Luminaire Selection Flashcards

A luminaire specification calls for an 'L70' rating of 50,000 hours. What does L70 describe?

Answer: The luminaire retains 70% of its initial lumens at 50,000 hours

L70 is the lumen maintenance rating indicating the point at which the LED light source retains 70% of its initial lumen output.

For a corridor emergency egress path, which IES luminaire classification best describes a luminaire directing light primarily downward at low angles along a pathway?

Answer: Type II

Type II distribution provides a lateral spread suited for corridors and walkways, directing light ahead along a path from a side-mounted position.

A designer selects a luminaire with a Unified Glare Rating (UGR) of 19 for an open office. What does this value indicate?

Answer: The luminaire meets the typical UGR <19 office glare limit

UGR <19 is the standard threshold for office spaces per EN 12464-1, and a UGR value of exactly 19 sits at the acceptable boundary for typical office tasks.

Which luminaire mounting configuration would a CLD specify to minimize veiling reflections on computer screens in an open office?

Answer: Indirect or direct/indirect pendants directing light toward the ceiling

Indirect and direct/indirect pendants bounce light off the ceiling, creating a diffuse luminous environment that minimizes specular reflections on monitor screens.

A theatrical performance space requires luminaires capable of tight beam control, color mixing, and remote dimming. Which category best fits this application?

Answer: Entertainment/theatrical ellipsoidal luminaires

Ellipsoidal luminaires (also called Leko or Source Four fixtures) provide precise beam shaping, gobo projection, and are designed for theatrical color and dimming control.

For a healthcare patient room, which color temperature range is recommended to support circadian rhythm and patient well-being during daytime hours?

Answer: 3500K–4000K tunable to 2700K for evening

Tunable white systems providing cooler 3500K–4000K during the day support alertness and circadian rhythms, while dimming to 2700K in the evening promotes sleep.

A specification requires luminaires with a minimum efficacy of 100 lumens per watt. Which technology is most likely to achieve this threshold?

Answer: LED with high-efficiency driver

Modern LED luminaires routinely achieve 100–200+ lm/W efficacy, far exceeding fluorescent, halogen, and most HID technologies at the luminaire level.