promise of green building in china, james connelly (february 2012)
DESCRIPTION
Buildings already account for 25% of China’s primary energy consumption, and this share will grow over the coming decades as China continues to urbanize and building energy use intensity increases. Green building presents an enormous opportunity to limit China's green house gas emissions, but to slow and eventually reduce building energy consumption requires the objective study and certification of what “green” really means. Two rating systems, China’s 3-Star system, and the United States Leadership in Energy and Environmental Design LEED system, are helping to ensure the promise of green building is more than just hype. By providing an objective and trusted seal of approval these rating system help create accountability -- transforming the building marketplace so that environmental performance metrics become part of the economic equation. The growth and popularity of these programs is an encouraging sign, but how effective are these rating systems in reducing energy consumption in practice? This presentation analyzes the factors behind the continuing increases in building energy consumption in China, compare LEED and the 3-Star system, and present preliminary findings into whether or not green building rating systems are truly living up to their promise.TRANSCRIPT
The Promise of Green Building in China The growth of building energy consumption and the potential of green building rating systems.
James Connelly LEED ap Fulbright Research Fellow Tsinghua University Dept. of Building Science
Shanghai Green Energy Research Center ★★★
Outline
� China Building Energy Current Situation � Factors Behind Building Energy Growth � Green Building Rating Systems
� LEED � 3-Star
� Conclusion
Current Situation
Source: Tsinghua University Building Energy Annual Report 2010
法国, 132
荷兰, 37 美国, 1431
日本, 245
希腊, 27
中国城镇, 453
德国, 143
英国, 227 加拿大, 155
韩国, 81
中国农村 , 204
澳大利亚, 24
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20
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60
80
0 1000 2000 3000 4000 5000 6000
单位面积建筑能耗
: kgc
e/(m
2 .a)
人均建筑能耗: kgce/(ca.a)
Current Situation
USA
CanadaUK
JP
Chinaurban
Building energy consumption per capita
Build
ing
ener
gy c
onsu
mpt
ion
per u
nit f
loor
are
a
UK
Building Energy Growth
� As countries develop building energy usage intensity increases � China Is at the same level as Japan in the 1960, US in the 1950’s.
Source: Tsinghua University Lectures, Professor Jiang Yi
Why do developed countries buildings consume so much energy?
� Chinese building on average have: � Less stringent building codes � Less insulation, leakier windows and doors � Less advanced heating and cooling systems
� Yet, they still only consume less than half of the energy of American buildings!
� Why? The answer lies in two interrelated factors: � Lifestyle and Culture � System Design and Operation
Culture and Lifestyle
� Chinese buildings have: � Less appliances, particularly clothes dryers � Less penetration of hot water � Greater range of acceptable indoor
temperature � Example my office in Beijing, Jiuzhaigou in the
Winter
� Utility bills are a greater proportion of income => � Culture of energy and water savings
System Design and Operation
� China: Part-time Part-Space
� Part-Time Lighting � Small Volumes � Operable Windows � Decentralized Systems
� Individual Control � Split Unit Air Conditioners � Point Source Heating
� US: Full-Time Full- Space
� Full-Time Lighting � Large Volumes � Sealed Buildings � Centralized Systems
� Centralized Control � Centralized HVAC VAV
Systems
Source: Tsinghua University Lectures, Professor Jiang Yi, 2011
Heating in North V South China Case study: space heating in China
调研城市
银川北京
上海武汉
沈阳
温州
苏州
调研城市
银川北京
上海武汉
沈阳
温州
苏州
Source: Tsinghua University Lectures, Professor Jiang Yi, 2011
North V South China
� North: � District Heating relatively
efficient, yet…
Full-Time Full-Space � 24 hour Operation � Fee by usage � Higher indoor temp
(20C)
� Heat Energy: 90 Kwh/m2 � Similar to developed
Countries w/ similar climates
� South: � Individual units relatively
inefficient, yet… Part-Time Part-Space
� Intermittent Operation � Fee By Sq Meter � Lower indoor temp
(14-16C)
� Heat Energy: 5-10 Kwh/m2 � Much Less than developed
Countries w/ similar climate (40-60 kwh/m2)
Source: Comparative analysis of energy use in China Building Sector: current status, existing problems and solutions, Energy Power and Engineering China, Shengyuan Zhang, Xiu Yan, Yi Jiang, Qingpeng Wei, 2010
Split Unit AC saves energy
� Unit itself is relatively inefficient, but… � Unit can controlled individually (decentralized) � When is comfortable, or unoccupied, unit is shut off
(intermittent operation) � Occupants actively control system to minimize
energy consumption
Centralized HVAC VAV systems waste energy through reheating Re-heat costs the most cooling & heating energy
AHU, typical state in October !!"℃
#$℃ !#℃ #%℃ !&℃
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� Cold air is provided at low set temp to each room � Fresh air must be provide to meet min req. (US 15cfm) � If the room is too cold => reheated at the terminal � Upenn Case Study: 50-70% of energy is used to Reheat � Reheating not technically allowed under Chinese codes
Source: Tsinghua University Lectures, Professor Xia Jianjun, 2011
Split Unit V Centralized AC AC energy for residential units in Beijing
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A B C D E
2006
2007
kWh/m2.a
Average of AC energy during summer for each building: kWh/m2.a
A，split unit
B：split unit
C：split unit
E
Centralized
AC
D
VRV
Source: Tsinghua University Lectures, Professor Jiang Yi, 2011
Lifestyle and System Design are Interrelated
� System design effects occupants ability to actively reduce energy consumption. � You can’t open the windows in a sealed office building. � You can’t turn on the AC in only one room when you
have a centralized system. � You can’t save energy by turning up the thermostat when
your HVAC VAV terminal just reheats the air.
