Dynamic Façades: Solving the Design Challenge without Compromise

Helen Sanders

SAGE Electrochromics, Inc.

Source: John Pierson. “If Sun Shines In, Workers Work Better, Buyers Buy More.” Wall Street Journal, 11/95.

“Ever since the first cave people crept indoors

for safety, humans have sought to bring

sunlight in from the outside.”

Why Do We Need Daylight?

“Daylight is a drug and nature is the prescribing physician”

(D. Burnet, Benya & Burnet Consulting)

Why Do We Need Daylight? •  Daylight entrains the circadian rhythms which impact

•  the immune system and wound healing

•  mood and behavior (depression)

•  hormone regulation

•  metabolism (weight management)

•  heart and blood pressure

•  Daylight changes throughout the day: morning light stimulates different

processes than afternoon/evening light

•  Removal of daylight cycles is linked to:

•  Increased risk of cancer

•  Obesity/diabetes/high blood pressure

•  Depression/behavioral issues

Today’s (Green) Design Challenge

Low Energy Consumption

Daylighting and views

Occupant thermal &

visual comfort

Challenge: How can we achieve

all three simultaneously?

•  Too much heat gain/loss?

•  Inadequate solar control?

•  Daylight not harvested?

•  Too hot/cold •  Glare problems

Battle for the Wall – Building Codes Windows: Are they the weak energy link in buildings?

Focus on thermal conductance and heat gain - But 20% of the building energy comes from electric lighting -  80% ends up as heat load

Daylighting: Energy Impact

6600

6800

7000

7200

7400

7600

7800

0 10 20 30 40 50

WWR, %

Ann

ual E

nerg

y U

se (S

ourc

e)

No lighting controls

With continuously dimming lighting controls Expected shape of energy performance in a high performance building Position and depth of minimum depends on many factors: •  Glass VT, SHGC, u-factor •  Depth of daylight zone

•  Interior design •  Dimming control details

Reducing window area compromises ability to have enough daylight/views AND misses significant energy savings

Occupant Comfort?

More daylight, if not managed well, can lead to: •  Glare/thermal issues •  Inadequate glare control promotes use of blinds •  Blind/shade use negates daylighting – reduces energy

savings •  Blind/shade use eliminates the view!!

Today’s (Green) Design Challenge

Low Energy Consumption

Daylighting and views

Occupant thermal &

visual comfort

Challenge: How can we achieve

all three simultaneously?

An Elegant Solution?

Example EC Glass Performance

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Glare control without needing shades/blinds

Product Technology – How Electrochromic Glass Works

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CASE STUDIES

A “Green” Glass Cube: Morgan Library – Colorado State University

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-  Enables highly glazed west facing high altitude façade

-  Preserves transparent design intent

-  Zoning for optimum

control

Morgan Library

Morgan Library - CSU

A Glass Cube in Miami?

A Glass Cube in Miami?

Creating a Usable Space: Kimmel Center, Philadelphia, PA

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Energy Efficient Historic Renovation: St. Johnsbury Athenaeum, St. Johnsbury, VT

A Very Challenging Problem – A view always Port of Entry, Torrington, WY

Naval Academy – Digital displays?

EC Glazing: Solving the Façade Design Challenge

•  Enabling sustainable designs

•  With high energy performance

•  Without reducing window area

•  Without compromising occupant comfort

•  Elegant and simple façade designs

•  Enabling unobstructed views – no shades/blinds