Sustainable Operation of Buildings: Low Energy Strategies at University of East Anglia

1. CRed Carbon Reduction Sustainability and the EnvironmentUniversity of Hertfordshire, 17th May 2007 Sustainable Operation – The ZICER Building and Low Carbon Strategies at the University of East Anglia Keith Tovey (杜伟贤) Energy Science Director HSBC Director of Low Carbon Innovation CRed Acknowledgement: Charlotte Turner

2. Sustainable Operation of Buildings • Low Energy Buildings at UEA. • Their operation and performance • Low Energy Buildings at UEA. • Their operation and performance • Providing Low Carbon Energy on the UEA Campus • Carbon Foot- printing Issues.

3. Teaching wall Library Student residences Original buildings

4. Nelson Court Constable Terrace

5. Low Energy Educational Buildings Nursing and Midwifery School Medical School Phase 2 ZICER Elizabeth Fry Building Medical School

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. 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

8. ZICER Building Heating Energy consumption as new in 2003 was reduced by further 57% 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.

9. 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 • ~ U – value ~ 1.0 W m2 K-1

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

11. ZICER Building • The Top Floor a Demonstration Area for PhotoVoltaics Photo shows only half of top Floor

12. Operation of the Main Building Regenerative heat exchanger Space for future chilling 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 Recovers 87% of Ventilation Heat Requirement. Return stale air is extracted from each floor Air enters the internal occupied space

13. 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 Draws out the heat accumulated during the day Summer night night ventilation/ free cooling

14. 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 The concrete absorbs and stores the heat – like a radiator in reverse Pre-cools the air before entering the occupied space

15. 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

16. 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

17. Good Management has reduced Energy Requirements 800 350 The space heating consumption has reduced by 57% Acknowledgement: Charlotte Turner

18. Winter Summer Effect of New Control Strategies on Thermal Comfort Winter Summer Only data for relevant Metabolic Rates included in above table

19. 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

20. Performance of PV cells on ZICER

21. 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

22. 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

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

24. Sustainable Operation of Buildings • Low Energy Buildings at UEA. • Their operation and performance • Providing Low Carbon Energy on the UEA Campus • Carbon Foot- printing Issues.

25. 3% Radiation Losses 11% Flue Losses GAS 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 Exhaust Heat Exchanger Engine heat Exchanger

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

27. Energy Conversion efficiency improvements Performance of UEA CHP plant 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

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

29. 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

30. Target Day Results of the “Big Switch-Off” With a concerted effort savings of 25% or more are possible How can these be translated into long term savings?

31. Sustainable Operation of Buildings • Low Energy Buildings at UEA. • Their operation and performance • Providing Low Carbon Energy on the UEA Campus • Carbon Foot- printing Issues.

32. Life Cycle Energy Requirements of ZICER as built compared to other buildings of same size and design Naturally Ventilated 221508GJ Air Conditioned 384967GJ As Built 209441GJ Materials Production Materials Transport On site construction energy Workforce Transport Intrinsic Heating / Cooling energy Functional Energy Refurbishment Energy Demolition Energy Main TermoDeck Building only 28% 54% 51% 34% 29% 61%

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

34. UEA Carbon Dioxide emissions Travel Travel element based on survey in November 2005 of auditable travel. Imported Electricity Gas 2005 - 06

35. UEA Space Heating Energy Requirements 2001 - 2006 • 2005 – 06 was 13.0% colder than 2001 – 02 • Floor area increased by 16.7% over period • Heat Energy delivered increased by 16.5% • Heating Energy consumption per unit area normalised for climate reduced by 12% or 2.6% per annum

36. UEA Electricity Imports 1999 - 2006 CO2 emissions from electricity imports As fuel mix for generation has changed, CO2 emissions are even worse

37. 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 electricity use in building to get the optimum value. • 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. • Promoting Awareness can result in up to 25% savings • The Future for UEA: 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

38. CRed Carbon Reduction Sustainability and the EnvironmentUniversity of Hertfordshire, 17th May 2007 Sustainable Operation – The ZICER Building and Low Carbon Strategies at the University of East Anglia This presentation is now accessible on the WEB at: www2.env.uea.ac.uk/cred/creduea.htm Keith Tovey (杜伟贤) Energy Science Director HSBC Director of Low Carbon Innovation CRed Acknowledgement: Charlotte Turner