Topic: Crimped or bonded thermal break

Crimped or bonded thermal break 

Hi All,
We are looking at getting thermally broken aluminium windows retrofitted and have come across two different options. Rylock use a system where the thermal break is crimped into the aluminium section and nulook and design windows have the break bonded in. Is one better than the other?

I instinctively think the crimped on will be better as I have previously tried to bond two pieces of aluminium together and found that after a few years the bond separated due to a fine layer of oxidation on the aluminium surfaces. On the other hand how good will the crimping be under the regular load of a window opening and closing?

I realise that uPVC is the favoured material here but with a supply only cost of nearly 70% higher than the fully installed aluminium cost it isn't an option. On top of that I'm not interested in companies spreading the risk by having one manufacter, another install, and another glaze.

Cheers,
Chris

Re: Crimped or bonded thermal break 

Have you checked out Bradnams as their AllSeasons product has the break integrated into the from using pour and debridge? Their website is very good

http://www.bradnams.co.nz/index.pl?page=allseasons_&m=284

Re: Crimped or bonded thermal break 

Oops, just seen nulook website and realised they're the same method.

I am thinking of getting the Bradnams ones for same reason, the product just looks better designed and engineered.

Re: Crimped or bonded thermal break 

I prefer the look of the rylock stuff and the larger sections they use seem to be stiffer.

It doesn't seem that the plastic break material is actually bonded in as such then but moulded in instead. I think I need to have another look at the sections.

Re: Crimped or bonded thermal break 

Yes but if you're talking about the Pacific Suite range I got put off by the fact that they're hung from the top of the frame and I just can't see the frames holding up over time.

Re: Crimped or bonded thermal break 

Have you thought about that a good performing windows system comes at a cost regardless of material used.
When you look at frames, thermal performance, hardware, convenient operation, and lasting function you might find yourself with a 70 % or more shortcut product compared to a quality window.
Bear in mind aluminium is the most expensive material used for windows/doors and it cannot be cheaper than other materials unless it is made with all possible and unthinkable shortcuts.
In Europe the aluminum window is the most expensive option. Wonder why ? Because it costs a lot of money to purchase the material to make an aluminium window with a reasonable good performance standard

Re: Crimped or bonded thermal break 

I am not sure if you are buying new frames and windows. Recently at the home show in Wellington there were a lot of firms demonstrating their retrofit double glazing. What worries me is that I wonder if the light aluminum frames used for single glazing are going to stand up to the weight of double-glazed units. Does anyone have experience here? Pricing for high quality DGU seems high in NZ. But you also get what you pay for. Leo

Re: Crimped or bonded thermal break 

A lot of those retro-fit guys are cowboys out for a fast buck. Most single glazed windows and hardware will not cope with the weight of double glazing.
A Porsche motor in an old Mitsi Lancer or so.. doesn't make it any better as a car. It will make it fall apart if you go a bit faster...

Re: Crimped or bonded thermal break 

I have but every time I contact your company I am lucky to get a response, latest was when enquiring about your imported Alu/wood and Alu windows.

Re: Crimped or bonded thermal break 

I don't see a problem with any non opening windows - and frankly I don't see much a problem with a lot of opening windows.
In the long run perhaps hinges will wear quicker - but how long is the long run?
Oh yes, the wheels on ranch sliders, which wear out in any case.
The question for an existing house perhaps should be:
Are really good curtains more cost effective, and what payback periods are there for double glazing?

JK

Re: Crimped or bonded thermal break 

Payback? Are you talking about a house which is for human habitat, comfort and well being or a business???
Wonder what is the "payback" on your car, plasma screen, heatpumps, boat, sky tv.....

Re: Crimped or bonded thermal break 

Be careful how you calculate that "payback"
A house (double glazed) around my area that would sell for around $430K would actually only fetch around $370K if it was only single glazed, (unbelievably there are a few).
Payback calculated on energy saving costs alone are not an accurate way of assessing the "payback"

Re: Crimped or bonded thermal break 

When it comes to payback on double glazing, one good way to look at it is that your health and comfort is also being invested in... surely the tough guys can stand the cold, but warmer home is a nicer and healthier place to live in...

