Designing for Uptime: Data Center Critical Lighting Factors

By Kris Gjini, Enterprise Solutions Architect, Cooper Lighting Solutions

The Unseen Backbone of the Digital Economy

Data centers are the unseen backbone of our modern lives. Every email, video stream, online transaction, and cloud-based tool relies on their continuous operation. These facilities are engineered with a relentless focus on uptime and performance. Yet in the race to optimize servers, cooling systems, and power infrastructure, lighting can easily slip into the background.

For specifiers, that oversight carries real costs. Lighting design directly influences reliability, worker safety, and the ability to maintain systems over time. Getting it right means more than checking boxes for compliance — it’s about creating an environment that supports both operational demands and the people who keep data centers running.

Below are five critical considerations specifiers should weigh when approaching data center projects:

High-Temperature Rated Fixtures

Unlike typical commercial spaces, data centers are defined by their hot/cold aisle configurations. While servers drive most of the thermal load, lighting must be designed to survive in these conditions. Fixtures installed in hot aisles may face continuous temperatures approaching 50°C.

Specifiers should prioritize products tested and rated for high ambient conditions, ensuring long-term reliability without premature failures. Beyond simple line items on a cut sheet, temperature ratings are fundamental to sustaining system performance in the harshest zones of the data center.

Balanced Horizontal and Vertical Illumination

Data center lighting involves much more than horizontal footcandles on the work plan. Maintenance staff also need clear, shadow-free visibility on the vertical faces of server racks, where the work actually happens.

Linear LED solutions with specialized optics are often the best fit for delivering both horizontal and vertical illumination. Careful photometric layouts are essential, particularly in hot/cold aisle environments where fixture placement can dramatically affect performance. Specifiers should design with vertical light levels in mind from the outset rather than treating them as an afterthought.

Reliable and Simple Controls Strategy

Because staff enter server halls only intermittently, large portions of a data center often sit vacant. This makes lighting controls an obvious opportunity for energy savings, but simplicity and reliability must guide the design.

Occupancy-based or scheduled controls can reduce energy use significantly while ensuring lights turn on instantly when needed. Complex control schemes may look impressive on paper, but in mission-critical environments, ease of use and predictable performance often outweigh advanced features. The operations team must be able to maintain the system without disruption, so specifiers should aim for straightforward, durable solutions.

Emergency and Redundancy Lighting

When power interruptions occur, safe egress is non-negotiable. In data centers, where downtime has major financial and operational implications, emergency lighting must go beyond code minimums.

Specifiers should consider centralized lighting inverters or distributed battery packs with self-diagnostic capabilities. These solutions simplify monthly and annual testing, reducing the operational burden on staff while ensuring compliance with life safety requirements. The design goal is straightforward: create a system that is reliable, resilient, and easy to maintain in mission-critical environments.

Beyond the White Space: Human and Sitewide Needs

While the server halls may define a data center, they’re not the only areas that matter. Offices, receiving zones, and break areas are also part of these facilities—and they benefit from the same human-centered lighting design considerations as any other workplace. Low-glare fixtures and comfortable light levels in these spaces can improve staff well-being and may even contribute to LEED points.

Outside the facility, security is paramount. Large-scale data centers often require stringent exterior lighting levels to protect critical assets and personnel. Precision optics allow designers to meet high footcandle requirements while minimizing light trespass into neighboring properties. Exterior and interior lighting should be considered as part of one integrated design strategy, reinforcing safety and security at every level.

Lighting as a Critical Design Partner

The design of mission-critical data centers is a complex puzzle, with cooling, redundancy, and resilience often commanding the spotlight. But lighting has an equally critical role to play in ensuring these facilities operate safely, efficiently, and sustainably.

For specifiers, that means looking beyond basic code compliance and approaching each project with a checklist:

• Are fixtures rated for the environment?
• Do layouts deliver vertical as well as horizontal illumination?
• Will controls be reliable and easy to maintain?
• Is emergency lighting resilient and simple to test?
• Have human and sitewide needs been considered?

Answering these questions not only supports uptime but also delivers long-term value to owners and operators. In the end, thoughtful lighting design is not a background detail—it’s a foundational element of mission-critical success.

About the Author

Kris Gjini, Enterprise Solutions Architect at Cooper Lighting Solutions, leverages nearly two decades of industry experience to help shape reliable, efficient, and innovative lighting strategies for mission-critical facilities, including data centers.