Lighting Design Basics for Businesses
Points to Consider
Brittany Petersen
Energy Analyst
National Center for Appropriate Technologies
When lighting becomes a problem
How is it addressed?
Under lit workspace
Over lit workspace
Road map
Basic elements of
lighting design
Assessment of
work environment
Why Energy
Efficiency
Application
Basic Lighting Design
Where do you work?
Common Commercial Spaces
- Office
- Warehouse
- Retail
- Hospitality
What kind of lighting?
Common Commercial Lighting
- Incandescent
- Compact Fluorescent (CFL)
- Linear Fluorescent
- High Intensity Discharge
Basic Lighting Design
Office
Basic Lighting Design: Office fixtures
Ceiling can
Fixed
Direct
indirect
Basic Lighting Design: Fluorescent fixtures
Basic Lighting Design: Fluorescent fixtures
Lamp
produces visible light by causing
phosphor to fluoresce
Ballast
provides starting and operating
current to excite phosphor in
fluorescent lamps
Fixture/
Luminaire
unit containing lamp and ballast
Basic Lighting Design: High bay fixtures
Basic Lighting Design: high bay fixtures
Typical high
intensity
discharge
Basic Lighting Design: high bay fixtures
Metal Halide
Mercury
Vapor
High/Low
Pressure
Sodium
Basic Lighting Design: retail fixtures
Track
Display
Fixed
Basic Lighting Design: flood bulbs
Incandescent Flood
CFL Flood
LED Flood
Basic Lighting Design: Quality & Quantity
How do you classify these two indicators
in lighting design and use them to your
advantage?
Basic Lighting Design: Quality
Correlated Color Temperature (CCT)
Describes the color appearance of the light that is
produced, in terms of its warmth or coolness.
The CCT relates the color appearance of the lamp to
the color appearance of a reference source when the
reference source is heated to a particular temperature,
measured on the Kelvin (K) temperature scale.
Source: Lighting Design Lab, Seattle
Basic Lighting Design: Quality
Basic Lighting Design: Quality
Warm light sources are generally preferred for the
home, restaurants, hospitality and high-end retail
applications to create a sense of warmth and comfort,
while neutral and cool light sources are generally
preferred for high-activity areas such as offices,
schools, supermarkets and similar applications to
create a sense of alertness.
cooler light sources, saturated in blue wavelengths,
appear to enhance visual clarity and brightness
perception at lower light levels
Source: Lighting Design Lab, Seattle
Basic Lighting Design: Quality
Color Rendering Index (CRI)
A measurement of the amount of color
shift that objects undergo when lighted by
a light source as compared with the color
of those same objects when seen under a
reference light source of comparable color
temperature.
Source: Lighting Design Lab, Seattle
Basic Lighting Design: Quality
CRI values generally range from 0 to 100
Older-style ‘warm-white’ lamps were 52 CRI
Newer-style ‘cool white’ lamps are 62
Today’s T8, T5 and CFL lamps range from 75-95 CRI
In general, spaces that are occupied for long
periods, whether it be for work or recreation, are
where highest-color-rendering sources would
be practical.
Source: Lighting Design Lab, Seattle
Basic Lighting Design: Quantity
Basic Lighting Design: Quantity
Lumens
quantity of
light emitted
from a light
source
Basic Lighting Design: Quantity
Illuminance - amount of light measured
on the workplane in a lighted space
footcandle (unit)
one lumen of
light density per
square foot
footcandle (fc) =
total lumens / area
in square feet
Image source: IESNA
Basic Lighting Design: Quantity
Basic Lighting Design: Quantity
Orientation
of space
Daylighting
Reflectance
Basic Lighting Design: Quantity
Lumens
per bulb
Fixture/Luminaire
direct/indirect, fixed
Mount
floor to ceiling height
Layout
Basic Lighting Design: Review
Luminaires
Common Commercial Lighting
- Incandescent
- Compact Fluorescent (CFL)
- Linear Fluorescent
- High Intensity Discharge
Quality
Quantity
Footcandles
Assessment
Lighting levels
Determine that the footcandle measurement falls
within the IES recommendations
Assessment: Tools
Hand calculations
1) Determine total number of lumens in the space
2) Measure square footage
3) Calculate footcandles
Footcandle meter readings
Assessment: Tools
Or...
Determine whether space is over lit or
under lit by checking for the following
characteristics
Assessment: Too bright?
Examples of over lit space:
Assessment: Too dim?
Examples of under lit space:
Energy Efficiency
Why does it matter?
