Carbon Reduction Strategies at the University of East Anglia Low Energy Buildings

1. CRed Carbon Reduction Institution of Civil Engineers 30th January 2006 • Carbon Reduction Strategies at the University of East Anglia • Low Energy Buildings • Providing Low Carbon Energy on Campus Keith Tovey (杜伟贤) MA, PhD, CEng, MICE, CEnv Energy Science Director HSBC Director of Low Carbon Innovation Charlotte Turner CRed

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. 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

6. 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

7. 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.

8. 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 Structural Engineers: Whitby Bird

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

10. Operation of the Main Building Regenerative heat exchanger Incoming air into the AHU Filter Heater Air passes through hollow cores in the ceiling slabs The return air passes through the heat exchanger Out of the building • Mechanically ventilated using 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

11. 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

12. 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

13. 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

14. 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

15. 350 Good Management has reduced Energy Requirements The space heating consumption has reduced by 57%

16. 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

17. Performance of PV cells on ZICER

18. 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

19. 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

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

21. 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

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

23. 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

24. 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 19

25. A 1 MW Adsorption chiller • 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

26. 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?

27. 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

28. WEBSITE cred-uk.org/ This presentation will be available from tomorrow at above WEB Site: follow Academic Links Carbon Reduction Strategies at the University of East Anglia Keith Tovey (杜伟贤) Energy Science Director HSBC Director of Low Carbon Innovation Charlotte Turner