Faรงade design strategies that can provide an optimal balance of energy efficiency with occupant comfort and well-being Helen Sanders SAGE Electrochromics, Inc.
The Façade Design Challenge
• •
Too hot? Too much glare?
Low Energy Consumption
Occupant Thermal & Visual Comfort
•
Too much heat gain/loss?
•
Inadequate solar control?
•
Daylight not harvested?
Daylight & Views
How do you achieve all three goals simultaneously?
How do we prevent this?
Heat and glare can counteract the positive benefits of daylight and views
And this?
And this?
And not not end up with faรงades like this?
Integrated Dynamic Façades Dimmable ligh%ng control Dynamic glare control
Energy efficient fenestra%on § Low u-‐factor § Dynamic solar control
Effec%ve dayligh%ng design
=> Control systems for fenestration and electric lighting integrated for optimum performance
Impact of lighting controls 7800
Annual Energy Use (Source)
No lighting controls
Expected shape of energy performance in a high performance building Op8mum window to wall ra8o (WWR) depends on many factors: • Climate zone • Orienta8on • Glass VT, SHGC, u-‐factor • Depth of daylight zone • Interior design • Dimming control details
With continuously dimming lighting controls 7600
7400
7200
7000
6800
6600
0
10 20 wall 30 Window to ratio
WWR, %
40
50
Most energy efficient design
Pathway to Net Zero Energy Buildings: Integrated Faรงades Annual Energy Usage Over Current Stock, in Quads: -3
Faรงade Technology:
-2
-1
0
Current Building Stock Average Properties of Windows Sold Low-e Dynamic low-e Triple Pane low-e Highly Insulating Dynamic Windows Integrated Insulating Dynamic Faรงades
Data from Arasteh et al., LBNL report number 60049
Heating Cooling Lighting
Highly Glazed Solutions for Sustainable & Elegant Architecture