Window Energy Ratings
Enhance the energy efficiency and comfort of a building
A variety of energy efficient glazing options are available to meet local requirements. Energy ratings of most windows sold in Australia can be found in the Window Energy Rating Scheme section of the WERS website.
With no fixed panes and blades that open almost fully horizontally (87 degrees) Altair Louvre Windows welcome fresh, cooling breezes. These cooling breezes reduce the need for power hungry electric air conditioning systems, thereby helping to save our fragile environment.
Altair Louvre Windows have an air infiltration rating that is significantly better than the standard required for residential windows. Tight sealing reduces draughts thereby allowing heating and cooling systems to run more efficiently.
Additional Benefits of External Screening
External screens deliver additional insulating and shading benefits to Altair Louvre Windows. The Easyscreen Altair Louvre Window is the only window system currently energy rated under the Window Energy Rating Scheme (WERS) with permanent, externally fitted metal mesh screens. WERS ratings of screened products can be found at their website.
Additional Benefits of the Altair Dualair Secondary Glazed Louvre System
The secondary glazing configuration of the Dualair System results in significant improvements to the thermal insulation of Dualair Window Systems due to the large air gap.
Breezway offers three formal CPD tutorials to Architects & Designers on Fall Prevention, Ventilation and AS2047 and AS1288. These have been accredited by AIS. Book today and collect your CPD points!
Choice of Glazing
A variety of energy efficient glazing options are available to meet local requirements. For example, in cooling climates toned glass blades or timber blades reduce the amount of hot sunlight that enters a building. In mixed and heating climates, the improved insulating properties of low e glass blades offer thermal performance comparable to clear double glazing.
Energy ratings of most windows sold in Australia can be found in the Window Energy Rating Scheme section of the WERS website.
In warm climates where “cooling stars” are the major consideration, the shading offered by tinted glass or timber blades have a positive impact on the window’s energy rating.
In cold and mixed climates where “heating stars” and the balance between “heating stars” and “cooling stars” are the major consideration, the insulating properties of clear low e glass blades give comparative thermal performance to clear double glazing.
Building Code Compliance
The energy efficiency requirements of the National Construction Code (NCC) are contained within Section J of Volume One and Part 3.12 of Volume Two. The complex interactions between the energy efficiency characteristics (U-value and solar heat gain coefficient), the size, the shading and the orientation of each window for each of the climate zones and for the various building types are expressed within extensive formulas and tables. The Australian Building Codes Board makes excel spreadsheets, known as ‘Glazing Calculators’ available on their website (www.abcb.gov.au) into which the data can be inputted to assess compliance. These glazing calculators make it easy to assess the impact of changes to the glazing, the window sizes or the window shading devices.
Analysis using the glazing calculators shows that Altair Louvre Windows can comfortably comply with the energy efficiency requirements of Section J and Part 3.12 in all climate zones, with high window area to floor area ratios possible in most climate zones when appropriate glazing and shading are used.
More information can be found by viewing the documents below.
- Obscure Glass WERS Ratings
- Timber and Aluminium Blade Energy Ratings
- Thermal & Solar Energy Performance Report for Altair Louvres with Timber Blades
To learn more about an easy way of comparing the U-values of Breezway windows with both louvre and fixed bays to the U-values of other window types, please read the Breezway Technical Bulletin below.
