A Guide to Lighting Control Strategies

Understanding various lighting control strategies is crucial for effective energy management and optimal functionality in commercial and industrial buildings. Implementing these strategies can lead to significant energy savings, reduced operational costs, and improved user comfort.

Two types of lighting controls we’ll discuss include networked lighting controls (NLC) and luminaire-level lighting controls (LLLC). NLC systems have bi-directional communication between sensors, network interfaces, and controllers that enable lighting changes in luminaires, retrofit kits, or lamps. LLLC is a subset of NLC, with sensing for occupancy and daylight on every networked luminaire.  

Using this technology to implement lighting control strategies plays a vital role in minimizing energy waste and enhancing building sustainability. By integrating advanced lighting controls strategies such as daylight harvesting, dimming, and occupancy sensing, individuals and businesses can achieve significant energy and cost savings. 

Understanding Lighting Controls Best Practices 

Dimming

Dimming is a control strategy used to adjust the light output of electric light sources. This technique not only enhances the ambiance of a space but also significantly contributes to sustainability  in lighting design. By implementing dimming controls, users can reduce energy consumption and lower operational costs while maintaining the desired lighting effects for various applications. 

According to a study by the Lighting Research Center, “dimming is a crucial feature for both residential and commercial lighting systems, allowing for energy savings and desired lighting effects depending on the application.”

Benefits of Dimming Controls

• Energy Savings: Dimming controls reduce energy consumption by adjusting light output to match the required level. By lowering the light intensity when full brightness is unnecessary, significant energy savings can be achieved. 

• Ambiance and Mood: Dimming controls can create different moods and atmospheres by varying light intensity. Whether it’s a cozy, dimmed setting for a relaxed evening or a bright, vibrant environment for work, dimming allows for versatile lighting customization. 

Types of Dimmable Lighting Technologies

• Line Voltage Dimming: For traditional electric light sources, like incandescent and halogen, dimming is achieved by reducing the voltage of the electricity powering the light fixture. In this scenario, the only wires between the dimming device and the light fixture are the two, and sometimes three, wires that deliver power. 

• 0-10v Analog Dimming: Most LED and fluorescent light sources utilize 0-10v analog dimming. With this technology, a pair of low voltage wires is run from the dimmer to the light fixture, in addition to the line voltage wires delivering power. 

• Digital Dimming Systems: Some advanced lighting control technologies, such as DALI-2, combine the dimming signal and the control network, allowing the system to achieve both accurate, reliable dimming performance and extract lifetime and maintenance data from each fixture. 

Luckily, dimming is also the easiest strategy to implement: over 99% of the fixtures on the DLC’s SSL (LED) Qualified Products List (QPL) are capable of dimming, and every Networked Lighting Control (NLC) system on the NLC QPL supports dimming. 

High-End Trim or Task Tuning

High-end trim, also known as task tuning, is a lighting control strategy that involves setting maximum light levels to optimize energy use without sacrificing necessary lighting quality. With this strategy, the everyday user is able to dim the lighting from 0-100% but the User’s 100% actually corresponds to 70% or 80% of the maximum potential light output. This process ensures that spaces are not over lit, which can lead to unnecessary energy consumption and higher operational costs.  

High-end trim/task tuning is applied across various settings to enhance both energy efficiency and lighting quality: 

• Commercial Buildings: Office spaces benefit from task tuning by ensuring workstations are adequately lit without excessive brightness, promoting productivity and comfort. 

• Retail Spaces: Retail environments use high-end trim to highlight products effectively without wasting energy on over lighting. 

• Hospitality Environments: Hotels and restaurants use task tuning to create inviting atmospheres while managing energy consumption. 

• Healthcare Facilities: In hospitals and clinics, appropriate lighting levels are critical for both patient care and energy efficiency. 

• Educational Institutions: Schools and universities implement task tuning to provide optimal lighting for learning activities and reduce energy costs. 

High-End Trim is implemented as a feature of a lighting control system and is a required capability for listing on the DLC’s NLC QPL. Facility managers and energy efficiency program administrators can see if a system is listed to verify capabilities.

Occupancy Sensing and Vacancy Sensing 

Occupancy sensing is a lighting control strategy that automatically manages lighting based on room occupancy. This approach ensures that lights are only active when spaces are occupied, optimizing energy use and enhancing user convenience. 

Occupancy sensors are set up in one of two ways depending on the space type and energy code requirements: 

• Auto On/Auto Off: Commonly known as Occupancy Sensing, in this mode when a sensor detects motion the lights activate automatically and remain on for a set period of time after last detecting motion. 

• Manual On/Auto Off: Commonly known as Vacancy Sensing, in this mode the user is required to push a button to activate the lights in a space. From there, the lights remain on for a set period of time after last detecting motion. 

Occupancy sensors function by detecting motion or the presence of occupants using various technologies such as passive infrared, ultrasonic, or dual technology. These sensors trigger lighting adjustments when movement or presence is detected, providing immediate and automated lighting control. 

Some of the primary detection methods include: 

• Passive Infrared Sensors (PIR): Detect movement of heat signatures from occupants, making them effective in spaces with clear lines of sight. 

• Ultrasonic Sensors: Use sound waves to detect movement, allowing them to sense motion around obstacles. 

• Dual Technology Sensors: Combine infrared and ultrasonic technologies to increase accuracy and reduce false triggers. 

Additional types of detection include: 

• Microwave: emit extremely low power electromagnetic energy to detect changes in pattern of reflections in a space which registers as occupancy. These do not require line of sight, so adjusting sensitivity is critical to ensure false activation.  

• Milimeter Wave: also emits very low power electromagnetic energy but is able to detect both movement and accelleration, and even multiple people in a space. 

