Buildings and Energy
Les Norford
Building Technology Program
Department of Architecture
Massachusetts Institute of Technology
CEE 1.964
Design for Sustainability
November 1, 2006
Outline
1. Buildings and energy – some data
2. Residential buildings
3. Commercial buildings
4. Buildings in other (mainly
developing) countries
† 5. Is current progress good enough?
†
†
†
†
CEE 1.964
Design for Sustainability
Global energy consumption
500.000
450 EJ = 14.3 TW
450.000
400.000
350.000
World Total
North America
Central/South America
Western Europe
250.000
Eastern Europe Former USSR
Middle East
200.000
Africa
Asia and Oceania
150.000
100.000
50.000
Year
CEE 1.964
Design for Sustainability
20
02
20
00
19
98
19
96
19
94
19
92
19
90
19
88
19
86
19
84
19
82
0.000
19
80
EJ
300.000
Does energy use correlate with quality of life?
Energy Consumption per Capita (MJ/Day)
Physical Quality of Life Index
100
0
40
80
120
160
200
80
Agric Exporter
60
Other Agric
Primary Exporter
Oil Exporter
Industrialized Countries
Balanced Economics
40
20
0
0
0.50
1.00
1.50
2.00
2.50
Kilowatts per Capita
CEE 1.964
Design for Sustainability
Figure by MIT OCW.
Source: Goldemberg et al.
Residential buildings
Transport
21%
27%
18%
34%
U.S. energy
end-use
Commercial
buildings
Industry
Figure by MIT OCW.
Total energy–
buildings 39%
Transport
0%
Residential
buildings
Industry
29%
36%
35%
Commercial buildings
CEE 1.964
Design for Sustainability
Figure by MIT OCW.
Electricity –
buildings 71%
Source:EIA
U.S. residential and commercial building
energy use intensities
Energy use intensity, GJ/m2
2.5
2.0
1.5
residential primary
residential site
1.0
Apparently not a lot of
progress in 25 years
0.5
0.0
1975
1980
1985
1990
1995
2000
2005
year
Energy use intensity, GJ/m2
2.5
2
1.5
commercial
primary
commercial site
1
0.5
0
1975
1980
1985
1990
1995
year
CEE 1.964
Design for Sustainability
2000
2005
1 GJ/m2 = 277 kWh/m2
Residential buildings end-use energy 2003
CEE 1.964
Design for Sustainability
Commercial buildings end-use energy 2003
CEE 1.964
Design for Sustainability
2. Residential buildings: savings
potential in new construction
† 30%: little or no increase in first cost
† 50%: about the same life-cycle cost
† Net-zero energy or carbon neutral: much
harder
† How? INTEGRATED, SYSTEMS DESIGN
„
„
„
„
Better walls
Better windows
Smaller HVAC equipment
Better appliances
Savings relative to early 1990s benchmark
CEE 1.964
Design for Sustainability
Doing better with houses: lots of
insulation!
Flickr photo courtesy of
Smalloy.
CEE 1.964
Design for Sustainability
-10
CEE 1.964
Design for Sustainability
00:13.0
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30:13.0
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30:13.0
45:13.0
00:13.0
Temperature (degrees C)
Taking advantage of free heating
for “elfhouse”
60
50
40
30
20
10
0
Time (hours)
Average Temperature First Week = 16.9 deg C
Average Temperature Second Week = 17.3 deg C
Insulation, glass and mass for a fullsize house
image: Montgomery Co.
Public Schools, VA
www.mcps.org
† Walden made of 15 cm extruded polystyrene (no
openings, no airflow):~1,000 W of heat needed at 0
oF.
