1. Area Lighting
Snapshot of retail CFL & LED
replacement bulbs
Lumens, cost, and light quality

2. Area lighting CFL vs LED
• LED and CFL at ~3000K color temp
– Major supplier and big-box home improvement store pricing and
availability

3. Area Lighting Costs
• 40W incandescent replaced by equivalent LED or CFL ~3000K
color temp
• Energy + bulb
– Incandescent bulb
– Compact Florescent
– LED bulb
– LED bulb

4. Area Lighting Costs
• 75W incandescent replaced by equivalent LED or CFL ~3000K
color temp
• Energy + bulb
– Incandescent bulb
– Incandescent spot
– Compact Florescent
– LED reflector spot

5. Area lighting comparison resources
• Energy Star CFL vs Incandescent (last updated 2008)
http://bit.ly/90mj7U
• DoE comparisons (current)
http://bit.ly/Kk4CC
– Note the Color Temp (CCT) and Color Rendering Index (CRI) are not directly
related. CCT is a measure of the color of the light produced and CRI measures
how objects look in that light.
– For example: we’ve all probably noticed how colors in a sodium lit parking lot
are dramatically different from in daylight, and how some florescent lights
make it difficult to match color of clothing. There is a new proposal for
measuring how a light source will render colors called Color Quality Scale
(CQS). (Next slide)

6. Comparison of light quality
• Summary: Color Temp and Color Rendering Index currently yield a poor
measurement of newer Solid State Lighting sources especially for very red or blue
sources. How object colors are perceived has a direct impact on lighting quality.
CRI is not good enough at predicting how light sources will render colors nor how
well the user will be able to differentiate colors when using that light source.
– Correlated Color Temperature (CCT) - light source color
– Color Rendering Index (CRI) 8 pastel colors – color of objects in that light
– Color Quality Scale (CQS) 15 deep long-wavelength colors (proposed)
• NIST paper (Wendy Davis and Yoshi Ohno) explaining CQS
http://physics.nist.gov/Divisions/Div844/facilities/photo/Publications/DavisOhnoLRO2006.pdf
• NIST physics site
http://www.nist.gov/physlab/div844/grp05/detector_color.cfm

7. Managing Expectations
• Retrofit (replacement bulbs)
– Compatibility with existing infrastructure
• Dimmers
• Airflow
• Location
– Quality of light
• Color rendering
• Dimming
• Safety
– ROI and payback period
• New construction
– Quality of light
– ROI and payback period

8. More to come…
Retrofit Challenges
• Dimming solutions
– Triac compatible controls
– Wireless
• ZigBee
• BTLE
• Dash7
• Other
– Other
• Reflectors and airflow
• Power supplies
• Lighting safety