Integrated Facades Symposium
Building Facades: Integrating Comfort and Energy Performance
Pacific Energy Center, SF, April 21, 2010
Defining and Measuring Performance
For High Performance Buildings
Stephen Selkowitz
Building Technologies Department
Lawrence Berkeley National Laboratory
SESelkowitz@LBL.GOV
Lawrence Berkeley National Laboratory
All new commercial
construction will be zero net
energy by 2030
Lawrence Berkeley National Laboratory
Driving Building Energy Use to “Zero”
Reducing Commercial Building Energy Use Index (EUI) from 90kBtu -> 15kBtu
Where we are today: average of stock
What we’ve
proven we can
do: Measured
case studies
Where we would be if all buildings were
built to current code
Where we could be with
current technologies
+ PV, wind, Biofuels
“Net Zero Energy Building”
Where we need to be for
Lawrence Berkeley
“net-zero-National
ready” Laboratory
3
U.S. Refrigerator Energy Use vs. Time:
Conclusion: its possible to reduce energy use by >75% and reduce costs!
United States Refrigerator Use v. Time
2,000
25
20
1,400
1,200
$ 1,270
Refrigerator Size
(cubic feet)
15
1,000
800
600
400
200
0
10
Energy Use per Unit
Refrigerator Price in 1983 Dollars
$ 462
5
Conclusion: Policy + technology + standards works
0
Lawrence Berkeley National Laboratory
Refrigerator volume (cubic feet)
1,600
19
47
19
49
19
51
19
53
19
55
19
57
19
59
19
61
19
63
19
65
19
67
19
69
19
71
19
73
19
75
19
77
19
79
19
81
19
83
19
85
19
87
19
89
19
91
19
93
19
95
19
97
19
99
20
01
Average Eerngy Use per Unit Sold (kWh per year)
1,800
Fenestration Impacts on
Building End Use Energy Consumption
5
Buildings consume 39% of total U.S. energy
•  71% of electricity and 54% of natural gas
42%
67%
Lawrence Berkeley National Laboratory
Building Innovation “Game Changers” for ZEB
6
Assumed: cheap, long lasting, reliable, specifiable, affordable, green, ….
MATERIALS AND SYSTEMS
LIFE-CYCLE OPERATIONS
•  Smart Glass/Dynamic Facades
•  High R Windows, Insulation
•  Thermal Storage
•  200 lumen/watt lighting
•  Daylight integration
•  Dimming, Addressable Lighting Controls
•
•
•
•
Task Conditioning HVAC
Climate Integrated HVAC
Building- and Grid- Smart electronics
Electrical Storage
•
•
•
•
•
•
Building Life Cycle Perspective
Benchmarks and Metrics
Building Information Models (BIM)
Integrated Design Process and Tools
Building Operating Controls/Platform
Building Performance Dashboards
•  Understanding Occupants
•  Facility Operators
Lawrence Berkeley National Laboratory
❏
❏
❏
1973: Typical Window:
❏  clear, single glazed,
❏  double or storm window in north,
❏  Uaverage = .85 BTU/hr-F-sq.ft.
2003: Typical Window:
❏  95% double glazed
❏  50% have a low-E coating
❏  30-65% energy savings vs. 1973
❏  Uaverage = .45 BTU/hr-F-sq.ft.
2030: Future Window:
❏  Zero net energy use (typical)
Net winter gain; 80% cooling savings
Uaverage = .10 BTU/hr-F-sq.ft.
Dynamic solar control
❏
❏
❏
2010 Cost
= $20B
What if all windows in commercial buildings were replaced
with...?
Today's
Tech.
Today's Typical Product
Future
Technologies
Current Stock
Dynamic
Low-e
Highly Insulating Dynamic
Saves
$15B
Heat
Cool
" " with Integrated Façades
Lighting Potential
-1.3
-1.0
-0.7
-0.3
0.0
0.3
0.7
1.0
Annual Primary Energy Consumption, Quads
1.3
Building Envelope as Dynamic Filter
Air Velocity
Dust, Dirt
Rain
Humidity
Air Velocity
Exterior Climate
Temperature
Outdoors
Large dynamic ranges
Highly variable over time
Humidity
Indoor
Env.
