design strategies for existing buildings · design strategies for existing buildings presented by...
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Design Strategies for
Existing Buildings
Presented by Megan Strawn, LC
Fall, 2015
So it’s time to update the lighting-
Most common reasons Energy Savings
Environmental Stewardship
Rebates
Improving Maintenance Cycle
Switching from Incandescent to Fluorescent
Switching to LED
Improve Lighting Quality
Visibility, Safety, Color Quality
Existing Fixtures are at End of Life
Space Use is Changing
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Energy Savings
Energy Savings
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Energy Savings
Maintenance
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Maintenance
Visibility, Safety, & Color Quality
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Fixture at end of life…
Life Safety Minimum light levels
Egress lighting issues
Seismic considerations
Energy Considerations Power consumption
Lighting Controls
Local Ordinances Dark sky considerations, etc
Code Concerns
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Controls
Lighting Quality
Do you want to change the quality of the
lighting? What does that even mean?
What is good lighting quality?
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Lighting Quality
Human Needs
Visibility
Task Performance
Visual Comfort
Social Communication
Mood & Atmosphere
Health, Safety, & Well Being
Aesthetics
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Visibility
Ability to extract visual information from the
scene Affected by task
Contrast
Size
Time
Luminance
Affected by observer’s age
Visibility
In Other Words, Is there Enough Light? The human eye is capable of operating within a
vast range of illuminances, from .001 fc
(starlight) to over 10,000 fc (full daylight).
How much light is there?
Is it enough?
Is it too much? More is not always better.
How much contrast is there?
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Visibility
Visibility
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Visibility
Task Performance
What kind of tasks take place in this space?
What are the illuminance recommendations?
What kind of light do you need?
What are the recommended luminance ratios?
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Task Performance
Combination of visual and non-visual factors
Non-visual factors include: Training Mood
Motivation Motor Skills
Lighting affects visual factors and some of the
non-visual factors
Uniform? Relaxed, unexciting atmosphere
Applicable for offices, schools, labs
Focused? More visually stimulating
Applicable for museums, restaurants
High contrast? Often visually chaotic
Applicable for some retail, entertainment venues
Type of Lighting
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Value of uniform illuminance must be assessed Easy to control contrast ratios
Can create non-stimulating environments
Need for accent lighting as visual interest
Promotes feeling of spaciousness
Uniformity
Uniform illuminance for a whole area generally
achieved with uniform lighting layout Used when specific tasks are unknown
Allows flexibility in furniture layout
Often requires supplemental localized task lighting
Uniformity
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Luminance Ratios
Eye operates on a logarithmic scale For something to appear twice as bright, it needs a
10:1 luminance ratio
Target luminance ratios of 10:1 to 15:1 for accent lighting
Focused lighting creates sense of intimacy
Focused
Focused
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Target luminance ratios for high end retail
lighting can be in excess of 20:1
High Contrast
Visual Comfort
Distribution of Light Humans are accustomed to a darker zenith and a
bright perimeter
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Visual (dis)Comfort
Glare - The sensation produced by luminances
within the visual field that are sufficiently
greater than the luminance to which the eyes
are adapted, which causes annoyance,
discomfort, or loss in visual performance and
visibility.
In other words, either too much light, or excessive
contrast within the visual field.
Typically, a luminance ratio of 1000:1
Glare
Direct glare Direct view of an
unshielded light fixture or
window without shading
Reflected glare Light reflected off of a
surface or bright objects
seen as a reflected image.
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Reflected Glare
Discomfort Glare Glare that is uncomfortable but does not hinder
performance
Disability Glare Glare that is so severe that it does hinder performance
Glare
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Human Needs
Visual Comfort Can affect task performance and productivity
Can affect health and safety
Can affect mood and atmosphere
Social communication
Facial modeling
Facial recognition
Color rendering
Human Needs
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Mood & atmosphere Emotional response to lighted environment
Human Needs
Mood & atmosphere Emotional response to lighted environment
Human Needs
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Human Needs
Health, safety & well-being Rotating & moving equipment
Emergency lighting
Visibility of curbs, stairs, etc.
Labels on chemicals & medications
Roadway intersections
Pedestrian walkways
SAD, circadian rhythms, phototherapy
Human Needs
Aesthetics
Color Temperature
Color Rendering/ Color Fidelity CRI - A numerical rating indicating how well a light
source renders the colors of objects. For a CRI
value of 100, the colors of objects can be
expected to be seen as they would appear under
an incandescent or daylight spectrum of the same
correlated color temperature (CCT). Sources with
CRI values less than 50 are generally regarded as
rendering colors poorly, that is, colors may appear
unnatural.
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Color
Color Rendering
Color Rendering A single number does not tell the whole story, as it
cannot fully characterize multidimensional experience
of color such as color appearance, color fidelity,
chromatic discrimination, vividness & observer
preferences.
Does not characterize highly structured narrowband
emissions such as those from SSL sources.
Color
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The numerical Index is derived from a small
number of color samples which are
unsaturated
R9-R12 are saturated samples but not figured
into the computation of general CRI.
Color Rendering Limitations
Color Quality Involves multiple facets of color quality, including
color rendering, chromatic discrimination, and
observer preferences
Different from CRI by Taking into account subjective color saturation
perception
Measures color fidelity with regard to color saturation
preferences
Moderate increase of saturation is often correlated
with desired color perception.
Color
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Color Temperature
Color Temperature
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Color Temperature
How much light do you need?
What kind of light do you need?
What is the hierarchy?
Does it meet code?
Is the system maintainable?
Is it aesthetically pleasing?
Establishing Criteria
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Hierarchy
Hierarchy
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Hierarchy
So Now What?
You know what you want to do, how do you do
it? What are your constraints?
Budget?
Just lamp replacement?
Architectural Limitations?
Asbestos, e.g.?
Can you improve the lighting quality of the space?
What is the existing controls system?
Will there be compatibility issues with new fixtures?
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So Now What?
How do you pick new fixtures? What are evaluation criteria for new fixtures?
$ Budget? Perhaps not…
Performance? Much better!
How do you know if you have a good fixture?
Fixture Selection – Wall Sconce
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Fixture Selection – Wall Sconce
Fixture Selection – Wall Sconce
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Fixture Selection – High Bay
www.ledwholesalers.com
Fixture Selection – High Bay
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Fixture Selection – High Bay
Fixture Selection – High Bay
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Fixture Selection – High Bay
Fixture Selection – High Bay