Keith Tovey ( 杜伟贤)

1. CRed Carbon Reduction University College London, 17th January 2006 • Energy Management as Part of a Long Term Strategy for Energy Efficiency at the at the University of East Anglia • Low Energy Buildings • Energy Management • Life Cycle Issues • Providing Low Carbon Energy on Campus • Energy Management as Part of a Long Term Strategy for Energy Efficiency at the at the University of East Anglia • Low Energy Buildings • Energy Management • Life Cycle Issues • Providing Low Carbon Energy on Campus Keith Tovey (杜伟贤) CRed Energy Science Director HSBC Director of Low Carbon Innovation Acknowledgement: Charlotte Turner

2. Teaching wall Library Student residences Original buildings

3. Nelson Court Constable Terrace

4. Medical School ZICER Nursing and Midwifery School Elizabeth Fry Building Low Energy Educational Buildings

5. Constable Terrace - 1993 • Four Storey Student Residence • Divided into “houses” of 10 • units each with en-suite facilities • Heat Recovery of body and cooking • heat ~ 50%. • Insulation standards exceed 2006 • standards • Small 250 W panel heaters in • individual rooms.

6. The Elizabeth Fry Building 1994 Cost 6% more but has heating requirement ~25% of average building at time. Building Regulations have been updated: 1994, 2002, 2006, but building outperforms all of these. Runs on a single domestic sized central heating boiler. Would have scored 13 out of 10 on the Carbon Index Scale. 8

7. Principle of Operation of TermoDeck Construction Quadruple Glazing Exhaust air passes through a two channel regenerative heat exchanger which recovers 85+% of ventilation heat requirements. Thick Insulation Air circulates through whole fabric of building Mean Surface Temperature close to Air Temperature

8. Conservation: management improvements – User Satisfaction thermal comfort +28% air quality +36% lighting +25% noise +26% Careful Monitoring and Analysis can reduce energy consumption. A Low Energy Building is also a better place to work in

9. ZICER Building Heating Energy consumption as new in 2003 was reduced by further 50% by careful record keeping, management techniques and an adaptive approach to control. Incorporates 34 kW of Solar Panels on top floor Low Energy Building of the Year Award 2005 awarded by the Carbon Trust.

10. The ZICER Building - Description • Four storeys high and a basement • Total floor area of 2860 sq.m • Two construction types • Main part of the building • High in thermal mass • Air tight • High insulation standards • Triple glazing with low emissivity

11. The ground floor open plan office The first floor open plan office The first floor cellular offices

12. Operation of the Main Building Regenerative heat exchanger Incoming air into the AHU Filter Heater The air passes through hollow cores in the ceiling slabs The return air passes through the heat exchanger Out of the building • Mechanically ventilated that utilizes hollow core ceiling slabs as supply air ducts to the space Return stale air is extracted from each floor Air enters the internal occupied space

13. Operation of Regenerative Heat Exchangers Fresh Air Fresh Air Stale Air Stale Air B Stale air passes through Exchanger A and heats it up before exhausting to atmosphere Fresh Air is heated by exchanger B before going into building A After ~ 90 seconds the flaps switch over B Stale air passes through Exchanger B and heats it up before exhausting to atmosphere Fresh Air is heated by exchanger A before going into building A

14. Cold air Cools the slabs to act as a cool store the following day Cold air Importance of the Hollow Core Ceiling Slabs The concrete hollow core ceiling slabs are used to store heat and coolness at different times of the year to provide comfortable and stable temperatures Summer Night – night ventilation/free cooling Draws out the heat accumulated during the day Summer night

15. Warm air Warm air Importance of the Hollow Core Ceiling Slabs The concrete hollow core ceiling slabs are used to store heat and coolness at different times of the year to provide comfortable and stable temperatures Summer Day Pre-cools the air before entering the occupied space Summer day The concrete absorbs and stores the heat – like a radiator in reverse

16. The concrete slabs absorbs and store heat Heat is transferred to the air before entering the room Importance of the Hollow Core Ceiling Slabs The concrete hollow core ceiling slabs are used to store heat and coolness at different times of the year to provide comfortable and stable temperatures Winter Day Winter day

17. When the internal air temperature drops, heat stored in the concrete is emitted back into the room Importance of the Hollow Core Ceiling Slabs The concrete hollow core ceiling slabs are used to store heat and coolness at different times of the year to provide comfortable and stable temperatures Winter Night Winter night

18. CRed Carbon Reduction • Energy Management as Part of a Long Term Strategy for Energy Efficiency at the at the University of East Anglia • Low Energy Buildings • Energy Management • Life Cycle Issues • Providing Low Carbon Energy on Campus University College London, 17th January 2006

19. Performance of ZICER Building 2005 2004 EFry ZICER New Management • Initially performance was poor • Performance improved with new Management Strategy

20. Performance of ZICER Building Temperature of air and fabric in building varies little even on a day in summer (June 21st – 22nd 2005)