Temperature
Indoors
Limited dynamic ranges
Controlled over time
Lawrence Berkeley National Laboratory
Vision: “Zero-Energy Building”
Facades: Energy Losers --> Neutral --> Suppliers
Lawrence Berkeley National Laboratory
DOE Multiyear Performance Goals
Lawrence Berkeley National Laboratory
3 Pathways for Use of Glass in
Commercial Buildings
•  Just meet the code
–  Small Windows, prescriptive properties, e.g. double
–  No special shading or daylighting
•  Conventional “good” solutions: (prescriptive packages)
–
–
–
–
–
Modest sized windows, skylights
Double glazing
Spectrally selective glass
Manually operated Interior shading
On-off lighting controls
•  Architectural Solution with “Transparent Intelligent Façade”
–
–
–
–
–
–
Highly glazed façade; extended daylighted zone
Reliable tools reduce risk
High Performance technology with Systems Integration
Dynamic, smart control- automated shading, dimmable lights
Economic from Life cycle perspective
Optimized for people and for energy, electric demand
Lawrence Berkeley National Laboratory
Annual Source
Energy Use
Upper:
Cooling Energy
vs. Solar Aperture
Lower:
Lighting Energy
vs. Effective
Aperture
Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory
Definition of a “Smart”,
“Dynamic” Building Skin
Interior or exterior sensors that measure relevant
quantities that are used by the controller
Operable
façade
components:
Motors or
actuators for
shading
devices, lightredirecting
elements,
operable
windows, or
switchable
glass coatings
Control algorithms: Accepts input from sensors or
computations then determines how to position the operable
façade components
Lawrence Berkeley National Laboratory
Challenges!
Glass is “cheap” and “robust”
Dynamic Building Skin Issues:
•  Complexity
– Design
– Installation
– Operations
•  Cost
– $$
•  Robustness, Reliability
– Routine change, e.g. aging component
– Unexpected change, e.g. sensor failure
Lawrence Berkeley National Laboratory
•  Highly insulating systems
—  Reduces winter heating loads
—  Multiple technologies for glass
•
Aerogel
•
•
Vacuum glazing
Multipane, low-E gas fill
—  Better Frames
—  Climate dependence
—  Cost
•  Dynamic windows for daylight - solar control
—  Dynamic optical switch from high transmission to low transmission
—  Reduces summer cooling load; reduces glare
—  Multiple technologies
•
Electrochromic, thermochromic, photochromic, LCD,…
—  Integration with window, building
—  Cost
•  Air Flow/Ventilation Control
—  HVAC/Cooling
—  Comfort
page 19
Insulating Windows Can Become
Energy Producers in Cold Climates
Annual
Heating
Energy
Balance
Single Glaze: U = 1.1
Double Glaze: U = .5
Double, Low “e” U = .3 -.4 (Energy Star)
Window U = .1 - .2 (Triple or Vacuum)
- Loss
Window U < .1
+ Gain
1973 1980 1990 2000
2010
2020
Minneapolis: Heating Climates:
static high solar, hi-R (U=0.1 Btu/h-ft2-F) can meet ZEH goals
Annual energy use vs. window properties
Minneapolis, MN - Combined Annual Heating and Cooling Energy (MBtu)
1
single clear
145
0.8
140
135
0.7
130
125
120
U-factor
U
0.6
115
double clear
110
0.5
105
100
high gain low-e Ar double
0.4
95
low gain low-e Ar double,
typical Energy Star
0.3
low gain low-e Ar triple
90
85
moderate gain low-e Kr triple (acrylic center layer)
