building energy benchmarks and rating tools
TRANSCRIPT
WHITE BOX TECHNOLOGIES
Building energy benchmarks and rating tools
Joe Huang
White Box Technologies
Moraga CA USA
The first China-US Energy Efficiency Forum
Shangri-La Hotel
Beijing CHINA
May. 26, 2010
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What are building energy
benchmarks and rating tools?
• Yardsticks to help us measure how well a building
performs, or should perform, in terms of energy use.
• Benchmarks establish an energy use intensity
(Btus/ft2 or W/M2) or efficiency level for a type of
building in a certain climate region that can be either
the average of the building stock, what’s required by
the building standard, or a target for the future, e.g.,
a net-zero building.
• Rating tools are similar except that they also provide
a rating with a number of stars, letter value, etc.
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Questions concerning energy
benchmarks and rating
• Is the rating for the physical building and equipment, i.e.,
the “asset value” of the property, or the actual
performance that can depend greatly on the operations
and use of the building?
• With cars, DOE’s mileage ratings indicate the fuel
efficiency in miles/gallon, but DOE does not attempt to
predict the car’s actual fuel consumption or savings.
• With refrigerators, the technical rating conforms closely to
the actual performance.
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Questions concerning energy
benchmarks and rating
• With buildings, its energy consumption depends partly on
its physical assets, but also with how the building is
operated and used.
• Technical ratings or benchmarks are largely derived
using computer simulations that show how the building
would perform under the assumed operating conditions.
• Performance ratings are done based on actual energy
usage and are possible only after the building is
completed and occupied.
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Examples of energy benchmarks
and rating tools in US and China• Building standards (both US and China) – basically a
technical rating
• Voluntary green building rating systems (LEED , MOHURD 3 Star Green Building Rating System) and building energy labels (various US efforts and MOHURD’s building energy efficiency labeling system) – based on building energy standards, therefore also a technical rating (?)
• EnergyStar Buildings (US) – a performance rating
• CDM (UN, World Bank) – a combined technical/performance rating
• DOE prototypical building models (originally called benchmark commercial buildings) – provides prototypical building models for commercial buildings that comply with local building standards and are high-performance target buildings.
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Benchmarks and ratings for several
recent demonstration projects
Agenda 21 building
(LEED Gold 2005)
Olympic Village
(LEED-ND Gold 2008)
“Micro-Energy” Building
(2008, unrated)
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Project development 1998 - 1999
Design development2000 – 2001
Construction 2002 – 2003
Monitoring2006 - 2009
The US-China
Agenda 21 Demonstration
Energy-Efficient Office Building
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First LEED Gold building in China
March 31, 2006
(no other rating system then available in China)
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Comparison of Agenda 21 heating load to those of 13
other buildings in Beijing
0
10
20
30
40
50
60
70
1 2 3 4 5 6 7 8 9 10 11 12 13
Agen
da21H
eati
ng
lo
ad
in
occu
pie
d h
ou
rs (
W/m
2)
average
* building energy consumption data and analysis (1999)
How is the energy performance of the Agenda 21 building ?
(60% lower heating EUI compared to the average
of 13 other Class A offices in Beijing)
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0
100
200
300
400
500
600
Agenda 21
building
total
electricity
first 8
months
Average
typical
Beijing
office total
annual
electricity
(Zhou
2003)
Average of
16 Beijing
dept.
stores and
hotels
cooling
only
Average of
9
Shanghai
offices and
dept stores
Average
total elec.
of
Japanese
office
bldgs in
similar
climate
Average
total elec.
of US
office
bldgs in
similar
climate
How is the energy performance of the Agenda 21 building ?
(about the same electricity consumption as typical
offices in Beijing, but less than a third that of US offices)
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Olympic Village finished Feb. 2008
LEED-ND Gold certification obtained June 2008
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The Beijing Olympic Village
Micro-Energy BuildingBuilding shell:
Roof k=0.2 W/m2•k (R-28)Wall k=0.3 W/m2•k (R-19)Vacuum windows
k=1.0 W/m2•k (U-0.17)SC=0.60 (SHGC-0.53)
Lighting:dimmable T-5s
w/daylighting and occupancy sensors
HVAC:Ground-source HPSeasonal thermal storage Hydronic radiant heatingand cooling
Liquid desiccant coolingw/solar regeneration
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Project development 2006 - 2007
Design development2007 – 2008
Construction 2009 –
Energy retrofit of the China
Association of Science and
Technology (CAST) office building
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Benefit of energy benchmarks and
rating tools
• A quantitative assessment of building energy
performance
• Can be used to compare the theoretical to the
actual performance of the building, and thus identify
problem areas or distinguish efficiency from
conservation.
• Benchmarks can provide a roadmap for future
improvements in building energy effiiciency
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Conclusions about benchmarking
building energy use in China• Need to establish appropriate benchmarks for building
types in each country
• Use of US-based rating systems is skewed towards high energy usage of mechanically efficient systems.
• The low electricity usage in Chinese buildings is due partly to curtailed services or comfort levels, but largely to less reliance on centralized mechanical systems that often overprovide them when they’re unnecessary nor even requested. This energy usage pattern should be promoted as a more sustainable lifestyle rather than disparaged as depravation, “energy poverty”, etc.
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Remaining technical issues for
rating and labeling efforts in China
• Almost all theoretical calculations, i.e., simulation
results, have not been correlated to actual building
performance. This is a particularly important issue for
China where “standard operating conditions” are quite
distinct from actual usage patterns.
• Existing Chinese ratings and labeling programs still lack
a clearly defined methodology for calculating building
energy efficiency.
• There is plenty of room for technical and policy
collaboration, but directly importing existing US
programs into China suffers from the same problem that
the calculational procedures do not fit well for Chinese
buildings.
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Thank you
谢谢
my contact information:
Joe Huang 黄昱
White Box Technologies
(925) 388-0265
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Following is a personal comment about
net-zero buildings
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BIRA Partners
(Slide courtesy of Bruce Baccei, formerly of Consul and now of SMUD)
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Side-By-Side Developments
(Slide courtesy of Bruce Baccei, formerly of Consul and now of SMUD)
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Premier Gardens
(Slide courtesy of Bruce Baccei, formerly of Consul and now of SMUD)
Premier vs Neighbor Sept 04 Electric Bills
-$30.00
-$10.00
$10.00
$30.00
$50.00
$70.00
$90.00
$110.00
$130.00
$150.00
$170.00
$190.00
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
House Number
Premier Sept 04 Bill Neighbor Sept 04 Bill
Premier Avg Sept 04 Bill Neighbor Avg Sept 04 Bill
Neighbor Avg Sept Bill
$66.68
Premier Avg Sept Bill
$19.99
SMUD Avg Res. Bill
$70.60