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Adoption and Compliance with Canadian Energy Codes - Lessons from BC

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Adoption and Compliance with Canadian Energy Codes - Lessons from BC - Presentation from RCIC conference in Edmonton Alberta

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Adoption and Compliance with Canadian Energy Codes - Lessons from BC

  1. 1. Lessons Learned from British Columbia Adoption and Compliance with Energy Codes: ASHRAE 90.1 and NECB Graham Finch, MASc, P.Eng Principal, Building Science Research Engineer RDH Building Engineering Ltd. Vancouver, BC RCIC 2013 Edmonton – May 1, 2013
  2. 2. Presentation Outline Energy Efficiency Requirements for Part 3 Buildings in BC Enforcement & Compliance ASHRAE 90.1 Overview & Lessons Learned NECB 2011 Similarities & Differences
  3. 3. In the Past: City of Vancouver (VBBL 2007), ASHRAE 90.1-2007 • ASHRAE in code for more than a decade • Enforcement boosted in past few years (checklists) Rest of BC (BCBC 2006), ASHRAE 90.1-2004 • ASHRAE added in 2008 • Enforcement up to the authority having jurisdiction (AHJ) Window Performance – BC Energy Efficiency Act (2009) LEED – ASHRAE 90.1-2007 PRM or MNECB 1997 Upcoming: City of Vancouver (VBBL 2013), ASHRAE 90.1-2010 or NECB 2011 Rest of BC (BCBC 2012+), ASHRAE 90.1-2010 or NECB 2011 Window Performance – BC Energy Efficiency Act & Within Code Overview of Energy Efficiency Requirements in BC
  4. 4. City of Vancouver released new building permit & occupancy documentation process to improve compliance with ASHRAE 90.1 Checklists signed off by each registered professional (mechanical, electrical, enclosure/architect) and coordinating professional Effective R-values on drawings/ “Insulation schedules” Energy model outputs Enforcement & Compliance
  5. 5. ASHRAE 90.1 “Energy Standard for Buildings Except Low-Rise Residential Buildings” Compliance involves meeting energy efficiency requirements in all sections: 5 – Building Envelope (Enclosure) 6 – Heating, Ventilating, and Air Conditioning 7 – Service Water Heating 8 – Power 9 – Lighting 10 – Other Equipment ASHRAE 90.1 Overview
  6. 6. Alternate compliance options within each section Prescriptive Trade-offs Energy Simulation Involves several disciplines with professional engineers coordinating their efforts plus one coordinating professional taking overall responsibility Chosen compliance path has implications for building design ASHRAE 90.1 Overview
  7. 7. Mandatory Provisions (Section 5.4) Insulation • Protection, Rating, Labeling, Installation Fenestration & Doors • NFRC certification, airtightness, labels Air Leakage • “continuous air barrier”, prescriptive sealing, Vestibules, weather seals Prescriptive Compliance Path (Section 5.5) All components must meet prescriptive tables, maximum 40% glazing area Building Envelope Trade-off Compliance Path (Section 5.6) Trade-off enclosure components using ASHRAE ENVStd software Energy Cost Budget (ECB) Path (Section 11) Whole building energy cost simulation & tradeoffs ($ not kWh) ASHRAE 90.1 Building Enclosure Compliance
  8. 8. Compliance pathway is heavily influenced by building enclosure design : Window to wall ratio • Maximum 40% for Prescriptive Option • No limit for BE Trade-off option or ECB Minimum assembly and component R-values • Prescriptive Option - difficult to comply with thermal bridging • BE Trade-off Option – detailed area weighted U-value calculations input into ENVStd software • Energy Cost Budget (ECB) - detailed area weighted U-value calculations input into energy model Changes to design during tendering and construction can erode final compliance – need for “factor of safety” ASHRAE 90.1 Building Enclosure Compliance
