7 minute read
How To Get What You Want in a Lighting Control System
Surprisingly, it is not by knowing the part numbers of all the widgets…
By Andrew Parker, P.Eng., LC, Salex Inc
START WITH THE OWNER’S PROJECT REQUIREMENTS
Lighting control system design begins with understanding the owner and the end-user. What does the owner want the lighting controls to do, and what requirements and limitations exist regulating their implementation in the design?
For the end-user, lighting controls should be unobtrusive – think smooth dimming over abrupt switching – and they should be able to be overridden when necessary with conveniently located and intuitive interfaces. All controls should be maintainable by the facility staff, who should be trained on the equipment.
At the outset, owner requirements should be defined by creating a design document called the Owner’s Project Requirements (OPR). The OPR will include the purpose of each facility and/or space, their operating schedules, applicable project codes and standards, integration needs, project goals (such as energy efficiency targets), and any preferred vendors. The OPR will often evolve throughout a project and become more detailed. At times, the OPR may not even exist, so the designer will be responsible for identifying the owner’s requirements through their knowledge of the project intent.
In a guest post for the Lighting Controls Association,(1) C. Webster Marsh offered the following list of questions to aid in developing the OPR:
• What is the vision for the project? What does the owner need and want for the project?
• Who are the users of each space, and how will they use these spaces?
• How will the spaces be lighted, including daylighting?
• What are the opportunities, requirements, and expectations for lighting control on the project, including integration with other building systems?
• What external requirements such as codes, standards, and regulations must be followed? Will there be elevated goals, such as LEED or WELL?
• What limitations impose boundaries for the controls design, such as budget?
WHAT ABOUT THE END-USER?
Best practice encourages the designer to interview people who will ultimately use the lighting – the end-users. End-user acceptance is critical for the ongoing viability of a lighting control system, particularly if it includes automated controls. Lighting controls that fail to satisfy user expectations may be regarded as intrusive or frustrating, leading occupants to possibly override the controls and negate the intent of the design. Unfortunately, as with the OPR, if contact with end-users is not possible, it will be up to the designer to assume the role on their behalf.
Principles to follow include:
• The lighting control system should make sense to the users.
• Lighting should be zoned in a way that is easily understood by the users.
• Lighting controls that turn off the lighting should be easy to override, typically via manual controls near the entrances.
• Automatic control effects should be slow, recognizable, and non-intrusive.
• Lighting with specific intent should be easy to adjust.
TRANSLATING USER EXPECTATIONS INTO A NARRATIVE
The following is an example of feedback from an end-user: “The cleaning staff changes from week to week and has trouble operating the lighting. They complain that they sometimes work in the dark because they can’t find the light switch. Other times, we find the lights have been left on all night. Can you make this simpler for the cleaners so they can get their job done and save energy? They say their work takes about an hour and a half.”
The feedback from the end-user gets translated into a narrative: When cleaning staff are in the space after business hours, a master override button at the entrance will be provided that is clearly marked “Cleaning”. This button will turn on the lights to 80% of normal brightness. Occupancy sensors or timer will ensure the lighting is turned off after cleaning is completed. Set timeout to at least 2 hours or to the maximum allowed by energy code.
CONTROL INTENT NARRATIVE
Now that we have our direction from the owner and the end-users, it is time to put together a comprehensive written description, summarizing this information. This document is called the Control Intent Narrative (CIN) and should focus on the interaction of the end-users and the desired outcomes, rather than a list of components or part numbers. Writing in non-technical language allows the owner to easily understand, approve, and visualize the operation and maintenance requirements of the lighting control system.
The CIN should describe the functionality of the lighting system for each different area, specifying how the lighting responds to user interaction (e.g. button presses or “overrides”), occupancy, time of day, and natural light levels. As a timesaving measure, designers may develop boilerplate CINs for various space types which can then be customized for future projects.
By clearly communicating the design intent, the control intent narrative serves as a blueprint for architects, engineers, installers and facility managers, ensuring that the control system is specified, sourced, installed and performs as intended to meet the desired goals. The control intent narrative informs all other documentation, going beyond what drawings can communicate, and provides a common guide and reference for the project. As a living document, the narrative may also be revised and improved during the project.
HOW TO DOCUMENT THE CONTROL INTENT NARRATIVE
The Illuminating Engineering Society outlines four major elements of a CIN in ANSI/IES LP-16-22, Lighting Practice: Documenting Control Intent Narratives and Sequences of Operations:(2)
• General description of the project goals
• Control strategies to satisfy these goals
• Description of the control system
• A basic sequence of operation for each typical space type
SEQUENCE OF OPERATION
After the control intent narrative is completed, the next step involves translating the general description into actionable steps that guide the specification, procurement, installation and commissioning of the lighting control system. This document is called the Sequence of Operation (SOO) and is typically undertaken by the engineer.
The process begins by breaking down the narrative into distinct control strategies for each unique area, detailing how and when each control action should occur. The descriptive language of the CIN is converted into specific set points, clear parameters and contractually enforceable language that are in alignment with the local building or energy codes. They include actionable steps that give definition to the specification of lighting control system and how each component should be programmed to function as intended in the project’s real-world scenarios.
Once the physical installation is complete, the system undergoes programming and commissioning, where each device is configured and tested. The CIN and SOO are critical documents at this stage to ensure the intent is met with the necessary settings.
Finally, training is provided to facility managers and end-users to ensure they understand what the system was designed to do and how to effectively operate and maintain it. This comprehensive approach ensures that the lighting system performs as intended and can be adjusted as needed for optimal performance and energy efficiency.
HOW THE LIGHTING CONTROLS SALES REP CAN HELP
The lighting controls sales representative can play a vital role in ensuring that the control intent narrative is accurately followed throughout the project lifecycle. The rep’s experience with user feedback in multiple scenarios, and expertise in relating the desired functionality to adequate solutions, can guide the specification from the beginning of the CIN process. The rep can serve in the translation to the more technical language of the SOO, ensuring that the scope is complete and accurate.
The next obvious step is for the rep to recommend products or systems to serve as the basis of design to align with the project’s documented goals. The rep may also recommend additional technical services to support a successful implementation, such as installer or end-user training, remote support and post-occupancy service.
By bridging lines of communication and providing ongoing support, the lighting controls sales rep ensures that the narrative's specifications are met, leading to a successful and efficient lighting system. Exactly what you wanted.
1.) March, C. Webster. “C. Webster Marsh Talks Owner Project Requirements” (25 January 2023). Lighting Controls Association. https://lightingcontrolsassociation. org/2023/01/25/c-webster-marsh-talks-owner-project-requirements/
2.) Illuminating Engineering Society. ANSI/IES LP-16-22, Lighting Practice: Documenting Control Intent Narratives and Sequences of Operations. New York: IES; 2022.
Photography Interior Design: iN Studio, Manufacturers: Artemide, Luminii, Senso