Energy consumption:
If you have 20m2 of glazing total (and many homes have much more) and keep your place at around 20C when it is 10C outside, you have (Uvalue*dT*surface*time) 5.7*10*20*24h = 27.36 kWh heat loss through the glazing. With the simple aluminium frame... add a bit more and the condensation.
Compare that with the glazing that is for example U value 1.1. Comes to 5.28 kWh. Over 20 kWh/day... surely you'll have some curtains to reduce the loss, but some homes don't. It's all about the big glazing and grand looks and views...
I don't think double glazing should be discussed at all... it should be a must unless you are talking about the space that is not heated. The only question is when are these robbers from Metro&Co are going to adjust the prices so people
don't have to look for alternatives to double glazing.

lionsong:
Your concern is correct about the weight of the glass with the skinny profiles, but you should know that probably not one of the new profiles have changed to carry a bit more weight... they have only changed the beading and that's it. I have seen some hinges adjusted so tight that you actually have to go out to push the windows closed, otherwise you would rip out the latch if you pulled from inside. Apparently that was a safety hinge. Looks more like a measure that holds a heavier glazing unit though...

Further problem is that even if you buy a thermally broken frame it will likely not be installed adequately so you'll have the same or a just a bit better performance than a simple aluminium...

See the head detail here:
http://www.bradnams.co.nz/index.pl?page=awning___casement_windows&m=285

The interior side if that thermally broken frame sits inside the cold cavity space uninsulated... not sure what is the point of the thermal break then??? Funny that there is no adequate installation option for thermally broken frames in BC or by WANZ... and these are the people providing us the professional advice and making sure we do things right... and those silly flanges around the windows... basically they are extra big on all NZ alu frames to release as much heat as possible to the outside... this design principle is also used when designing the heat sinks... maximize the surface to maximize the heat exchange.

If you don't want to just buy thermally broken alu windows, but also utilize your investment properly you'll have to install it differently. Basic principle is weather tightness from the outside vapor diffuse outwards, then insulation in the middle (PU foam) and air tight towards the inside, but also vapor diffuse, so you don;t trap any moisture between the frame and the framing/wall. Pro Clima has great tapes that have Code Mark compliance, so nobody can stop you from using it. If you are retrofitting, you can do whatever you think is right anyway... no consent needed...

Re: Crimped or bonded thermal break 

Dejan,

you are right . The current "acceptable" solution for
window installation belongs in the bin and those behind this should be sacked for incompetence.
I know a number of people in the aluminium joinery industry on different levels and it appears that building science and physics are extremly remote or unknown subjects to them.

Re: Crimped or bonded thermal break 

Forgot to mention. The "acceptable solution" applies to aluminium windows and is not quite suitable or applicable for the European style timber, timber/alu or uPVC.
The pro-clima tapes are quite good for the external weathertighness part around the window.

Re: Crimped or bonded thermal break 

Dejan, could you explain a bit more about the Bradnams thermal break? Are you saying that they aren't designed correctly?

I think the hardest thing for consumers is that they obviously have to put their faith in the companies so I thought the Bradnams ones looked better than the alternatives.

I just wish it was easier to pick out which system was the best. All I want is someone to say which of the thermally broken Ali systems is the best.

Re: Crimped or bonded thermal break 

Well if it has to be aluminium. There is www.unicco.co.nz in Whangarei.
They do Schueco which is one of the best in the world.
There is nothing amongst the NZ aluminium systems which is proven longterm to work well with insulated glazing or made with good hardware.

Re: Crimped or bonded thermal break 

I wish it didn't have to be aluminium but I have just got to the point where I am thinking 'when in Rome' as it's just so hard to get alternatives and also to get the builders/designers/councils to buy into the alternatives

Re: Crimped or bonded thermal break 

Hi Langers,
Sorry if I missed something but why have you ruled out PVC and timber frames?