† Henry David needs fresh air, which requires another
500 W to heat.
CEE 1.964
Design for Sustainability
Walden with south-facing, double-pane
glazing and water for thermal storage
Indoor and outdoor temperatures
40
30
temperature (oC)
20
10
Tout
Tin,n
0
1
10 19 28 37 46 55 64 73 82 91 100 109 118 127 136 145 154 163
-10
-20
-30
time (hour)
5 m2 glazing, 1000 kg water
CEE 1.964
Design for Sustainability
Building America
USDOE-sponsored partnerships between consulting
engineers and building industry, leading to
prototypes and large-scale production
† ~33,000 houses constructed
† Goals
„ Design and construct more energy efficient homes
„ Reduce construction costs to provide more affordable
housing
„ Improve comfort
„ Improve health and safety and indoor air quality
„ Increase resource use efficiency
„ Increase building durability
† Energy target: 35-45% reduction in heating, cooling
and hot-water energy use
†
CEE 1.964
Design for Sustainability
Glazing
Annual Cooling Energy Cost for a Typical House in Phoenix, AZ
$0
Window Type
$200
$400
$600
visible
$800
Single clear
Aluminum frame
Single tint
Aluminum frame
Double clear
Wood/Vinyl frame
Double clear
Low-solar-gain low-E
Wood/Vinyl frame
Full spectrum
6% Savings#
~1/2 visible,
1/2 infrared
16% Savings#
32% Savings#
Annual Heating Energy Cost for a Typical House in Boston, MA
Window Type
$0
$400
$800
$1200
27% Savings#
Double clear
High-solar-gain low-E
Wood/Vinyl frame
32% Savings#
Triple clear
Mod.-solar-gain low-E
Insulated frame
39% Savings#
Visible
transmittance
$1600
Single clear
Double clear
Double low e
Double low e tint
Double low e, Ar fill,
spectrally selective
Single clear
Aluminum frame
Double clear
Wood/Vinyl frame
Window
0.90
0.81
0.76
0.45
0.72
Solar heat
gain
coefficient
0.86
0.76
0.65
0.35
0.40
#Compared to the same 2000 sf house with clear, single glazing in an aluminum
frame.
Figure by MIT OCW.
CEE 1.964
Design for Sustainability
http://www.efficientwindows.org/BuilderToolkit.pdf
The builders’ perspective: pros and cons
† Durability is key
„
„
„
„
Better moisture management
Fewer warranty problems
Happier customers and builders
More referrals, sales
† Less construction waste
„
„
Fewer dumpsters
Reduced tipping fees
† New construction system to learn
† New concepts may require changes to local building
codes
CEE 1.964
Design for Sustainability
The systems approach
Feature
Advanced framing
Insulating sheathing
Insulate basement
Slab-edge insulation
Unvented, conditioned attic
Eliminate roof vents
Eliminate housewrap
High-performance windows
Reduce infiltration
Controlled ventilation system
Locate ducts in conditioned
space
Simplify or downsize duct
distribution
Downsize air conditioner
High-efficiency, direct-vent
furnace
Power-vented gas water
heater
Dehumidifier
Set-back thermostat
Total premium
Annual homeowner savings
CEE 1.964
Design for Sustainability
Minneapolis
-250
Grayslake,
IL
-250
0
+600
Atlanta
Tucson
Banning,
CA
+250
+400
+200
+250
+150
+1,000
+100
+125
0
-250
-300
-350
-750
+750
+300
+750
-500
+750
-400
+250
+300
+750
+150
+150
+250
-750
-1,000
+400
+400
+100
390
+2,150
370
+150
+175
-150
225
+100
+1,525
480
-25
400
Refrigerators
1974, California law authorizes
energy-efficiency standards (1,825 kWh)
Annual energy consumption (kiloWatt-hours)
2000
1977, first California standards take effect (1.546 kWh)
1600
Average before U.S. standards
(1,074 kWh)
1200
1990 U.S. standard (976 kWh)
800
1993 U.S. standard (686 kWh)
400
2001 U.S. standard (476 kWh)
0
1960
1970
1980
1990
2000
Time (years)
Source: Collaborative Labeling and Appliance Standards Program
CEE 1.964
Design for Sustainability
Figure by MIT OCW.
Lighting efficacies
Standard Incandescent
Tungsten Halogen
Halogen Infrared Reflecting
Mercury Vapor
Compact Fluorescent (5-26 watts)
Compact Fluorescent (27-40 watts)
Fluorescent (Full size and U-tube)
Metal Halide
Compact Metal Halide
High Pressure Sodium
White Sodium
0
20
40
60
80
100
Lumens/watt
lamp plus ballast
Source: IESNA
CEE 1.964
Design for Sustainability
Figure by MIT OCW.
Potential gain from solid-state lighting
Efficiency (lm/W)
200
Projected
with accelerated
effort
100
Fluorescent
Semi-conductor
0
without
accelerated
effort
Halogen
Incandescent
1970
1980
1990
2000
2010
2020
Year
Source: Sandia National Lab
CEE 1.964
Design for Sustainability
Figure by MIT OCW.
