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Proposed Changes to Homes and Small Buildings for Energy Efficiency Joan Maisonneuve CHBA-Alberta.

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Presentation on theme: "Proposed Changes to Homes and Small Buildings for Energy Efficiency Joan Maisonneuve CHBA-Alberta."— Presentation transcript:

1 Proposed Changes to Homes and Small Buildings for Energy Efficiency Joan Maisonneuve CHBA-Alberta

2 A Tale of Two NECB – complete document Applies to large buildings > 3 stories Published by NRC in fall of 2011 Not yet adopted by the province Concerns with window to wall ratios CHBA working with builders on this Part 9 Changes Currently out for review by NRC Publishing anticipated late 2012

3 Scope of Part 9 For EE Housing and small buildings Includes secondary suites < 600 m 2 and 3 storey in height (dwellings) Buildings with dwelling units w/common space < 20% of floor area Building envelope HVAC Service water

4 Early Work by CHBA National A reasonable step forward not an arbitrary EnerGuide 80 Elimination of window/door to wall ratios Reduction of insulation at the attic perimeter Air tightness is prescriptive areas versus blower door testing Opaque & vertical area RSI trade-off

5 Three Compliance Paths Prescriptive path No specific ENERGUIDE target No air leakage target No wdw/wall ratios Trade-off option Performance Path Comparison against a reference house Energy target = annual energy consumption of reference house Air change rate of 3.2 or 2.5 or tested

6 Conventions for Units Effective RSI values for walls, ceiling and floors i.e. transmission through framing combined with insulated areas U-value for windows and doors Overall window value by A440.2

7 Calculation of Thermal Resistance of Assemblies Includes: Studs, joists, lintels, sills, plates (ladders?) Excludes: Minor penetrations (pipes, ducts) Areas not intended to be heated Need to calculate major structural penetrations Balcony slabs, beams, columns Total area of such penetrations is limited to max 2% of the gross wall area If an area exceeds 2% it must be taken into account

8 Continuity of Insulation To prevent a break in the continuity of the insulation of the building envelope Partitions, chimneys, fireplaces, columns beams, flues Compensate by insulating for a distance of 4X the thickness of the penetrating element, inward and outward Also applies where one bldg components meets another

9 Requirements for Bldg. Envelope RSI Location by Climatic Zones Depends on HRV or NO HRV Climate Zone, Heating Degree Days o C Zone 4Zone 5Zone 6Zone 7aZone 7B Zone 8 < to to to to 6999 > 7000 Lethbridge Edmonton Red Deer Calgary Grande Prairie

10 Minimum ASSEMBLY RSI RED = without HRV Black = with HRV AssemblyZone 6 Lethbridge Zone 7a Edm, R.D, Calgary Zone 7B G.P. Ceilings below attics 8.66/8.66 (R-50) 10.43/8.66 (R-60) 10.43/10.43 ( R-60) Cathedral ceilings and flat roofs 4.75/4.75 (R- 27) 5.07/5.07 (R-30) Walls 3.27/3.16 (R- 18.5) 4.13/3.27 (R-24) Floors over unheated spaces 4.75/4.75 ( R-27) 5.07/5.07 (R-30) Rim joists 3.46/ 3.32 (R-20) 3.67/3.46 (R-21) Foundation walls 3.17/3.17 (R-18) 3.57/3.17 (R-20) 3.57/3.17 (R20) Unheated Floors below frost line uninsulated

11 Examples of Assemblies Appendix has tables with examples of assembles and the nominal R-value in various zones: Trade-off path available