Re: Crimped or bonded thermal break 

The problem is in New Zealand that the aluminium window industry is holding a commanding position for political reasons not because their products are any good compared to most of the other (European systems)
However the Councils can get the Government into hot water with the WTO if they obstruct the use of other(imported) window systems. The only way to stop the imported systems would be lack of performance required in New Zealand.
In most cases the European systems exceed the NZ requirements by far.

Re: Crimped or bonded thermal break 

Nikoftime

I am English so have no problem with uPVC, we had it in our house 30+ years ago! but I am worried about the clouded perception of it here affecting resale if I ever have to sell.

I have looked at timber (Eurovision and Heirloom) but I don't know if I can stretch to it as I am replacing an entire household of windows and the quotes so far for Thermal Alu are approaching $30K

Re: Crimped or bonded thermal break 

As always things seem to have deteriorated into a debate about aluminium versus uPVC. In my case, there isn't a company locally that takes responsibility for the whole process with uPVC and given the record that the building industry has of trying to shift blame around I'm only interested if the one company manufacters, glazes, transports and installs all of the windows. Even the local agent for for one of the manufacturers only does the local delivery and glazing but has a builder do the install.

The one company that does do the whole thing (NK Windows) has to drive up from Christchurch with a team of guys and isn't really interested unless it's for a whole house which I can understand.

Therefore, even aside from the additional cost, I don't see how the uPVC option can work for me.

Re: Crimped or bonded thermal break 

Hello Langers,

the profile actually looks pretty nice. Thermal break is probably around 10 mm which is not a lot, but should be fine unless you live in a colder place.
The whole idea is that with thermally broken frame there is inside and outside and the thermal break between is reducing the thermal transmission between the in and outside. The inside should be kept insulated, otherwise it will cool down as much as the outside.
The typical building code installation is obviously very outdated as it has absolutely no consideration for the energy efficiency and certainly no one has thought of thermally broken aluminium either. It also assumes that every window has a flange around the outside and therefore will be installed pretty much in the cladding as opposed in the line with the wall... They have come up with this brilliant (not serious) idea that the window should be sitting on some support profile because the cladding can not hold it alone.
Sitting a thermally broken frame directly on a peace of aluminium would be bad as you would bridge the in and out and entirely cancel the effect of the thermal break.
As you see on the illustrations they have on the page (link from my previous post), they have put some form of insulation/separation between the frame and the support bar to prevent the bridging to happen. But then on the top side and quite sure the sides the problem is left unsolved... the frame is just sitting in the cold cavity with no thermal protection.

The only thing that would make sense is to move that window back in the line with framing, tape up the edge to the frame with a weather protective tape (there are tapes that are water and wind proof, but allow the vapor diffusion) and fill the space between the window and the frame with the PU foam and make it air tight on the inner side (again, there are tapes you could use or PEF rod and similar products). On the outside you'd want to return the cladding against the frame and put a bead of silicone.
This would use your thermal break to its full potential and you'd be sure to never get the condensation on the inside.

The main problem is that the specifiers/architects like to follow the good old way of installing windows since they might have to explain to some council why they would want do it different. The sad consequence is that you can find people on some forums saying thermal break does not do anything and they still have the condensation after investing a lot of money and hope:
(http://www.buildyourdream.co.nz/forum/viewtopic.php?t=781&start=0&postdays=0&postorder=asc&highlight=thermally+broken).

Re: Crimped or bonded thermal break 

dejan, i know that moving the window back to the framing,in line with the insulation is best,but " On the outside you'd want to return the cladding against the frame and put a bead of silicone." is not a good idea.you are relying on silicone and it will leak.ive just spent a year recladding a poly black house with this detail,and all the exposed windows had rotten framing around them.they were installed 6 years ago.

Re: Crimped or bonded thermal break 

Of course you can recess windows. Without exposed silicone.