Residential clothes washers and
central A/C
Residential A/C peak power
Washing machine energy
3.5
6
3.0
5
peak-load kW
kWh/cycle
2.5
2.0
1.5
1.0
4
3
2
1
0.5
0
0.0
Federal
2004
Energy Star
2004
Aailable
2006
Federal
2007
Energy Star
2007
1978
average
Federal
1992
Federal
2006
Energy
Star 2006
Manufacturers identify Energy Star products. A/C and
furnace/boiler producers list efficiencies but clothes washer
manufacturers do not tout energy consumption for their
equipment, which only costs ~$20/year in electricity
CEE 1.964
Design for Sustainability
Available
2006
GSHP
2006
Lakeland, Florida, PV house
Annual energy use, kWh
2500
Photograph of a
photovoltaic house.
Image removed for
copyright reasons.
4700
18400
net
Better choice of envelope construction would
drop payback period from 23 to 9 years
without PV and 40 to 28 years with PV.
CEE 1.964
Design for Sustainability
PV
efficiency
Habitat for Humanity houses, Tennessee –
Oak Ridge National Lab
† Five low-energy houses with very advanced technologies:
wall panels, mechanical ventilation, waste-heat scavenging
for hot water, PV
† Heating, cooling and hot water costs about $0.70/ day (!!)
† “Other” costs $1.00-1.38/day – Christmas lights (!!)
† Research houses: not cost effective locally ($20K efficiency
investment to save $400/year)
CEE 1.964
Design for Sustainability
NREL’s rational approach to efficiency
and zero-net energy in houses
Source:
Ren Anderson, NREL
CEE 1.964
Design for Sustainability
Automated search for best combination of
improvements
CEE 1.964
Design for Sustainability
Tuning efficiency investments for a
given location
CEE 1.964
Design for Sustainability
PV is expensive, at least for now
Savings at
minimum
cost, %
Present value
of efficiency
investment,
minimum cost,
$
Atlanta
32
Chicago
Savings at
NZE, %
Present value
of efficiency
investment,
NZE, $
PV cost
1,749
49
10,351
42,000
28
3,899
46
15,168
57,000
Houston
38
2,585
51
8,762
46,500
Phoenix
39
2,585
52
9,553
40,500
San Francisco
27
1,337
43
8,432
36,000
Location
CEE 1.964
Design for Sustainability
Figure by MIT OCW.
Solar Decathlon National Mall 2005
CEE 1.964
Design for Sustainability
Canadian Solar Decathlon House
Heat recovery from PV boosts efficiency from ~8% to ~35%
CEE 1.964
Design for Sustainability
3. Commercial buildings
† Systems approach is lacking
„
„
„
„
No Building America equivalent
Optimization tools are not as well developed
Standards do not take systems approach
Few buildings go beyond basic code compliance
† Notable successes
„ Individual buildings, 1/3 -1/2 below average
„ Expanding data base of high-performance
buildings
„ Private-sector labeling program (LEED) a help
„ Guideline for small commercial buildings
CEE 1.964
Design for Sustainability
Massachusetts State Transportation Building,
Boston: a 20-year oldie but goodie
Aerial photograph of the State
Transportation Building.
Image removed for copyright reasons.
CEE 1.964
Design for Sustainability
Atrium as thermal buffer, source of daylight
and central plaza
Photographs of atrium.
Images removed for copyright reasons.
CEE 1.964
Design for Sustainability
What’s missing in this schematic?
AC-1
cooling
coil
AC-2
cooling
coil
AC-3
cooling
coil
AC-4
cooling
coil
CT-1
CT-2
CHWR
Perimeter
Zones
CWS
HWR
Storage Tank 3
Condenser
water pumps
HE-3
Chilled
water pumps
Hot water
pumps
Storage Tank 3
HE-2
RU-1
Storage Tank 1
HE-1
RU-2
RU-3
CWR
HWS
CHWS
KEY
HWS = Hot water supply HWR = Hot water return CWS = Condensed water supply
CHWS = Chilled water supply CHWR = Chilled water return
CWR = Condensed water return
Hint: not what you would expe ct in New England winters
CEE 1.964
Design for Sustainability
Figure by MIT OCW.
Potential for wasted energy: simultaneous (same
instant, same day) heating and cooling
Perimeter zone
Mild weather: perimeter may
need heat in early morning,
cooling in afternoon (like
houses)
Core
Year-round: core needs
cooling constantly, even
when perimeter must be
heated
CEE 1.964
Design for Sustainability
Energy consumption
† 173 kWh/m2 year (277 – US average)
† End use energy:
„
„
„
„
„
„
„
Lights 41.6% (13.7 W/m2 peak)
Variable mechanical 26.1%
Steam 11.2%
Appliances 5.4%
Elevators 6.2%
Computer rooms 5.4%
Base mechanical 4.0%
CEE 1.964
Design for Sustainability
Is this a low-energy building?
