Experience at the University of East Anglia Chongqing - 23rd September 2005 2005 9 23 Low Energy...
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Transcript of Experience at the University of East Anglia Chongqing - 23rd September 2005 2005 9 23 Low Energy...
Experience at the University of East Anglia
‘ ’节能城市 论坛Chongqing - 23rd September 2005
2005 年 9 月 23 日
Low Energy Buildings and Low Carbon Strategies
Keith Tovey ( 杜伟贤 ) M.A., PhD, CEng, MICEHSBC Director of Low Carbon Innovation: and Charlotte Turner: School of Environmental SciencesCRed
• Construction of Low Energy Buildings
• Careful Monitoring of performance and adaptation where relevant
• Fuel efficient and alternative methods to provide energy
• Promoting awareness among occupants
• Tackling issues for reducing energy in existing buildings which are Grade 2 listed and of historic interest.
Low Energy and Low Carbon Strategies at UEA
• Low Energy Student Residencese.g. Constable Terrace
• Low Energy Educational Buildings using “TermoDeck” construction
• Elizabeth Fry Building
• ZICER Building
Low Energy Building Projects at UEA
In all cases Capital Cost was an issue
The Termodeck buildings cost just 5% more yet consume only one quarter of energy
Constable Terrace - 1993
Low Energy Building Projects at UEA
Student Residence: Constable Terrace – 1993
Over 50% of ventilation heat is recovered
U-Values (Wm-2K-1)
Walls Windows Roof Floor
Actual 0.22 2 0.15 0.18
1990 standard
0.45 5* 0.25 0.45
1994 0.45 3 0.25 0.45
2002 0.35 2.2 0.16 0.25
2005 0.35 2.2 0.16 0.25
Constable Terrace - 1993
The building has a low energy consumption.
It shows a significant saving on carbon dioxide emissions.
The Elizabeth Fry Building
Heater
Diffuser
Supply duct to
hollow core slabs
Two channel regenerative heat exchanger Floor Slabs
Incoming
Air
Exhaust Air
Filter
Exhaust Airfrom rooms
Principle of TermoDeck Operation
• Air is circulated through whole fabric of building • Uses regenerative Heat Exchangers ~ 85% efficient
Quadruple Glazing
Thick Insulation
Air circulates through whole fabric of building
Principle of Operation
Mean Surface Temperature close to Air Temperature
• Heated using a single domestic heating boiler (24 kW)
• No heating needed at temperatures as cool as 6 - 7oC
• 87% of ventilation heat recovered
• In summer building is pre-cooled overnight
Key Facts
Performance of Elizabeth Fry Building
thermal comfort +28%User Satisfaction
noise +26%
lighting +25%
air quality +36%
A Low Energy Building is also a better place to work in
Actual Low Energy
Normal
kg CO2/ m2 / yr
5.8 34 41
Carbon Dioxide Emissions for Space and Water Heating
Performance of Elizabeth Fry BuildingCareful Monitoring and Analysis can reduce energy consumption
• “Termodeck” construction
Zuckerman Institute for Connective Environmental Research
The ZICER Building
• 34 kW Photo Voltaic Array
ZICER Construction
Ducts in floor slab
Performance of ZICER Building
• Initially performance was poor• Performance improved with new Management Strategy
20052004 EFry
ZICER
Temperature of air and fabric in building varies little even on a day in summer (June 21st – 22nd 2005)
Performance of ZICER Building
• Construction of Low Energy Buildings
• Careful Monitoring of performance and adaptation where relevant
• Fuel efficient and alternative methods to provide energy
• Promoting awareness among occupants
• Tackling issues for reducing energy in existing buildings which are Grade 2 listed and of historic interest.
Low Energy and Low Carbon Strategies at UEA
EngineGenerator
36% Electricity
GAS
61% Flue Losses
3% Radiation Losses 36%
efficient
Generation of Electricity with a Gas Engine
EngineGenerator
36% Electricity45% Heat
GAS
Engine heat Exchanger
Exhaust Heat
Exchanger
11% Flue Losses
3% Radiation Losses 81%
efficient
Combined Heat and Power at UEA
Localised generation can make use of waste heat.