21. No Heating Management of Energy: Heating/ Hot Water/ Cooking Gradient of Heating Line is Heat Loss Rate Cooking/ Hot Water

22. Analysis of Energy Consumption in a house 9th December 2006 – 14th January 2007

23. 350 Good Management has reduced Energy Requirements The space heating consumption has reduced by 57%

24. CRed Carbon Reduction • Energy Management as Part of a Long Term Strategy for Energy Efficiency at the at the University of East Anglia • Low Energy Buildings • Energy Management • Life Cycle Issues • Providing Low Carbon Energy on Campus University College London, 17th January 2006

25. Materials Production Transport of Materials On site Energy Use Transport of Workforce Constructionof Building On site Electricity Use Specific Site energy – landscaping etc Furnishings including transport to site Functional Electricity Use Operational heating Operation of Building Intrinsic Refurbishment Energy Operational control (electricity) Functional Refurbishment Energy Intrinsic Energy Site Specific Energy Demolition Functional Energy Regional Energy Overheads Life Cycle Energy / Carbon Emissions

26. Life Cycle Energy Requirements of ZICER compared to other buildings

27. Naturally Ventilated 221508GJ Air Conditioned 384967GJ As Built 209441GJ Materials Production Materials Transport On site construction energy Workforce Transport Intrinsic Heating energy etc. Functional Energy Refurbishment Energy Demolition Energy Life Cycle Energy Requirements of ZICER compared to other buildings 28% 54% 34% 51% 29% 61%

28. Life Cycle Energy Requirements of ZICER compared to other buildings Compared the Air-conditioned office, ZICER as built recovers extra energy required in construction in under 1 year.

29. CRed Carbon Reduction • Energy Management as Part of a Long Term Strategy for Energy Efficiency at the at the University of East Anglia • Low Energy Buildings • Energy Management • Life Cycle Issues • Providing Low Carbon Energy on Campus University College London, 17th January 2006

30. ZICER Building • Top floor is an exhibition area – also to promote PV • Windows are semi transparent • Mono-crystalline PV on roof ~ 27 kW in 10 arrays • Poly- crystalline on façade ~ 6/7 kW in 3 arrays Photo shows only part of top Floor

31. Performance of PV cells on ZICER Load factors Output per unit area Little difference between orientations in winter months

32. Performance of PV cells on ZICER - January All arrays of cells on roof have similar performance respond to actual solar radiation Radiation is shown as percentage of mid-day maximum to highlight passage of clouds The three arrays on the façade respond differently

34. Performance of PV cells on ZICER

35. Arrangement of Cells on Facade Individual cells are connected horizontally If individual cells are connected vertically, only those cells actually in shadow are affected. As shadow covers one column all cells are inactive

36. Use of PV generated energy Peak output is 34 kW 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

37. Performance of PV cells: Unit Cost of Electricity Generated Annual Electricity generation Unit cost Discounted Income from generation in the nth year of operation is: Cumulative Income over all n years of lifetime must equals capital cost C and is: is Rearranging and adding an annual maintenance cost m (expressed as a percentage of capital cost gives:

38. Performance of PV cells on ZICER Cost of Generated Electricity Grant was ~ £172 000 out of a total of ~ £480 000

39. 3% Radiation Losses 11% Flue Losses GAS Exhaust Heat Exchanger Engine Generator 36% Electricity 50% Heat Conversion efficiency improvements – Building Scale CHP Localised generation makes use of waste heat. Reduces conversion losses significantly 36%efficient 61% Flue Losses 86%efficient Engine heat Exchanger

40. Conversion efficiency improvements Before installation After installation This represents a 33% saving in carbon dioxide

41. Conversion efficiency improvements 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

42. Heat from external source Desorber Compressor Heat Exchanger W ~ 0 High Temperature High Pressure Heat rejected Absorber Condenser Throttle Valve Evaporator Low Temperature Low Pressure Heat extracted for cooling Conversion efficiency improvements Normal Chilling Adsorption Chilling 19

43. A 1 MW Adsorption chiller 1 MW 吸附冷却器 • 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 • Save 500 – 700 tonnes Carbon Dioxide annually

44. Conclusions • Buildings built to low energy standards have cost ~ 5% more, but savings have recouped extra costs in around 5 years. • Ventilation heat requirements can be large and efficient heat recovery is important. • Effective adaptive energy management can reduce heating energy requirements in a low energy building by 50% or more. • Photovoltaic cells need to take account of intended use of cells to get the optimum use of electricity generated. • Building scale CHP can reduce carbon emissions significantly • Adsorption chilling should be included to ensure optimum utilisation of CHP plant, to reduce electricity demand, and allow increased generation of electricity locally. • The Future: Biomass CHP? Wind Turbines? "If you do not change direction, you may end up where you are heading." LaoTzu (604-531 BC) Chinese Artist and Taoist philosopher

45. This presentation will be posted on the WEB tomorrow at: • www.cred-uk.org • From main page follow Academic Links k.tovey@uea.ac.uk Keith Tovey (杜伟贤)