Energy Efficiency - Lunch & Learn

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The presentation addresses the thermal comfort requirements of the NSW Building Sustainability Index (BASIX) and how lightweight wood-based construction systems can be easily used to meet these requirements. Emphasis is placed on simple techniques to insulate walls, roofs and sub-floor areas of suspended floors for new construction as well as alterations and additions. The presentation will highlight cost effective design and building details, ventilation issues and smart use of thermal mass.

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  • To operate properly, it requires:clear exposure to the sun on north facing windows for living rooms (attractive views in other directions may compete with this requirement or solar access may be restricted by vegetation or buildings)a site that allows for a long rectangular building on the East-West axis (to allow large north-facing façade & windows)householders who are prepared to leave living room (and other) windows ‘unscreened’ during winter days to allow sunlight penetration (this may conflict with privacy considerations, especially in denser developments)a construction method that allows for wall and ceiling insulation (it is difficult to place insulation in cavity brick walls
  • Lightweight timber framed construction is very cost effective. And it’s not just the timber industry saying that. This graph, in a report by Think Brick based on research by the University of Newcastle shows the cost of different external walling systems with the differences in annual energy consumption. The differences they found in this study, which we don’t agree with by the way, are very minor. However the differences in costs of construction are huge
  • Energy Efficiency - Lunch & Learn

