Strategies for ultra-low energy buildings

Sustainable housing standards Domestic carbon and energy model Non domestic buildings

Sustainable housing standards ventilation? thermal mass? insulation?

Sustainable housing – thermal mass HEEBPp GIR53, GIL72 New Autonomous House Hockerton BedZED NZ Earthships For thermal mass: Against thermal mass: CIBSE Guide F (2004) Finney, BFF Levermore, BEMs AJ No position on thermal mass: Passive-house standard IEA Solar Houses UK building regs

Sustainable housing – simple model T

ESP-r heating investigation Matrix repeated for 3 ventilation rates plus 0.45 insulation standard (1999 regs) also north glazing orientation.

Annual heating energy ESP-r heating investigation

Effect of thermal mass: [(Heat(hi) – Heat(lo))/Heat(lo)]*100%

ESP-r heating investigation HRV Eff 0.21 ac/h ‘Passivhaus’ 0.45 ac/h (tight) 1 ac/h

ESP-r heating investigation 10% heating from solar gains in north 20% heating from solar gains in south

ESP-r cooling investigation Birmingham and Paris Climates Exposed, Shaded, Shuttered glazing Constant v Occupied-only ventilation High v Low thermal mass Advanced v 2005 insulation standards Standard and High occupancy / gains

ESP-r cooling investigation Advanced insulation (0.1), Birmingham, std occupancy / gains (maximum dry bulb temp)

ESP-r cooling investigation 2005 insulation (0.3), Birmingham, std occupancy / gains (maximum dry bulb temp)

ESP-r cooling investigation 2005 insulation (0.3), Birmingham, high occupancy / gains (maximum dry bulb temp)

ESP-r cooling investigation Advanced insulation (0.1), Paris, std occupancy / gains (maximum dry bulb temp)

Sustainable housing standards Conclusions Part A

Sustainable housing standards Insulation to Advanced standard can give a significant benefit over current building regulations for heating

Sustainable housing standards HRV as used in Passive-house and UK Best Practice examples can give a significant heating energy benefit.

Sustainable housing standards Shading and shuttering have significant impact on peak summer temperatures

Sustainable housing standards Thermal mass can have a significant effect on heating and cooling but the effect on heating is dependent on climate, occupancy and gains

Sustainable housing standards Conclusion

Sustainable housing standards ‘1-size fits all’ guidelines have limitations Simulation should be used at the design stage to evaluate options Simulation should consider a range of relevant climate, occupancy and gains scenarios

Strategies for ultra-low energy buildings Sustainable housing standards Domestic carbon and energy model Non domestic buildings

SERT: Scottish Energy Rating Tool

SERT – concept Housing stock rating and upgrade strategy generation SERT ( ESP-r + Java ) Scottish house condition survey (SHCS)

Insulation: Infiltration: Glazed area: Capacity: Gains: Operation: Exposure: Hot water use: Heating system efficiency: poor ave high eco leaky ave tight Climate: Low carbon heating: std large low high low med frugal ave profl high std Var.. high no med profl frugal ave high low med h-m UKCIP m-lavelow super SERT model – performance determinants Energy performance of any dwelling can be characterised by the appropriate combination of key parameters Energy efficiency lights: Appliances: Low carbon electricity: high no med all no med high low med high low med high low med Water heat sys efficiency: Emissions factors:

thermo -dynamic class heating system electrical system climate emissions SERT model – performance determinants

SERT – concept Housing stock rating and upgrade strategy generation SERT Scottish house condition survey (SHCS)

SERT – concept Housing stock rating and upgrade strategy generation SERT Scottish house condition survey (SHCS) CONTEXT policy, climate, £, fuel, demographics

SERT – concept SERT Housing stock rating and upgrade strategy generation Scottish house condition survey (SHCS) CONTEXT climate, £, fuel, demographics

SERT – concept SERT Housing stock rating and upgrade strategy generation Scottish house condition survey (SHCS) CONTEXT climate, £, fuel, demographics