Energy Efficiency: Annual operating costs
Energy Efficiency: Electricity consumption
Energy Efficiency: Lighting in energy use
Energy Efficiency: Common terms
Watt (W)
rate of energy conversion, used
by utility to measure demand
1000 W = 1 kW
Kilowatt Hour (kWh)
measure of energy used over
time, used by utility to measure
and bill for energy consumption
Energy Efficiency: Lamp efficacy
Efficacy
efficacy = lumens / watt
Lamp efficacy is
equivalent to miles
per gallon in
measuring efficiency
Energy Efficiency: Guidelines in design
Set ambient lighting levels close to minimum recommended
foot-candle values, but not below
Boost lighting levels in specific areas, as needed to support
specific tasks, using task lighting strategies
Use lighting sources with high lumen/Watt values and adequate
CRI values
Retrofit projects should target 1.0-1.5 Watts/square foot
Consider combinations of de-lamping and re-lamping to address
lighting system improvements
Consider benefit of reduced lighting levels on reducing air-conditioning loads
Applications: Case studies
Applications: PAR-TV Building
Applications: PAR-TV Building
Existing
Fixture
40 watt incandescent
Quality
CCT: 2000 (warm range)
CRI: 97-100
Quantity
Lumens: about 1,000 per mirror
Problem
Too much heat in space
Too much energy use
Applications: PAR-TV Building
Solution: Remove incandescents, replace
with linear, two foot fluorescent lamps
Fixture
1 lamp, 2’ linear fluorescent, three
per mirror
Quality
CCT: 3500 (mid range)
CRI: 86
Quantity
Lumens: about 3,000 per mirror
Applications: Warehouse
Applications: Warehouse
Existing: High bay metal halide
Fixture
400 watt metal halide
Quality
CCT: 3000 (mid range)
CRI: 70
Quantity
Lumens: 28,000
Problem
Metal halide depreciation
Low footcandles (5-10)
for the task in space
Applications: Warehouse
Applications: Warehouse
Solution: high output fluorescents with
occupancy sensors
Fixture
6 lamp T5 HO
Quality
CCT: 3000 (mid range)
CRI: 85
Quantity
Lumens: 27,000
Solution
Better CRI with little depreciation
Increased footcandles (15-20) for the
task in space
Applications: Warehouse
Energy Savings
Annual Savings
= $1,500
40 fixtures with an
average of 70 hours
on per week
Increases to $2,500
with occupancy
sensors
Applications: T12 to T8 retrofit
Applications: T12 to T8 retrofit
Existing: Eight foot T12 fixtures
Fixture
2 eight foot lamps, magnetic ballast
Quality
CCT: 3000 (mid range)
CRI: 70
Quantity
Lumens: 12,000
Problem
Poor illumination on product
Applications: T12 to T8 retrofit
Applications: T12 to T8 retrofit
Solution: 4 lamp T8 fixtures
Fixture
4 four foot lamps, electronic ballast
Quality
CCT: 4100 (blue light)
CRI: 86
Quantity
Lumens: 8,880
Solution
Whiter light on product makes it
appear as if there is more light
Energy savings
Applications: T12 to T8 retrofit
Energy Savings
Annual Savings = $700
40 fixtures with an average of 70
hours on per week
Increases to $ 1,000with installation of occupancy sensors
Applications: Relamping
Applications: Relamping
Existing: 4 lamp, 32 watt, T8 fixtures
Fixture
Standard four lamp, four foot
electronic ballast fixtures
Quality
CCT: 2500 (warm to mid range)
CRI: 78
Quantity
Lumens: 10,800
Problem
Warm color temperature
Higher annual energy costs
Applications: Relamping
Applications: Relamping
Solution: 4 lamp, 25 watt, T8 fixtures
Fixture
Quality
Energy saving four lamp, four foot,
electronic ballast fixtures
CCT: 4100 (blue light)
CRI: 86
Quantity
Lumens: 8,880
Solution
Blue light better illuminates the work
plane for reading and writing
Lower annual energy costs
Applications: Relamping
Energy Savings
Project cost for district = $500,000
Rebate for district = $134,000
Annual Savings for district = $108,000
3.5 year simple payback
Applications: Layout upgrade
Applications: Layout upgrade
Existing
Some areas too dim, others too bright
Applications: Layout upgrade
Ceiling finish
Shading
Wall finish
Applications: Layout upgrade
Solution: New layout for brighter space
Daylighting
Wall finish
Ceiling finish
Cleaner appearance while saving energy!
In case you missed it ...
Basic elements of lighting design
Identify fixture, quality and quantity of light
Assessment of work environment
Over lit or under lit?
Application
Solve lighting problems by determining what
the quality and quantity of light in a given
space should be