� As countries develop => adopt developed country standard heating and cooling technology => lifestyle changes and energy usage intensity increases
� Slowing and preventing this transition is critical to reducing building energy consumption in China
China’s 2 Modes of Development � Modern Western
style office towers in central business districts
� Standard concrete housing and office blocks surrounding and in the suburbs
Profile of Energy Consumption � Low Energy cluster around 30-40 Kw/m2 � High Energy cluster around 120-150 Kw/m2
Source: Tsinghua University Lectures, Professor Jianjun Xia, 2011
Are Green Building Rating Systems (GBRS) the answer?
Source: USGBC project Directory, MOHURD (does not included 3-Star data for November & December 2011)
2011 China Green Building Action Plan proposed a 75 RMB subsidy per sq. meter to developers seeking to achieve 3-Star.
Similarities: LEED and 3 Star
� Both checklist rating systems � Break green building into categories:
� Land Saving, Energy Saving, Water Saving, Material Saving, Indoor Environment
� 3- Star has one additional category, Operation
� Pre-requisites (or Control items) in each category � Different levels of achievement (1,2,3 star) � Comparison to a theoretical “baseline” design
LEED uses a developed country baseline
Source:
New Building Institute, Energy Performance of LEED® for New Construction Buildings, March 4, 2008, Tsinghua University Building Energy Annual Report 2010
China “Large Public Building” Average: 36
LEED Uses Energy Models for Certification
New Building Institute, Energy Performance of LEED® for New Construction Buildings, March 4, 2008
Current Energy Models are not an accurate predictor of building energy consumption.
Is 3-Star Better?
� Chinese standards and codes � Pre-certification, 1 year post occupancy
evaluation, 3 Year follow up � More pre-requisites, minimum
achievement in each category � Focus on on simpler and cheaper solutions,
less on advanced technology
3-Star Performance
Ministry of Housing and Urban Development Green Label Management Office
Project Name Building Area (m2)
Energy Consumption (kwh/m2a)
Energy Consumption (kbtu/ft2a)
Energy Savings
(%) Rating
Shandong Transportation College Library 15837 40.0 12.7 50 ★★�
Shanghai Building Technology Institute Green Engineering Research Center 1994 38.0 12.1 65 ★★★�
Shanghai Expo Center 142000 146.4 46.5 62.65 ★★★�
Shanghai Power Plant and Chimney Renovation (City Hall) 31088 164.6 52.2 62.6 ★★★�
Shangai Eco-Home World Expo Best Practices Area 3147 45.7 14.5 61 ★★★�
US CBEC Survey: On Average US Commercial Buildings Consumed 91 (kbtu/ft2a) or 287 (KWh/m2a)
Different But Complementary Philosophies
� LEED is an industry run organization � => greater focus on market transformation
� 3-Star is run by government and universities � => greater focus on energy policy goals
Different Market Segments
Raffles City Chengdu | LEED CS Vanke Gardens Shenzhen | ★★
LEED: Class A Office, Luxury Residential
3-star: Government, Public, High-End Residential
Conclusions � GBRS must consider a country’s state of
development and energy baseline. � Attention must be paid to the relationship
between system design, lifestyle, and consumption.
� LEED and 3-star are complementary. � Green building represents an enormous
market opportunity.
Thank You James Connelly [email protected]
ChinaBuildsGreen.com EcoCityNotes.com
Xizhuang Integrated Building Shanghai ★★★