Fabric loss (exp, ins): Infiltration: Glazed area: Capacity: Gains: Operation: Hot water use: Energy efficiency lights: Appliances: Low carbon electricity: Heating system efficiency: v.high high …… low leaky ave tight Climate: Low carbon heating: std large low std high no med high no med std all no med high low med std high low med Water heat sys efficiency: v.low Emissions factors: SERT – ‘SAP CONTEXT’ for EPBD rating individual dwelling statement options restricted to align with SAP assumptions

Certificate and improvement advice Individual dwelling statement (IDS) SERT – concept SERT Individual dwelling EPBD rating and action plan generation

Certificate and improvement advice Individual dwelling statement (IDS) SERT – concept Individual dwelling EPBD rating and action plan generation SERT Housing stock rating and upgrade strategy generation Scottish house condition survey (SHCS) CONTEXT policy, climate, £, fuel, demographics

Strategies for ultra-low energy buildings Sustainable housing standards Domestic carbon and energy model Non domestic buildings

P.Tuohy ESRU 17th Jan 2005 sensorsactuators Control Decisions algorithms external inputs building features comfort Control of Low Energy Climate Adaptive Buildings

P.Tuohy ESRU 17th Jan 2005 sensorsactuators Control Decisions external inputs building features comfort Control of Low Energy Climate Adaptive Buildings Empirical Fuzzy logic Neural Network Simulation (Inverse,ESP-r) Uncertainty Adaption Self learning climate forecasts web algorithms Plant options Sensor options Thermal Mass Light options Heat options Cool options Occupancy / Gain options Shading options Ventilation options, HR Responsiveness Zoning options

P.Tuohy ESRU 17th Jan 2005 Strategies for Ultra Low Energy Buildings Comfort: vent for occupants vent algorithm for free cooling (Roche) CO2 control (Sweden) night vent for free cooling Mech cool - last resort: prefer night? (£) Adaptive comfort control (Nicol) Climate Gains internal / solar Heat recovery? Building Model Solar shading Daylighting Occupancy patterns Rapid response heating / cooling Slow response heating / cooling Rad. v Conv. v Comfort. ( ) Effective use of thermal mass (Ren, Braun) Mech v Nat Slab v Air v Rad sensors Forecast conditions Current and recent conditions Simulation in design (Braun) Simulation in real time (Clarke,Ren) TREND BEMS Model Optimisation algorithms BRE LEOELIZ FRY

P.Tuohy ESRU 17th Jan 2005 Low Energy Buildings – Case study 1: LEO Case study 1: Low Energy Office 14 thermal zones 17 node airflow network

P.Tuohy ESRU 17th Jan 2005 Airflow Network Analysis: X-vent: 6.0 ac/h Stack-Hi: 1.8 ac/h Hopper: 1.2 ac/h Slab: 4.0 ac/h Closed: 0.2 ac/h Model results consistent with LEO measured data (Fisher et al) LEO airflow and thermal model

P.Tuohy ESRU 17th Jan 2005 LEO BEMS MANUAL (84 pages) LEO controls

P.Tuohy ESRU 17th Jan 2005 LEO control map

P.Tuohy ESRU 17th Jan 2005 LEO control summary +2deg? -1? +/-3? no trigger for night cooling based on inside temperatures? mechanical midnight? Slab free 4am? U-floor cooling valve control error “cool” == heat!!! U-floor cooling valve control “cool” v. heat?!!! +1?

Simulation incorporated into the design process for optimisation of building, plant and controls Simulation in BEMS: implementation, operation, monitoring, fault diagnosis Simulation used in commissioning and validation testing of buildings “Damn lies and Simulation” an issue to be overcome? Strategies for ultra-low energy buildings

Building CAD System energy performance optimisation: building, plant, controls. climate, patterns of use. worst-case simulations. BEMS software: Monitoring (6sigma, SH), fault responses (FMEA). self learning / adapt. commissioning and validation test plan: validate time constants fault coverage, fault simulation, worst-case tests. best practice feedback quality control Strategies for ultra-low energy buildings Analogy to silicon chip design…