BCA SECTION J CHANGES OVERVIEW. THE BCA: THE GOOD THE BAD & THE UGLY 20 August 2013 MICHAEL SHAW ESD MANAGER

Transcription

1 J1,J2,J3 J6 J7 J5 J8 BCA SECTION J CHANGES OVERVIEW THE BCA: THE GOOD THE BAD & THE UGLY 20 August 2013 MICHAEL SHAW ESD MANAGER Refresher J1 Insulation and Rooflights J2 Glazing and Shading, J3 Building Sealing J5 Air-Conditioning & Ventilation J6 Artificial Lighting & Power J7 Pools & Spas, J8 Metering 1

2 Major Changes since 2009 Major Changes since 2009 Section J major overhaul in BCA2010. Class 2&4-6 star HERS rating, commercial buildings 2:1 benefit/cost ratio. BCA2013 changes: Application of J1, J2 & J3 Building fabric non-conditioned space exemption clause rewritten Fan motor power limits redefined Glazing & rooflight clarification: U-value and SGHC are whole system values Application of glazing & rooflight area limits to nonconditioned buffer spaces to allow reduced insulation in internal envelope wall 2

3 J1.3 DTS Insulation Changes Roof/Ceiling } R2.2/3.2 R R3.0/3.2 R R2.7/3.2 R R3.2 unchanged R3.8/3.2 R3.7 R4.3 R4.8 J1.3 DTS Insulation Changes Roof/Ceiling Table J1.3b introduced to increase ceiling insulation where there is significant (>0.5%)loss of insulation 3

4 J1.5 DTS Insulation Changes External Walls } R1.4/1.8 R3.3 R1.7/1.8 R2.8 R1.4/1.8 R2.8 R1.7/1.8 R2.8 R1.9/1.8 R2.8 R2.8 R3.8 J1.6 DTS Insulation Changes Susp. Floors Worst case exposure (d) from Table 1.6 } Nil/R1.5 R2.0 Nil/R1.5 R2.0 Nil R2.0 R1.0/1.5 R2.0 R1.0/1.5 R2.0 R2.5 R3.5 4

5 J1.4 DTS Rooflights Changes BCA2009 allowed <10%, now 5% maximum allowed Section J1.4 Rooflight areas for rooflight shaft index<0.5 Rooflight area as % of floor area served <2% 2-3% 3-4% 4-5% SHGC max U-value max Example SG clear Low-E clr DG supergreen J2.4 DTS Glazing stringency between BCA 2009 and Control of internal glazing thermal performance in envelope between conditioned and buffer space Façade glazing area limits dependent on: Climate zone Exposure: window orientation and external shading U-value and SHGC of glass and frame Building type: 1) shopfront, 2) other, 3)accommodation (classes 3 and 9c) AND Internal Wall insulation type (option A or B) 5

6 *allowed glazed area in BCA2010 as a percentage of BCA 2009 allowance Zone J2.4 DTS Glazing stringency* between BCA 2009 and 2010+, classes 5-8, 9a & 9b (non-residential) *as an exact percentage of BCA 2009 allowance *allowed glazed area in BCA2010 as a percentage of BCA 2009 allowance Zone J2.4 DTS Glazing stringency* between BCA 2009 and 2010+, classes 3 and 9c (residential accommodation) *as an indicative percentage of BCA 2009 allowance 6

7 J3 DTS Building Sealing refresher J3.2 Dampers in chimneys & flues solid fuel appliances J3.3 Weather-sealed rooflights J3.4 Weather-sealed windows and doors (clause J3.4(d) BCA2010+ requires all entrances to conditioned spaces >50m 2 to have airlock, self-closer or revolving door) J3.5 Self-closing dampers for exhaust fans (NEW habitable rooms in climate zone 5 added in BCA2010+) J3.6 Sealing of roof, walls, floors and openings therein J3.7 Self closing dampers for evap coolers (NEW habitable rooms in climate zone 5 added in BCA2010+) J5.2 DTS Airconditioning & Ventilation Systems BCA2010+ BCA2013: Fan motor power targets increased by 30% - New definition includes fan motor losses for all configs Reed switches for Class 3 external doors open >1 min VSD s for fans where supply air quantity varies (no PACs) Economy cycle threshold lowered from 50-35kW r o BCA2011+ Eco cycle: frozen food areas of supermarkets, labs etc exempted, BCA2012+ processes where humidity control needed 7

8 J5.2 DTS Airconditioning & Ventilation Systems BCA2010+ Fan power allowances reduced in 2010 & expressed as fan power the power delivered to a fan Fresh air (Part F4) oversupply limit reduced from 50-20% Energy reclaim or modulation extended to all other building classes (not just 9b) with density <1 person/m 2 Maximum fan power to air flow rate ratio reduced by 10% for mech (not A/C) ventilation systems BCA2012+: Elec Substation exemptions J5.4 DTS Heating & Cooling BCA2010+ Variable speed pump threshold reduced to 3kW pumps Maximum pump power targets altered - expressed separately for chilled, condenser and heating water Slight changes to min efficiencies for water heaters Direct electric heating prohibited in most cases Condenser fan power clauses (e) to (h) simplified 8

9 J6 DTS Artificial Lighting & Power BCA2010+ J6.2 Illumination Power Density target for class 2&4 Minor changes to Maximum Illumination Power Density Formula for room aspect adjustment factor changed Table J6.2b adjustment factors for control devices added: timer for corridor lighting (0.7 adj factor) J6.3 (c)(ii) switching zone max size: function-related refinement to exempt single functional use spaces J7 DTS Hot Water Supply BCA2010+ J7.3 swimming pool heating & pumping added J7.4 spa pool heating & pumping added Water heating fuel must not be electric resistance Cover, time switch for water heater & pump 9

10 J8 DTS Access for Maintenance & Monitoring BCA2010+ Exempt: Class 2 > 2,500m 2 and common areas < 500m 2 Gas and/or elec: building or SOU s > 500m 2 Building > 2,500m 2 o A/C plant, heating, cooling, air handling o Artificial lighting o Appliance power o Central hot water supply o Lifts, escalators, travelators o Other ancillary plant OR Alternative Solutions permitted JV3 modelling comparison to DTS Reference Building Glazing/shading requirements too restrictive (e.g. clear glazed retail shopfronts) Larger rooflights preferred Green star projects (e.g. IEQ increased fresh air rates) Energy efficient design solutions to multi-res commercial buildings (3 and 9c) 10