drop-in workspace or locate another employee’s workspace, and customers can get directly to the department they seek. In case of emergency, the systems can direct occupants automatically and safely out of the building.

• Powering new retail experiences: In retail environments, smart lighting powered by the network can be used to:

 -  Measure store traffic patterns; better understand customer and staff behaviour and traffic flow to identify premium locations for featured products and services and optimize sales.
 - Feature special promotions, sale items and continually change them without having to make physical lighting changes.
 - Guide customers to specific items or areas with light.
 - Closely mimic natural light to show truer colours and reduce return rates.

3. Powering Intelligent Lighting Systems

The majority of intelligent lighting systems consist of a centralised LED power system that provides a DC current to luminaires or sensors installed in the ceiling. There are two ways of achieving this:
• Power over Ethernet (PoE): A standard that allows both power and control signals to be transmitted along the same RJ45 cable to an intelligent light containing an electronic LED and control interface.

• PaE solutions: A system where manufacturers provide power to LED fixtures from centralised LED driver units, which may include the ability to use sensors with RJ45 or other connection methods.

3.1. Power over Ethernet (PoE) Systems
PoE systems are commonly used today within buildings to support VoIP telephone and security CCTV systems, where devices have low power requirements. There are two reasons why PoE is not currently being deployed in lighting installations:
1. No ratified standard for high power (>25W) devices.
2. Current high power systems are hugely expensive (>£250 per luminaire point).
PoE systems have a significant cost implication as the only high power (>25W) systems available are proprietary, which limits high volume deployments.

Table 1: Comparison of PoE and PaE solutions

3.2. Power and Ethernet (PaE) solutions
A new, highly cost effective DC-based solution from Integrated System Technologies termed Power and Ethernet (PaE) offers improved benefits over standard PoE, without the cost prohibitive PoE end points (similar to LED drivers), whilst improving overall system reliability.
In contrast to PoE, the PaE digital lighting system provides Ethernet connectivity to a centralised LED driver rack unit, which then provides DC power to remote fixtures or sensors via standard PoE RJ45 Category 6A cabling infrastructures.

3.2.1. The advantages of PaE Solutions
There are significant advantages of the iDrive® Power and Ethernet solutions, including:
• Installation Phase Savings:
o Rapid setup and programming compared to traditional control systems, such as DALI. Ethernet-based systems offer 500x speed improvement for commissioning.
o Reduced commissioning costs: no need for programming engineers.
o Simple low voltage wiring required: no need for specialised electricians, as mains voltages are not prevalent in the system.
o Reduces the need for large mains distribution boards within confined riser cupboards.
o Significantly fewer issues with inrush currents and RCD trip currents compared to standard LED driver solutions.
o Category 6A cabling infrastructure reduces installation costs up to 20% for Ethernet-based connected lighting systems, compared with conventional AC-powered systems.
o Enables project timetables to be accelerated: secondary works can be undertaken during lighting installation as low voltage safe.
• Maintenance Phase Savings:
o Centralised iDrive® LED drivers are easy to access, reducing the need for high level maintenance work.
o Reduces downtime and out of hours labour costs: LED drivers are easy to access, without disrupting retail spaces, school, hospital and commercial buildings.
o Less client disruption results in improved customer satisfaction.
o Very easy to change lighting configuration, as systems are DC-based with simple RJ45 plug-and-play connections.
o Simple to add, remove or replace fixtures/drivers as recommissioning is very simple, without the need for expensive engineers.

A simple way of comparing traditional high voltage DALI-enabled lighting and low voltage PaE installations is shown in Figures 1a and 1b, which clearly demonstrate how low voltage DC PaE systems reduce the amount of wiring and complexity for installations.

Figure 1(a) Traditional installation Figure     1(b) Power and Ethernet installation

In order to operate PoE++ systems, it is advised buildings are future-proofed and equipped with Category 6A cabling, as this enables easily up to 100W of power whist reducing cable power losses through 24AWG cores.
• Optimization of business operations
PaE systems and digital lighting creates business value beyond pure lighting by utilising built-in sensors and harnessing big data analytics to drive better business outcomes:
• Improved building use: With in-depth analytics it is possible to gain visibility into use of spaces to better manage, plan, and optimize a building’s use.
• Improved physical security: Lighting powered by the network can use sensor-activated closed-circuit television (CCTV) and access controls to secure sensitive areas, or in a retail environment to reduce theft.

With the current ability of standard Ethernet solutions, PaE systems allow scalable lighting systems to many tens of thousands of devices, making them uniquely positioned compared to RF based solutions, which are limited to hundreds of devices at most.

4. Low Voltage Lighting: low cost installation and more flexibility
The overall capital expenditure, installation and commissioning costs for a variety of LED technology solutions and installation methods are shown in Figure 2, which compares five solutions, including centralised Power over Ethernet (PoE); decentralised zonal PoE; centralised PaE with intelligent control platform; PaE system controlled by an existing in-house BMS, plus a traditional high voltage LED solution.

Figure 2: Comparison of relative costs of LED lighting solutions

As expected, PoE solutions are twice as expensive as traditional high voltage LED solutions, even when the reduction in cabling costs is taken into consideration.  In comparison, the PaE solution including the intelligent control system offers a significant benefit over traditional high voltage LED solutions and reduces costs by 65% compared to PoE based solutions. 

Figure 3: iDrive® Intelligent Lighting Platform

5. Conclusions
Through Integrated System Technologies’ iDrive® Power and Ethernet (PaE) lighting solution, the structured cabling industry has a significant opportunity to deploy large scale intelligent lighting solutions using category 6A cabling and LED light fixtures at a project pricing level substantially less than tradition high voltage electrical works.

The iDrive® PaE solution utilises exactly the same infrastructure as traditional PoE solutions, but improves maintenance aspects whilst offering clients a future-proofed building infrastructure fit for the next 25 years. It is anticipated the amount of additional cabling points required for lighting and related sensors will create a renascence over the next decade for the cabling industry.