1. Key Communities Meeting: Newmarket: 17th October 2007
Sustainability in Building and Occupation
Keith Tovey (杜伟贤) MA, PhD, CEng, MICE, CEnv
Recipient of James Watt Medal
5th October 2007
Energy Science Director
HSBC Director of Low Carbon Innovation
CRed
CRed
Carbon Reduction
Acknowledgement: Karla Alcantar

2. Sustainability in Building and Occupation
Background
Background
Issues of Sustainable Building Construction
Thermal Performance
Renewable Energy
Life Cycle analyses
Integration of Design
Future Proofing Buildings
Management of Building Energy Use
Behaviour of the Occupants
Conclusions

3. Changes in Temperature

4. Latest Temperature Data from GISS 10/09/2007

5. Increasing Occurrence of Flood Increasing Occurrence of Drought
Change in precipitation
Source: Tim Osborne, CRU
Increase in storminess since 1970
Heavy winter rainfall over the UK has increased by 50%
Runs of wet days have increased
More heavy rain events
Total winter precipitation
Total summer precipitation

6. Sustainability in Building and Occupation
Background
Issues of Sustainable Building Construction
Thermal Performance issues
Future Proofing Buildings - Fabric Cooling?
Renewable Energy and Integration of Design
Life Cycle issues
Management of Building Energy Use
Behaviour of the Occupants
Conclusions

7. Thermal Performance Issues: Future Proofing
Thermal performance has improved with better insulation.
With better fabric insulation, ventilation can represent up to 80+% of heating energy requirements.
Careful design of ventilation is needed
lower capital costs vs lower environmental running costs.
Are ESCO’s a way forward?
Provide optional environmentally efficient systems within all new buildings.
Improved control – Smart (Sub) Metering
Is traditional Cost Benefit Analysis the correct way to appraise low carbon systems?

8. The Climate Dimension
Thermal Comfort is important: Even in ideal environment 2.5% of people will be too cold and 2.5% will be too hot.
Estimate heating and cooling requirements from Degree Days
Index 1960 = 100
Heating requirements are ~10+% less than in 1960
Cooling requirements are 75% higher than in 1960.
Changing norm for clothing from a business suite to shirt and tie will reduce “clo” value from 1.0 to ~ 0.6.
To a safari suite ~ 0.5.
Equivalent thermal comfort can be achieved with around 0.15 to 0.2 change in “clo” for each 1 oC change in internal environment.
Care in design is needed to avoid overheating in summer and to minimise active cooling requirements

9. Fabric Cooling using Hollow Core 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
Cold air
Cools the slabs to act as a cool store the following day
Draws out the heat accumulated during the day
Summer night
night ventilation/ free cooling

10. Fabric Cooling using Hollow Core 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
Warm air
No air conditioning is needed even though the norm would have been to install air-conditioning
Summer day
Pre-cools the air before entering the occupied space
The concrete absorbs and stores the heat – like a radiator in reverse
In future, with Global Warming, when air-conditioners may be installed, they will be run over night to pre-cool building and improve efficiency of chillers

11. Heat Pumps: A solution for a Low Carbon Future
Ground Source Heat Pumps are an effective route to low carbon heating – can save 50 – 60% of carbon emissions.
Work most efficiently with under floor heating.
Can be used with fabric pre-cooling in summer with very modest air-conditioning
Can be to provide some inter-seasonal heat store
i.e. reject heat in summer to acquifer/ground – recover during winter. There is ~ 3 months thermal lag in peak temperature in ground corresponding with early heating season use, and much improved coefficients of performance.

12. Thermal Properties of Buildings
Heating energy requirement is strongly dependant on External Temperature.
Thermal Lag in Heavy Weight Buildings means consumption requirements lags external temperature.
Correlation with temperature suggests a thermal lag of ~ 8 hours.
Potential for predictive controls based on weather forecasts
Data collected 10th December 2006 – April 29th 2007

13. Sustainability in Building and Occupation
Background
Issues of Sustainable Building Construction
Thermal Performance issues
Future Proofing Buildings - Fabric Cooling?
Renewable Energy and Integration of Design
Life Cycle issues
Management of Building Energy Use
Behaviour of the Occupants
Conclusions

14. Options for Renewable Energy: Solar Thermal
Solar Collectors installed 27th January 2004
Annual Solar Gain 910 kWh

15. Options for Renewable Energy: Solar Thermal
Performance of an actual solar collector 9th December 2006 – 13th October
2007
Average gain (over 3 years) is kWh per day
Central Heating Boiler rarely needed for Hot Water from Easter to ~ 1st
October
More Hot Water used – the greater amount of solar energy is gained
Optimum orientation for solar hot water collectors for most houses is NOT
due South

16. Options for Renewable Energy: Solar Thermal
Significant surplus of energy in summer
Explore increasing temperature limit
provided there is an anti-scald device fitted.
Training needed to educate users to get optimum from solar collector in mid-
season (setting of Central Heating Hot Water timers)
Energy/Carbon benefits to be gained by providing solar hot water on a multi-
house basis.