WERS Certified Products Directory – AFRC (available at https://www.awawers.net)
|Blade Type||WERS Windows ID||WERS Glazing Code||WERS Cooling Stars9||WERS Heating Stars9||Uw6||SHGC7||Tvw8|
Breezway Easyscreen Altair Louvre Window System - Single Glazed1
|6mm SolTech Neutral||BRZ-006-11||6SolT Ntl||4.5||0.41||0.48|
|6mm thick clear glass||BRZ-006-01||6Clr||6.2||0.64||0.68|
|6mm thick grey tinted glass||BRZ-006-07||6Gy||6.2||0.51||0.49|
|6mm thick bronze tinted glass||BRZ-006-02||6Bz||6.2||0.48||0.39|
|6mm thick green tinted glass||BRZ-006-06||6Gn||6.2||0.46||0.57|
|6mm thick super green tinted glass||BRZ-006-05||6SG||6.2||0.4||0.5|
|6mm thick clear low E glass2||BRZ-006-08||6LE||4.4||0.47||0.66|
|6mm thick E-Vantage clear glass2||BRZ-006-03||6EVan||4.8||0.48||0.5|
|6mm thick E-Vantage grey tinted glass2||BRZ-006-04||6EVanGy||4.8||0.32||0.21|
Easyscreen Altair Louvre Window System - Single Glazed - 105.6mm Gap - Crimsafe Security Screen on Exterior3
|6mm thick clear glass||BRZ-990-01||6Clr||4.6||0.3||0.27|
|6mm thick grey tinted glass||BRZ-990-07||6Gy||4.6||0.24||0.13|
|6mm thick bronze tinted glass||BRZ-990-02||6Brz||4.6||0.25||0.15|
|6mm thick green tinted glass||BRZ-990-06||6Gn||4.6||0.25||0.23|
|6mm thick super green tinted glass||BRZ-990-05||6SpGn||4.6||0.23||0.2|
|6mm thick clear low E glass2||BRZ-990-08||6ET||3.6||0.25||0.25|
|6mm thick E-Vantage clear glass2||BRZ-990-03||6EVClr||3.7||0.23||0.21|
|6mm thick E-Vantage grey tinted glass2||BRZ-990-04||6EVGrey||3.7||0.2||0.1|
Easyscreen Altair Louvre Window System - Single Glazed - 108.8mm Gap - Invisigard Security Screen on Exterior3
|6mm thick clear glass||BRZ-991-01||6Clr||4.5||0.31||0.28|
|6mm thick grey tinted glass||BRZ-991-07||6Gy||4.5||0.26||0.13|
|6mm thick bronze tinted glass||BRZ-991-02||6Brz||4.5||0.27||0.16|
|6mm thick green tinted glass||BRZ-991-06||6Gn||4.5||0.26||0.24|
|6mm thick super green tinted glass||BRZ-991-05||6SpGn||4.5||0.25||0.21|
|6mm thick clear low E glass2||BRZ-991-08||6ET||3.6||0.26||0.26|
|6mm thick E-Vantage clear glass2||BRZ-991-03||6EVClr||3.7||0.25||0.22|
|6mm thick E-Vantage grey tinted glass2||BRZ-991-04||6EVGrey||3.7||0.21||0.1|
Easyscreen Altair Louvre Window System - Single Glazed - 109mm Gap - Prowler Proof ForceField Security Screen on Exterior3
|6mm thick clear glass||BRZ-992-01||6Clr||4.5||0.31||0.28|
|6mm thick grey tinted glass||BRZ-992-07||6Gy||4.5||0.25||0.13|
|6mm thick bronze tinted glass||BRZ-992-02||6Brz||4.5||0.26||0.16|
|6mm thick green tinted glass||BRZ-992-06||6Gn||4.5||0.26||0.24|
|6mm thick super green tinted glass||BRZ-992-05||6SpGn||4.5||0.24||0.21|
|6mm thick clear low E glass2||BRZ-992-08||6ET||3.6||0.26||0.26|
|6mm thick E-Vantage clear glass2||BRZ-992-03||6EVClr||3.7||0.24||0.22|
|6mm thick E-Vantage grey tinted glass2||BRZ-992-04||6EVGrey||3.7||0.20||0.10|
Breezway Easyscreen Fixed Lite Window System - Single Glazed1
|6mm thick clear glass||BRZ-007-01||6Clr||6.2||0.72||0.76|
|6mm thick grey tinted glass||BRZ-007-07||6Gy||6.2||0.56||0.55|
