Low Energy Buildings and Low Carbon Strategies Chongqing
Low Energy Buildings and Low Carbon Strategies ‘节能城市’论坛 Chongqing - 23 rd September 2005年 9月23日 Experience at the University of East Anglia Keith Tovey (杜�� ) M. A. , Ph. D, CEng, MICE CRed HSBC Director of Low Carbon Innovation: and Charlotte Turner: School of Environmental Sciences
Low Energy and Low Carbon Strategies at UEA • 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 Building Projects at UEA • Low Energy Student Residences e. g. Constable Terrace • Low Energy Educational Buildings using “Termo. Deck” construction • Elizabeth Fry Building • ZICER Building 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 U-Values (Wm-2 K-1) Actual 1990 standard 1994 2002 2005 Walls 0. 22 Windows 2 Roof 0. 15 Floor 0. 18 0. 45 5* 0. 25 0. 45 0. 35 3 2. 2 0. 25 0. 16 0. 45 0. 25 Over 50% of ventilation heat is recovered
Constable Terrace - 1993 The building has a low energy consumption. It shows a significant saving on carbon dioxide emissions.
The Elizabeth Fry Building
Principle of Termo. Deck Operation Filter Incoming Supply duct to Air hollow core slabs Heater Exhaust Air Two channel regenerative heat exchanger Exhaust Air from rooms Floor Slabs Diffuser • Air is circulated through whole fabric of building • Uses regenerative Heat Exchangers ~ 85% efficient
Principle of Operation Quadruple Glazing Thick Insulation Air circulates through whole fabric of building Key Facts • Heated using a single domestic heating boiler (24 k. W) • No heating needed at temperatures as cool as 6 - 7 o. C • 87% of ventilation heat recovered Mean Surface Temperature • In summer building is close to Air Temperature pre-cooled overnight
Performance of Elizabeth Fry Building Carbon Dioxide Emissions for Space and Water Heating Actual Low Energy Normal kg CO 2/ m 2 / yr 5. 8 34 41 User Satisfaction thermal comfort +28% air quality +36% lighting +25% noise +26% A Low Energy Building is also a better place to work in
Performance of Elizabeth Fry Building Careful Monitoring and Analysis can reduce energy consumption
The ZICER Building Zuckerman Institute for Connective Environmental Research • “Termodeck” construction • 34 k. W Photo Voltaic Array
ZICER Construction Ducts in floor slab
Performance of ZICER Building 2004 2005 EFry ZICER • Initially performance was poor • Performance improved with new Management Strategy
Performance of ZICER Building Temperature of air and fabric in building varies little even on a day in summer (June 21 st – 22 nd 2005)
Low Energy and Low Carbon Strategies at UEA • 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.
Generation of Electricity with a Gas Engine 61% Flue Losses 3% Radiation Losses 36% efficient GAS Engine Generator 36% Electricity
Combined Heat and Power at UEA 3% Radiation Losses 11% Flue Losses 81% efficient Exhaust Heat Exchanger GAS Reduces conversion losses significantly Engine heat Exchanger 45% Heat Localised generation can make use of waste heat. Generator 36% Electricity
Performance of CHP units Before installation 1997/98 electricity gas oil 19895 35148 33 MWh Total Emission factor kg/k. Wh 0. 46 0. 186 0. 277 Carbon dioxide Tonnes 9152 6538 9 15699 After installation 1999/ 2000 Electricity Heat Total CHP export import boilers CHP site generation MWh 20437 Emission kg/k. Wh factor Carbon Tonnes dioxide 15630 oil total 977 5783 14510 28263 923 -0. 46 0. 186 0. 277 -449 2660 2699 5257 256 10422 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
Normal Air-conditioning Adsorption Air-Conditioning Heat from external source Heat rejected High Temperature High Pressure Desorber Heat Compressor Exchanger Condenser Throttle Valve W~0 Evaporator Absorber Heat extracted for cooling • • Low Temperature Low Pressure 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
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 Peak output is 34 k. W 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
Low Energy and Low Carbon Strategies at UEA • 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.
Raising Awareness Each person in UK causes the emission of 9 tonnes of CO 2 each year. What do 9 tonnes of CO 2 look like? 5 hot air balloons China: 2. 5 tonnes or 1. 4 balloons
Raising Awareness Comparison of emissions of different countries
Raising Awareness • Computers do NOT switch off when using the soft “SHUT DOWN”. Typically they will waste 60 kg CO 2 a year. • 10 gms of carbon dioxide has an equivalent volume of 1 party balloon. • A Mobile Phone charger: > 20 k. Wh per year ~ 1000 balloons each year. • Standby on electrical appliances 80 k. Wh a year - 4000 balloons. • A Toyota Corolla (1400 cc): 1 party balloon every 60 m.
Results of the “Big Switch-Off” Target Day With a concerted effort savings of 25% or more are possible How can these be translated into long term savings?
Conclusions - 1 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. Effective design of low energy buildings will cost little more than conventional buildings. 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 - 2 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. Promoting effective awareness can reduce energy consumption in low energy buildings dramatically. Ways to prevent “backsliding” must be researched Some Regional, National, and International legislation is not conducive to promoting the most energy efficient strategies in communities.
Low Energy Buildings and Low Carbon Strategies ‘节能城市’论坛 Chongqing - 23 rd September 2005年 9月23日 Experience at the University of East Anglia Keith Tovey (杜�� ) M. A. , Ph. D, CEng, MICE CRed HSBC Director of Low Carbon Innovation: and Charlotte Turner: School of Environmental Sciences
- Slides: 31