0.2
target performance region
0.1
0.1
0.2
0.3
0.4
0.5
75
energy
ws use
o
d
in
w
energy
provide
s
w
o
d
win
0.6
SHGC
SHGC
0.7
0.8
80
70
0.9
1
Combined Annual Heating and Cooling Energy (MBtu)
0.9
Residential Energy
Use (MBTU/yr) vs
Window Thermal
Properties (U,
SHGC)
Specific windows
plotted on map of
iso-energy use
House with no
windows uses
82MBTU
Riverside CA - Mixed Climates:
static medium solar, hi-R (U=0.1 Btu/h-ft2-F) can meet ZEH goals
Annual energy use vs. window properties
Riverside, CA - Combined Annual Heating and Cooling Energy (MBtu)
1
single clear
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
0.8
0.7
U-factor
U
0.6
double clear
0.5
high gain low-e Ar double
0.4
low gain low-e Ar double,
typical energy star
0.3
low gain low-e Ar triple
0.2
moderate gain low-e Kr triple (acrylic center layer)
target performance region
0.1
0.1
0.2
0.3
0.4
0.5
SHGC
0.6
SHGC
0.7
0.8
0.9
1
Combined Annual Heating and Cooling Energy (MBtu)
0.9
Residential Energy
Use (MBTU/yr) vs
Window Thermal
Properties (U,
SHGC)
Specific windows
plotted on map of
iso-energy use
Daylighting
•  Improve distribution of light within the
room to reduce glare,
•  Increase room cavity brightness,
•  Increase %year daylit to reduce electric
lighting energy
•  Architectural strategies
•  Light-redirecting technologies
•  Energy savings strategies
GTU Library, UC Berkeley
Lawrence Berkeley National Laboratory
(Day)Lighting Control Elements
A Systems Integration Issue
ballast controller
ballast
lamp
sensor
Selec +
Sdaylt
Ambient Illum
Fluorescent
Light
Task Illum
View
Daylight
Lawrence Berkeley National Laboratory
Good Lighting Controls (Daylight Dimming) Work
Daily Energy Use (6 A.M to 6 P.M.)
kWh/12 hr/zone
40
G
South Daylit
J
North Daylit
Reference
H
35
30
25
20
15
10
5
HH
H
H
H
HH
H
H
H
H
H
H
H
H H H
HH
H
H
H
H
H
HH
H
H
HH
H
H
HH
H
H
H
HH
H
H
H HH
H
H
H
HH
H
HH
H
H
HHH
H
HH
H
H
H
H
H
H
H
H
HH
HH
H
H
H
H
HH
HH
H
H
HH
HH
H
HH
H
H
HH
HH
HH
HH
H
H
H
H
H
H HH
HH
H
H
H
H
HH
H
H
H
H HH
H
H
H
H
H
H
HH
H
H
H
H
H
H
HH
H
H
H
HH
H
H
H
H
H
H
H
HH
H
HH
H H H
H
H
H
H
H
H
HH
HH H H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
HHHH HH HH H
H
H
H
HH
HHHH
HH H
HH
H
H
HHH
HH
H
HHHH
HH
H
40-60%
Savings
40-80%
SavingsG
G
GGG
G G
G
J
GGG G GG
GGG
G G
GG G
JG
G
G
G
G
G
G
G
G JG
G
J
GGG
G GG GGG
G
G
GG
GGGG
G
G
G GG G
JGJJJJJ JJG
J JG
J
G GG
JJJJJJJG
G
G
G
G
G
G
G
G
G
G
JJJJJJG
G
G
G
G
G
G
G
JG
JJJJG
GG G
G
G
G
G
J
G
G
G
G
GGGJ
G
G
G
G
G
G
G
G
G
J
G
G
G
G
G
G
J
J
J
G
JG
JG
G
G
G
G
G
G
G
G
G
G
J
G
G
G
G
J
G
JJ GJG GGG HG GG
G
G
G
G
G
G
G
G
G
J
G
J
G
G
G
G
G
G
G
J
G
G
G
G
J
J
J
J
GGG GG
G G G
G
G
JJ JJJJJJJJ J
GG
G
G
JJ JJ JJJJJJJJJJJJJJJ JG JG GG GG
G GJG GGGG
G
GG
GGG
G
G
GGG G
GG
GG
GG
GG
JJJJJJJ J J
G G
GGGG GGGGGG
G
GG
JJJ J
G
G
G
J
G
G
G
G
G
G
J
G
G
G
J
J
G
G
G
J
J
G
GG
G
G
G
G
G
GG
G GG
JJ J
G
J JJJJ JJJ
JJJJJ JJ J
JJ
J
J
J
J
J
J
JJ JJJJ
J
J JJ JJJJJJJJ
J
JJJ J JJJ JJJ
JJ JJ
J
J JJJJJJJJ JJJ JJJ J J J JJJJJJJJJ JJJJJJJJJJJJ JJ JJJJ
G
J
J
J
J
J
J
J
J
J
J
J
J
J
J
J
JJ
J
G
J
J
J
J
G
J
J
J
J
J
J
J
J
JG
J
J JJJJJJJ J
G
JG
J
J
J
0
H
JG
H
0
50
100
150
H
200
Day of Year 1990
H
JG
H
250
300
H
350
Data from
advanced
lighting controls
demonstration
in Emeryville, CA
(1990)
!!!
