Browse Forums Windows & Doors Re: Double glazing - VERY important? 122May 04, 2010 12:37 pm Rudy dymonite69 How does one define a zero emission house? Does it include the emissions to build the house versus the emissions saved by running the house? A very interesting question for another discussion perhaps... however, regarding importance of double glazing... this is not such a significant concern in my opinion. I would be interested to see your house plans, elevations and block site. If you can't get any useful sunlight particularly to your living areas then everything you do to reduce heat loss will be much more important. I have relatives in Melbourne who have a Victorian style two storey single glaze which faces north. But they have small north windows to the one living area and their house is way colder than ours. Last night it dropped to 8 degrees overnight inside our house in the Adelaide Hills but it was still 18 this morning. No active heating for past 22 hours. Re: Double glazing - VERY important? 123May 05, 2010 6:35 am dymonite69 windowexpert What on earth is a 16/4/16 glass?, getting a bit confused here mate. And you also know that my U value is based on a tiny window. I must disappoint you You think you know it all? So why don't you know that the Deceuninck profiles used in OZ are not the same profiles as in Europe ?. Our window frames are exactly the same as used in Germany. The U values you mentioned wouldn't even meet the requirements in Germany. You best argument is based on a typo? 4/16/4 for your benefit. You may this forum in an .au domain - not .nz or .de. or .uk So our local consumers are limited to the choice of IGUs that are supported here in Australia with the specs and prices associated with them. What relevance is there about referring to arbitrary Euro spec or prices. Did I say that DG doesn't reduce energy losses? No this is indisputable. Did I say that DG may reduce artificial heating requirements? No. But your mileage may vary. Did I say that DG won't reduce uncomfortable convective currents? No (but not necessarily eliminate them. Did I say that DG has no role in energy efficient building? No but it will have variable relative benefit and does not solely reach the aim of minimal heating requirements. Te degree of benefit it produces will be variable depending greatly on existing climate and the baseline thermal efficiency of the house. The discussion is about the duration required to recoup the savings in annual artificial heating to produce adequate comfort in comparison to the initial capital outlay for installing DG. But you seem to like to take the discussion onto non-quantifiable tangents, straw man arguments and hyperbole. DG is more beneficial than what most people think but much less than what manufacturers want to claim. Why don't you provide a real life quantifiable before and after energy audit about the best savings you have ever provide to a client who had DG solely retrofitted to their building. Eliminate the contribution of any other interfering variables such as improved weathersealing, insulation or change in their heating unit that may have affected the result at the time. Provide Pre-installation energy use versus post-installation energy use. Give details of the U-value of the product, window area covered and cost of installation and the climate averages for that district. Real figures are what people want, not theoretical equations or exaggerated opinions. A rough breakdown is: Energy losses in a standard non-insulated building would be 35% ceilings, 20% air leaks, 20% walls, 20% windows, 5% floor To reduce these energy leaks by > 75% - capital outlay for a 300m2 home would be $3582 for Ceiling insulation, $282 for wall insulation, $200 for air leaks To reduce the leaks to > 95%: do the above but add $6600 to upgrade to DG The customer wants what is working practically not some theoretical numbers and figures of recouping some costs and making saving by using single glazing or partly. People don't want to run aroud the house and shut curtains and other stuff at sunset in order to maybe achive you unpractical theories. People want a comfortable home and double glazing doesn't break the bank but it makes a big difference and regardless of country the industry standard are similar (or should be). Yes climate varies but physical principals don't change. PVC is not PVC, aluminium is not aluminium as you my have realised that window frames are not made of solid material and every chamber increases the u value. Using your expressions yes your arguing is not practical but it is non-quantifiable theories without daily life application. Never argue w............ Change is what we need! Can we? YES WE CAN!!!!! Re: Double glazing - VERY important? 