† 173 kWh/m2 yr transp bldg
† 653
state office bldg
† 717
state office bldg
† 270
comm office bldg
† 196
comm office bldg
† 186
comm office bldg
The lower-energy buildings all recover
heat from the building core
CEE 1.964
Design for Sustainability
UK Office #1
† Three-story office
building
† 5,100 m2 (54,900
ft2) net floor area
† Sealed windows
† 100% mechanical
conditioning
† 1+ year of
monitoring and
modeling
CEE 1.964
Design for Sustainability
Photograph of office building.
Image removed for copyright
reasons.
Open atrium but closed conference rooms
Photographs of atrium.
Images removed for copyright reasons.
CEE 1.964
Design for Sustainability
Airflow Measurements
Very important!! Air must be heated
or cooled, seasonally
40 L/s-person
Photograph of people taking
airflow measurements.
Image removed for
copyright reasons.
About four times code
requirements
One-half expected occupancy
Conference rooms controlled
design
Heat-recovery system broken
CEE 1.964
Design for Sustainability
CO2 in conference rooms
1200
CO2 Levels (ppm)
1000
800
600
400
200
Outside CO2 Levels
= 415 ppm
0
Sun Sun Mon Mon Tue Tue Wed Wed Thur Thur Fri Fri Sat Sat
12am 12pm 12am 12pm 12am 12pm 12am 12pm 12am 12pm 12am 12pm 12am 12pm
CO2 levels were typically well below the 1000 ppm limit
CEE 1.964
Design for Sustainability
Figure by MIT OCW.
Savings due to heat recovery and lower airflow
CO2 emissions, kg/m2
Energy consumption, kWh/m2
Natural gas
Electricity
Total
30.8
162
71.7
156
102.5
318
Current
19.8
airflow and
104
heat recovery
71.7
156
91.5
260
Reduced
24.7
airflow and
130
heat recovery
45.0
98
69.7
228
Current
CEE 1.964
Design for Sustainability
Savings potential due to better
operation of buildings
† California: energy crisis
„ 9% electrical demand reduction in 2001
relative to 2000, due to increased prices
† Texas: continuous commissioning
„ 20+% energy savings in 100+ large
buildings, less than 3 year payback
„ For 20 buildings
† 28% savings in chilled water
† 54% savings in hot water
† 2-20% savings in electricity (fans, pumps)
CEE 1.964
Design for Sustainability
UK Office #2: nearby, naturally ventilated
building
The following pages contained
photographs of the office building,
atrium views, interior views
including windows and blinds,
exposed structural mass, and open
doors for airflow.
Images removed for copyright
reasons.
CEE 1.964
Design for Sustainability
CEE 1.964
Design for Sustainability
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Temperature (C)
Interior Temperatures: July 2003
Luton July 2003
ground floor average
first floor average
second floor average
outside
35
30
25
20
15
10
5
0
CEE 1.964
Design for Sustainability
8/31/2003
8/30/2003
8/30/2003
8/29/2003
8/28/2003
8/27/2003
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8/26/2003
8/25/2003
8/24/2003
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8/3/2003
8/2/2003
8/1/2003
8/1/2003
Temperature (C)
Interior Temperatures: August 2003
Luton August 2003
outside
First floor average
Ground floor average
40
Second floor average
35
30
25
20
15
10
5
0
Results from occupant survey – views on temperature
Occupant Response (%)
100
80
60
Too Hot
Hot
Warm
40
20
0
1) Warm inside building
this summer but...
2) Not overly hot for
most occupants
Slightly
warm
Neutral
Temperature
Figure by MIT OCW.
CEE 1.964
Design for Sustainability
Comparison of UK #1 and UK #1,
kWh/m2 year
MV std MV GP
NV std
NV GP Sunbury Luton
UK #1
UK #2
A
Total
NG
178
97
151
79
162
140
Total
elec
226
128
85
54
156
76
L +OE
85
50
65
42
55
51
Refrig
31
14
0
0
29
0
Fans +
cntls
60
30
8
4
50
5
CEE 1.964
Design for Sustainability
Dealing with conference rooms:
San Francisco Federal Building
CEE 1.964
Design for Sustainability
Façade details coordinated
• Trickle vent and heater
at floor
• Manual operable window
at desk height
• Motorized window above
3250 (conc. high pt.)
2800 (Top of cabin)
1350
800
2400
740
CEE 1.964
Design for Sustainability
3050 (conc. low pt.)
