CLD Lighting Design Codes, Standards & Regulations 5 — Questions and Answers
Question 1: When calculating compliance with ASHRAE 90.1 using the Space-by-Space method, which of the following spaces receives a higher LPD allowance to account for specialized visual tasks?
- Hospital/medical surgical suite (Correct answer)
- Open office
- Hotel guest room
- Lobby/atrium
Correct answer: Hospital/medical surgical suite
Surgical suites require very high illuminance for precision tasks and therefore receive a higher LPD allowance under the Space-by-Space method.
Question 2: The Occupational Safety and Health Administration (OSHA) Standard 29 CFR 1926.56 specifies minimum illuminance levels for which setting?
- Construction sites and temporary work areas (Correct answer)
- Permanent commercial office spaces
- Hazardous materials storage
- Emergency egress routes
Correct answer: Construction sites and temporary work areas
OSHA 29 CFR 1926.56 establishes minimum illuminance standards for construction sites to protect worker safety in temporary conditions.
Question 3: Which international standard, also adopted in the US, defines the Unified Glare Rating (UGR) calculation method for interior luminaires?
- CIE 117 / ISO 8995-1 (Correct answer)
- IES TM-15
- ANSI/IES RP-1
- EN 12464-1
Correct answer: CIE 117 / ISO 8995-1
CIE 117 defines the UGR formula, and ISO 8995-1 (also EN 12464-1 in Europe) incorporates UGR limits for various interior tasks.
Question 4: A designer proposes tunable white lighting in a LEED project. Which LEED v4.1 credit category would this most directly support?
- Indoor Environmental Quality — Interior Lighting (controllability/individual control option) (Correct answer)
- Energy and Atmosphere — Optimize Energy Performance
- Sustainable Sites — Light Pollution Reduction
- Materials and Resources — Building Product Disclosure
Correct answer: Indoor Environmental Quality — Interior Lighting (controllability/individual control option)
Tunable white lighting provides occupant control over color temperature, directly supporting the Interior Lighting credit's individual controllability option.
Question 5: Under NFPA 70 (NEC) Article 410, what minimum clearance is required between a recessed incandescent or non-IC-rated luminaire and adjacent combustible insulation material?
- 3 inches (Correct answer)
- 1 inch
- 6 inches
- No clearance required with IC-rated fixtures
Correct answer: 3 inches
NEC Article 410 requires non-IC-rated recessed luminaires to maintain a 3-inch clearance from combustible insulation to prevent fire hazards.
Question 6: Which IES standard document defines the method for classifying and measuring Backlight-Uplight-Glare (BUG) ratings for outdoor luminaires?
- IES TM-15 (Correct answer)
- IES LM-79
- IES LM-80
- IES RP-8
Correct answer: IES TM-15
IES TM-15 established the BUG rating system to quantify light trespass, sky glow, and glare potential of outdoor luminaires.
Question 7: A lighting designer finds that a proposed design for a parking structure exceeds the maximum LPD allowed under ASHRAE 90.1. Which design strategy would directly reduce LPD while maintaining required illuminance levels?
- Switch to higher-efficacy LED luminaires with optimized optical distributions (Correct answer)
- Increase mounting heights to spread light further
- Reduce lamp color temperature to 2700K
- Add emergency battery backup units to existing fixtures
Correct answer: Switch to higher-efficacy LED luminaires with optimized optical distributions
Higher-efficacy LEDs deliver more lumens per watt, allowing the same maintained illuminance with lower installed wattage, directly reducing LPD.
CLD Lighting Design Codes, Standards & Regulations 5
When calculating compliance with ASHRAE 90.1 using the Space-by-Space method, which of the following spaces receives a higher LPD allowance to account for specialized visual tasks?