17. Options for Renewable Energy: Solar Photovoltaic
Data based on Actual ZICER Building PV Costs
Actual Situation excluding Grant
Actual Situation with Grant
Discount rate 3% 5% 7%
Unit energy cost per kWh (£)
1.29
1.58
1.88
0.84
1.02
1.22
Avoided cost exc. the Grant
Avoided Costs with Grant
0.57
0.70
0.83
0.12
0.14
0.16

18. Photo shows only part of top Floor
ZICER Building
Photo shows only part of top Floor
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

19. Arrangement of Cells on Facade
Options for Renewable Energy: Solar Photovoltaic
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

20. Options for Renewable Energy: Solar Photovoltaic
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

21. Options for Low Carbon Technologies: Micro CHP
Potential to substantially reduce CO2 emissions
Significant reduction is losses from transmission
but
problem of heat disposal in summer
Does not make sense to provide CHP with solar hot water heaters
Consider using absorption chilling to provide cooling where required

22. Sustainability in Building and Occupation
Background
Issues of Sustainable Building Construction
Thermal Performance issues
Future Proofing Buildings - Fabric Cooling?
Renewable Energy and Integration of Design
Life Cycle issues
Management of Building Energy Use
Behaviour of the Occupants
Conclusions

23. Sustainability in Building and Occupation
Life Cycle Issues – an issue in Sustainability
Does local sourcing of materials necessarily lead to a low carbon construction?
In case of PV it emits LESS CO2 if cells are manufactured in Spain and transported to UK!
despite the transport!!!!
Need to be aware of how fuel mix used for generation of electricity affects CO2.
UK ~ 0.52 kg/kWh, Spain ~ 0.46 kg/kWh
France ~ 0.06 kg/kWh
To what extent does embodied carbon from construction and demolition affect total carbon emission?
Example: ZICER Building

24. Naturally Ventilated 221508GJ
Life Cycle Energy Requirements of ZICER as built compared to other heating/cooling strategies
As Built GJ
Naturally Ventilated GJ
54%
28%
Air Conditioned GJ
34%
51%
Materials Production
Materials Transport
On site construction energy
Workforce Transport
Intrinsic Heating / Cooling energy
Functional Energy
Refurbishment Energy
Demolition Energy
29%
61%

25. Comparison of Life Cycle Energy Requirements of ZICER
Comparisons assume identical size, shape and orientation
Compared to the Air-conditioned office, ZICER recovers extra energy required in construction in under 1 year.

26. Sustainability in Building and Occupation
Background
Issues of Sustainable Building Construction
Thermal Performance
Renewable Energy
Life Cycle analyses
Integration of Design
Future Proofing Buildings
Management of Building Energy Use
Behaviour of the Occupants
Conclusions

27. 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.

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

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

30. Sustainability in Building and Occupation
Background
Issues of Sustainable Building Construction
Thermal Performance
Renewable Energy
Life Cycle analyses
Integration of Design
Future Proofing Buildings
Management of Building Energy Use
Behaviour of the Occupants
Conclusions

31. The Behavioural Dimension
Household size has little impact on electricity consumption.
Consumption varies by up to a factor of 9 for any given household size.
Allowing for Income still shows a range of 6 or more.
Education/Awareness is important

32. Personal Attitudes to Energy Use can be significant

33. Social Awareness of Occupational Impact on Climate Change

34. Social Awareness of Occupational Impact on Climate Change

35. Conclusions Sustainable Buildings require:
Initial sound design addressing: high insulation standards, effective control of ventilation: Attention to Future Proofing.
Integration of use of building with provision of services.
Avoidance of combining novel technologies which are incompatible.
Use of most sustainable materials: Local provision of materials is NOT ALWAYS best – careful Life Cycle Assessments are needed.
Provision of optional extras for all buildings including renewable technologies etc perhaps with alternative financing methods.
Provision of SMART sub metering to inform the user.
Improvements in training of users where newer technologies are used.
a need for awareness raising.
"If you do not change direction, you may end up where you are heading."
Lao Tzu ( BC) Chinese Artist and Taoist philosopher

37. Is Global Warming man made? actual predicted Prediction: Natural only
1.0
0.5
0.0
-0.5
Temperature Rise (oC)
Is Global Warming man made?
actual
predicted
Prediction: Natural only
good match until 1960
1.0
0.5
0.0
-0.5
Temperature Rise (oC)
actual
predicted
Prediction: Anthropogenic only
Not a good match between 1920 and 1970
1.0
0.5
0.0
-0.5
Temperature Rise (oC)
actual
Predictions include:
Greenhouse Gas emissions
Sulphates and ozone
Solar and volcanic activity
predicted
Prediction: Natural and Anthropogenic
Generally a good match
Source: Hadley Centre, The Met.Office