124May 05, 2010 7:37 am Well actually I do bother to pull down my cellular blinds over my double glazed windows when it is not sunny. And it does make a difference by reducing convective currents and radiant heat loss. And I will fairly shortly after our 12 month occupancy give a before and after energy audit of this effect (no blinds for the first 4 weeks of moving in). And I do pull my north blinds up during sunny winter days because then I don't need any heating then. Occupancy behaviours account for 50% of home energy use. As far as Oz being the same climate as NZ, why I find many of you moving to Queensland? Or why do you have a longer skiing season than Falls Creek? Or why was I seeing snow in November last time I hiked the Milford Track and climbed Mr Remarkable? I can claim 75% reduction in heating/cooling use for our energy efficient house for same level of comfort by using all the interventions of mentioned on other posts. What real world figures have you got for DG alone? Re: Double glazing - VERY important? 125May 07, 2010 9:07 pm We are currently building a nine star rated house in Preston (Melb) with double glazed windows. The windows are costing a fair whack of the total budget, and then we are spending another almost $10k on top of that for Duette blinds (we'd be needing window coverings anyway, so we decided to get the Duettes to keep things just a bit cooler upstairs). I thought I'd share three of our reasons for prioritising d/g, because I don't think they have been mentioned in this thread. Firstly, we like to sit near windows in the day time, and if you sit near s/g windows in Melbourne in winter, you get cold. Our son has a play space directly under a very large window in our current place, and it's really not viable to sit there for long in the winter months - at least without a hat and a scarf on. I suspect that a lot of people who have s/g will have their heater's thermostat up around 23 degrees, because they are constantly needing to 'warm up' after sitting or standing in cold spots. Secondly, payback period depends on what you pay for electricity. We have 100% green power, and so our payback period for d/g will be less because we will save considerably more on our energy costs. Thirdly (and this was the deal maker for us), if one is considering installing d/g for environmental reasons, one also needs to consider the source of the electricity that would be used to heat and cool the home. Being from brown coal, Victorian electricity is some of the dirtiest in the world. So the environmental cost of s/g and using a conventional power source is much greater here than in some other parts of Australia. I guess you could have a huge bank of solar panels or invest in some other form of renewable energy source and keep with your s/g house. But cost wise I doubt that would be efficient, and personally, if I could affort that many panels, I'd rather be putting that energy back into the grid. Apologies if these issues have been discussed ... I must admit to skimming over several pages of what appeared to be Deep Maths - all credit to Window Expert, Ed & Dymmonite , but the tech stuff is a bit beyond me! e. Re: Double glazing - VERY important? 126May 07, 2010 10:27 pm I'd be really interested if you could send through some details of your home & it's design as to how you attained 9 stars. Peter Clarkson - AusDesign Australia www.ausdesign.com.au This information is intended to provide general information only. It does not purport to be a comprehensive advice. Re: Double glazing - VERY important? 127May 07, 2010 10:40 pm Hi Peter I was actually wondering tonight whether I should start a little blog, or at least post a little write up of our journey thus far, especially in terms of the decisions we've made along the way. I don't want to spend a whole lot of time writing if nobody is going to read it, but then again, we want to open our house for Sustainable House Day so I'm sure whatever I put together will be useful there. I might post a thread asking who's interested ... In brief, we have: waffle pods with uncovered concrete floor double glazing reverse brick veneer on west and east walls, and half of the north side three openable skylights to vent hot air out of upstairs passive solar design very wide eaves on north, west and east minimal glazing on south - just enough to facilitate breezes solar hot water. We originally had 8 point something stars, but the waffles have tipped us into 9. We will wire up for photo voltaics but the budget won't stretch that far at the moment. We are trying for low embodied energy in our materials, although we have recently decided to use Ikea kitchen and cabinetry so that's kind of blown us miles-wise. Hmm. It's late and I'm tired, so I could have left out something really important. If I did, I'll post more later. Oh, our designer/builder says that the Duettes will mean that the house will perform even better than 9 stars ... as you know, because they're not permanent, they can't be factored into the rating. Gotta go. It's bed time. e. Re: Double glazing - VERY important? 128May 07, 2010 10:59 pm Definitely start up a blog. I'm sure there will be many interested in the process you have gone through & the decision making that's gone into the home design. Peter Clarkson - AusDesign Australia www.ausdesign.com.au This information is intended to provide general information only. It does not purport to be a comprehensive advice. Re: Double glazing - VERY important? 