Lighting the spatial envelope

Dr. Robert G. Davis

Director, Product Innovation & Marketing

The Brain:

It’s all about connections

100,000,000,000 neurons $1/sec 24/7/365 1 AD 1/3 left

The Brain:

It’s all about connections

100,000,000,000 neurons 3 neurons can connect in 8 ways 4: 64 5: 1,024 6: 32,768 100,000,000,000: ????

“The number of combinations possible – and hence the number of possible different thoughts or brain states each of us can have – exceeds the number of known particles in the entire known universe.” Dr. Daniel J. Levitin Neuroscientist, McGill University

Traditional lighting design

• Average footcandles • Watts per square foot

Sustainable lighting design “Sustainable lighting design meets the

qualitative needs of the visual environment, with the least impact on

the natural environment.”

IESNA/IALD Committees

Studies of Lighting Quality Carnegie Mellon University’s Center for Building Performance  



Examined lighting impacts on productivity Small improvements from increasing light levels (2 studies: 0.7%, 2.0%) Much larger improvements from using indirect instead of only direct lighting (4 studies: 3%, 6%, 8.5%, 26.1%)

LIGHTING ARCHITECTURAL SURFACES

Study 1 Study 2

Study 3

Study 4

INCREASING LIGHT LEVELS

Study 1

Study 2

Studies of Lighting Quality CONCLUSIONS: 



Good lighting quality is more important than adding more quantity Good lighting quality comes from lighting architectural surfaces, not just tasks

Light the spatial envelope

Learning Objectives Consider lighting the spatial envelope as a stimulus for: 1. 2. 3. 4. 5. 6.

Providing coherence Assisting wayfinding Affecting impressions Attracting the eye Reducing stress during healing Balancing daylight

Light provides coherence 

Searching for a cognitive match for the environment 



need to “make sense” of the environment by matching it to representation stored in memory familiarity (based on a memory match) should then produce higher preference

Cognition and environment: Functioning in an uncertain world by Kaplan and Kaplan

Light provides coherence

Light provides coherence Desire to “make sense” is coupled with a desire for “involvement” “In fact, our research on preference has over the years repeatedly pointed to two underlying purposes that people are concerned with throughout their waking hours.”

Light provides coherence

Light provides coherence Kaplan & Kaplan  Environmental psychology research  “Coherence” is a key attribute of pleasant environments  Coherence depends on drawing attention to important spatial properties

“something that draws one’s attention within the scene should turn out to be an important object or boundary.” Kaplan & Kaplan on coherence

“If what draws one’s attention and what is worth looking at turn out to be different properties, then the scene lacks coherence.” Kaplan & Kaplan

COHERENCE & PREFERENCE

PREFERENCE

COHERENT

COMPLEXITY

COMPLEXITY IN MUSIC “When a musical piece is too simple we tend not to like it, finding it trivial. When it is too complex, we tend not to like it, finding it unpredictable – we don’t perceive it to be grounded in anything familiar. Music, or any art form for that matter, has to strike the right balance between simplicity and complexity for us to like it.” (“This is your brain on music,” Levitin, 2006)

Emotional Response Emotional responses mediate between the environment (stimulus) and behavioral responses THE ENVIRONMENT

Sense modality variables

(e.g., color and temperature)

Information rate

(characterizing the spatial and temporal relationships among the stimulus components of an environment)

PRIMARY EMOTIONAL RESPONSES

Pleasure Arousal Dominance

Characteristic emotions associated with PERSONALITY

BEHAVIORAL RESPONSES

Approach-avoidance (which includes physical approach, exploration, affiliation, performance, or other verbal and nonverbal communications of preference)

An approach to environmental psychology, Mehrabian & Russell

Emotional Response



PLEASURE: How pleasant?



AROUSAL: How stimulating?



DOMINANCE: How much control?

Primary Emotional Response: Dominance 

Users want control 







Increased savings when users can manually control lights User complaints for entirely automatic systems

Users don’t want to be dominated by lighting controls Relates to Kaplans’ “involvement”

Light influences wayfinding 





Classic study by Taylor & Sucov at Westinghouse in the 1970s Observed how people moved around a barrier in their path Changed lighting emphasis to see the impact on wayfinding

Light influences wayfinding • 1:1 ratio of light on walls • 67% chose the path to the right (right-hand bias)

Taylor & Sucov

• 1:10 ratio of light on walls (L:R) • 79% chose the path to the right

Taylor & Sucov

• 1:100 ratio of light on walls (L:R) • 100% chose the path to the right

Taylor & Sucov

• 10:1 ratio of light on walls (L:R) • 80% chose the path to the left

Taylor & Sucov

• 100:1 ratio of light on walls (L:R) • 73% chose the path to the left • Right-hand bias is strong!

Taylor & Sucov

Light influences impressions Flynn studies on “Lighting Psychology” 

Series of studies over several years



Kent State, Penn State, GE Institute



Defined impressions and lighting modes that influenced them

Light influences impressions Lighting modes that influence impressions: 

central vs. perimeter 



bright vs. dim

uniform vs. nonuniform 

cool vs. warm

CENTRAL, UNIFORM

PERIMETER, UNIFORM

PERIMETER, NON-UNIFORM

CENTRAL, NON-UNIFORM

Light influences impressions Impressions influenced by perimeter lighting: 

spacious or closed



public or private 



clear or hazy

pleasant or unpleasant

Perimeter lighting only

Central down lighting only

(Images courtesy of Gary Steffy, from the estate of John Flynn)

Average subjective ratings for spaciousness (Flynn data)

Central down lighting + end wall lighting

Central diffuse lighting only

(Images courtesy of Gary Steffy, from the estate of John Flynn)

Average subjective ratings for pleasantness (Flynn data)

Light attracts the eye 

Phototropism: to seek light



Plants & animals exhibit it



Light attracts visual focus



Reflexive reaction

Reduces stress in healing 





Conceals the light source Minimizes visible fixtures Reduces risk of direct glare

Balances daylight 



Reduces contrast Counteracts brightness of fenestration

 Reduces

glare

“The layer of light on the interior wall was important to balance the daylight & improve the perceived brightness of the space.” Dane Sanders, Clanton & Assoc. Lighting designers for USGBC Headquarters

Learning Objectives Consider lighting the spatial envelope as a stimulus for: 1. 2. 3. 4. 5. 6.

Providing coherence Assisting wayfinding Affecting impressions Attracting the eye Reducing stress during healing Balancing daylight

Wall Washing  Asymmetric

fixtures 2-4’ from wall

 Fairly

uniform lighting down the wall

 Good

for vertical task lighting USGBC Headquarters

Grazing wash  Fixtures

in continuous slot with no visible equipment

 Brighter

at top but still distributes light down the wall

 Creates

a “floating ceiling” effect

Cove & wall-mounted fixtures  Fixtures

integrated into the architecture

 Optics

important for pleasant light distribution

 Emphasis

on architectural surfaces

Lighting the spatial envelope For more information:  Light the Walls brochure  Feb 2011 LD+A article  Blogs at litecontrol.com  Twitter: drbobdavis  [email protected]

Lighting the spatial envelope

Dr. Robert G. Davis

Director, Product Innovation & Marketing