CLD Sustainable & Energy-Efficient Lighting Solutions 3

Question 1

Under LEED v4.1, which credit category directly rewards reductions in exterior lighting power and control of uplight?

Accepted Answer

Sustainable Sites: Light Pollution Reduction

Answer

LEED v4.1 Sustainable Sites credit 'Light Pollution Reduction' awards points for meeting uplight, backlight, and glare limits using the BUG rating method.

Question 2

What is the key difference between 'connected load' and 'demand load' when calculating lighting energy use?

Accepted Answer

Connected load is the sum of all installed fixture wattages; demand load accounts for controls reducing average power draw

Answer

Connected load is the total installed wattage, while demand load reflects actual average consumption after controls (dimming, occupancy) reduce operating levels.

Question 3

A hospital corridor is lit to 30 fc for normal operation and automatically steps down to 5 fc when unoccupied at night. This strategy is best described as:

Accepted Answer

Bi-level switching

Answer

Bi-level switching (or stepped dimming) uses occupancy sensors to reduce light levels to a standby level rather than switching fully off, balancing safety with energy savings.

Question 4

Which lamp type is prohibited by US DOE regulations phased in from August 2023 due to its inefficiency?

Accepted Answer

General service incandescent and halogen lamps below 45 lm/W

Answer

The DOE's 2023 ruling effectively banned general service lamps that do not meet a 45 lm/W minimum efficacy, eliminating most incandescent and halogen A-lamps.

Question 5

In a daylight harvesting system, 'closed-loop' control differs from 'open-loop' control because it:

Accepted Answer

Measures actual workplane illuminance and adjusts electric light to maintain a setpoint

Answer

Closed-loop systems use a photosensor aimed at the task plane to measure combined daylight and electric light, continuously adjusting output to hit a target illuminance level.

(CLD) Certified Lighting Designer Practice Test

(CLD) Certified Lighting Designer Practice Test

CLD Sustainable & Energy-Efficient Lighting Solutions 3