Glass of the FutureBurnham‐Moores Center for Real EstateUniversity of San DiegoMaster of Science in Real Estate Program
March 2014Lori Malins
Smart Glass | University of San Diego, MSRE
Table of Contents• Introduction – What is smart glass?
• Types of Smart Glass in Commercial Buildings
• Electrochromic Case Study
• Electrochromic Example in San Diego
• Benefits and Challenges of Electrochromic Glass
• Future of Smart Glass
Smart Glass | University of San Diego, MSRE
Inefficient windows = wasted energy
• According to the U.S. Department of Energy, 25% to 35% of energy wasted in buildings is due to inefficient windows
• The California Energy Commission estimates that around 40% of a typical building’s cooling requirements are due to solar heat gain through windows
• Windows are important factors in energy efficient buildings
Smart Glass | University of San Diego, MSRE
Smart Glass in Commercial Buildings• Glass or glazing that varies light transmittance and/or thermal properties
of windows
Types of Smart Glass
Liquid Crystal Low‐E Thermochromic Electrochromic
Smart Glass | University of San Diego, MSRE
Liquid Crystal Low‐E Thermochromic Electrochromic
• Allows light flow with privacy
• Used for privacy control
• Changes on demand with an electric current
• Advantages: Privacy at the flip of a switch, no window coverings needed
• Disadvantages: Does not conserve energy
• Detailed description here: http://www.switchlite.com/home.html
Smart Glass | University of San Diego, MSRE
Liquid Crystal Low‐E Thermochromic Electrochromic
• Traditionally used energy efficient glass
• Glass treated with invisible metallic coating to reflect or trap light and heat
• Reduces the amount of ultraviolet light that enters your home without blocking visible light
• Advantages: Limits UV rays, reduces energy bill, prevents furniture from fading, reduces sound levels in home
• Disadvantages: More costly than regular glass, slight haze to windows, no manual control, no control over visible light
• Detailed description here: http://www.efficientwindows.org/lowe.php
Smart Glass | University of San Diego, MSRE
Liquid Crystal Low‐E Thermochromic Electrochromic
• Tint level based on temperature of the material
• Adapts directly to changing sunlight intensity
• Combined with low‐e technology
• Advantages: Continuously adapts tint to sunlight to manage heat and glare, installation the same as traditional windows, No power supply needed,
• Disadvantages: Cannot be manually controlled, glass may not receive enough heat from direct sunlight to darken, added weight to insulated glass units
• Detailed description here: http://www.commercialwindows.org/thermochromic.php
Smart Glass | University of San Diego, MSRE
Liquid Crystal Low‐E Thermochromic Electrochromic
• Electrical current creates chemical reaction causing window to tint
• Depending on electrical current, selectable darkness allows more control over sun levels
• Current is not required to maintain tint level, only to change color states
• Very little current needed (power entire building of electrochromic windows equal to one light bulb)
• Detailed description here: http://www.commercialwindows.org/electrochromic.php• http://home.howstuffworks.com/home‐improvement/construction/green/smart‐
window4.htm
Smart Glass | University of San Diego, MSRE
Traditional BuildingU Factor: 0.29 BTU/hr.ft2.FSHGC: 0.38Tvis: 70%
Manual shades on all sidesOverhang on south façade
Dynamic BuildingU Factor: 0.29 BTU/hr.ft2.FSHGC: 0.09 – 0.46Tvis: 3% – 58%
Manual shades on north façade
VS
Case Study Comparison | Low‐E vs. Dynamic Glass
Low Rise Office
4 stories, 80,000 sf
• $15.5M new construction
• 40% window to wall
punched‐opening
windows
• Packaged rooftop unit VAV
• Dynamic glass on E+W+S
facades
* Provided by View Dynamic Glass
Smart Glass | University of San Diego, MSRE
Glazing
Electrical
HVAC
Internal shades
External shades
0.75
0
1.5
0.19
0.10
1.25
.02
1.3
0.06
0
0.50
.02
(0.21)
(0.13)
(0.10)
Total 2.54 2.62 0.08
Low-e Dynamic Difference
Cap Ex Low Rise Office Costs ($M)
$1/sf premium for Dynamic Glass0.5% premium of total building cost
Energy
HVAC maint
Shading maint
85
6
3
78
5
1
(7)
(1)
(2)
Annual Operating Costs Low Rise Office ($k)
11% lower OPEX Low-e Dynamic Difference
Smart Glass | University of San Diego, MSRE
Savings8%
Dynamic Building
Traditional Building
Windows40%
Walls & Roof6%
InternalLoads54%
Windows31%
InternalLoads55%
Walls & Roof6%
8% lower peak cooling load
Savings14%
Dynamic Building
Traditional Building
Lighting45%
Airflow/Pumps8%