|6mm thick bronze tinted glass||BRZ-007-02||6Bz||6.2||0.53||0.43|
|6mm thick green tinted glass||BRZ-007-06||6Gn||6.2||0.51||0.64|
|6mm thick super green tinted glass||BRZ-007-05||6SG||6.2||0.44||0.56|
|6mm thick clear low E glass2||BRZ-007-08||6LE||4.1||0.53||0.74|
|6mm thick E-Vantage clear glass2||BRZ-007-03||6EVan||4.5||0.53||0.56|
|6mm thick E-Vantage grey tinted glass2||BRZ-007-04||6EVanGy||4.5||0.35||0.27|
Breezway SL2 Altair Louvre Window System - Single Glazed1
|6mm thick clear glass||BRZ-003-01||6Clr||6||0.72||0.52|
|6mm thick grey tinted glass||BRZ-003-02||6Gy||6||0.5||0.26|
|6mm thick super grey tinted glass||BRZ-003-06||6SpGy||6||0.31||0.05|
|6mm thick bronze tinted glass||BRZ-003-03||6Bz||6||0.54||0.32|
|6mm thick evergreen tinted glass||BRZ-003-04||6EG||6||0.46||0.39|
|6mm thick arctic blue tinted glass||BRZ-003-05||6AB||6||0.46||0.33|
|6mm thick clear low E glass2||BRZ-003-13||6LE||4.1||0.62||0.48|
Breezway Innoscreen Altair Louvre Window System - Single Glazed1
|6mm thick clear glass||BRZ-009-01||6Clr||6.9||0.63||0.63|
|6mm thick grey tinted glass||BRZ-009-02||6Gy||N/A||6.9||0.50||0.46|
|6mm thick green tinted glass||BRZ-009-08||6Gn||N/A||6.9||0.45||0.54|
|6mm thick ever green tinted glass||BRZ-009-09||6EG||N/A||6.9||0.40||0.47|
|6mm thick E-Vantage clear glass2||BRZ-009-04||6EVanClr||5.7||0.48||0.48|
|6mm thick E-Vantage grey glass2||BRZ-009-10||6EVanGy||5.7||0.32||0.23|
|6mm thick EnergyTech clear glass2||BRZ-009-03||6ET||5.5||0.53||0.58|
|6mm thick EnergyTech grey glass2||BRZ-009-07||6ETGy||5.6||0.37||0.28|
|6mm thick SolTech Neutral glass2||BRZ-009-05||6SolTNtl||5.6||0.41||0.45|
|6mm thick Sunergy glass2||BRZ-009-06||6Sn||5.8||0.46||0.48|
Breezway Innoscreen Fixed Lite Window System - Single Glazed1
|6mm thick clear glass||BRZ-008-01||6Clr||6.3||0.73||0.76|
|6mm thick grey tinted glass||BRZ-008-02||6Gy||6.3||0.58||0.55|
|6mm thick green tinted glass||BRZ-008-08||6Gn||6.3||0.52||0.64|
|6mm thick ever green tinted glass||BRZ-008-09||6EG||6.3||0.46||0.56|
|6mm thick E-Vantage clear glass2||BRZ-008-04||6EVanClr||4.7||0.55||0.58|
|6mm thick E-Vantage grey glass2||BRZ-008-10||6EVanGy||4.7||0.36||0.27|
|6mm thick EnergyTech clear glass2||BRZ-008-03||6ET||4.5||0.61||0.69|
|6mm thick EnergyTech grey glass2||BRZ-008-07||6ETGy||4.6||0.41||0.34|
|6mm thick SolTech Neutral glass2||BRZ-008-05||6SolTNtl||4.5||0.47||0.54|
|6mm thick Sunergy glass2||BRZ-008-06||6Sn||4.9||0.52||0.58|
Breezway Altair Louvre Components in a timber frame - Single Glazed1
|6mm thick clear glass||BRZ-005-01||6Clr||4.9||0.58||0.62|
|6mm thick grey tinted glass||BRZ-005-02||6Gy||4.9||0.41||0.29|
|6mm thick super grey tinted glass||BRZ-005-06||6SoGy||4.9||0.25||0.06|
|6mm thick bronze tinted glass||BRZ-005-03||6Bz||4.9||0.44||0.34|
|6mm thick evergreen tinted glass||BRZ-005-04||6EG||4.9||0.37||0.47|
|6mm thick arctic blue tinted glass||BRZ-005-05||6AB||4.9||0.37||0.37|
|6mm thick clear low E glass2||BRZ-005-13||6LE||3.4||0.49||0.57|
|6mm thick Sunergy glass2||BRZ-005-14||6Sn||3.7||0.42||0.48|
