LED vs. Fluorescent Lighting
Emile Lauzzana, AIA, LEED AP Director, Energy and Sustainability
Detroit Public Schools
MSBO Annual Conference – April 2015
“We believe that part of the answer lies in pricing energy on the basis of its full costs to society. One reason we use energy so lavishly today is that the price of energy does not include all of the social costs of producing it. The costs incurred in protecting the environment and the health and safety of workers, for example, are part of the real costs of producing energy—but they are not now all included in the price of the product.”
Richard Nixon (1969 – 1974)
Detroit Public Schools LED Lighting Retrofit Pilot
GOALS:
1. Improve learning environments
2. Reduce costs
Teacher Survey Responses:
SCOPE:
Brighter light, better color, easier for students to see assignments, no shadow spots
1. Use limited resources for classrooms only
2. Retrofit all classrooms in 8 schools The lights are no longer flickering.
Describe your Satisfaction with the light in your Classroom 5.00
4.05
4.00
3.00
2.90
2.00
1.00
0.00
1
BEFORE
AFTER
1= Very Dissatisfied; 2= Dissatisfied; 3= Neutral; 4= Satisfied; 5= Very Satisfied
Much brighter and I love how they shut off automatically
The lights turn on as I walk into the classroom. It is bright and cheery in the classroom now. The lighting in the room has really made the room conducive for learning!
BEFORE
Nichols Elementary‐Middle School
AFTER
Nichols Elementary‐Middle School
AFTER
Davis Aerospace Technical High School LED Retrofit VS LED – Major Considerations:
1. Economics
2. Design and Engineering
How much savings is really out there?
DPS average school annual electric spend =
$104,000 x 26% = $27,040
If we saved 50% the annual savings would =
$13,520
DPS average school size = 106,000 SF
Potential savings per SF =
$0.127/SF/YR
Potential savings district‐wide=
$0.127/SF/YR x $10M SF = $1,270,000/year
Let’s do the Math:
Assumptions: 1. No labor costs including – assuming lights are either T12 or for some other reason need replacement
2. Annual increase of 4% in electricity costs included
3. Based on current FY 15 DTE Incentive Program
How much savings is really out there?
How much savings is really out there?
One for One Replacement
Cummulative COSTS
$250.00
$75/fixture in 10‐year savings
$200.00
$150.00
$100.00
$50.00
$‐
1
2
3
4
5
6
7
8
9
10
YEAR
A‐FL
A‐LED
De‐Lamp Scenario (3 tubes to 2 tubes)
Cummulative COSTS
$400.00
$350.00
$300.00
$200/fixture in 10‐year savings
$250.00
$200.00
$150.00
$100.00
$50.00
$‐
1
2
3
4
5
6
YEAR
B‐FL
B‐LED
7
8
9
10
There is some savings – but who can I trust???
Materials and samples from various sales representatives . . . . Engineering and Design Considerations
•
•
•
•
•
•
Foot‐candles (FC)
Efficacy (Lumens/Watt)
Color Temperature Color Rendering Index (CRI)
Light Distribution
Warranties and Certifications
Footcandles (FC)
Footcandle (FC) is a measure of how much illuminance is on a surface. One footcandle is equivalent to the amount of light a candle makes on a 1 square foot piece of white paper held one foot away. While full daylight can reach as high as 10,000 FC, typical indoor lighting levels are significantly lower. Recommended lighting levels for schools at 30” above the floor:
Classrooms: Offices:
Computer Labs:
Cafeterias:
Hallways:
Exterior: 50fc
50fc
30fc
30fc
30fc
1‐5fc (depending on level of activity)
NOTE: Both Under‐ and Over‐illumination can cause eye‐strain and headaches. Studies have shown long‐term exposure to improper illumination levels can have lasting negative health impacts
Efficacy (Lumens/Watt)
Efficacy is a measure of how much light is produced in Lumens to the amount of energy input in Watts. This is the most basic measure of energy efficiency.
Source: LED Academy
DPS Minimum Efficacy for strip fluorescent LED replacements is 100 lum/watt. Laboratory tests on LEDs have exceeded 250 lum/watt, however commercially available lamps are typically in the 90‐110 range.
Color Temperature
Daylight
New DPS Standard
Old DPS Standard
Typical Residential Source: SEESMART Lighting
*Studies have shown students have significant increases in visual acuity with higher color temperature lighting
Color Rendering Index (CRI)
CRI measures how a color appears when lit by artificial lighting on a scale of 0 (bad) to 100 (good). Inferior LED may have high lumen outputs, but low CRIs. DPS Minimum CRI is 80.
Source: Yuji LED
Source: Phillips Lighting
Lighting Distribution (Photometry)
Down Light
Up/Down Light
Warranties and Certifications
Typical for LED Fluorescent Tube Replacements
•
•
5 Year Limited Warranty
50,000 Hours
New LED Lights
• 7‐10 Year Limited Warranty
• 70‐100,000 Hours
NOTE:
2 main reasons and LED light will fail
• Over‐heating (Exterior retrofits)
• Driver failure
Detroit Public Schools Required Certifications: