Energy Ratings

Energy Ratings
March 26, 2018 admin

Nothing is more important when designing your home than the window & door selection. The 3 most important ‘S’ factors to consider are: Sustainability (Energy Efficiency), Style and Security. The whole character and thermal performance of your home will be decided by the choices you make at the design phase.

What are the advantages of PVC or Timber versus aluminum for windows?

High thermal and acoustical insulation

High dimensional stability.

Good surface aspect

Good Fire resistance

No Moisture Absorption

Good weathering

Very low maintenance

Good compromise impact / rigidity.

Very good chemical resistance

Possibility To Be Welded

Design Flexibility

Energy Ratings

The performance of a window is measured by its U-value, the amount of heat loss or gain through a material. The lower the number the better the insulation of the material. Tests using this common measure repeatedly show that u-PVC and Timber out performs Aluminium. The following table shows results calculated by WERS A single or double glazed u-PVc or Timber framed window performs better than a single or double glazed aluminium framed window. 2009 WERS Certified Products Directory – AFRC

Notes

  • Uw is the whole window U-value
  • SHGCw is the whole window solar heat gain coefficient
  • Tvw is the whole window visible (light) transmittance
  • Percentage improvement figures are compared with using base-case
  • Generic Window 1 (3mm clear in standard aluminium frame)
  • A negative percentage improvement figure indicates performance worse than the base-case window
  • A positive percentage improvement figure indicates performance better than the base-case window
  • Maximum air infiltration is 5.0L/s.m2 at a positive pressure difference of 75 Pa as measured according to AS 2047
  • Static performance (Uw SHGCw Tvw Tdw) calculated using Window 5.2 and Therm 5.2 software (LBNL), 2000-2003
  • Annual energy performance (stars and % improvements) calculated using Nationwide House Energy Rating Software (AccuRate) according to procedures of WERS 2008.10. Results disclosed at National Fenestration Rating Council (NFRC) regulations.
  • Comparative Insulation Values of Different Framing Types Cool% Heat% Total Window – NFRC

Comparative Insulation Values of Different Framing Types

KEY: Cool% Heat% Total Window – NFRC

Window ID Glazing Cooling Stars Heating Stars Uw SHGC Tvw Air Inf.
WERS Generic Standard Industry Typical Aluminium Window – Single Glazed
WERS Generic Standard Industry Typical Timber Window – Single Glazed WERS Generic Standard Industry Typical uPVC Window – Single Glazed
WER-03-001 3Clr 0% -5% 7.7 0.78 0.75 5.00 WER-03-002 3Clr 21% 24% 5.5 0.69 0.72 5.00 WER-03-002 3Clr 21% 24% 5.5 0.69 0.72 5.00
WER-03-003 6.38LE 37% 11% 5.8 0.48 0.49 5.00 WER-03-005 6.38LE 52% 33% 3.7 0.41 0.47 5.00 WER-03-005 6.38LE 52% 33% 3.7 0.41 0.47 5.00
WER-03-015 5Toned 21% -13% 7.7 0.57 0.41 5.00 WER-03-016 5Toned 38% 16% 5.4 0.50 0.39 5.00 WER-03-016 5Toned 38% 16% 5.4 0.50 0.39 5.00
WER-03-017 5SuperToned 24% -15% 7.7 0.53 0.62 5.00 WER-03-018 5SuperToned 40% 15% 5.4 0.47 0.59 5.00 WER-03-018 5SuperToned 40% 15% 5.4 0.47 0.59 5.00
WERS Generic Standard Industry Typical Fibreglass Window – Single Glazed WERS Generic Standard Industry Typical Aluminium Window – Double Glazed WERS Generic Standard Industry Typical Timber Window – Double Glazed
WER-03-002 3Clr 21% 24% 5.5 0.69 0.72 5.00 WER-03-006 3/6/3 21% 26% 5.4 0.69 0.68 5.00 WER-03-008 3/6/3 38% 47% 3.3 0.61 0.65 5.00MATERIAL
WER-03-005 6.38LE 52% 33% 3.7 0.41 0.47 5.00 WER-03-009 3/12/3 22% 31% 5.0 0.69 0.68 5.00
WER-03-016 5Toned 38% 16% 5.4 0.50 0.39 5.00 WER-03-012 3/12/4LE 31% 41% 4.0 0.65 0.62 5.00
WER-03-018 5SuperToned 40% 15% 5.4 0.47 0.59 5.00 WER-03-019 5SuperToned/6/5 40% 16% 5.3 0.47 0.36 5.00