  9. 9. All building envelope assemblies (including details) must meet Table 5.5 thermal requirements (by climate zone) Opaque Walls/Roof: Assembly Maximum U-value (Minimum effective R-value) or Insulation Minimum R-value (nominal insulation) Windows/Doors/Skylights: Maximum U-value and SHGC restrictions Maximum of 40% window to wall ratio Maximum of 5% skylight to roof ratio Basic area take-offs only necessary to verify window-wall ratio (and skylight to roof ratio) Can be difficult to comply with for many common building designs Prescriptive Building Envelope Option
  10. 10. Two alternate ways to meet prescriptive requirements Assembly Maximum U-value (Minimum R-value) • Accounts for all materials in assembly including air-films • Easiest method to comply with and greatest flexibility in design Insulation Minimum R-value • Prescriptive rated R-value of installed insulation (nominal minimum) • Many assemblies prescriptively require continuous insulation (ci) Prescriptive Building Envelope R-value Tables
  11. 11. Only screws/nails are considered “fasteners” (or adhesives) Where any continuous or discontinuous framing (girts, studs, clips, brick ties, shelf angles, slab edges) penetrate through the insulation – it is not considered c.i. Note: Continuous insulation is not necessarily a mandatory requirement for prescriptive compliance (high enough R- values can be achieved without true ci) Continuous Insulation (ci)
  12. 12. Nominal R-values = Rated R-values of insulation which do not include impacts of how they are installed For example R-20 batt insulation or R-10 foam insulation Effective R-values or Real R-values = Calculated R-values of assemblies/details which include impacts of installation and thermal bridges For example nominal R-20 batts within steel studs becoming ~R-9 effective, or in wood studs ~R-15 Nominal vs Effective R-values
  13. 13. Thermal bridging occurs when a more conductive material (e.g. aluminum, steel, concrete, wood etc.) provides a path for heat to flow such that it bypasses a less conductive material (insulation) The bypassing “bridging” of the less conductive material significantly reduces its effectiveness as an insulator Examples: Wood framing (studs, plates) in insulated wall Steel framing in insulated wall Conductive cladding attachments through insulation (metal girts, clips, anchors, screws etc) Concrete slab edge (balcony, exposed slab edge) through a wall Window frames and windows themselves Thermal Bridging
  14. 14. Effective R-values account for thermal bridges and represent actual heat flow through enclosure assemblies and details Heat flow finds the path of least resistance Disproportionate amount of heat flow occurs through thermal bridges Often adding more/thicker insulation can’t help Required for almost all energy and building code calculations Energy code compliance has historically focused on assembly R-values – however more importance is being placed on details and interfaces & whole building impacts of thermal bridges Why Thermal Bridging is Important
  15. 15. ASHRAE/NECB/NBC Climate Zone Divisions • >7000 HDD • 6000 to 6999 HDD • 5000 to 5999 HDD • 4000 to 4999 HDD • 3000 to 3999 HDD • < 3000 HDD
  16. 16. Wall, Roof & Window Requirements for Alberta (Part 3) Climate Zone Wall – Above Grade: Minimum R-value (IP) Roof – Flat or Sloped: Minimum R-value (IP) Window: Max. U- value (IP) 8 31.0 40.0 0.28 7B 27.0 35.0 0.39 7A 27.0 35.0 0.39 6 23.0 31.0 0.39 NECB2011 ASHRAE90.1-2010– ResidentialBuilding Climate Zone Wall (Mass, Wood, Steel): Min R-value Roof (Attic, Cathedral/Flat) : Min R-value Window (Alum, PVC/FG):Max. U-value 8 19.2, 27.8, 27.0 47.6, 20.8 0.45, 0.35 7B 14.1, 19.6, 23.8 37.0, 20.8 0.45, 0.35 7A 14.1, 19.6, 23.8 37.0, 20.8 0.45, 0.35 6 12.5, 19.6, 15.6 37,0, 20.8 0.55, 0.35 *7A/7B combined in ASHRAE 90.1