129May 07, 2010 11:27 pm According to NATHERS, a 9 star rating in Melbourne would consume 25MJ/m2/year in heating and cooling. This is better than a German Passivhaus with R10 insulation, triple glazing and heat recovery ventilator. So if we assume the house is 200m2 in size that would be less than 5000MJ/year or 1400kWh/year. This works out to be less than 7.5kWh/day for the heating season (assuming 180 days of heating) In other words: Combustion stove: 1/3 tonne of wood RCAC: $100/year of electricity Gas heater: $70/year of natural gas This excludes any offsets gained from PV since the energy star rating only evaluates the intrinsic efficiency of the house. Re: Double glazing - VERY important? 130May 08, 2010 4:30 pm For those interested, to show a comparison & expand on dymonites figures - 8 stars equates to 54 mj/m2, 7 stars 83, 6 stars 114, & 5 stars 149 Peter Clarkson - AusDesign Australia www.ausdesign.com.au This information is intended to provide general information only. It does not purport to be a comprehensive advice. Re: Double glazing - VERY important? 131May 08, 2010 9:04 pm Elizabeth Hi Peter I was actually wondering tonight whether I should start a little blog, or at least post a little write up of our journey thus far, especially in terms of the decisions we've made along the way. I don't want to spend a whole lot of time writing if nobody is going to read it, but then again, we want to open our house for Sustainable House Day so I'm sure whatever I put together will be useful there. I might post a thread asking who's interested ... e. I'm interested!!! I would love to read about your journey Building on an acre in Macedon ......one day. Re: Double glazing - VERY important? 132May 15, 2010 8:40 pm Rowena Eskay40 Our builder uses A&L as well and we wanted DG. They make them in a Casement Window. That means they have a winder like the awning but they wind out sideways and open like a small door. Great for catching a breeze and directling it back into the house.SK Oh, why didn't our building company suggest this option? We would have much preferred double glazing rather than low-e glass. We have north facing windows but are on a main road, so would have preferred the advantages of noise reduction that double glazing gives. Not happy Jan. Our builder also uses A&L and we are having double glazed awning windows and sliding doors. Re: Double glazing - VERY important? 133Jun 04, 2010 10:18 pm Hi folks, just thought I'd pop in and let you know I have started the blog. I'd love feedback about it! It's at: http://buildingour9starhome.blogspot.com/ Thanks for your encouragement e. Re: Double glazing - VERY important? 134Jul 12, 2010 1:36 pm so after 7 pages of reading im none the wiser ill just double glaze everything and insulate the hell out of the ceiling and walls the barossa valley is stinking hot in the summer and freezing cold in the winter Re: Double glazing - VERY important? 135Jul 12, 2010 3:26 pm windowexpert The customer wants what is working practically not some theoretical numbers and figures of recouping some costs and making saving by using single glazing or partly. People don't want to run aroud the house and shut curtains and other stuff at sunset in order to maybe achive you unpractical theories. People want a comfortable home and double glazing doesn't break the bank but it makes a big difference and regardless of country the industry standard are similar (or should be). Yes climate varies but physical principals don't change. PVC is not PVC, aluminium is not aluminium as you my have realised that window frames are not made of solid material and every chamber increases the u value. Using your expressions yes your arguing is not practical but it is non-quantifiable theories without daily life application. Never argue w............ In the home we are currently building we haven't got as good an orientation as I would like, but I have still swapped windows around to maximise the passive solar effect...... The reality for us is that whilst DG would have been lovely, we just couldn't afford it! With considered thinking we will still have a home and garden which will contribute to a comfortable lifestyle with as little negative impact on our environment as WE can make within our budget. Deemaree Kyndylan Capers: viewtopic.php?f=36&t=46852 My blog: http://www.sufficientlysufficient.blogspot.com/ Re: Double glazing - VERY important? 136Jul 13, 2010 9:53 am And here I was thinking that the reason people closed curtains was to stop people seeing into rooms...clearly I missed an important lesson somewhere! A huge round of applause to everyone so far on entertaining me with the debate - and I'm impressed no one resorted to (much) name calling - good job! Now, to hijack the thread (if that's allowed and if not I shall continue to live in ignorance) - where does tinting fit into all this? And will the cooling effect in summer be worth the cooling effect in winter? This is one of the reasons I decided to go overseas for my double glazed windows. As the builder indicated, he's worked on many upmarket builds, these were the most well… 13 19254 The worst thing you can do is sign a building contract without a pre contract review. Over the years many people have come to me with disputes where they just signed… 0 8350 Hi - thanks for your reply. Yes I think 'Ill go for whitish with very speckly bits rather than pure white something like this. PS was actually 2008 I built the… 2 11708 |