Breezway Dualair Altair Louvre System in the Alspec Hunter EVO Acoustic 150mm Frame – Secondary Glazed11
|6mm Clear / 101mm Air Gap / 6mm Clear||BRZ-010-01||6Clr/101/6Clr||3.8||0.46||0.48|
|6mm LowE (#2)10 / 101mm Air Gap / 6mm Clear||BRZ-010-02||6LE/101/6Clr||3.2||0.15||0.14|
|6mm LowE (#2)10 / 101mm Air Gap / 6mm LowE (#2)10||BRZ-010-03||6LE/101/6LE||2.9||0.11||0.05|
|6mm EnergyTech (#2)10 / 101mm Air Gap / 6mm Clear||BRZ-010-04||6ET/101/6Clr||3.4||0.40||0.44|
|6mm EVantage Clear (#2)10 / 101mm Air Gap / 6mm Clear||BRZ-010-05||6EVanClr/101/6Clr||3.4||0.37||0.38|
Breezway Dualair Altair Louvre System in the Alspec McArthur EVO 150mm Centre Pocket Frame – Secondary Glazed11
|6mm Clear / 101mm Air Gap / 6mm Clear||BRZ-011-01||6Clr/101/6Clr||3.4||0.47||0.49|
|6mm LowE (#2)10 / 101mm Air Gap / 6mm Clear||BRZ-011-02||6LE/101/6Clr||2.8||0.14||0.14|
|6mm LowE (#2)10 / 101mm Air Gap / 6mm LowE (#2)10||BRZ-011-03||6LE/101/6LE||2.4||0.10||0.05|
|6mm EnergyTech (#2)10 / 101mm Air Gap / 6mm Clear||BRZ-011-04||6ET/101/6Clr||3.0||0.40||0.45|
|6mm EVantage Clear (#2)10 / 101mm Air Gap / 6mm Clear||BRZ-011-05||6EVClr/101/6Clr||3.0||0.37||0.39|
Ratings by co-principal developer of WERS Dr Peter Lyons
Based on WERS calculation methodology but beyond current AFRC procedures (not available at https://www.wers.net, only available at www.breezway.com.au)
Breezway Easyscreen Altair Louvre Window System - Single Glazed4
|14mm thick Western Red Cedar timber 5||4.39||0.095||0|
|6mm thick hollow extruded aluminium5||6.55||0.076||0|
- Results disclosed at Australian Fenestration Rating Council (AFRC) regulations.
- These blades have a microscopically thin low emissivity coating that is invisible to the naked eye and improves insulation and reduces solar heat gain.
- Results disclosed in Standard International Units. Results calculated to the procedures of WERS Screen Rating Methodology, 2012.
- These ratings are not authorised WERS ratings and should be regarded as a research report, they have been generated using the WERS calculation methodology but are beyond current AFRC procedures. Calculated performance indices are suitable for comparison with information on the WERS database.
- As the optical properties of cedar timber and aluminium are not contained in the International Glazing Databse (IGDB), known, default properties were used.
- Uw is the whole window U-value.
- SHGCw is the whole windows solar heat gain co-efficient.
- Tvw is the whole window visible (light) transmittance.
- Star ratings calculated using Nationwide House Energy Rating Software (AccuRate) according to procedures of WERS 2008.
- LowE (#2) refers to the coated surface of each glazing layer in a secondary glazing unit. 2 being the internal face of the glass.
- The glazing is reported in the same orientation as it is simulated so that the outside is always on the left, inside is always on the right.
Static Performance (Uw SHGCw Tvw Tdw) calculated using Window 6.3 and Therm 6.3 software (LBNL), 1999-2010.