Energy Use
before retrofit:
After retrofit:
South zone:
North zone:
Dimming is 3% of
lighting sales
Lawrence Berkeley National Laboratory
“In God We Trust”,
All Others Bring Data
An understanding of what to do in the future should be
built on a foundation what works and how well, either
based on, or derived from, measured performance.
Design intent, expectations, and wishful thinking will
not reduce energy and carbon use
Lawrence Berkeley National Laboratory
LBNL Glazing/Shading
“User Facilities”
•
•
•
•
•
•
•
•
•
Façade test facility/testbed
Mobile Thermal Test Facility
IR Thermography chamber
Large integrating sphere
Optics laboratory
Scanning Goniophotometer
HDR Imaging
Field Data Collection systems
Commissioning systems
•  Virtual Building Controls Testbed
•  Lighting controls laboratory
Lawrence Berkeley National Laboratory
LBNL Façade Testbed Facility
Highly instrumented, assess occupant response as well as energy balance
2003-2006
Electrochromic
windows w/
daylighting
Industry Advisory
Group:
Manufacturers
Glazing, Shading
Framing, Lighting
Controls
Designers
Architects, Engineers
Specifiers
2007-2009
Automated Shades
w/ daylighting
Owner/Operators
Public, Private
Utilities
Lawrence Berkeley National Laboratory
Automated daylight blind: concave-up slats with
mirrored coating in upper zone and light grey
finish in lower zone
Lawrence Berkeley National Laboratory
Time Lapse of Interior Room Luminance
with Dynamic Shading
Lawrence Berkeley National Laboratory
LBNL Integrated Building Systems User Facility
6 New Testbeds under Development
LBNL
Net‐Zero
Energy
Buildings
User
Facility
Concept
4th Floor
E q u ip m en t
Ro o m
#1
Integrated
Building
Systems
Testbed
#5
3rd Floor
Intelligent
Building
Controls
Testbed
Ground
level
#3
Roof
Systems/
Skylight
Testbed
#2
#6
#4
Façade/
Low
Energy/Low
Demand
Daylighting
HVAC
Systems
Systems
Integration
Testbed
Integration
Testbed
Building
Interiors
Integration
Testbed
#7
Virtual/Hybrid
Building
Controls
Testbed
#8
Virtual
Design
Environment
Testbed
Lawrence Berkeley National Laboratory
Pilot Demonstration:
Emerging Integrated System
•  Site: conference room
in DOE building;
retrofit
•  Monitoring underway
•  Separate control of
view and daylight
•  Electrochromic
Windows:
–  Automated control
–  Manual override
•  Lighting controls:
–  DALI dimmable
ballasts
–  Architectural scenes,
occupancy, daylight
controls
Lawrence Berkeley National Laboratory
Managing glazing and lighting for
Electric Load Management
Typical commercial
building load profile
30000
30000
25000
25000
A/C
20000
15000
20000
Peak demand reductions
during curtailments
Lighting:
Air conditioning:25%
Other:
Dimmed
lighting
15000
Lighting
10000
75%
10%
A/C
10000
Other
5000
Other
5000
0
1
3
5
7
9
11
13
15
Time of Day
17
19
21
23
0
1
3
5
7
9
11
13
15
17
Time of Day
Lawrence Berkeley National Laboratory
19
21
23
Exploring Intelligent Control Systems
Task
Requirements
Dynamic
Window
(active control of daylight,
glare, solar gain)
User
Preferences
Interior Conditions
Smart
Controllers
Lighting
Systems
(with dimming
ballasts, sensors)
Weather
Conditions
Load Shedding/
Demand Limiting
Signal
Sensors, meters,…
Energy Information
System
Building
Performance
(cost, comfort,
operations)
Lawrence Berkeley National Laboratory
H
V
A
C
Building Controls Virtual Testbed (BCVTB)
Lawrence Berkeley National Laboratory
Active Fenestration Control is
key to Cooling Strategy
Morphosis/Arup design/GSA Owner
