Dynamic Faรงades: Solving the Design Challenge without Compromise
Helen Sanders SAGE Electrochromics, Inc.
“Ever since the first cave people crept indoors for safety, humans have sought to bring sunlight in from the outside.”
Source: John Pierson. “If Sun Shines In, Workers Work Better, Buyers Buy More.” Wall Street Journal, 11/95.
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
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mood and behavior (depression)
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hormone regulation
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metabolism (weight management)
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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
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Obesity/diabetes/high blood pressure
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Depression/behavioral issues
• •
Today’s (Green) Design Challenge Too hot/cold Glare problems
Low Energy Consumption
Challenge: How can we achieve all three simultaneously?
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Occupant thermal & visual comfort
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Daylighting and views
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Too much heat gain/loss? Inadequate solar control? Daylight not harvested?
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 7800
Annual Energy Use (Source)
No lighting controls
Expected shape of energy performance in a high performance building
With continuously dimming lighting controls 7600
7400
Position and depth of minimum depends on many factors: • Glass VT, SHGC, u-factor • Depth of daylight zone • Interior design • Dimming control details
7200
7000
6800
6600
0
10
20
30
40
50
WWR, %
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
Occupant thermal & visual comfort
Challenge: How can we achieve all three simultaneously?
Daylighting and views
An Elegant Solution?
Example EC Glass Performance
Glare control without needing shades/blinds
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Product Technology – How Electrochromic Glass Works
12
CASE STUDIES
A “Green” Glass Cube: Morgan Library – Colorado State University
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Morgan Library
- Enables highly glazed west facing high altitude façade - Preserves transparent design intent - Zoning for optimum control
Morgan Library - CSU
A Glass Cube in Miami?
A Glass Cube in Miami?
Creating a Usable Space: Kimmel Center, Philadelphia, PA
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
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Without reducing window area
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Without compromising occupant comfort
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Elegant and simple façade designs
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Enabling unobstructed views – no shades/blinds