Reduces conversion losses significantly
1997/98 electricity gas oil Total
MWh 19895 35148 33
Emission factor kg/kWh 0.46 0.186 0.277
Carbon dioxide Tonnes 9152 6538 9 15699
Electricity Heat
1999/
2000
Total site
CHP generation
export import boilers CHP oil total
MWh 20437 15630 977 5783 14510 28263 923Emission
factorkg/kWh -0.46 0.46 0.186 0.186 0.277
Carbon dioxide
Tonnes -449 2660 2699 5257 256 10422
Performance of CHP unitsBefore installation
After installation
This represents a 33% saving in carbon dioxide
Load Factor of CHP Plant at UEA
Demand for Heat is low in summer: plant cannot be used effectively
More electricity could be generated in summer
Condenser
Evaporator
Throttle Valve
Heat rejected
Heat extracted for cooling
High TemperatureHigh Pressure
Low TemperatureLow Pressure
Heat from external source
Absorber
Desorber
Heat Exchanger
W ~ 0
Normal Air-conditioning
• Adsorption Heat pump uses Waste Heat from CHP• Will provide most of chilling requirements in summer• Will reduce electricity demand in summer• Will increase electricity generated locally
Compressor
Adsorption Air-Conditioning
Legislation can help and hinder effective use of energy
The method by which electricity is traded in the UK ( The BETTA System) has adversely affected viability of CHP in the UK.
The European Union Emission Trading System has anomalies which hinder effective developments such as Adsorption Chilling.
Building Regulations can hinder the building of most energy efficient buildings
Performance of Photo Voltaic Array
Sometimes electricity is exported
Inverters are only 91% efficient
Most use is for computers
DC power packs are inefficient typically less than 60% efficient
Need an integrated approach
Peak output is 34 kW
• Construction of Low Energy Buildings
• Careful Monitoring of performance and adaptation where relevant
• Fuel efficient and alternative methods to provide energy
• Promoting awareness among occupants
• Tackling issues for reducing energy in existing buildings which are Grade 2 listed and of historic interest.
Low Energy and Low Carbon Strategies at UEA
Raising Awareness
Each person in UK causes the emission of 9 tonnes of CO2 each year.
What do 9 tonnes of CO2 look like?
5 hot air balloons
China: 2.5 tonnes or 1.4 balloons
Comparison of emissions of different countries
Raising Awareness
Raising Awareness
• Computers do NOT switch off when using the soft “SHUT DOWN”. Typically they will waste 60 kg CO2 a year.
• A Toyota Corolla (1400cc): 1 party balloon every 60m.
• 10 gms of carbon dioxide has an equivalent volume of 1 party balloon.
• Standby on electrical appliances 80 kWh a year - 4000 balloons.
• A Mobile Phone charger: > 20 kWh per year ~ 1000 balloons each year.
Target Day
Results of the “Big Switch-Off”
With a concerted effort savings of 25% or more are possibleHow can these be translated into long term savings?
An integrated approach to Energy Efficiency is needed.
• Technical – initial good design
• Effective management – up to 50% can be saved.
• Awareness on the part of the user. Up to 25% can be saved.
Ventilation heating requirements are becoming a dominant issue in low energy buildings
To achieve full potential of low energy buildings effective record keeping, analysis, and management is essential.
Conclusions - 1
Effective design of low energy buildings will cost little more than conventional buildings.
Combined Heat and Power can be effective in reducing carbon emissions when GAS is available.
Tri-generation should always be considered when there are significant summer or year long chilling requirements.
Incorporation of renewable energy systems into buildings is attractive. However an integrated approach to generation and use in needed.
Conclusions - 2
Promoting effective awareness can reduce energy consumption in low energy buildings dramatically. Ways to prevent “back-sliding” must be researched
Some Regional, National, and International legislation is not conducive to promoting the most energy efficient strategies in communities.
Experience at the University of East Anglia
‘ ’节能城市 论坛Chongqing - 23rd September 2005
2005 年 9 月 23 日
Low Energy Buildings and Low Carbon Strategies
Keith Tovey ( 杜伟贤 ) M.A., PhD, CEng, MICEHSBC Director of Low Carbon Innovation: and Charlotte Turner: School of Environmental SciencesCRed