  17. 17. Wall, Roof & Window Requirements for Alberta (Part 9) Climate Zone Wall - Above Grade: Minimum R-value (IP) Roof – Flat/Cathedral : Minimum R- value (IP) Roof – Attic: Minimum R-value (IP) Window: Max. U- value (IP) / Min. ER 8 21.9 28.5 59.2 0.25 / 29 7B 21.9 28.5 59.2 0.25 / 29 7A 17.5 28.5 59.2 0.28 / 25 6 17.5 26.5 49.2 0.28 / 25 WithoutaHRV Climate Zone Wall - Above Grade: Minimum R-value (IP) Roof – Flat/Cathedral : Minimum R- value (IP) Roof – Attic: Minimum R-value (IP) Window: Max. U- value (IP) / Min. ER 8 17.5 28.5 59.2 0.25 / 29 7B 17.5 28.5 59.2 0.25 / 29 7A 16.9 28.5 49.2 0.28 / 25 6 16.9 26.5 49.2 0.28 / 25 WithaHRV For Comparison to NBC 2010 (2012 Update) Section 9.36
  18. 18. Excerpt from 90.1-2010 Table 5.5-7 (Edmonton, AB) Building Enclosure Component Climate Zone 7 – Residential Buildings Minimum Assembly R-value ft2 ⋅°F⋅ h/Btu Minimum Insulation R-value ft2 ⋅°F⋅ h/Btu Roof – Insulation Above Deck R-20.8 R-20 c.i. Roof – Attic R-37.0 R-38 Above Grade Wall – Wood-Frame R-19.6 R-13 + 7.5 c.i. Above Grade Wall – Steel Frame R-23.8 R-13 + 15.6 c.i. Above Grade Wall – Mass R-14.1 R-15.2 c.i. Below Grade Wall – Concrete R-10.9 R-10.0 c.i. Windows Maximum Window U-value Btu/h∙ft2∙°F Non Metal Frame (Vinyl, Fibreglass and Wood) U-0.35 (no SHGC requirement) Metal Framed Windows (Aluminum, Window Wall) U-0.45 (no SHGC requirement) Metal frames (Curtainwall & Storefront) U-0.40 (no SHGC requirement) * c.i. = continuous insulation
  19. 19. Window-wall ratios >40% Curtain-wall or window-wall spandrel panels Balconies & exposed slab edge projections Mass concrete walls with interior insulation Roof parapet, overhang details, canopies Insulation placed between steel studs or z-girts Best suited for simple buildings Common Difficulties in Meeting Prescriptive Compliance
  20. 20. Structural Stud Framing in Taller Multi-Unit Residential Buildings Common Difficulties in Meeting Prescriptive Compliance
  21. 21. Spandrel Panels Common Difficulties in Meeting Prescriptive Compliance verticals
  22. 22. Cladding Attachment through Exterior Insulation – Minimize Thermal Bridging Solutions for Meeting Prescriptive Compliance
  23. 23. Alternate Cladding Support Comparison
  24. 24. Cast-in-Place Concrete Balcony & Slab Edge Thermal Breaks Solutions for Meeting Prescriptive Compliance
  25. 25. Allows for greater flexibility in architectural design Common path for Multi-Unit Residential Buildings where more complex enclosure designs are utilized Necessary where window-wall ratios exceed 40% and enclosure assemblies/details may not meet minimum prescriptive requirements Requires determination of effective thermal performance of all enclosure assemblies, details, and components Trade-offs made between any enclosure component (i.e. between walls and windows, or walls and roofs etc.) Building Envelope Trade-off Option
  26. 26. Compliance is assessed by calculation of Envelope Performance Factor (EPF) calculated using ASHRAE EnvStd software EPF approximates the total heating and cooling energy associated with a single square foot of surface. A lower EPF is better than a high EPF Overall U-value of building enclosure driving factor in EPF plus day- lighting and solar-heat gain through windows Proposed building enclosure is compared to a minimally prescriptively compliant baseline building enclosure Baseline building construction is identical except that all building enclosure assemblies meet maximum U-value (minimum R-value) requirements within each class of construction and a 40% window-wall ratio is assumed Building Envelope Trade-off Option
  27. 27. Step 1: Identify Building “Spaces” Step 2: Define “Surfaces” within each Space Step 3: Coordinate Surfaces & Assemblies Step 4: Summarize Windows/Doors for each surface Step 5: Summarize Data and Calculate Areas Step 6: Enter Data and run EnvStd Program Building Envelope Trade-off Option Process
