While double glazing is a step in the right direction if you are looking for energy efficiency, comfort and security, triple glazing is even better. Especially in a Passive House project where triple glazing with soft-coat low-E glass is used.
In a double-glazed insulated glass unit (IGU) there are 2 panes of glass, sealed, with space in between. This space can either contain air or is argon gas-filled for higher performance. The most energy-efficient distance in between the glass panes is from 12mm to 20mm. This is set with a spacer.
In a triple glazed insulated glass unit (IGU) there are 3 panes of glass with the middle pane creating 2 spaces, again either filled with air or argon gas. When used with high-quality frames, the resulting window can have a U-value which is reduced to an extremely low 1.1 compared to a single glazed aluminium window of as high as 7.4 – and remember – the lower the U-value, the better the window performance.
Different coatings, like soft-coat low-E glass, can also be used for triple glazing. Depending on whether more heating or cooling efficiency is required, these should be on different layers of the glass, e.g. either surface 5 or 2, or even on both.
The more stars, the better the product
In Australia, windows that have been independently tested and rated are listed on the WERS (Window Energy Rating Scheme) website and are provided with a star value indicating a rating for the product. Whitegoods also use a clear visual reference indicating star ratings to enable shoppers to make educated purchases.
For example, what does it mean when a single glazed aluminium window is rated with 1 ½ cooling stars and 2 ½ heating stars, and an energy-efficient high-performance window with triple glazing is rated with 7 ½ cooling stars and 7 heating stars? The star rating shows that using the highly energy-efficient triple glazed window would reduce cooling and heating requirements by up to 85%. By using triple glazed products, the outstanding insulation performance translates into large savings in energy costs for the homeowner.
Paarhammer products can be ordered with double or triple glazing. The energy-saving between them is not as dramatic as when comparing single glazing and triple glazing as the double-glazed products already have excellent ratings, but it could still equal about a 20% difference in energy efficiency for only around 5% additional cost for the triple glazed products.
Something that cannot be easily measured is comfort. With a single glazed product, the indoor temperature must be regulated with constant heating or cooling. The higher the star rating, or the higher the insulating qualities of the window, the more consistent the indoor temperature. And if the indoor temperature is comfortable and consistent there is a lesser to no need for heating and cooling of the home by a heating source or air conditioner.
The third layer of glass can also improve security as this glazing is harder for vandals to break.
Upgrading to triple glazing is offset by savings on heavy curtains or drapes – unless required for privacy – and on energy costs while increasing comfort levels.
PAARHAMMER WINDOWS & DOORS
Tel: 03 5368 1999 | Website: paarhammer.com.au