Browse Forums Windows & Doors Re: Low E glass - are you using it, pros and cons 3Aug 17, 2013 9:37 am Miglas High Performance Composite Double Glazed Windows Phone 1300 MIGLAS Fax (03) 9728 3555 http://www.miglas.com.au Re: Low E glass - are you using it, pros and cons 12Sep 25, 2013 6:57 pm Sydney Double (and now Triple) Glazed Windows and Doors mob 0412 717 066 Sydney, Canberra, Newcastle, Wollongong www.doubleglazedwindows.net.au Re: Low E glass - are you using it, pros and cons 13Sep 30, 2013 5:55 pm bdn OP, where do you live and what are you trying to achieve with Low E glass? This is important information when it comes to Low E. For example, Low E is not recommended for sun control in Melbourne. This is because Low E glass only works in one direction - depending on which way you install it, it either keeps the heat IN your house or it keeps the heat (of the sun) OUT of your house. You can see that in some climates, this means that any benefit gained in the warm months (keeping the heat of the sun out) might be lost in the winter (because you get solar heat gain from your windows). If your plan is to use it for insulating (i.e., keeping your house warm in winter), my understanding is that Low E is a compliment to DG, and not really an alternative. If you are worried about keeping heat inside in the winter, you might consider your window furnishing choices and include pelmets and drapes, or pelmets and well fitting roman blinds. eScreen type roller blinds also claim to have insulating properties, although I have my doubts about these. Another option is honeycomb blinds, which trap air between the layers and can add an insulative layer to your windows. Consider that you will probably need to purchase window coverings anyway, so making smart choices with these could be a good solution for little to no additional cost. The good thing about window furnishings is that it allows you to keep your North facing windows uncovered in winter during the day, to collect lots of free heat from the sun. Then you can close them up tight at night to keep all that heat inside overnight. Think of Low-E as a heat mirror for radiant heat. So it works in summer to help keep heat out but also in winter to keep it in the house. It is a lot better than ordinary glass, but double glazing or double glazing with Low-E are even better performers for keeping your home comfortable. FYI North facing clear windows with Low-E also work with passive solar heating / thermal mass. Re: Low E glass - are you using it, pros and cons 14Sep 30, 2013 6:20 pm Windowfactory Low - e glass. Pfft. Sure it works, but we now regularly supply triple glazed windows, and our customers have been very impressed; the difference between single low-e glazing and ordinary double glazing is like night and day; but the jump from double to triple glazing takes the performance into the next dimension! There is nothing that the glass supplier can do to the glass - low-e it, tint it, low-e and tint it, fiddle with it, tweak it etc that will ever come close to matching the performance of ordinary double glazing. Incidentally, overseas research indicated that double glazing with low-e on both sides and a gas infill attempts to replicate the effectiveness of triple glazing, but actually triple glazing is less expensive and more effective! Low-e glass eat your heart out! Agree with some of what you said and disagree with other parts of it. Agree about double glazing being superior to plain low-e. But for people on a budget, having windows with low-e is still a decent step up and energy savings vs ordinary glass. Also I agree that triple glazing is a premium product and has generally superior conductive insulation benefits over double glazing... However most of Australia has to deal with summer heat issues. In this case whether it is single/double/triple glazing all are useless at stopping direct sun / radiant heat without either tint in the glass or an energy efficient coating. For most climates around Australia, double glazing is sufficient (no severe colder temps like in Europe). Look at almost every quality commercial building around Australia and you will find it has coated glass in a double glazed unit... Now if you were trying to build yourself a 9 or even 10 Star energy neutral home... then bring on the best Re: Low E glass - are you using it, pros and cons 15Sep 30, 2013 6:42 pm Quote: Good stuff, can you also give the relative performance (U value) of hard and soft coat low-Es. Ed Hi Ed, Sure - but remember that softcoats can only be in a double glazed unit. Here are some rough guideline numbers for the glass only peformance (window frames can affect this number as you'd know ) .......................................................Rough U-Values (glass only) Ordinary Glass........................................................ 5.8 Hardcoat Low-E in single sheet.................................. 3.5-3.8 Double glazed unit (no Low-E)...................................... 2.7 Hardcoat Low-E in double glazed unit + argon gas.............. 1.6 Softcoat Low-E in double glazed unit............................. 1.6 Softcoat Low-E in double glazed unit + argon gas.............. 1.3 Softcoat Low-E in double glazed unit + argon +hardcoat...... 