The lighting system in major engineering projects —whether residential complexes, factories, warehouses, or commercial centers— is one of the most vital systems and has an impact on the success of the project. Despite significant technological advancements in this field, the design and implementation phases often witness serious errors that lead to significant financial and operational losses in the long term.

In this article, we discuss the top 5 common mistakes when designing lighting systems in large projects and how to avoid them with a scientific and engineering perspective.

1. Selecting an inappropriate ability (Over or Under Specifying)

Some people mistakenly believe that choosing spotlights with a higher wattage (Watt) always means better lighting, or vice versa; randomly reducing wattage to save money. Both represent a catastrophic design error:

• Overcapacity (Over-lighting): It causes huge waste of electrical energy, high temperatures inside the building, as well as inconvenience to users as a result of the phenomenon of visual flare (Glare).
• Poor power (Under-lighting): This leads to not achieving the required lighting intensity (Lux) specified in the engineering codes, which negatively affects operational safety and worker productivity.
• Alternative solution: Rely on calculating the actual luminous flux in Lumens and not in Watt, as what matters is the efficiency of the detector in converting energy into light (\text{Lumen/Watt}).

2. Poor distribution of lighting units (Poor Light Distribution)

Even if spotlights from the highest international brands are selected, their random or ergonomically thought-out distribution within the space spoils the entire system.

• Resulting problems: the appearance of “dark spots” (Dark Spots) in workspaces, sharply varying lighting levels, or focusing light in underutilized areas and ignoring areas of movement of machinery and pedestrians.
• Absence of homogeneity (Uniformity): Light heterogeneity causes eye strain in workers because the pupil has to expand and contract repeatedly while moving within the space.
• Alternative solution: Rely entirely on 3D simulation software such as Dialux before purchase and implementation, to ensure that optical angles (Beam Angles) are distributed covering the entire area in complete homogeneity.

3.Ignore maintenance and access factors (Neglecting Maintenance Factors)

Large projects last for many years, and neglecting to develop a maintenance plan during the design phase is a trap that many companies fall into.

• Difficulty of access: Installing spotlights in high ceilings (such as the High Bay in warehouses) without studying how to access them to replace or clean them raises subsequent maintenance costs insanely.
• Ignore the light loss factor (LLF): Headlights lose some of their light intensity over time due to component aging and dust buildup. Failure to accurately include the $Light\Loss\Factor$ coefficient in preliminary engineering calculations makes lighting appear very weak after a year or two of operation.

4. Failure to observe the protection factor (Ignoring IP Rating)

Each working environment has its own climatic conditions, and an error in choosing the appropriate protection factor ($IP\Rating) threatens to damage the entire system or cause electrical disasters.

• In outdoor and landscape environments: Installing spotlights with a low protection factor (IP20 or IP44, for example) in areas exposed to rain, garden washing, or heavy dust immediately leads to the burning of the spotlights and the risk of electrical short circuits.
• In factories and warehouses: Environments containing fumes, high humidity, or chemical dust require completely insulated searchlights (such as IP65 or IP66). Always remember:

o The first number in the IP indicates the degree of protection against solid objects and dust (from 0 to 6).

o The second number indicates the degree of protection against liquids and moisture (from 0 to 9).

5. Neglecting operating efficiency and intelligent control systems

Equipping a large project with 100% manual lighting without any smart solutions represents a constant financial waste for the facility.

• Continuous operation without need: Keeping the lighting of warehouse corridors, parking lots, or compound gardens operating at its highest power throughout the night —even in the absence of movement— drains the lifespan of the spotlights and raises the electricity bill.

Alternative solution: Incorporating intelligent control systems including motion sensors (Motion Sensors), daylight sensors (Daylight Harvesting), and astronomical timers (Astronomical Timers). These systems ensure that lighting intensity is reduced (Dimming) or automatically disconnected when not needed, which increases operating efficiency and achieves a rapid return on investment (ROI).