Cooling47%
Lighting38%
Airflow/Pumps7%
Cooling41%
14% HVAC and lighting electricity savings
Smart Glass | University of San Diego, MSRE
Example Project – Marine Corps Air Station Miramar, California• Part of Department of Defense’s Environmental Security Technology Certification Program (ESTCP)
• Retrofit project – 1,700 square feet of low performing clear glass replaced
Estimated Results
23% reduction in HVAC peak cooling load
18% decrease in gas use
9% decrease in total energy use on annual basis
Smart Glass
Smart Glass | University of San Diego, MSRE
Electrochromic Glass
Benefits
Energy Savings and greater energy management
Can include sensor to automatically tint windows
Manual control of tint level of individual windows
Greater management of heat and glare
More natural light and uninterrupted views
Increase occupant comfort and productivity
Allows for greater window to wall ratios, while still meeting codes and energy efficiency objectives
Applicable in new construction and retrofit buildings
Earns points towards Leed
Challenges
New technology with technical glitches
Higher upfront costs
Instillation more difficult
Higher maintenance costs
Without proven track record, hard to prove cost benefits
Does not replace blinds or other window treatments
Long transition times
Smart Glass | University of San Diego, MSRE
Dynamic Glass and LEED
LEED Certification Points (up to 28 pts)
Energy and atmosphere 18
Indoor environment quality Thermal comfort 1 Daylight 3 Quality views 1 Interior lighting 2
Sustainable sights 1
Material and Resources 2
* View Dynamic Glass
Smart Glass | University of San Diego, MSRE
Future of Smart Glass• Increase cost efficiencies
• Integration of smart glass with other electrical systems within building such as the HVAC and lighting systems
• Photovoltaic smart glass – generating electricity while darkening windows with thin film of PV panel
• Wireless systems
• Other electronics in glass such as thermometer or display
Smart Glass | University of San Diego, MSRE
Links + Resources• Ander, Gregg D. "Windows and Glazing."WBDG. Whole Building Design Guide, 18 June 2010. Web. 03 Mar. 2014.
<http://www.wbdg.org/resources/windows.php>.
• "Category: Dynamic Glass ‐ Suntuitive® by Pleotint ‐ Dynamic Windows." Suntuitive® by Pleotint. N.p., 17 Jan. 2014. Web. 03 Mar. 2014. <http://www.pleotint.com/1/category/dynamic‐glass/1.html>.
• DeBusk, Steve. "New Low‐e Glass or Window Film? A Comparison to Help You Decide." Buildings.com. Buildings, 25 June 2012. Web. 03 Mar. 2014. <http://www.buildings.com/article‐details/articleid/14300/title/new‐low‐e‐glass‐or‐window‐film‐a‐comparison‐to‐help‐you‐decide.aspx>.
• "Dynamic Sun‐Activated SolarSmart Glass." Innovative Glass. N.p., n.d. Web. 03 Mar. 2014. <http://www.innovativeglasscorp.com/solar‐smart>.
• Gromicko, Nick, and Ethan Ward. "Low‐E Windows." Int'l Association of Certified Home Inspectors (InterNACHI). N.p., n.d. Web. 03 Mar. 2014. <http://www.nachi.org/low‐e‐windows.htm>.
• "Guide to Low‐E Glass." Lowes. N.p., n.d. Web. 3 Mar. 2014. <http://www.lowes.com/cd_Guide+to+LowE+Glass_1277235128_>.
• Heuser, Chris. View Workplace Low Rise Case Study. N.p.: View Dynamic Glass, n.d. PPT.
• Khowal, Deepika. "View Windows at MCAS." Telephone interview. 28 Feb. 2014.
• "Marine Corps Air Station ‐ View." View. N.p., 2013. Web. 03 Mar. 2014. <http://www.viewglass.com/miramar.php>.
Smart Glass | University of San Diego, MSRE
Links + Resources continued• "Pros and Cons of Low‐E Windows." DIY Home Improvement Information. N.p., n.d. Web. 03 Mar. 2014.
<http://www.doityourself.com/stry/pros‐and‐cons‐of‐lowe‐windows#b>.
• "Smart Glass." Glazette. N.p., n.d. Web. 03 Mar. 2014. <http://www.glazette.com/Glass‐Knowledge‐Bank‐93/Smart‐Glass.html>.
• "Understanding Windows." Efficient Windows Collaborative. N.p., n.d. Web. 03 Mar. 2014. <http://www.efficientwindows.org/glossary.php>.
• Walsh, Dennis. "Smart Glass with a View." Green@work. Green@work, 12 Dec. 2013. Web. 03 Mar. 2014. <http://greenatwork.com/?p=694>.
• Wasco, Mick. "View Windows at MCAS." Personal interview. 27 Feb. 2014.
• "What Are Smart Windows." Ravenbrick. N.p., n.d. Web. 03 Mar. 2014. <http://www.ravenbrick.com/what‐are‐smart‐windows/how‐it‐works/>.
• "Windows and Glazing | ISustainable.org." ISustainable.org. N.p., n.d. Web. 03 Mar. 2014. <http://www.isustainable.org/windowsandglazing.php>.
• "Windows for High‐performance Commercial Buildings." Http://www.commercialwindows.org/. N.p., n.d. Web. 03 Mar. 2014. <http://www.commercialwindows.org/dynamic.php>.