Outcome: “Class A” office building;
•  Comfortable work environment
•  First cost savings, operating savings
•  Key: quantify performance and risk
Status: Occupied 2007
Extensive Energy design assessment
•  Extensive climate, energy modeling
•  Comfort analysis under peak conditions
•  CFD modeling for air flow details
—  Orientation, section, plan optimized
—  Automated operable windows and night
vent cooling
—  Exposed concrete ceiling stores “coolth”
—  No mechanical cooling for perimeter offices
in tower
page 36
— Control system development, testing
— Commissioning process developed
— Post-occupancy evaluations planned
Testbeds - > Market Impact
Owners program:
•
•
Highly glazed façade gives workers views
and allows the city to see “news” at work
But glare, cooling, visibility etc
Need/Goal:
•
Develop integrated , automated shading and
dimmable lighting system
—  Affordable, reliable and robust
•
Transform the market- push these solutions
toward widespread use
Challenge:
•
•
page 37
How to develop a workable, affordable
integrated hardware/software solution
How to “guarantee” that such a solution will
work in practice
Renzo Piano/ Fox & Fowle/ Gensler/
Flack+Kurtz/ Susan Brady Lighting
Façade Layers
External layer: Fixed
-- Shading, light diffusion
Glazing layer: Fixed
-- Low-E, spectrally selective
- thermal control
- solar gain control
-- Frit - solar, glare control
Internal layer: Dynamic
-- Motorized Shade system
-- Solar control
-- Glare control
Façade Layers: Floor to Floor
floor to desk
desk to head
head to ceiling
plenum
Lawrence
Berkeley National Laboratory
North
A
•  Shading,
daylighting,
employee feedback
and constructability:
~4500 sf mockup
•  Concerns with glass
facade:
—  Window glare (Tv=0.75)
—  Control of solar gain/cooling
—  Daylight harvesting potential
•  Real sun and sky
conditions near
construction site,
12-month monitored
period
page 39
B
•  Automated Shaded
•  (Multifunctional)
•  Dimmable lighting
•  Addressable
•  (Affordable)
(1/3 original cost estimate)
•  (Multifunctional)
Occupied 2007
New York Times office with dimmable
lights and automated shading
High Performance Windows need
Skilled Architects & Engineers
•  Do architects and engineers have the expertise
and/or tools to “optimize” designs of intelligent
facades?
•  Other impacts:
– Specification
– Construction
– Commissioning and Acceptance
– Occupant training
– Facility manager training
Lawrence Berkeley National Laboratory
culation
ording to
metric
acteristics)
Software Tools
Download from http://windows.lbl.gov/software/
Optics
IGDB
(Window
Glass)
(Specular
Glass Data
Source)
calculation
THERM
(Window
Frame)
calculation
CGDB
WINDOW
(Complex
Glazing Data
Base)
Design /
Simulation Tools
DOE-2, EnergyPlus
Radiance
(Whole Window)
COMFEN
(Whole Building
Commercial)
RESFEN
(Whole Building
Residential)
Lawrence Berkeley National Laboratory
Modeling Visual Performance
and Comfort
RADIANCE
simulation of
conventional and
electrochromic
windows for
different day types
and seasons in
Phoenix, Arizona.
Façade Design Tool
http://www.commercialwindows.org
COMFEN: Estimating Energy and Daylighting
Impacts in Early Design
Sample Output
Overview
Performance
Relative Cost
Energy
Thermal Comfort
Benchmarks
Design Advisor
Façade Gain
Daylight Penetration
Advanced Façade and
Daylighting Systems
•  Tremendous exploratory phase in progress in real projects
–  What works, how well, how to improve?
