Interior Design Lighting Design & Illumination 2 — Questions and Answers
Question 1: What is glare in lighting design?
- The warm glow produced by incandescent lamps
- Excessive brightness that causes visual discomfort or reduces visibility (Correct answer)
- The reflection of light off polished surfaces
- The halo effect produced around LED fixtures
Correct answer: Excessive brightness that causes visual discomfort or reduces visibility
Glare occurs when a light source or surface is excessively bright relative to its surroundings, causing discomfort or impairing visual performance.
Question 2: Which lighting control system allows users to program and recall multiple preset lighting configurations with a single button press?
- Occupancy sensor
- Standard dimmer switch
- Scene controller / preset dimming system (Correct answer)
- Daylight harvesting sensor
Correct answer: Scene controller / preset dimming system
A scene controller or preset dimming system allows users to save and recall specific lighting scenarios suited for different activities such as dining, entertaining, or working.
Question 3: What type of luminaire distributes light both upward toward the ceiling and downward into the room?
- Recessed downlight
- Torchiere floor lamp
- Direct/indirect fixture (Correct answer)
- Track light
Correct answer: Direct/indirect fixture
A direct/indirect fixture emits light upward (bouncing off the ceiling for ambient glow) and downward (for task illumination), combining both lighting functions.
Question 4: What does the spacing criterion (SC) help determine in a lighting layout?
- The required distance between a fixture and the ceiling plane
- The maximum spacing between luminaires relative to their mounting height (Correct answer)
- The number of fixtures allowed on a single circuit
- The beam angle of a spotlight fixture
Correct answer: The maximum spacing between luminaires relative to their mounting height
The spacing criterion (SC) defines the maximum allowable distance between luminaires as a ratio of their mounting height to maintain uniform illumination across a surface.
Question 5: Which ASHRAE standard specifically sets lighting power density (LPD) limits for energy efficiency in commercial buildings?
- ASHRAE 55
- ASHRAE 90.1 (Correct answer)
- ASHRAE 62.1
- ASHRAE 189.1
Correct answer: ASHRAE 90.1
ASHRAE 90.1 (Energy Standard for Buildings Except Low-Rise Residential) establishes lighting power density limits and energy efficiency requirements for commercial buildings.
Question 6: What information does a photometric report (IES file) provide for a luminaire?
- Paint color and finish specifications for fixture housings
- Light distribution, intensity levels, and efficiency data for a specific fixture (Correct answer)
- Daylight penetration measurements through windows
- Color rendering index readings from installed lamps
Correct answer: Light distribution, intensity levels, and efficiency data for a specific fixture
A photometric report (IES file) documents the light distribution pattern, candela values, and efficiency data for a luminaire, used in lighting layout calculations and simulations.
Question 7: What is the generally accepted minimum CRI value for most commercial interior spaces to ensure adequate color rendering?
- 60
- 70
- 80 (Correct answer)
- 95
Correct answer: 80
A CRI of 80 or above is the accepted industry minimum for commercial spaces such as retail, offices, and hospitality to ensure colors appear accurate and natural.
Interior Design Lighting Design & Illumination 2
What is glare in lighting design?