  28. 28. Wall and Roof Areas and U-values input into ENVStd Software by construction type, orientation and occupancy Window/door areas entered within each of the assemblies Output from ENVStd shows Pass/Fail & No. of EPF Points Building Envelope Trade-off Option
  29. 29. Assessing Reasons for Non-Compliance Lower EPF is better Current Design Proposed Base Margin % Difference Roof 981 1011 30 -3% Skylight 0 0 0 Exterior Walls and Windows 6552 5753 -799 14% Floor 873 779 -95 12% Slab 0 0 0 Below Grade Wall 0 0 0 Daylighting Potential 3478 4140 663 -16% Total 11884 11683 -201 1.7% FAILS Component Area UxA % of Heat Loss Windows 10,884 4,898 55.7% Doors 1,093 492 5.6% Wall EW1 8,479 1,495 17.0% Wall EW2 894 147 1.7% Wall EW3 168 26 0.3% Curb and slab edge details 1,585 652 7.4% Floor and Soffit Areas 7,466 622 7.1% Roof and Deck Areas 7,474 460 5.2% TOTAL 38,043 8,791 Overall Effective U-Value 0.23 Overall Effective R-Value 4.33
  30. 30. Impact of Window to Wall Ratio on Overall Performance
  31. 31. Value of High Performance Windows on ASHRAE Compliance ASHRAE, Maximum 40% Glazing Area Non-Compliant Compliant 1. Allows for Higher Window-Wall Ratios Improve Enclosure R-value
  32. 32. Whole building energy simulation considers building envelope plus HVAC, DHW, lighting and power. Trade-offs allowed between BE and mechanical systems Energy cost ($) of proposed building compared to baseline building (with minimally compliant enclosure and baseline HVAC system) Used where building envelope performance cannot meet BE Trade-off or prescriptive requirements Requires detailed building envelope R-value calculations for energy model input – same level of detail as required for BE Trade-off with overall R-values ECB energy model is different the LEED PRM energy model Energy Cost Budget Option
  33. 33. Energy Cost Budget – depends on $ savings, not necessarily energy Bigger benefit to addressing higher cost fuel (often electricity) rather than higher energy use (ie gas heating) Common approach for compliance for buildings undergoing LEED or other energy modeling Mechanical systems often make-up for poor enclosure choices – not great from long-term or passive approach Allows for most flexibility in design, higher window to wall ratio, more thermal bridging (to a point) Trends with Energy Cost Budget Option
  34. 34. ASHRAE Mandatory Provisions Checklist City of Vancouver Submission Checklist “Insulation Schedule” and Effective R- values on Drawings Comparison of actual vs prescriptive R- values Energy Modeling outputs Compliance Documentation
  35. 35. National Energy Code of Canada for Buildings (NECB) 2011 replaces MNECB 1997 Similar compliance paths to ASHRAE 90.1 – Prescriptive, Trade-offs, and Energy Modeling 3 – Building Envelope 4 – Lighting 5 – HVAC 6 – Service Water Heating 7 – Electrical Power Systems and Motors 8 – Building Energy Performance Compliance Path Building Envelope: Maximum window to wall ratio from 40% (HDD <4000) down to 20% (HDD >7000) Energy Consumption vs Energy Cost NECB 2011 Similarities & Differences
  36. 36. ASHRAE 90.1-2010 vs NECB 2011 Climate Zone Wall – Above Grade: Minimum R-value (IP) Roof – Flat or Sloped: Minimum R-value (IP) Window: Max. U- value (IP) 8 31.0 40.0 0.28 7B 27.0 35.0 0.39 7A 27.0 35.0 0.39 6 23.0 31.0 0.39 NECB2011 ASHRAE90.1-2010– ResidentialBuilding Climate Zone Wall (Mass, Wood, Steel): Min R-value Roof (Attic, Cathedral/Flat) : Min R-value Window (Alum, PVC/FG):Max. U-value 8 19.2, 27.8, 27.0 47.6, 20.8 0.45, 0.35 7B 14.1, 19.6, 23.8 37.0, 20.8 0.45, 0.35 7A 14.1, 19.6, 23.8 37.0, 20.8 0.45, 0.35 6 12.5, 19.6, 15.6 37,0, 20.8 0.55, 0.35 *7A/7B combined in ASHRAE 90.1
  37. 37. Builder Insight Bulletins & Building Enclosure Design Guides www.hpo.bc.ca City of Vancouver Checklists ASHRAE 90.1 User Guides NECB 2011 Presentations For More Information & Assistance
  38. 38. Graham Finch, MASc, P.Eng gfinch@rdhbe.com 604-873-1181 Discussion

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