    1. 1. Wood and Energy Efficiency<br />Lightweight Timber Framed Construction and NSW’s BASIX Thermal Comfort<br />
    2. 2. Learn more about wood at UTAS<br />Centre for Sustainable Architecture with Wood<br />Graduate Certificate in Timber (Processing & Building)<br />4 units, part time, online<br />Areas covered include:<br />Wood science<br />Design for durability and service for life<br />Timber as a renewable resource<br />Sustainable design and construction<br />Engineered wood products<br />International technologies and developments<br />Plus, selected topics of individual interest<br />More information: Associate Professor Greg Nolan <br />(03) 6324 4478 or enquiries@arch.utas.edu.auwww.csaw.utas.edu.au<br />
    3. 3. Learning Objectives<br />After this presentation you should be able to:<br />Understand the thermal comfort methods of BASIX<br />Understand the thermal properties of wood<br />Understand how wood products can meet BASIXs thermal comfort requirements<br />For architects - AACA Competencies:<br />Design<br />Documentation<br />
    4. 4. This Presentation<br />Thermal comfort requirements of BASIX<br />How wood-based construction systems can meet these requirements<br />Simple techniques to insulate:<br />walls, roofs<br />sub-floor<br />Ventilation issues<br />Smart use of thermal mass<br />
    5. 5. BASIX - Thermal Comfort Requirements<br />Methods:<br />Simulation (AccuRate, BERSPro, Firstrate5)<br />Whole house must not exceed maximum (separate) heating and cooling loads<br />Deemed-to-satisfy<br />DIY<br />Rapid – simple single storey detached dwellings<br />All methods require some form of additional insulation<br />
    6. 6. Thermal Properties of Wood<br />1calculated based on values and method provided in BCA 2010 Volume One Specification J1.2 Table 2a. <br />
    7. 7. R-values for Timber Framed Elements<br />
    8. 8. Roof<br />Insulation is required in all climate zones in NSW<br />
    9. 9. Walls<br />Insulation is required in all climate zones in NSW<br />
    10. 10. Floors<br />Increase in floor system R-value required in most climate zones in NSW<br />Additional insulation required in Rapid Method <br />
    11. 11. Floors: BASIX requirements<br />
    12. 12. Floors: Increase system’s R-value<br />Additional insulation techniques:<br />Insulate above the floor (e.g. carpet)<br />Enclose sub-floor perimeter wall<br />Decrease air-flow:<br />Cover ground with plastic / halves ventilation<br />Install cavity barrier into external wall cavity<br />Insulate under floor:<br />Insulate sub-floor perimeter wall <br />Insulate directly under floor<br />
    13. 13. Sub-floor: Enclose sub-floor perimeter<br />
    14. 14. Floors: Enclose sub-floor perimeter<br />Increase R-value of perimeter enclosure - depends on height of floor above ground<br />Can increase system R-value by R1.0<br />
    15. 15. Floor: Decrease sub-floor air flow<br />Decrease air flow <br />Cover ground with plastic<br />Reduced ventilation requirements <br />Source: BCA 2010 Volume Two Figure 3.4.1.2<br />
    16. 16. Floor: Cavity barrier<br />Increases R-value of floor by at least R0.5<br />
    17. 17. Floor: Insulation below the floor<br />Additional insulation below ground floor:<br />Insulate inside of sub-floor perimeter wall<br />May be cheaper<br />Thermal connection maintained with ground (better for hot conditions)<br />Insulate under the floor<br />Foil integrated with flooring (e.g. R-Flor – no gluing issues)<br />Under floor joists with plywood, foil etc<br />Bulk insulation<br />
    18. 18. High Mass House<br />Solar Mass House<br />
    19. 19. Energy Efficient Housing<br />High mass house<br />Main features and limitations<br />Pending research<br />Lightweight house<br />Main features and benefits<br />Hybrid and combination houses<br />
    20. 20. High Mass House: Main features<br />Main design features:<br />Zoned design with living rooms to the north and bedrooms to the south. Main heating in living areas<br />A length-to-width ratio of approximately 1 to 1.5 on the E-W axis<br />Cavity/solid brick and slab-on-ground construction<br />Ceiling and walls may be insulated (recommended values vary with climate)<br />
    21. 21. High Mass House: Main features<br />Main design features:<br />North facing windows, sometimes with a recommended area as a function of floor area<br />No, or minimum glass facing east and west<br />Shading devices to windows during summer <br />e.g. eaves projection, deciduous trees for north facing windows<br />shutters etc. for east and west facing windows<br />
    22. 22. High Mass House<br />To operate properly requires:<br />Clear exposure to north facing sun<br />Site that allows for building on East-West axis<br />Living room (and other) windows ‘unscreened’ during winter days to allow sunlight penetration<br />Construction method that allows for wall and ceiling insulation<br />
    23. 23. Thermal Mass<br />How much mass is required?<br />Suggested that 1,200 kg of thermal mass per m2 will produce a zero heating house in cold European climates (Vale and Vale 2000) <br />Southwell, UK – 723 kg/m2 sufficient (Vale)<br />Bairnsdale, AUS – 580 kg/m2 sufficient (Oppenheim) <br />More theoretical work needs to be undertaken for temperate climates<br />
    24. 24. Thermal Mass<br />Suitable when:<br />Climate is suitable<br />Diurnal range > 8 degrees<br />Site is suitable<br />Allotment is oriented and sized adequately<br />
    25. 25. Wood and Energy Efficiency – Lightweight Construction © FWPA 2011 <br />
    26. 26. Diurnal Range<br />Source: Your Home Technical Manual<br />
    27. 27. Lightweight House<br />
    28. 28. Lightweight House<br />Structural framework supports the building<br />Other materials provide spatial separation and infill<br />Great flexibility <br />Providing excellent operational environmental performance<br />
    29. 29. Lightweight Timber: Benefits<br />Less sensitive to orientation and solar access<br />Northern orientation is not critical<br />Provides much more flexibility for sighting on a block<br />Greater flexibility in design, layout and internal zoning<br />Adaptable over time <br />
    30. 30. Lightweight Timber: Benefits<br />Reduced capital costs compared with mass house<br />Ease of construction – no cut and fill on sloping blocks, easy installation of insulation in walls and ceiling.<br />Reduced carbon footprint through whole life<br />
    31. 31. Lightweight Timber: Cost effective <br />$20,0000<br />100 kWh/pa<br />Source: Think Brick (2009) Wasting Energy. Available at http://www.thinkbrick.com.au/assets/documents/position_papers/PP2-Wasting-Energy.pdf <br />
    32. 32. Lightweight Timber: Cost effective and energy efficient <br />Largest difference is 100 kwHper annum to heat/cool<br />Extra cost ~ $20 per year<br />Compare cost of construction: <br />insulated double brick $52,000<br />insulated timber $32,000 <br />saving $20,000<br />House life >1,000 years to pay for the difference<br />Enough to buy a big solar power system and make house greenhouse neutral<br />Calculations don’t include the greenhouse gases emitted in brick production or absorbed during tree growth<br />
    33. 33. Lightweight Timber: Lower carbon footprint<br />Total GHG emissions - 5 star <br />
    34. 34. Lightweight Timber & Thermal Mass<br />The difference in thermal mass between standard new build masonry and insulated lightweight timber frame construction is not a significant factor affecting either thermal comfort or energy consumption, now or within the lifetime of the building.<br />
    35. 35. Lightweight Timber: Lower carbon footprint<br />GHG emissions reductions using timber<br />
    36. 36. Wood is an insulator<br />Thermal image <br />
    37. 37. Hybrid house<br />The heavy mass and lightweight house hybrid: <br />It’s not always a simple decision of either/or! <br />If site allows access to some northern sun, mass can be incorporated in specific locations to use the solar heat in wintere.g. composite concrete/timber with lightweight timber-frame walls<br />
    38. 38. Composite concrete/timber floor<br />Tim Gibney and Associates :: Office Development – Surrey HillsImage 5 of 10<br />
    39. 39. Combination Lightweight House<br />+<br />
    40. 40. Learn more about wood at UTAS<br />Centre for Sustainable Architecture with Wood<br />Graduate Certificate in Timber (Processing & Building)<br />4 units, part time, online<br />Areas covered include:<br />Wood science<br />Design for durability and service for life<br />Timber as a renewable resource<br />Sustainable design and construction<br />Engineered wood products<br />International technologies and developments<br />Plus, selected topics of individual interest<br />More information: Associate Professor Greg Nolan <br />(03) 6324 4478 or enquiries@arch.utas.edu.auwww.csaw.utas.edu.au<br />
    41. 41. More Information<br />

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