High Performance Lighting
Terry Egnor
Senior Consultant
NBI
Design Issues
• Energy Efficiency is
not difficult
• Lighting Quality is
not difficult
• Together, it is a
challenge
• GOAL: Energy
Effective Lighting
Illuminating Engineering Society of North America,
Lighting Handbook, 9th Edition.
Basic Lighting Strategies
• Use high efficiency fixtures
• Use task lighting for primary visual task if possible
• Don’t over light for ambient conditions
– Offices general lighting: 30-40 fc average, not 50+.
– Classrooms general lighting: 30-50 fc average, not 50+
• Use light colored finishes
– Light colored space (Reflectivity: 80% ceiling, 70% walls)
• Incorporate Daylighting
– Fenestration design and glazing performance
– Light level sensors
• Controls
– Occupancy control or vacancy control
– Coupled to plug load, daylighting and HVAC
“Intelligent” Lighting in Offices
• Workspace-specific,
suspended
• Separate up-down for
layered controls
• Personal control for
dimming downlight
• Research shows 20%
improvement in worker
comfort and improved
motivations
• 60-80% energy savings!
Light Right Consortium
research project, Albany, NY.
www.lightright.org for findings
High Performance T8 Savings
Light
Output
(MLPW)
% Efficacy
Improvement Over
Generic T8
Generic T8 32-watt 700 series
with rapid-start electronic
ballast
75
N/A
“Super” T8 32-watt 800+ series
with program-start electronic
ballast
92
23%
“Super” T8 32-watt 800+ series
with instant-start electronic
ballast
98
31%
Technology
Task/Ambient
Task and Ambient Lighting
• Promotes using lower ambient lighting
and better-than-normal task lighting.
• Relies heavily on good task lighting.
Only appropriate for projects that allow
for extra attention to this detail.
• Don’t rely on furniture supplier task
lights to do the job.
• One solution: 1 lamp T5 or LED task
lights over tables and desks
Integrated Daylight Controls
Potential savings of
10% to 50%
Lighting Control Requirements
• Automatic Lighting Reduction
– Offices ≤ 300 s.f. automatic occupancy sensor
– All other spaces, automatic occupancy sensor or time
device
• Bi-level or Continuous Control In Daylit Areas
– Reduce connected load uniformly by at least 50%
– Skylights - photocells for 50% reduction in load
Controls and Energy Savings
• Advanced Lighting
Controls Tested
• Savings of occupancy
sensors vs. dimming
was dependent on
occupant behavior
Control Strategy
Energy
Saved
Single Level Switching
0%
Bi-Level Switching
23%
Occupancy Sensors
20-26%
Dimming - Photo Sensors
27%
Occupancy and Photo
Sensors
46%
Dimming - Task Tuning
23%
Office building, 7 months, 5 controls scenarios, April 2000, http://eetd.lbl.gov/btp/pub/Lgpub.html
Occupancy Sensors
• Available in Passive-Infrared & Ultrasonic
• Most common problem is mis-application
Occupancy Sensors
Range of Effectiveness
Sensitivity
Infrared
- covers areas in “beams”
- smaller range
- lower sensitivity
Ultrasonic
- covers area evenly
- larger range
- highly sensitive
(can be susceptible to false
triggering from air currents)
Time clock vs. Occupancy
Sensors
Outdoor Lighting
• Efficacy
– 60 lumens/watt or better
– Motion Sensor control
– Exceptions (monuments, safety, pools,
LED, etc)
• Controls-photosensors or timeclocks
• Cutoff Fixtures
ABSIC / CBPD Guidelines for
High Performance Lighting
• Provide daylighting as a dominant light source
• Separate task from ambient lighting
• Introduce direct-indirect lighting to reduce shadowing
and create spatial dynamics
• Maximize lighting quality with high performance
luminaires
• Provide for re-configurability by design for continuous
change in zones and technologies
• Pursue innovative lighting system integration for
thermal and air quality, resource conservation &
environmental health.
Advanced Building Systems Integration Consortium / Center for Building Performance and Diagnostics –
Carnegie Mellon University
ALG Online
• Advanced Lighting Guidelines Online
– Comprehensive coverage
– Detailed examples
– Design tools
– Continuous updates
• Available this Fall:
http://www.advancedbuildings.net/ALGOnline.htm