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If you parallel glaze a double glazed window, there is a degree of transmission caused by the outer pane vibration "pumping" the cavity air and in turn exciting the inner panel severely limiting isolation.
To avoid this in isolation windows for recording studios etc, the panes are arranged to be non parallel by offsetting one pane vertically in the frame by about 75-100mm, and the other horizontally by a similar amount. For extreme isolation, a third pane is sometimes added between.
Another piece of the puzzle is the use of differing thicknesses of glass in the double/triple glazing.
As I understand it, a pane of glass will resonate at a particular frequency based on it's dimensions. By altering the thickness of the glass, that resonant frequency is changed, so what resonates the outside pane doesn't transfer through the inside pane.
I have no idea if the thicker pane should be on the inside or outside, or if it matters.
If you are looking for timber frame windows that use european methods of hanging and sealing (ie. methods that have been proven to work) I can suggest and recommend Paarhammer. (Not my company, just a happy customer): http://www.paarhammer.com.au/
woodbe.
We have a similar issue and have been doing lots of research. Its a minefield!
We're looking to replace a house full of windows, as they are 37 yrs old. We want to upgrade some of them for security purposes and others for acoustic purposes. The best option on the acoustic side is secondary glazing, without a doubt. However we aren't keen as our windows are really old and need replacing anyway, and secondary glazing doesn't look particularly attractive.
It does seem to be the case that insulated units (double glazing) are designed for thermal not acoustic insulation. It seems impossible to find prefabricated ones with a larger than usual gap (the standard 16mm gap would apparently do little to reduce the noise of traffic and the party house next door). Also, we might then want to upgrade the glass for security purposes.
We also talked to leading window companies. However the window manufacturers we visited knew little about their more unusual window products and weren't keen to help further. Remarkable, as we want to throw money at this!! They seem to just supply direct to builders for complexes who want the standard cheaper products. They told us to ask builders/ installers about the different glazing options etc.
However, the builders/ installers we talked to were also used to standard glazing and referred us back to the window manufacturers - so its a catch 22!
Even a leading window manufacturer/ installer company couldn't advise us in regard to acoustic options.
At this stage we were thinking of becoming certified in window manufacturing just to figure it out!
Its also the case that acoustic ratings are influenced by the window as a whole, not just the glazing. So we tried a different tack, and asked a leading windows manufacturer if they could provide acoustic ratings for their own windows made using certain Pilkington glass. However, they could only give generic acoustic ratings, as they only had ratings for their more standard windows.
Basically it has been left to us to figure out the best glazing option, then specify this to a builder/ installer or windows manufacturer/ installer, and hope for the best.
We're keen on Pilkington glass, as for increased security their product "Lamguard" seems excellent, and for acoustic insulation (certain frequencies only) "Optilam Phon".
1. Pilkington Lamguard 6.52mm (note has a 1.52 interlayer, which is what gives it the extra strength)
2. Pilkington Optilam Phon 6.5
3. Pilkington Optilam Phon 8.5
4. Pilkington Optilam Phon 10.5
5. Pilkington Optilam 11.5mm (is made up of 2 x 5mm + 1.52mm interlayer)
So we spoke to Pilkington (glass manufacturer) directly, but without great success, as they prefer to deal with companies. In the end they talked to us, but unfortunately their advice seemed off the cuff - it didn't match their website and didn't resolve things.
BTW it looks like Pilkington has recently become "Viridian". See http://www.viridianglass.com/Products/vlam-hush/default.aspx?ProductType=HouseHolder.
We did discover that a decent laminated glass window would cost about the same as double glazing (ie double the price of single glazing). We also discovered that insulated units could be made using different thicknesses and types of Pilkington glass, but would be way too expensive. We have also lightened up on the security factor as we want a chance of getting out if there's a fire.
So this probably leads to single glazed Pilkington Optilam 6.5 or 8.5. Just not clear on how well this would mute voices/ music (which are different frequencies) and traffic.
Thats where we are up to!! Course, we also want multi point ventilation key locks http://www.vantagealuminium.com.au/slidwind/slidwind.htm.
Next we will probably try for quotes from http://www.taylorswindows.com.au/residential.html.
If anyone can recommend a good windows manufacturer/ installer that uses windows with Pilkington glass and multi point ventilation key locks and services Canberra, it would be great to hear from you!
Hope this helps in some way. Sorry for the essay.
P.S. some useful general info is in http://www.adelaidecitycouncil.com/scripts/nc.dll?ADCC:STANDARD::pc=PC_420
We got a bedroom window replaced a while ago by Certainteed (www.certainteed.com.au). Double glazed, 4mm and 6mm, with a high density gas pumped into the gap (not sure which gas).
