Presentation on theme: "Key Communities Meeting: Newmarket: 17th October 2007"— Presentation transcript:
1 Key Communities Meeting: Newmarket: 17th October 2007 Sustainability in Building and OccupationKeith Tovey (杜伟贤) MA, PhD, CEng, MICE, CEnvRecipient of James Watt Medal5th October 2007Energy Science DirectorHSBC Director of Low Carbon InnovationCRedCRedCarbon ReductionAcknowledgement: Karla Alcantar
2 Sustainability in Building and Occupation BackgroundBackgroundIssues of Sustainable Building ConstructionThermal PerformanceRenewable EnergyLife Cycle analysesIntegration of DesignFuture Proofing BuildingsManagement of Building Energy UseBehaviour of the OccupantsConclusions
5 Increasing Occurrence of Flood Increasing Occurrence of Drought Change in precipitationSource: Tim Osborne, CRUIncrease in storminess since 1970Heavy winter rainfall over the UK has increased by 50%Runs of wet days have increasedMore heavy rain eventsTotal winter precipitationTotal summer precipitation
6 Sustainability in Building and Occupation BackgroundIssues of Sustainable Building ConstructionThermal Performance issuesFuture Proofing Buildings - Fabric Cooling?Renewable Energy and Integration of DesignLife Cycle issuesManagement of Building Energy UseBehaviour of the OccupantsConclusions
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 neededlower 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) MeteringIs traditional Cost Benefit Analysis the correct way to appraise low carbon systems?
8 The Climate DimensionThermal 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 DaysIndex 1960 = 100Heating requirements are ~10+% less than in 1960Cooling 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 temperaturesCold airCools the slabs to act as a cool store the following dayDraws out the heat accumulated during the daySummer nightnight 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 temperaturesWarm airNo air conditioning is needed even though the norm would have been to install air-conditioningSummer dayPre-cools the air before entering the occupied spaceThe concrete absorbs and stores the heat – like a radiator in reverseIn 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-conditioningCan be to provide some inter-seasonal heat storei.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 forecastsData collected 10th December 2006 – April 29th 2007
13 Sustainability in Building and Occupation BackgroundIssues of Sustainable Building ConstructionThermal Performance issuesFuture Proofing Buildings - Fabric Cooling?Renewable Energy and Integration of DesignLife Cycle issuesManagement of Building Energy UseBehaviour of the OccupantsConclusions
14 Options for Renewable Energy: Solar Thermal Solar Collectors installed 27th January 2004Annual Solar Gain 910 kWh
15 Options for Renewable Energy: Solar Thermal Performance of an actual solar collector 9th December 2006 – 13th October2007Average gain (over 3 years) is kWh per dayCentral Heating Boiler rarely needed for Hot Water from Easter to ~ 1stOctoberMore Hot Water used – the greater amount of solar energy is gainedOptimum orientation for solar hot water collectors for most houses is NOTdue South
16 Options for Renewable Energy: Solar Thermal Significant surplus of energy in summerExplore increasing temperature limitprovided 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 CostsActual Situation excluding GrantActual Situation with GrantDiscount rate3%5%7%Unit energy cost per kWh (£)1.291.581.880.841.021.22Avoided cost exc. the GrantAvoided Costs with Grant0.570.700.8126.96.36.199
18 Photo shows only part of top Floor ZICER BuildingPhoto shows only part of top FloorTop floor is an exhibition area – also to promote PVWindows are semi transparentMono-crystalline PV on roof ~ 27 kW in 10 arraysPoly- crystalline on façade ~ 6/7 kW in 3 arrays
19 Arrangement of Cells on Facade Options for Renewable Energy: Solar PhotovoltaicArrangement of Cells on FacadeIndividual cells are connected horizontallyIf 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 kWSometimes electricity is exportedInverters are only 91% efficientMost use is for computersDC power packs are inefficient typically less than 60% efficientNeed an integrated approach
21 Options for Low Carbon Technologies: Micro CHP Potential to substantially reduce CO2 emissionsSignificant reduction is losses from transmissionbutproblem of heat disposal in summerDoes not make sense to provide CHP with solar hot water heatersConsider using absorption chilling to provide cooling where required
22 Sustainability in Building and Occupation BackgroundIssues of Sustainable Building ConstructionThermal Performance issuesFuture Proofing Buildings - Fabric Cooling?Renewable Energy and Integration of DesignLife Cycle issuesManagement of Building Energy UseBehaviour of the OccupantsConclusions
23 Sustainability in Building and Occupation Life Cycle Issues – an issue in SustainabilityDoes 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/kWhFrance ~ 0.06 kg/kWhTo 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 strategiesAs Built GJNaturally Ventilated GJ54%28%Air Conditioned GJ34%51%Materials ProductionMaterials TransportOn site construction energyWorkforce TransportIntrinsic Heating / Cooling energyFunctional EnergyRefurbishment EnergyDemolition Energy29%61%
25 Comparison of Life Cycle Energy Requirements of ZICER Comparisons assume identical size, shape and orientationCompared to the Air-conditioned office, ZICER recovers extra energy required in construction in under 1 year.
26 Sustainability in Building and Occupation BackgroundIssues of Sustainable Building ConstructionThermal PerformanceRenewable EnergyLife Cycle analysesIntegration of DesignFuture Proofing BuildingsManagement of Building Energy UseBehaviour of the OccupantsConclusions
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 Satisfactionthermal 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%800350Acknowledgement: Charlotte Turner
30 Sustainability in Building and Occupation BackgroundIssues of Sustainable Building ConstructionThermal PerformanceRenewable EnergyLife Cycle analysesIntegration of DesignFuture Proofing BuildingsManagement of Building Energy UseBehaviour of the OccupantsConclusions
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 1.00.50.0-0.5Temperature Rise (oC)Is Global Warming man made?actualpredictedPrediction: Natural onlygood match until 19601.00.50.0-0.5Temperature Rise (oC)actualpredictedPrediction: Anthropogenic onlyNot a good match between 1920 and 19701.00.50.0-0.5Temperature Rise (oC)actualPredictions include:Greenhouse Gas emissionsSulphates and ozoneSolar and volcanic activitypredictedPrediction: Natural and AnthropogenicGenerally a good matchSource: Hadley Centre, The Met.Office