870
Figure by MIT OCW.
WINDOW WALL CONDITION
TYP BOTH SIDES MAX
ALLOW CLEAR OPENING TO
BE 90MM TYP
2250 @ 14th Floor
(width Varies)
PERF
SUNSCREEN
Testing the configuration: predicted
degree-hours above base temperature
Base
temperature (oF)
Wind
only
Internal
stack
Int & ext
stack
Int stack +
wind
Int & ext stack +
wind
72
288
507
432
279
285
75
80
118
103
76
76
78
13
25
19
11
12
CEE 1.964
Design for Sustainability
DOE’s high performance buildings
data base
4 Times Square 201 kWh/m2
simulated; daylight, fuel cells,
a little PV
EPA office, NC, 89 kWh/m2
simulated; shading, daylight,
outside air when suitable
CEE 1.964
Design for Sustainability
Chesapeake Bay Foundation
Fans/pumps
0%
Lights
26%
26%
20%
Cooling
Plug loads
20%
8%
Other
Heating
Figure by MIT OCW.
Chesapeake Bay Foundation, Annapolis 131 kWh/m2 measured
consumption, 117 kWh/m2 purchased, 10% of consumed energy
generated from solar thermal and PV on site; shading, daylight, natural
ventilation, ground-source heat pumps
CEE 1.964
Design for Sustainability
Zion National Park Visitor Center
Image courtesy of the National Park Service.
CEE 1.964
Design for Sustainability
California Courthouse
candidate for night cooling
Photograph of courthouse windows.
Image removed for copyright reasons.
CEE 1.964
Design for Sustainability
Annual Building-Total Electricity Costs
Ratchet
On-Peak kW
Mid-Peak kW
On-Peak kWh
Mid-Peak kWh
Off-Peak kWh
Annual Electricity Cost (k$/year)
200
160
120
80
40
0
1
2 3
4 5
6 7 8
9 10
11 12 13 14 15
Case #
CEE 1.964
Design for Sustainability
Figure by MIT OCW.
Energy Design Guide for Small
(< 20,000 ft2) Commercial Buildings
† 30% savings relative to 1999 standard
† Strategies
„ Reduce loads
„ Use properly sized, efficient equipment
„ Refine systems integration
† Climate-specific prescriptive
recommendations:
„ roof, walls, floors, slabs, doors
„ windows, skylights, lighting
„ HVAC, ventilation, and hot water
CEE 1.964
Design for Sustainability
4. Good enough?
† Lifestyle vs. efficiency
† Market acceptance and technology
gains for lights, appliances and HVAC
† Growing but still modest evidence of
cost-driven efficiency gains
† Opportunity to contribute to carbon
stabilization
† Integrated design needs to be pushed
CEE 1.964
Design for Sustainability
Floor area counters efficiency gains
2500
Single-family
(median)
2000
US New Housing
Floor Area: Single-Family
(1950-2000)
1500
Floor
area/cap
1000
Single-family (mean)
500
0
1950
1960
1970
1980
1990
2000
Year
Figure by MIT OCW.
CEE 1.964
Design for Sustainability
Source: LBNL report
Major potential gains from market
acceptance
† CFL sales up 10x in Northwest, 2001 –
2004, but only 11% of market during
energy crisis (source: J. DiPeso)
† High-efficiency appliances and HVAC are on
the market now
„ Clothes washers 2x code efficiency
„ Residential A/C 1.5x code efficiency
† Near-maximum efficiency gains have been
realized in some cases: fridges, furnaces
CEE 1.964
Design for Sustainability
Atmospheric CO2 stabilization wedges
–Pacala and Socolow
Renewable electricity
and fuels
14 GtC/y
CO2 capture
and storage
Forests and
soils
Stabilization
Triangle
2004
7 GtC/y
2054
Energy efficiency
and conservation
Fuel switch
Nuclear Fission
Efficiency option: cut building and appliance emissions by 25% relative to business as usual
CEE 1.964
Design for Sustainability
Figure by MIT OCW.
To-do list
† Promote market acceptance
„ Information
„ Carbon tax
„ Emissions trading at micro-level
† Work to do
„ Cheaper, more efficient technologies
† Lights
† PV, using waste heat
† Ventilation: demand-controlled, heat recovery,
night cooling
„ Ubiquitous integration tools for new construction and
retrofits
† Individual buildings
† Communities (heat capture, local power
generation)
† Component-level optimization is NOT enough!!
Think at systems level.
CEE 1.964
Design for Sustainability