If you're putting in double glazing, it's preferable to specify insulated frames.
Aluminium is a popular material for making window frames. It's also a really good conductor of heat. This means the inside temperature of an aluminium window frame is going to be almost the same as the outside. And that means cold when it's cold outside.
Those cold window frames cause moisture in the nearby air to cool enough to condense into water. That's how condensation forms on the cold window frames – even if the windows themselves are double glazed.
Reducing condensation
What's the answer? If the frames are already installed, you're stuck with them. All you can do is to keep down the household moisture levels as much as you can during cold weather.
But if you are renovating or building from scratch you have some choices. You could choose wooden or PVC window frames, which don’t have the same condensation problems as aluminium.
But if you go with aluminium there are a couple of options for dealing with unwanted moisture.
You could specify timber-faced aluminium, where the inside surfaces of the joinery have timber facings. This can look nice and the timber acts as an insulator that reduces the heat flow through the frames.
Thermal-break frames insulate even better. The frame is made with separate internal and external aluminium components. The inner and outer aluminium frames are separated internally (and invisibly) by high-strength plastic spacers. The spacers keep the inside and outside frames insulated from one another.
Both of these options are more expensive than standard aluminium frames. But they save those annoying puddles of water.
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We added onto our house and chose double glazed UPVC windows, by EuroWindows,we love these windows they are beautiful and great quality, we loved dealing with EuroWindows, they are absolutely awesome and really know their stuff. We can recommend them very highly.
I had acrylic panels with a magnetic rim attached to existing single pane aluminium windows. The windows have a channel on the inside at base to collect condensation and holes to let it escape. The panels sit on these channels. Some moisture finds its way upwards and gets between the panels.
I have single glazed aluminium windows that let out a lot of heat. I am thinking of getting my windows double glazed but also thinking of getting uPVC window frames installed so as to reduce the heat loss and condensation. Can anyone recommend these types of window frames as they don't seem to feature in the double glazing report put forward by Consumer (only thermal breaked aluminium frames).
Thanks
Jenni
when replacing or getting new windows the only sensible choice now, is to use thermally broken aluminium joinery,which is not new, but now is available from all suppliers.Also you need to specify thermally broken spacers in the glass joinery-as all window companies use an aluminium spacer in the glass which conducts the cold-so on a frosty morning, the edge of the glass could get frosted up-this is very important in areas that get frosts/snow.The aluminium spacer also has plastic thru the centre.If you do the right job with the windows, no need for a DVS type air system at all(waste of money)
Neville W
It would be great to see Consumer review double glazing options in more detail, as there are so many different suppliers (yet many - most using the same basic "metro glass" product & simply providing their own frames....
One gnuinely useful site is that of the Window Association of NZ - this lists accredited manufacturers http://www.wanz.org.nz/manufacturers.htm and also has a condensation star rating system for various types of windows; http://www.wanz.org.nz/condensation_stat_chart.htm ....THIS would have been invaluable in the original Consumer article....
Graeme Sawyer (Kristin Aitken)
We have just built with thermal break double glazed windows and doors and are very pleased with the absence of any inside condensation on our frames this winter - so definitely consider this worth the extra - especially if you are anywhere other than perhaps Northland or the east coast. However, I do agree that the choice and quality of profiles and catches leaves a lot to be desired - why can't static panes have the same appearance as sliding panes for example? The industry needs to get more style / quality savie
Can anyone comment on their experience of un insulated double glaze aluminum in Auckland? We are considering Thermal heart but wonder if it would be overkill and it is considerably more expensive if not necessary. Thanks.
We built an extension in 2009 with all new double glazed aluminium windows. I was surprised that we do get condensation on the odd occasion if the night is very cold.
But the windows do have drainage holes and gutters to collect the condensation and take it outside so not a big deal.
More importantly I got all windows with passive ventilation grills installed which helps with airflow and reducing all humidity build up. Note that I had to ask for this as it was not offered by any salespeople of any company I got quotes from. And it is very inexpensive to get added to your windows.