CLD Sustainability 2

Question 1

Which lighting control strategy saves the most energy by reducing output when daylight is available?

Accepted Answer

Daylight harvesting (daylight dimming)

Answer

Daylight harvesting automatically dims or switches off electric lighting in response to available natural light, directly offsetting electric energy use.

Question 2

A lighting designer specifies luminaires with a Unified Glare Rating (UGR) below 19. What sustainability co-benefit does this primarily provide?

Accepted Answer

Improved occupant visual comfort and productivity

Answer

Low UGR reduces glare-induced visual discomfort, supporting occupant well-being and productivity, a key human-centric sustainability outcome.

Question 3

Under LEED v4.1, which credit category specifically addresses light pollution reduction through exterior lighting control?

Accepted Answer

Sustainable Sites – Light Pollution Reduction

Answer

LEED v4.1 Sustainable Sites credit 'Light Pollution Reduction' requires shielding and limiting uplight and trespass from exterior luminaires.

Question 4

A project targets net-zero energy. What is the correct order of the energy hierarchy a designer should follow?

Accepted Answer

Reduce, optimize, generate

Answer

Best practice is to first reduce demand through efficiency, then optimize controls and systems, and finally generate on-site renewable energy to offset remaining loads.

Question 5

Which metric best quantifies the visual efficacy of a luminaire for a sustainable design comparison?

Accepted Answer

Luminous efficacy (lm/W)

Answer

Luminous efficacy (lm/W) measures how efficiently a luminaire converts electrical power to visible light, making it the primary metric for sustainable comparisons.

(CLD) Certified Lighting Designer Practice Test

(CLD) Certified Lighting Designer Practice Test

CLD Sustainability 2