Browse Forums Windows & Doors 1 May 11, 2017 1:10 pm Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ So you have been given the bad news by your energy rater, your home needs thermally broken windows, you have been told that this will add 50% - 100% to the cost of your windows. But is it true? Why do they say you need thermally broken windows? Generally energy raters assume that a particular level of performance in a window can only be achieved with thermally broken windows. So it is not that you must have thermally broken windows, it is that your windows must achieve a certain standard of performance. When we all enjoy lots of windows in our homes, and windows are a huge energy leak, then more and more we are needing to upgrade our windows to more energy efficient designs. Thermally broken windows perform at a level better than non-broken windows of the same design, but the window still performs only as well as that window design permits and the test results that back that up. (refer to http://www.WERS.net ) So to decide whether you need thermally broken windows with their inherent costs and lack of competitive pricing, the only thing you need to know is what is the U value (Uw) required of the window, and this is on your energy report. (SHGC - Solar Heat Gain Coefficient is also a factor but is generally easily managed). Your energy report may even specify a window brand or manufacturer, but none of that matters, only the numbers are critical. If the Uw is the same, there is no difference between one window and another in energy terms. The only information you need to work this out is the Uw in your energy report. The EcoEco EcoTech window outperforms many thermally broken windows when you compare like for like... e.g. clear glass in both windows, the EcoTech window is more energy efficient - and that is all you need to know. Our opening window rates Uw 3.4 with clear glass shown as 4/12/4 in WERS. And will perform equally well to any other window with all of those different glass types. 90% of the time you won't need thermally broken windows... and if you use EcoTech, you will have a window which is able to withstand 300kph wind. Drop in, ring or email for advice and opinion... If you are not in Victoria, yes, it's a little harder, but we do supply interstate. Don't pay for what you don't need... a little thought can save you heaps. Ed "ECOECO" At 'EcoEco', we design windows, we design the best windows, we do it for you, so that when you’re happy we are happy. Tel. 1800 326 326 Re: Thermally Broken Windows - You don't need them!!! 3May 11, 2017 2:04 pm I will happily provide my proof anytime you like... for you and anybody else. Please re-examine your experience... I can update that for you. Drop by and I will show you. If I am wrong, I will supply windows to you for free... My claims are born out by the AWA, and certain major suppliers who saw it like you... 100% accurate... But having said that, it is our window and only our window that achieves this. Ed "ECOECO" At 'EcoEco', we design windows, we design the best windows, we do it for you, so that when you’re happy we are happy. Tel. 1800 326 326 Re: Thermally Broken Windows - You don't need them!!! 4May 11, 2017 3:00 pm Truth is that it would be counter productive for me to exagerate the performance of our windows, because in the end the certificate of occupancy relies upon the finished home achieving the specification. "ECOECO" At 'EcoEco', we design windows, we design the best windows, we do it for you, so that when you’re happy we are happy. Tel. 1800 326 326 Re: Thermally Broken Windows - You don't need them!!! 5May 21, 2017 1:14 pm arcadelt Well, this sounds a lot like advertising, and this advertising does not accord with my experience. Hi Arcadelt, Would you like to discuss your comment. I understand your experience, I understand windows and the industry. I can show you why we are different. Let me know. Thanks Ed "ECOECO" At 'EcoEco', we design windows, we design the best windows, we do it for you, so that when you’re happy we are happy. Tel. 1800 326 326 Re: Thermally Broken Windows - You don't need them!!! 6May 21, 2017 2:19 pm Hi ECOECO. My comment related to my experience. Numbers and statistics only tell you so much, but the difference in touch and comfort derived from thermally broken aluminium frames is real. If sun or cold touches the outside of frames that are not thermally broken, that transfers directly inside the building. This does not occur with thermally broken frames and so the inside feeling of comfort is less affected. Now your turn. Re: Thermally Broken Windows - You don't need them!!! 7May 21, 2017 2:48 pm arcadelt Hi ECOECO. My comment related to my experience. Numbers and statistics only tell you so much, but the difference in touch and comfort derived from thermally broken aluminium frames is real. If sun or cold touches the outside of frames that are not thermally broken, that transfers directly inside the building. This does not occur with thermally broken frames and so the inside feeling of comfort is less affected. Now your turn. Me... Sure you can touch things and get an appreciation of the conductivity of the material. A coin in a room which has a comfortable temperature will be cold to touch. A thermally broken frame in a heating climate will be cold to touch. For exactly the same frame, in both thermally broken or non-broken, the thermally broken frame will perform better in terms of insulation. Measured in software and physically the answer is the same. If you happen to want to touch it, then the non broken frame and the broken frame will perform exactly the same until the heat (not temperature) reaches body heat, which will take a slightly shorter time with thermally broken frame. However that leaves us to examine the range of heat transfer/insulation across all the different window designs (I am not counting glass changes which have the same effect more or less across all designs). Our casement window has a Uw of 3.4 with clear glass (4/12/4)... meaning it will conduct 3.4 Watts/m2/oC and with EnergyTech (low-E) and argon, the Uw is 2.6. Take any window without low-E and compare that to our window... Stegbar casement STG-024-39 4/12/4 = Uw4.0 EcoTech casement ECO-010-02 4/12/4 = Uw3.4 This difference is real, our window was physically tested for energy as well as the software rating. The difference is in the design. If a thermally broken window does not achieve Uw 3.4 with clear glass, then it is not as energy efficient as our window. These numbers will pay out in the energy bill... Ed "ECOECO" At 'EcoEco', we design windows, we design the best windows, we do it for you, so that when you’re happy we are happy. Tel. 1800 326 326 Re: Thermally Broken Windows - You don't need them!!! 8Jun 09, 2017 2:20 am Hi ECOECO, What about thicker glass? E.g. many vendors use 5 mm or even 6 mm glass on their windows as well as some also use bigger air/argon gap (e.g. 16 mm). What are pros and cons here? Thanks WBR, Alex Re: Thermally Broken Windows - You don't need them!!! 9Jun 09, 2017 2:29 pm The only impact that thicker glass has is to reduce the airgap. Some suppliers have a small glazing rebate to receive the double glazed unit, so thicker glass may mean a smaller air gap. The minimum thickness of the glass, and whether it is toughened or annealed, is covered in AS1288. However some varieties of glass may not be available in all thicknesses. A supplier with a 14mm rebate with 5mm glass will have a 4mm air gap (5/4/5) which reflects badly in the Uw. Also thick glass makes sashes and door panels heavier and creates unnecessary wear on rollers and hardware. The ASHRAE Handbook of Fundamentals (2001) contains an analysis of data based upon a physical test for the U value for the double glazing gaps for argon, air and krypton, across a range of gaps, the analysis shows a curve, with the bottom of the curve being the lowest U value. That point for air and for argon is 12mm. Smaller gaps and larger gaps show an increase in U value, making the performance worse. And both air and argon very quickly show significant increases either side of the optimum, this would, for example, negate the improvement when changing from air to argon. Ed "ECOECO" At 'EcoEco', we design windows, we design the best windows, we do it for you, so that when you’re happy we are happy. Tel. 1800 326 326 Re: Thermally Broken Windows - You don't need them!!! 12Jun 20, 2017 3:04 pm Hi EcoEco, (and anyone else who many know). I'm looking for a sanity check/advice. We're building a house and I requested a quote from the builder for double glazing all windows and glass doors (except the window in the garage). The windows are aluminium as we need to meet BAL29 bushfire requirements. The majority of our windows are double hung. To upgrade to double glazing for double hung windows, we needed to go the more premium range of windows. Otherwise would need to change all window styles. I like double hung for the benefits of air flow. Our windows I believe will be 5-6-5mm Argon filled. They will also require toughened glass for bushfire requirements. When compared to the original windows in the house (its a project home design), the additional cost to upgrade over the existing cost of windows will be $25K for 19 windows, 1 sliding door and 1 stacker door. Does this sound reasonable or nuts? Thanks in advance, Re: Thermally Broken Windows - You don't need them!!! 13Jun 20, 2017 3:11 pm Hmm, on the other side my friend yesterday got a quote from YY - US$10K for 23 windows TOTAL, all 5-12A-5 (mostly sliding and chained winder awnings though, but also including 1 sliding and 1 stacker door). This will be around AUD$17K delivered and customs+GST paid. I guess 6 mm is not much of a air space, you would need at least 12 mm to get benefit from double glazing. Re: Thermally Broken Windows - You don't need them!!! 14Jun 20, 2017 3:20 pm Wow that was quick. I guess to get them from the US it would be much cheaper as they are more readily available and used alot more commonly over there (colder weather). I know where I'm from (europe) they are not at all expensive... standard costing. However, due to our building circumstance, they're coming through the builder and the price I've quote is the delta to standard windows. The actual cost is $33K. Just hard to know if its what I should expect here. Based on the wers website, I'm happy that a 5-6-5mm argon will give us sufficient improvement in both comfort and energy benefits. Otherwise the past 4 months of trying to convince my husband has been an utter waste of time! Thanks for the feedback. Re: Thermally Broken Windows - You don't need them!!! 15Jun 20, 2017 3:23 pm "ECOECO" At 'EcoEco', we design windows, we design the best windows, we do it for you, so that when you’re happy we are happy. Tel. 1800 326 326 Thermally Broken Windows - You don't need them!!! 19Jun 20, 2017 6:13 pm allatonce Does this sound reasonable or nuts? To mangle a common saying, premium is in the eye of the beholder. The double-glazed windows in our home are coming in at around $150K. Provided they meet your efficiency and BAL requirements, your windows look like a bargain to me. Re: Thermally Broken Windows - You don't need them!!! 20Jun 21, 2017 12:01 pm Thank you arcadelt. Thats an incredible cost for glazing. However, I've seen your pictures and wow - impressive. Thanks for the feedback. I actually looked further into it last night, and based on the WERS website, the benefits of going to a 5-6-5 over the standard range the builder would install normally is a 25-30% improvement on cooling and 20-25% improvement on heating and for Uw values, it reduced from 6.3 to 4.4, SHGC reduced from 0.74 to 0.53. Another important one for me was air flow and that reduced from 4.45 to 0.62. The best benefit I saw was on the sliding doors and stacker doors for up to 40% improvement on heating, and a reduction in Uw value to 3.8. Overall, this will improve the overall efficiency of the house dramatically and improve the comfort of air-flow through the windows both hot and cold. The one thing I can't stand is the breeze I feel in my bedroom at night in winter. (currently single glazed) Where we live we get as high as 47 (this summer) and as low as -2 (3 degrees this morning!). So I needed something to help with both heat and cold. It meant compromising a little, but its a balance. To go to greater argon gaps, only improves the heat and cooling efficiency marginally by a 2-3% (probably not worth the extra cost) and the greatest improvement on cooling efficiency was to tint the windows, which I didn't want to do. As you said, in the eye of the beholder, and I'm confident that we will definitely see the benefits, despite the cost. I have an investment property and tenants moved out recently. However the Property manager noticed one of the floor tiles is broken and the kitchen Island countertop is… 0 419 wondering anyone built with omaxe homes and care to share their experiences. thanks 0 8846 Hi everyone. I am a single mother with little daughter, living in a small tourist town in WA Australia. 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