The window itself is great, but it has highlighted all the other areas where noise gets in (we live near a freeway). It's an old weatherboard place, so I guess that's to be expected...
Hi.
You seem to be looking at aluminium sliding frames? I'm not sure if it has the same effect for sound as it does for thermal insulation, but most of the aluminium frames that achieve good thermal ratings have what is called a 'break' which is a method of separating the inside window frame from the outside frame using timber, pvc, whatever. Those Vantage frames you linked don't seem to do this.
One of ways of getting better frames is to ask for commercial sections instead of domestic. If you look in places like hotels etc, you will notice that the window frames are generally better and beefier than what gets installed by default in houses.
Harping back to my favorite window company, this is what they offer in regards to noise reduction:
http://www.paarhammer.com.au/Noise.htmlQuote:
Paarhammer double- or triple-glazed windows with their wider air gap and a thick laminated glass on the outside provide outstanding sound proofing . Together with our unique seals and well installed frames, noise reductions of up to 45dB can be achieved, reducing noise levels by approximately 80%. That is considerably more than conventional windows (particularly aluminium framed windows).
They only seem to do timber frame windows though. I think there is an aluminium facing option, but the frame will always be timber with that company. I've seen aluminium versions of the same type of frames, but don't know where to get them in Australia, sorry. Someone must be doing it.
See if you can get a look at a euro window opening/locking system. You might have to hunt around, but the first time I saw one, I wondered why we were bothering with the same old agricultural framing and locking systems we do in Australia. The first window we put in is also an upstairs emergency exit - we can tilt the top of the window inwards for ventilation, or open the whole window to one side on it's side hinges. The window has terrific seals and a positive multi-point ratcheting locking system. It faces the road, and the reduction in noise in that area is pronounced with just their standard double glazing.
Hope that all helps.
woodbe.
The outside glass can be a laminated glass and the internal a safety glass.Quote:
As I understand it, a pane of glass will resonate at a particular frequency based on it's dimensions. By altering the thickness of the glass, that resonant frequency is changed, so what resonates the outside pane doesn't transfer through the inside pane.
You have two different panes of glass with different properties so they vibrate at a different resonance.
The gas between the two different panes also provides a reduction in resonance.
For security there is tints called liquid metal used in commercial applications to prevent bricks through windows. I think you can bounce a sledge hammer of it?
There is a commercial aluminium section which provides the profile to produce a double glaze. The section is also much wider which allows easier post installation of windows. The Pilkington double unit gas filled is the most efficient specifically designed. You have to remember nearly every house has double glaze in the UK.
For close freeway/motorway living triple glaze is installed.
Personally I would go to the smaller custom guys than the larger window manufacturers for acoustic/security type of construction. The companies that build commercial window section that can accommodate double glazing units on a smaller more custom scale for shop fronts, etc etc.
Refit windows are made slightly smaller to fit in post fix or refix windows to fit in existing openings that maybe distorted during initial installation. They will be custom sizes not standard opening sizes.
Having read all this thread - its hard not to come to the conclusuion that no-one wants to guaranteee their products, and double glazing is pushed as the be all and end all of sound reduction/. i am suspicious that this is a falsity.
Why? well the theory of air seperation to give isolation reduction applies far more at very low frequencies - think next to a train track that actually vibrates the house - same as for directly under a flight path, or next toi a road that has b doubles trundling passed. the old wine glass on a high cbinet would be the test for this - do they tingle with the noise?
Now i have 2 windows seperated by 3 metres and a door facing a major arterial road thats about 150m away and 30m below us. one is 4mm float, and almost sounds like the window is open at night it blocks so little noise. the other windows are 6mm float (i think - its a louvre and i cant see a laminated film) and large expanse of 6.38 laminated. the difference is chalk and cheese for normal audible noise.
I'd go a replacement from a glazier with 6.38 lam in a test room - if you really want to go overboard try 10.38 - or whatever will fit in the frame. the problem with comparisons to cold countries like the UK, is that all windows are DI units - the addition of a triple for sound reduction implies that the DI of themselves arent very effective and they are adding density with the 3rd layer (i'd bet my left nut its laminated as well)
Went to the home show in Melbourne yesterday and the magnetite guys were there.
I explained our circumstances to him which are similar to others in that we wanted sound insulation and thermal insulation.
He explained that both can be done but requires 2 layers.
A gap of 20mm for the thermal insulation and 100mm for the sound insulation.
The panels they display with were very light, you expect a heavy sheet of glass but we were able to pick up or take of the window easily. So if you wanted to open the windows during the day it is easily removed then when you close them easily put back.
