Alternative Technology Assn Forums

1. 

   lorri
   Member

   Hi can you tell me in easy terms what difference having thermally broken double glazed windows compared to non broken ones, what heat/cold.
   I have to work out if it's worth the extra cost to get them and if our builder, if we ever find one will let us use them.
   Cheers
   Lorri

   Posted Thursday 28 May 2015 @ 12:03:30 pm from IP #
2. 

   Annette
   Member

   Depends on what type of frames you are planning to get. No need if wooden.

   Posted Thursday 28 May 2015 @ 12:41:22 pm from IP #
3. 

   Bushwalker
   Member

   There is a comparison tool that will give you some idea:

   http://www.efficientglazing.net/consumers.aspx

   Posted Thursday 28 May 2015 @ 1:20:21 pm from IP #
4. 

   Greg
   Member

   Here is my 2cents worth. Not definitive by any means, your supplier will have more information.
   There are two parts to the thermally broken Double Glazing. There is the frame, thermally broken to separate internal and external temperature effects of the frame and now recently the DGU (double glazing unit) itself can be thermally broken so that the two panes of glass are separated by insulation rather than the standard forms so reducing thermal conductivity.
   If you can afford it and your climate has more extreme temperature variations it offers the best performance.
   Next is Thermally broken frame with standard DGU
   Then Non thermally broken frames (Better the insulating properties of the frame the better the performance generally eg Timber better than Aluminium)
   There are also different DGU thicknesses like 5 - 12 - 5 etc. The first and last numbers are glass thickness and the middle number is the air gap. Bigger air gap generally attenuates noise better but when it gets too large causes convection currents and that drives greater heat loss. lastly if you are in a bush fire zone there may be minimum glass and frame requirements.

   Posted Thursday 28 May 2015 @ 11:13:13 pm from IP #
5. 

   Morbo
   Member

   find good tradies, skip the builder

   Posted Friday 29 May 2015 @ 12:03:08 am from IP #
6. 

   lorri
   Member

   Morbo, it's hard enough to to get a quote out of one, never mind anything else.
   Cheers
   Lorri

   Posted Saturday 30 May 2015 @ 2:43:40 pm from IP #
7. 

   Morbo
   Member

   I see, your place is pretty secluded.
   A friend in rural VIC got let down by his carpenter. So he end up ordering the frame at Bunnings. Seems they prefabricate. Actually delivered on time and fit. Maybe something to consider, prefab house? Hobart is not so far away from your place? Just get a slab poured and away you go?

   Posted Saturday 30 May 2015 @ 10:44:14 pm from IP #
8. 

   Benny
   Member

   Lorri - in terms of "whats the difference" this should show up in the specs. ie the overall window U value. How much is it decreased when thermally broken frames are added? If a supplier can't tell you that then don't use them.

   Posted Sunday 31 May 2015 @ 4:30:27 am from IP #
9. 

   johnmath
   Member

   Double glazed windows made with metal frames without the "thermal break" are Clayton's double glazing, i.e. the double glazing you have when you don't have the (thermal) benefits of double glazing...

   Posted Sunday 31 May 2015 @ 9:37:59 am from IP #
10. 

    lorri
    Member

    That's what I figured johnmath got to try and work it out how much more $ it will cost to do the whole house when we build.
    At the rate we are going it's going to be a while....
    Cheers
    Lorri

    Posted Sunday 31 May 2015 @ 10:29:59 am from IP #
11. 

    ghostgum
    Member

    You can get the window energy ratings from
    http://www.wers.net/wers-home

    When my house was built, the rough figures were:
    U=6 single glazed, aluminium frame
    U=4 double glazed, aluminium frame
    U=3 double glazed, thermal break frame
    U=2 double glazed, argon filled, coated glass, wood frame.

    Posted Sunday 31 May 2015 @ 11:08:56 am from IP #
12. 

    axess
    Member

    Hi Lorri,

    Double glazed windows are the "windows" these days. Try and get the best quality windows you can afford but start at double glazed even if they are the minimum thermally broken aluminium frames. Sealing around the frames carefully will pay off big time when they are installed.

    We fitted Certainteed PVC windows 15 years ago when we built our house and they are excellent performers. One of the unintended benefits is the acoustic performance if, like us, you live in the city.

    There are good builders in Tassie like anywhere else. They are up to date with their skills and material knowledge because it gives them a competitive advantage and they care about performing at a high level.

    Who do your neighbours use? Has any of your friends in Cradoc built a house recently? Do you attend any sustainable building events in the southern area of Tasmania? Are you planning to contract out the house building or do it as owner builder? Doing any building in a semi-rural area is more difficult to cost and plan.

    What about contacting the Tasmanian Master Builders or HIA branch for advice on local "Green Builders"? They might not be able to take the job on themselves but could put you in touch with someone who could quote to your plans. They will also raise the topics of sealing, heating and cooling your building shell as part of the minimum 6 Star rating.

    I recently spoke to a house designer who was scratching his head about a client who refused to fit double-glasing in a large renovation job when he had the opportunity to do the entire house for an additional $3000.00. As he said, the future energy costs to run the house in question, made $3000 look like a pittance.

    Good luck with your house.

    Posted Sunday 31 May 2015 @ 11:13:01 am from IP #
13. 

    Morbo
    Member

    try to get them shipped from Melbourne? Or even the entire prefab frame with windows in?

    Posted Monday 1 Jun 2015 @ 12:04:45 am from IP #

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