Retro-fitted double glazing?

[oldrider]

Sounds exactly like what I am looking at.

I already got a gummint subsidy to fit a heat pump - couldn't insulate because of flat roof but you get it anyway...

Our window glass is very thin (old gov't department house) so we had some of our windows done, expensive but it does work well!

Subsidies, never get any of those out here! Winston's card is a dead loss down here too!

[JimO]

Our window glass is very thin (old gov't department house) so we had some of our windows done, expensive but it does work well!

Subsidies, never get any of those out here! Winston's card is a dead loss down here too!

you can use it on the buss eh

[specter]

i used to be a glazier and double glazing is the shit!

find out what glass mix they are using? my preferred best is laminate and safety. have no idea about this nitrogen mix and shit? even a basic air inter layer will make a huge difference.

[JimO]

my wifes x boss had their large house double glazed in the mid 90s including a big conservatory, now all the windows have gone milky and need replaced , the firm who made the windows called Nebulite have gone, its going to cost them around 20k to replace them

[imdying]

Go round to their place and smash them for them. Insurance job then. Don't tell them for a few years, be like a late Christmas present.

[JimO]

Go round to their place and smash them for them. Insurance job then. Don't tell them for a few years, be like a late Christmas present.

na they are cunts

[Wannabiker]

na they are cunts

...just smash them anyway....

[Kickaha]

My father had this fitted and said it made a huge difference to his place

A glazier friend of mine is very uncomplimentary about it and threatened physical violence if I fitted it at my place more to do with longevity and discolouration of the product

[Ocean1]

My father had this fitted and said it made a huge difference to his place

A glazier friend of mine is very uncomplimentary about it and threatened physical violence if I fitted it at my place more to do with longevity and discolouration of the product

Quality. Again. The most common type consists of two pieces of glass stuck either side of a frame made from an alloy extrusion. The extrusion has very fine slots / holes on the inwward facing side and it's filled with a dessicant, (sucks up moisture).

The glass is around 5mm larger than the outside dimensions of the extrusion and once the glasee is stuck in place the gap between the glass is filled with a sealant, (buytl based, usually).

Your father's right, as an insulating system it works OK. Your glazier mate's right too. Most common problem is the sealant not forming a perfect gas-tight seal. Air breaths in / out as temperature changes and eventually the dessicant becomes saturated and condensation forms inside the cavity.

20K sounds about 10x the cost I'd expect to replace a failed batch of glass. Unless some bright spark has designed a frame you can't remove the glass from...

[Winston001]

Here's what flyingcrocodile46 had to say on another thread which I blinged him for:


"Timber and UPVC window frames provide superior thermal resistance, (though be sure to research your UPVC options very carefully). however the component that most needs to achieve an insulation value (R Value) is the glass rather than the frame as the frame is a very small area compared to the window.

Appraised double glazed window panels can be retro fitted to most existing windows including timber. There may or may not be any NZ timber joinery manufacturers who have a formally tested whole joinery system (don't know) but it isn't needed.

Here's one company making a nice business out of catering to everyone's irrational lust to have double glazing.
http://www.aucklanddoubleglazing.co.nz/

To give an idea as to the significance of double glazing insulation values as opposed to single glazing, here are the NZBC H1 Acceptable Solution R values for Non-solid construction – minimum R-values for schedule method (Climate Zone 1);
Single Glazed = Min R . 19
Double Glazed = Min R . 26
Roofs/ceilings are =>R 2.9
Walls are =>R 1.9
Floor are =>R 1.3
As you can see, the difference between single and double glazing is only R .07 (2% of the value of roof insulation) So it's all a big deal over fuck all For my money thermal drapes meet my needs fine but that is too easy.

I know TA's are famous for causing problems for designers in respect to acceptance of detailing on matters of compliance but as far as I am aware, most of the reputation isn't justified and is more likely a symptom of insufficiently detailed compliance with the NZBC by people who often don't have a clue about what the requirements actually are. Of course this can be exasperated by individuals at TA's who also don't know up from down.


If anyone needs more info on the issue here are a couple of helpful sites
http://www.branz.co.nz/H1_support
http://www.consumer.org.nz/news/view...double-glazing"

[JimO]

20K sounds about 10x the cost I'd expect to replace a failed batch of glass. Unless some bright spark has designed a frame you can't remove the glass from...

this is a massive 2 storey house with a very large conservatory with glass in the roof so you think 2k would cover that?? including the conservatory there would be over 40 panels

[Ocean1]

this is a massive 2 storey house with a very large conservatory with glass in the roof so you think 2k would cover that?? including the conservatory there would be over 40 panels

Easy enough to find out, go directly to Metroglass or Veridian.

One of the peculiarities of the business in NZ is the sizes available, you can have whatever you want, and pretty quickly too. If you need a window 1234mm x 567mm it's made to order. That means every piece is a different job, and that forces jobing shop economics.

Overseas your options are limited to a range of pre-made nominal sized complete units. Much less expensive to run a couple of hundred at a time. You can still get a custom size window, say 1185 x 775, but it'll cost five times the price of an off-the-shelf 1150 x 800.

[flyingcrocodile46]

Here's what flyingcrocodile46 had to say
As you can see, the difference between single and double glazing is only R .07 (2% of the value of roof insulation) So it's all a big deal over fuck all For my money thermal drapes meet my needs fine but that is too easy.

I rather feared that would come back and bite me in the arse.

In some ways what I said was/is true, but in most real world applications it actually isn't. For instance, fitting double glazing wont make any meaningful difference if you have fuck all or no wall or roof insulation, but when all your walls, floors and roof are well insulated you will still lose a big chunk of heat through your windows, so double glazing makes a worthwhile difference .. though perspective-wise questionable on a cost benefit basis as a mandatory requirement when considering that our building costs are already all but unfordable.

I guess I have a bit of an issue with mandatory minimum requirements driving up the cost of building to a point where it is unfordable for the majority of kiwis. I think it is silly that you can't factor thermal drapes into the Schedule or calculation methods to satisfy H1 requirements (because they aren't fixed closed)

Fact is that any form of sealed second skin that stops air from passing from one layer to the other will provide a measurably worthwhile heat loss reduction due to the fact that still air is a lousy thermal (heat loss) conductor.

What has been said in the thread (particularly by Ocean1) is all good info. Don't want to tarnish it with my anti H1/$ bias.

[ducatilover]

I thought you'd just use a blanket like a real old fulla slowfox?

[Winston001]

I rather feared that would come back and bite me in the arse.

In some ways what I said was/is true, but in most real world applications .... double glazing makes a worthwhile difference ..

LOL. The main thing is you provided sensible information on R values. I'm a believer in double glazing but realistic enough to know it has low R. The soundproofing is a bonus and it has a cooling effect in summer.

My research and reading on the subject over years suggests retro glazing is worthwhile as long as there is a sufficient air gap. Low-e glass, argon, thermal breaks are all nice to have extras but I'm not convinced they have a cost/benefit.

Retro glazing is less expensive than new windows because the existing frames are left in place and new windows swopped in. They need to be stronger than the originals because of the extra weight and depth.

Apart from that, a second layer of batts in the ceiling is a good idea because our house insulation is generally less than ideal.