•  Dynamic, Responsive systems essential
–  Maximize energy performance and satisfaction
–  Static systems inadequate, particularly with large glass area
•  Areas for Innovation with integration:
–  Sun control, daylight control, glare control
–  Ventilation, Air flow- heat extraction
–  Sensors and controls
•  Key Issues:
–  Glass Area “Debate”- optimal size??
–  Engineering vs Occupant Comfort, Satisfaction
–  Design -> engineering -> installation
–  Performance feedback: Operations --> Design
–  Tools for Design, Analysis, Optimization
Lawrence Berkeley National Laboratory
–  Cost, Reliability
Facades and Zero Energy
Building Performance Issues
•  Importance of Building Controls
– “Smart” controls
– Self-diagnostic
– Learn from occupants
– Address “Conflict”: Occupant- owner-utility
•  Dynamic Load management
– Electricity cost and availability
– Rethink relationship of building to “grid”, autonomy
•  Occupant issues
– Better environments for people
– How do people interact with their built environment?
•  Understanding and quantifying costs and risks
Lawrence Berkeley National Laboratory
Commercial Building Performance
Issues, Trends, Needs
Lawrence Berkeley National Laboratory
Information Technology-based Building
Life-Cycle Performance View
Interoperable
Tools, open building
information model
BIM
Metrics,
Maintenanc
e&
Operations
Automated
Diagnostic
Tools
buildingSMART
International
Alliance for
Interoperability
IAI
Program
Requirements
Retrofit
Tools
Building
Information
Model
Information Monitoring
& Diagnostic System
Energy Analysis
And
Design Tools
Commissionin
g
Tools & Active
Tests
Lawrence Berkeley National Laboratory
Web-based Decision Support Tool
“Action-oriented benchmarking”
extends whole-building benchmarking
Whole Building
Energy Benchmarking
Action-Oriented
Energy Benchmarking
Investment-Grade
Energy Audit
Screen facilities for overall
potential
Identifies and prioritizes
specific opportunities
Estimates savings and cost for
specific opportunities
Minimal data requirements
(utility bills, building features)
Requires sub-metered end-use
data; may require additional
data logging
Requires detailed data
collection, cost estimation,
financial analysis
Highly applicable for RCx and
CCx
Necessary for retrofits with
capital investments
Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory
Making Performance Visible
Ex: European building energy certificates
•  Display energy certificates based on
actual energy use, not just theoretical.
We need to save real, not virtual
emissions.
•  Transparency between expectations and
outcomes.
•  Multiple performance indicators
•  California is launching similar initiatives,
e.g. AB1103
•  Subtleties:
–  Asset Rating
–  Operational Rating
Lawrence Berkeley National Laboratory
Life-Cycle Owner Costs in Perspective
% of 30-year Total Owner Cost
•
•
•
•
Design Fees:
Construction:
Annual operations:
Staff Salaries
<1%
4%
12%
84%
Lawrence Berkeley National Laboratory
Annual Energy Costs in Perspective
Cost / Sq. M. Floor -Year
•
•
•
•
•
Energy Cost:
$20.00
Maintenance:
$30.00
Taxes:
$30.00
Rent:
$300.00
“Productivity” $3000.00
Lawrence Berkeley National Laboratory
Importance of Comprehensive
Balanced Program
People
Technology
Policy
Process
Markets
Economics
Solutions fail without this balance
Lawrence Berkeley National Laboratory
Approaching a Zero Energy Future
•  “If I had asked people what they wanted, they would
have said faster horses."
– Henry Ford
•  The best way to predict the future is to invent it
– Alan Kay
•  Think Big, Start Small, Act Now
Lawrence Berkeley National Laboratory
Information Resources
Stephen Selkowitz
Building Technologies Department
Lawrence Berkeley National Laboratory
Building 90-3111
Berkeley, CA 94720 USA
E-mail: SESelkowitz@lbl.gov
More Info:
http://windows.lbl.gov
New York Times project
http://windows.lbl.gov/comm_perf/newyorktimes.htm
Advanced Facades project
http:lowenergyfacades.lbl.gov
http://gaia.lbl.gov/hpbf
Commercial Web Site
http://www.commercialwindows.org
http://buildings.lbl.gov
Lawrence Berkeley National Laboratory