Recently there have been major advances in the Australian glass industry, resulting in a wide range of glass solutions available to improve control over thermal comfort and energy efficiency in Australian homes.
With homes subject to increasingly stringent star ratings – the BCA 2010 will introduce a minimum 6 star rating for new homes and renovations effective from May 2011 – perhaps one of the most significant characteristic of glass is its ability to dramatically reduce the amount of artificial heating and cooling used by homes.
One of the simplest ways to gain more control over a home’s thermal comfort is to use suitably glazed windows. This is backed up by a Queensland University of Technology (QUT) study, which found that improved glazing choices can increase a home’s star rating by 1.5 to 2.5 stars. If all Australian homes were fitted with high performance glazing, greenhouse gas emissions would be reduced by approximately 8 million tons per annum, which is the equivalent of taking 1.6 million cars off the road.
Windows with standard single pane, 3mm flat glass are generally the thermal “weakest link” in residential buildings. Up to 87% of heat gain and up to 49% of heat loss occurs through unsuitably glazed windows, meaning that homes with ordinary windows are using up to a 60% more energy to heat and cool their home than necessary. Energy efficient glazing can significantly reduce the amount of heat that travels through windows, improving thermal comfort and saving homeowners money at the same time. There are many energy efficient glazing solutions available, all of which can be achieved without heavy tinting or mirror like coatings that can detract from a home’s appearance.
Low E (low emissivity) glass can reduce the amount of heat that is conducted through the glass by around 30% compared to ordinary glass and reduce the need for air-conditioning and heating, however the most comprehensive solution is found by combining a Low E coating with double glazing.
Double glazed units (also known as Insulated Glass Units or IGUs), comprise two or more panes of glass separated by an air (or gas) filled cavity, providing improved thermal insulation. When combined with a Low E coating and suitable frame, this option can stop up to 70% of heat loss and 77% of heat gain when compared to standard 3mm glazing.
“The ideal insulating glass choice allows occupants to forget about monitoring their home’s energy performance and focus on enjoying the increased comfort of their indoor environment,” says Nigel Carpenter, Australian Glass & Glazing Association ’s Executive Director. “People don’t often realise it, but ordinary glass in windows is old technology – there’s a wide range of performance glass available that has so much more to offer than the 3mm clear window glass we all grew up with.”