1.1 Re: Low E glass - are you using it, pros and cons 16Sep 30, 2013 9:31 pm Sure, Viridian, that's all good and fair, but if a customer had a solar gain issue, ideally they would utilise an outside form of shading eg roof/awning/trees/neighbouring property etc; for it is also true that ANY OUTSIDE FORM OF SHADING WILL PERFORM MUCH BETTER THAN ANY GLASS TREATMENT, won't you agree? A bit of strategic planning goes a long way when it comes to windows... By the way, we love your Pyroguard 40 product, our windows are BAL40 compliant when used in conjunction with Pyroguard 40! Sydney Double (and now Triple) Glazed Windows and Doors mob 0412 717 066 Sydney, Canberra, Newcastle, Wollongong www.doubleglazedwindows.net.au Re: Low E glass - are you using it, pros and cons 17Oct 01, 2013 8:52 am Windowfactory Sure, Viridian, that's all good and fair, but if a customer had a solar gain issue, ideally they would utilise an outside form of shading eg roof/awning/trees/neighbouring property etc; for it is also true that ANY OUTSIDE FORM OF SHADING WILL PERFORM MUCH BETTER THAN ANY GLASS TREATMENT, won't you agree? A bit of strategic planning goes a long way when it comes to windows... By the way, we love your Pyroguard 40 product, our windows are BAL40 compliant when used in conjunction with Pyroguard 40! Totally agree. Stopping heat from getting into the building is best. External shading/eaves/shade devices, etc all help. Re: Low E glass - are you using it, pros and cons 18Oct 21, 2013 11:27 pm Thank you for the information. It certainly gives food for though and has given me some points to think over. We have been told that we need to get a 6 star energy rating and to do that we have been presented with four options, one is to use low e glass and increase insulation. It bugs me that we are told this now and it wasn't allowed for in the quote we got but building seems to be a minefiled of extra costs. It sounds like DG is the go, not sure we can afford it but I also don't know how it compares price wise. Is it worth putting DG on the main large living areas but not applying it to all windows? I am taking on the point that preventing sun from entering is a major factor and we intend to do this by having our alfresco area extended to provide more shade. It seems that taking the alfresco off was a suggestion on how to meet the 6 star rating so that confuses me more. I will have to speak with the guy about this. We are building in Adelaide Hills so we have the extremes of hot weather in the summer but cooler weather in the winter. The temps range from 42 to -2. Re: Low E glass - are you using it, pros and cons 19Oct 22, 2013 5:06 am hills_kiwi Thank you for the information. It certainly gives food for though and has given me some points to think over. We have been told that we need to get a 6 star energy rating and to do that we have been presented with four options, one is to use low e glass and increase insulation. It bugs me that we are told this now and it wasn't allowed for in the quote we got but building seems to be a minefiled of extra costs. It sounds like DG is the go, not sure we can afford it but I also don't know how it compares price wise. Is it worth putting DG on the main large living areas but not applying it to all windows? I am taking on the point that preventing sun from entering is a major factor and we intend to do this by having our alfresco area extended to provide more shade. It seems that taking the alfresco off was a suggestion on how to meet the 6 star rating so that confuses me more. I will have to speak with the guy about this. We are building in Adelaide Hills so we have the extremes of hot weather in the summer but cooler weather in the winter. The temps range from 42 to -2. To reduce solar heat gain, best option as mentioned, is shade the window, second best is to use low-E, IMO only in double glazing. Double glazing on it's own has no effect on solar heat gain. In single glazing low-E can suffer from thermal shock, and is difficult to maintain. Plus if you use double glazing it will help with the -2 temperatures. Double glazing in one area will aid the conservation of heat inside the home, it won't help solar heat gain. I would say that you live in a primarily heating area in the energy rating software, and taking the alfresco off aided the heating component at the expense of cooling. It's based on averages and statistics, so, like the man with one leg encased in ice and one in boiling water, on average he was comfortable. 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: Low E glass - are you using it, pros and cons 20Oct 22, 2013 7:55 am ed @ ecoclassic To reduce solar heat gain, best option as mentioned, is shade the window, second best is to use low-E, IMO only in double glazing. Double glazing on it's own has no effect on solar heat gain. In single glazing low-E can suffer from thermal shock, and is difficult to maintain. Plus if you use double glazing it will help with the -2 temperatures. Double glazing in one area will aid the conservation of heat inside the home, it won't help solar heat gain. I would say that you live in a primarily heating area in the energy rating software, and taking the alfresco off aided the heating component at the expense of cooling. It's based on averages and statistics, so, like the man with one leg encased in ice and one in boiling water, on average he was comfortable. Ed Agree with Ed. If you are trying to reduce the direct sun passing through glass by using tint/colour, thermal stress is created due to heat build up or temperature differences across the glass. Tinted glass may need to be toughened to resist thermal breakage. You should have your glazier do a thermal assessment of the windows. This generally applies to both single and double glazing. Low-E coatings will increase the thermal stress on tinted glass too. In Hills_kiwi's case with that temperature range, I'd also recommend double glazing with Low-E where you can afford it and single glazed Low-E where you are in budget mode! Standard uninsulated double brick has an R value of around 0.7. An insulated standard 90mm stud timber frame can have an R value of around 2.7. Even if you insulate a… 17 12113 0 2100 4 6229 |