12 Table A Minimum Residual Thermal Resistance Value for Insulation, Sheathing(1) and other Materials for Walls Above and Not in Contact with the Ground Assembly description Required Effective Thermal Resistance RSI in m² K/W (See Article ) Description of base assembly Stud SpacingNominal insulation between studs mm (in.) m² K/W Minimum required residual nominal thermal resistance (1) (3) (5) (RSI) in m² K/W 2x6 wood framing 12.7mm gypsum board, vinyl siding, no strapping 406 (16)3.34 (R19) (2)RSI 0.11 (R 0.6)RSI 0.36 (R2)RSI 0.47 (R2.7)RSI 1.33 (R7.5) 3.87 (R22)RSI 0.14 (R0.8)RSI 0.25 (R1.4)RSI 1.11 (R6.3) 4.23 (R24)RSI 0.11 (R 0.6)RSI 0.97 (R5.5) 610 (24)3.34 (R19) (2)RSI 0.04 (R 0.2)3 RSI 0.27 (R1.5)RSI 0.38 (R2.2)RSI 1.24 (R7) 3.87 (R22)RSI 0.02 (R 0.1)RSI 0.13 (R 0.7)RSI 0.99 (R5.6) 4.23 (R24)RSI 0.84 (R4.7) 2x4 wood framing 12.7 mm gypsum board, vinyl siding, no strapping 406 (16)2.11 (R12)RSI 1.01 (R5.7)RSI 1.24 (R7)RSI 1.35 (R7.7)RSI 2.20 (R12.6) 2.46 (R14)RSI 0.85 (R4.9)RSI 1.08 (R6.1)RSI 1.19 (R6.8)RSI 2.05 (R11.7) 610 (24)2.11 (R12)RSI 0.95 (R5.4)RSI 1.18 (R6.7)RSI 1.29 (R7.4)RSI 2.15 (R12.2) 2.46 (R14)RSI 0.82 (R4.6)RSI 1.05 (R6)RSI 1.16 (R6.6)RSI 2.02 (R11.5)

13 Allowable Reduction In Attic Reduction in required insulation level at perimeter of attics under sloped roofs Minimum nominal RSI 3.52 (R20) at exterior of wall Maximum 1200 mm from interior/ exterior of wall Minimum height at outside surface of exterior of wall depends on: Minimum 1 vent clearance Roof slope and location of top-bottom chord junction Issue for scissor trusses?

14 Foundations Building Assembly Below or in Contact With the Ground Heating Degree-Days(HDD) of Building Location, in Celsius Degree-Days Zone 4Zone 5Zone 6Zone 7aZone 7bZone 8 < to to to to Minimum Effective thermal resistance (RSI) in m² K /W Foundation Walls Unheated Basement Floors – below frost line uninsulated – above frost line1.96 Floors on Permafrost Heated Basement Floors ) Structural Slab on grade

15 Windows & Doors No prescriptive area limits U-values for doors and windows of 1.6 or 1.4 OR Energy Rating values of 25 & 29 17% to 22% FDWR used as references in building envelope trade-off option 3 Used in performance compliance path

16 Trade-Off Option Above ground opaque – Above-ground opaque Decreased insulation in a wall area compensated by increased insulation in an equal area of ceiling or another wall Limits placed on maximum permitted reduction in performance i.e. Tall wall areas Windows – Windows increased U-value (decreased R-value) of one window area compensated by decreased U-value (increased R-value) for another equal window area

17 Air tightness Prescriptive details Materials, properties, joints, penetrations NO testing required in prescriptive path Testing may be used in the performance path Assembly Specification Qualified Assemblies plus junctions

18 Air Tightness Properties specified for materials intended to provide air tightness Construction details described for joints and junctions in the airtight material Service penetrations including chimneys, ducts, vent stacks, wiring and electrical boxes Foundations and sill plates, sill plates and rim joists Windows/doors/skylights and walls/ceilings Interior walls and exterior walls/ceilings

19 HVAC Equipment sized to Can/CSA F-280 HVAC Ducts - generally Sizing to good practice Ducts outside the plane of insulation Sealed joints Insulated to same level as required for above-grade walls Ducts – under insulated floors over unheated spaces Sealed Insulated to wall RSI Sides can be insulated to compensate for reduction on top & bottom Round ducts? At rim joist area?

20 HVAC Intakes and Outlets Dampers in most cases Temperature controlled within 1C Eliminate conflicts with cooling Zone adjustment capability required Automatic humidity control required

21 HVAC Efficiencies Table of minimum efficiencies Gas-fired boilers 90% AFUE Gas-fired furnaces 92% AFUE Gas-fired fireplaces 62.4% FE Air conditioners, air cooled 14 or 14.5 SEER Concern: Table includes equipment even where there is no specified minimum efficiency

22 Ventilation HRVs optional Reduced level of insulation may be installed in the building envelope Where used must have: Sensible heat recovery efficiency of 60%

23 Service Water Service water = domestic water heating equipment Gas-fired storage tanksEF> 0.62 ElectricEt > 98% Gas-fired tankless 0.8 Heat traps above water heaters NOT required

24 Performance Path No EnerGuide specified Comparison between Reference House and Proposed House Reference house = prescriptive requirements

25 Top Issues From Review Variation in degree-days Fireplaces as heating appliances Overlap of insulation to foundation HRV installation Tall walls/trade-off Guidance for plans examiners Calculating walk-out basements

26 Costing Dave

27 Questions Additional Information:

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