A couple of factors he gave us to consider as we have a 50 year old weatherboard home which has no insulation in the walls is to double clad the walls with plaster and make sure the ceiling has good insulation.
He indicated that doing the windows alone would help marginally but as the house is weatherboard there is a large amount of nooks and crannies that heat and sound can still come in.
We will certainly consider once we get other things tidied up.
From my experience I'd stick with the 'comfort' 6.38 mm or so laminated. DI units will give you better thermal insulation, but unless they are specifically engineered for sound reduction / noise attenuation any claims of reduced sound pressure levels are dubious. The comments about varying thickness and offset panes are correct and the gap size is also vital to achieve noise reduction.
If you really want to be dicked around and treated like an idiot go to Stegbar. The last order we did they changed three times, rang up to say the Pilkington laminated glass we ordered (and payed for up front) was not in stock and they wanted to charge us an additional $500 for a "special run" (they claimed this was Pilkingtons cost), and they didn't call to tell us they weren't going to be delivered on the delivery date, we rang them 3 days later and they realised they hadn't sent them.
Its finding the best solution. Considering a lot of housing sits within "close" range of Motorways and large volume traffic the triple glaze units are "best" solution they have found. There is so many variables in sound ingress that manufacturers and suppliers, sure are reluctant to guarantee with the possibility of litigation on a topic that is a complex science.Quote:
Having read all this thread - its hard not to come to the conclusuion that no-one wants to guaranteee their products, and double glazing is pushed as the be all and end all of sound reduction/. i am suspicious that this is a falsity.
Like I said the best would be a double glaze with an internal vacuum between the 2 panes.
Vibration is complex and establishing the transportation of sound waves can be like finding a needle in a haystack.
While DI maybe insinuated in the UK the fact is at least 95% is performed by installers.
Installation isn't quite that simple. People purchase their windows/doors/conservatories with all good intentions then realise they need to spend an awful amount of money on tools and without a trade background the job can be a disaster from many angles.
The existing windows tear at plaster, brickwork pulls away, some windows serve a structural purpose especially in bay windows not to mention the large amount of glass coming out. Post fixing windows to existing, modified or newly created openings is not an easy task.
The ideal is don't expect miracles. The most effective solution at reasonable cost to the weakest point in a house "Windows" for sound, light and climate ingress/egress is what people want to achieve. :)
Thicker glass still vibrates through ground, walls and roof space in regards to rail, air traffic. Having a manufacturer specify exact results is a minefield of disappointment. :)
Pharmaboy, the reason no-one guarantees results in your own home, is that there are so many factors involved. The sound can be coming in through the walls, the floor, the doors or the ceiling and the window supplier can only control the sound coming in through the window. Probably, the windows are the weakest link in most houses, so there is better than reasonable chance of achieving a noise reduction though.
My first house was a townhouse built near a busy road. It was brick veneer, but there were so many gaps at window and top of walls etc, that you could feel the internal plaster vibrating to the traffic noise. In retrospect, the windows were crap, and I put raven seals on them all which helped some, but until the walls stopped vibrating we were never going to get any peace in that joint. Thankfully, our first kid arrived, and we dumped the townhouse for something more kid-suitable (and quieter)
woodbe.
hello,
on trips to europe i was amazed to see windows in countries like Hungry and Bulgaria which are basically a "double shutter" timber window,
so one opens inside and the outer opens out and clipped off, this in 100yr old buildings, rubber seals and great hardware,
they provided a 100mm air cavity and had basic single glazing, the performance is outstanding,
if building new, sealing around windows and doors would be more important than DG units,
thankyou
myla
is there any form of tinting that reduces noise?
i am installing some wooden shutters... i was wondering if that would help cut down the noise much or at all
Tinting would probably reduce some vibration, but I wouldn't expect miracles.
We have some internal WRC plantation shutters, and they don't seem to reduce the noise at all. too many air gaps I guess.
woodbe.
Yes in this case you really need to get some insulation in the walls. Sure, double cross lap gyprock sheets. Id take boards off and get some pump in before I went with the double sheets.Quote:
A couple of factors he gave us to consider as we have a 50 year old weatherboard home which has no insulation in the walls is to double clad the walls with plaster and make sure the ceiling has good insulation.
He indicated that doing the windows alone would help marginally but as the house is weatherboard there is a large amount of nooks and crannies that heat and sound can still come in.
If you do go the sheets cross lap them and make sure the internal sheet is different thickness to the outside sheet.
At least 100mm of insulation in the ceilings right over the wall insulation to get a seal before you even considered windows. Weather board houses are like an acoustic drum without insulation. If you do have weather board consider building some timber shutters for extreme sound reduction.