Syndey based Houzz contributor, Rebecca Gross has written a great guide to uPVC window frames and their thermal-energy performance, acoustic properties and durability....
uPVC Windows Alliance
Read all the latest news and information regarding uPVC Windows, the energy efficient and low maintenance alternative to traditional window frames.
Windows lose and gain heat by conduction, convection, radiation and air leakage. This heat transfer is expressed with U-values.
As a rating of energy efficiency, U-value can be used to consider performance of windows, exterior doors, skylights and all other exterior building components, including exterior walls.
In windows, the U-value measures how well heat is transferred by the entire window, that is the frame, sash and glass combined.
The lower the U-value, the more insulated the window unit and therefore the better the window will be in retaining the interior’s heat in the winter and keeping heat out during summer.
U-values are important because they form the basis of any energy or carbon reduction standard.
A significant part of the thermal energy transmission can be through the frames, or profiles, depending on how well the profile material conducts heat. Metals are generally good conductors which is why they feel hot to touch when exposed to the sun. This makes them poor thermal insulators.
Timber and plastics such as uPVC are poor conductors which therefore stops the heat transfer from the heat-exposed side to the non-exposed side. PVC and timber window frames are approximately thermally equivalent and provide a high level of energy efficiency compared to a standard aluminium frame.
It’s a simple goal in modern-day home life ... keep cool in the summer and warm in the winter. But up to 70 percent of heat is gained or lost through standard 3mm window panes and even more can be lost with heat transfer through metal frames.
In winter, a single-glazed, 3mm-deep pane of glass can lose up to 15 times more heat than an insulated wall of the same area. In summer, single glazed standard windows of an average home account for over 25 percent of total heat gain.
Double glazing creates an air pocket between the two glass panes providing an insulating barrier, which significantly improves the window's thermal and acoustic insulation. The greater the gap between window panes, the greater the temperature and acoustic insulation.
Using double glazing with uPVC window frames will further improve the result as uPVC doesn’t conduct heat well and therefore doesn’t transfer temperatures from inside to outside, or outside to inside.
The low conductivity of uPVC as a material, the tight seals uPVC windows provide and the ease with which they can be fabricated for double and triple glazing, make uPVC double glazed windows an excellent choice in energy efficient buildings.
uPVC Windows are proven. Available across Europe and America for the past 60 years, uPVC window profiles are today the most popular choice to deliver superior performance: worldwide, uPVC windows accounted for 55% of all new and replacement residential windows. That was almost 290 million window units in 2012, chosen for their durability, low maintenance, high energy efficiency performance and style. Here’s our five reasons why uPVC windows are the best choice:...
Tasmanian company and Vinyl Council member Envorinex is expanding a recycling program, leading to 125 bulker bags of waste from various Melbourne-based uPVC window fabricators being recycled into new products.
Since 2011, Envorinex has been working with the Oakleigh Centre for Intellectually Disabled Citizens in Melbourne who were supplied a granulator by the company to manage recycling of the uPVC waste collected. The Oakleigh Centre inspect the material to the Quality Assurance standard required, granulate and pack it into new bulker bags which are then shipped to Envorinex in George Town, Tasmania to be manufactured into 100% recycled commercial products.
“Envorinex recognises the importance of environmental sustainability. That our Melbourne recycling program has seen over 200 tonnes of uPVC waste diverted from landfill so far and made into commercially viable recycled products is not only exciting, but fitting with our sustainability responsibility and our recycling mandate,” said Ms Jenny Brown, Managing Director, Poly Marketing Pty Ltd trading as Envorinex™.
Envorinex has been collecting waste uPVC from window fabricators in Tasmania for the past three years. Due to the overwhelming demand for its recycled product range, Envorinex sourced additional waste uPVC material from Melbourne as feedstock for converting into new products.
Ms Sophi MacMillan, Chief Executive of Vinyl Council of Australia explained: “uPVC windows are the most commonly used window type in regions such as Europe and the US, and today, we are seeing growing demand in Australia for these high performance windows to improve home energy efficiency and reduce carbon emissions.
“As the use of uPVC windows frames increases, we will see growth in fabricator waste volumes available for recycling programs such as this one. The uPVC material is very recyclable, as evidenced by the tens of thousands of tonnes of fabrication and post-consumer uPVC windows that are recycled every year in Europe.”
“Envorinex is a great example of a company putting its PVC Product Stewardship Program commitments into practice,” concluded Ms MacMillan.
Many of the imported profiles used to make uPVC windows in Australia already contain recycled post-consumer window material, demonstrating the feasibility of cyclic management of the product’s materials.
Currently, Envorinex are in discussions with a disability centre in Sydney to replicate the Melbourne recycling business and meet ongoing demand for PVC recyclate