Energy-Saving Lighting Controls For A Historic Building

See how lighting controls were added to a university administrative building originally constructed in the early 1900s.

Engineers often relish a good challenge, as problem-solving is a core aspect of their work. This holds especially true in fields like lighting and lighting controls. Projects can vary in complexity, with some having straightforward control requirements, making them relatively easy to handle. Others come with control needs and energy-saving objectives, introducing extra layers of complexity. Lastly, there are projects that encompass control requirements, energy efficiency goals, architectural features, and historical preservation considerations. These particular projects provide an opportunity for electrical engineers and lighting designers to truly demonstrate their areas’ expertise.

The challenge lies in balancing the budget, lighting requirements, and constructability while minimizing energy usage, and preserving the structure’s aesthetic and historical value. Meeting these multifaceted needs demands meticulous planning and clear communication throughout the process.

Maintaining An Historic Building While Updating Lighting Controls

The McClure Engineering team recently took on a project that encompassed all the aforementioned requirements. This involved designing a lighting control system for a university administrative building that holds iconic status and was originally constructed in the early 1900s. Within the expansive 9,000 sq. ft. space, specific lighting needs had to be addressed, with an overarching mandate to preserve the building’s historic integrity. The team had to ensure the preservation of historic fixtures, and any proposed solutions that might compromise the historical character of the structure were off the table. Furthermore, the project’s owner was determined to achieve LEED Silver certification, making energy efficiency an imperative component of our approach.

This building is divided into two wings, each featuring a central linear hallway that runs through the middle, connecting public entrances and vertical circulation points at both ends. Recent renovations to the space, driven by growth requirements, sometimes prioritized expansion over architectural coherence and the preservation of historic details. However, the renovation project the McClure team undertook had a different goal in mind. It was commissioned to promote workplace communication, collaboration, and transparency, a departure from the traditional higher-education model that emphasizes privacy, hierarchy, and isolation.

The project’s overarching objective was to devise lighting control strategies that harmonized with a day-lit open office area seamlessly transitioning into a contemporary public entry corridor. The challenge was to achieve this while ensuring a smooth blend of flexibility, user-friendliness, and scalability. As a result, the design aimed to eliminate the necessity for most control wiring.

The team implemented an IoT based luminaire level lighting control (LLC) strategy. This alone played a role in saving additional energy. Additionally, to attain the desired energy savings sought by the owner, the team implemented specific control strategies. Every fixture was fitted with a micro sensor and controller, ensuring superior performance and coverage. In contrast, many systems tend to only place a sensor near the windows for daylight harvesting, but that approach only allows for accurate sensing capabilities in that area near a given window. With the “sensor in every fixture” strategy, however, the McClure team could fine tune the space so that it remains uniform. This is true for a fixture 2’ vs 20’ from a natural lighting source, while also accommodating for areas with shadows, for example on the interior side of columns. Each sensor having the ability to accommodate the conditions within their area of coverage.

This need for a micro sensor in every fixture was challenging to coordinate. The team had to collaborate with several manufacturers in order to embed the micro sensors in fixtures that previously hadn’t been integrated with. The fixtures had to maintain UL listing with a goal such that most arrive prewired from the factory. This would make installation easier and reduce any mistakes that could occur in the field and ensure that the zoning of the control system boils down to primarily programming. Another detail was embedding additional sensors in fixtures adjacent to the historical fixtures. The McClure team still needed to control them but couldn’t incorporate a sensor.

Each micro sensor utilized not only sensed occupancy, but also natural light levels, temperature and energy usage with the ability to report back on all of the data it collected. These strategies allowed for daylight harvesting, local dimming, scene control, scheduling, and task tuning for under-cabinet, toe-kick, and cove lighting. Essentially, this design allows the occupants to automate and manually control at a much higher level of granularity than usual.

This wireless solution allowed the team to incorporate all control features while eliminating most raceways and cabling in the space via dedicated lighting control system Wi-Fi. A more traditional system would have required more drywall and plaster removal in conjunction with some surface mounted raceways. The integration was meticulously designed to be fully expandable, networked, and configured, effectively leading to a significant reduction in energy consumption and installation cleanliness.

Through strategic placement of remote power supplies and input/output devices, individual luminaire control was accomplished throughout the corridor. The design achieved a goal of showcasing various shape/size pieces of art while maintaining historic fixtures and providing additional ambient lighting uniformity. This goal wouldn’t have been attainable without the selection of a lighting solution with flexibility to integrate asymmetric, spot, and general Lambertian luminaires in one, while offering controllability of each source.

To ensure a consistent control protocol, careful manufacturer-specific coordination was maintained from schematic design through owner occupancy. This ensured that both the lighting system and control system operated seamlessly within the constraints of a conservative budget while also taking into consideration future growth and campus networking.

The significance of working with a great architect on a project like this can’t be understated. The team can’t do their best without collaboration from the entire design team. The architect partner employs a dedicated lighting designer. Having a lighting designer on the architectural team in combination with one on the engineering team allowed for continual collaboration on possibilities for integration. One of the greatest contributions from this collaboration was the implementation of a low voltage ‘Uni-strut’ format lighting solution throughout the different corridors of the building. By using this form factor, the design team could easily hide sensors and even wires for aesthetic purposes. Additionally, with this system being low voltage and hot swappable similar to that of track lighting, it allows all the flexibility to utilize spotlights, downlights, wall wash lights, or any combination thereof. This allowed the team to address the corridor’s general ambient lighting needs while simultaneously washing walls and highlighting the Chancellor’s art collection.

Maintaining the historical significance of the building was a prerequisite. The McClure team took special care to pay homage to the building’s classical architectural elements while also aligning with modern values. The integrity of the classic architecture remained uncompromised, and as mentioned above, particular attention was dedicated to how the art should be illuminated in the main corridor.

Designing a lighting control system that balances utility, meets energy-saving goals for LEED certification, and preserves the historical charm of a space can present significant challenges. It’s crucial to fully grasp the objectives of the design. Solutions do exist, but they require experienced designers to uncover and apply them.

Steve Dietiker

Published January 9, 2025 in Facility Executive

Steve Dietiker is a principal at McClure Engineering, a mechanical and electrical consulting engineering firm dedicated to the development of innovative solutions to unique engineering problems.