Mechanical Construction - strength, metal gage, thickness of lens, alignment, and rigidity. Aesthetics - appearance, appropriateness, scale, finish. Efficacy and Luminaire Efficiency. Reliability of Manufacturer - backing up the product and reliable delivery of product. Luminaires must be periodically maintained to keep them at peak performance.
Maintenance includes changing lamps and cleaning the surfaces that collect dirt.
To facilitate lamp changing, the luminaire should be constructed so that maintenance personnel can easily and rapidly reach the lamps. A latch and hinge arrangement is best because it avoids handling of the lens. The construction of the luminaire should be examined in terms of its rigidity, strength, and durability. These factors will determine the long-term usefulness of the luminaires. The design of the luminaire will affect the infiltration and movement of dirt inside the luminaire, which results in dirt accumulation and light loss.