• Camera: utilize captured images (high or low resolution) and image processing software to determine human proximity in the space. Benefits of Occupancy Sensing 

• Energy Efficiency: Occupancy sensing significantly reduces energy waste by ensuring lights are only active when needed. This leads to considerable energy savings, especially in spaces with variable occupancy patterns. 

• Reduced Maintenance Cost: By reducing unnecessary operating hours, occupancy sensing can extend the lifespan of lighting fixtures, leading to lower maintenance costs. 

According to the DLC’s lighting contols best practices document, “Implementation of occupancy/vacancy sensing is largely driven by the various energy codes that apply to most projects. Both the ASHRAE 90.1 and IECC codes specify occupancy or vacancy sensing by space type, and many versions call for a maximum timeout length of 20 minutes. In some space types, such as restrooms and stairwells, timeout lengths longer than 20 minutes can greatly reduce energy savings.” 

Daylight Harvesting

Daylight harvesting is a lighting control strategy that responds to available natural light in indoor spaces to reduce reliance on electric lighting. By leveraging the natural light available, daylight harvesting systems help create energy-efficient and sustainable lighting environments. 

Benefits of Daylight Harvesting

• Energy Savings: Daylight harvesting reduces energy consumption by dimming electric lighting during periods when sufficient natural light is available. This leads to lower utility costs as artificial lighting is minimized during periods of sufficient daylight. 

• Sustainability: Implementing daylight harvesting promotes environmental sustainability by reducing carbon emissions and supporting green building practices. It decreases the need for electric lighting, thus conserving energy and contributing to a healthier planet. 

Daylight Harvesting System Functionality 

Daylight harvesting systems utilize sensors to measure natural light levels and adjust electric lighting accordingly. These systems ensure that indoor spaces are adequately lit while minimizing the use of electric lighting when natural light is available. 

According to a study by Western Michigan University, “Daylight harvesting using continuous dimming equipment automatically controlled by a photo sensor can generate 30 percent to 40 percent savings in lighting energy consumption, significantly reducing operating costs for the owner.” 

Scheduling

Scheduling is a lighting control strategy that involves turning lights on or off at predetermined times. This approach ensures that lighting is provided precisely when needed and turned off during unoccupied periods, optimizing energy usage and improving efficiency. 

Benefits of Scheduling

• Energy Conservation: Scheduling reduces energy consumption by ensuring lights are only on when needed. By programming lighting systems to align with occupancy patterns, significant energy savings can be achieved. This is particularly beneficial in commercial settings where lights may otherwise remain on after hours or during periods of low activity. 

• Consistency and Reliability: Scheduling provides consistent lighting patterns, enhancing both security and convenience. Consistent lighting schedules can deter unauthorized access and ensure that areas are well-lit during operational hours. This reliability is crucial for environments like offices, schools, and public spaces, where predictable lighting patterns support daily activities and safety. 

Implementation of Scheduling Controls

• Time Clocks: Individual Time Clocks allow users to set schedules to control individual lighting circuits. Most time clocks are relay-based devices that are only capable of turning lighting on or off, and cannot dim. The inability to dim precludes combining time clock-based scheduling with other lighting control strategies such as high-end trim or daylight harvesting. 

• Networked Lighting Control Systems: NLC systems allow adjustment of lighting based on pre-set schedules. These systems provide a more advanced and flexible solution, allowing for precise control over lighting schedules. Some systems can be integrated with other building management systems for comprehensive energy management and optimization. Scheduling is a reported capability on the DLC’s NLC QPL. Make sure to see if your system is listed to verify capabilities. 

Luminaire Level Lighting Controls (LLLC)

Luminaire Level Lighting Control (LLLC) systems represent a significant advancement in lighting technology, enhancing traditional controls by integrating networked sensors and controllers into lighting fixtures. Integrating sensors and controllers into every fixture allows for faster and easier lighting and controls upgrades in existing buildings. These systems are extremely flexible and may allow for both distributed and centralized management and even real-time control over lighting operations across facilities. 

Key Advancements in LLLC systems include: 

• Wired or Wireless Networking: LLLC systems can utilize wired or wireless networking, or a combination of the two. Wired networks may be more appropriate for new construction projects where wires can be installed before the ceiling and walls are closed. For existing buildings, wireless systems can usually be installed without running new wires, making them ideal for lighting retrofit projects. 

• Simplified Installation: With wireless systems not requiring new control wires, installation in existing buildings can be as easy as removing the old fixture and directly replacing it with a new LLLC fixture. 

• Centralized or Decentralized Networks: Some LLLC systems require a central server that provides a single interface with the system, collects and stores system data such as energy monitoring, and supports integration with Building Management Systems. Other LLLC systems utilize a decentralized network architecture that can lower upfront system costs. When selecting a system, be sure to check the NLC QPL for unbiased data on each system’s parameters and capabilities.  

By implementing Luminaire Level Lighting Controls, organizations can achieve significant energy savings, enhance operational efficiency, and improve lighting quality across commercial, and industrial settings. 

Training and Resources

Still want to learn more? Various training options exist for those interested in networked lighting controls: 

• NEMA Academy: Offers over 67 hours of online courses covering topics like technology, design, and commissioning. Courses are recognized for continuing education credits. 

• Certified Lighting Controls Professional: The International Association of Lighting Management Companies (NALMCO) offers a certification test, based on the NEMA Academy curriculum designed by the lighting controls industry. 

• Short Videos: Available on topics like common misconceptions, non-energy benefits, system configuration, and cybersecurity of networked lighting controls. 

These resources cater to contractors, designers, engineers, and building managers looking to enhance their knowledge and skills in lighting control technologies. Don’t hesitate to reach out to the DLC with specific questions on the SSL/LED or NLC QPLs. We can be reached at info@designlights.org.