Differences between Alu Window Types

Phaictan

I'm looking at buying windows for my new house build in Co. Leitrim. I have quotes from a number of companies all selling very different types of windows. So far my criteria has been the U value and ultimately the price of the windows.

I have read on Boards.ie that AluClad windows can be worse than AluWood windows. As far as I can tell the difference is that one window uses all wooden windows that are covered on the outside with Aluminium and the other uses an Aluminium window that is filled with a wooden composite.

Can someone shed some light for me on the pros and cons of the two different window types and maybe personal experience on some products available on the Irish market.

The 3 front runners for us at the moment are <SNIP>. Also looked at <SNIP> but seem much more expensive.

Cheers

PT

Mod Edit: Please read the charter, in this forum keep company names to PM, or face a ban.

mr_edge_to_you

Some people argue that the AluTimber offers better protection from the weather. In a poorly made aluclad it is possible that some of the timber may be exposed as the cladding by its nature just sits on top of the timber. This particular point was raised a few months back. I'm not sure of the link because i'm using my phone but i'll dig it out later. That would be the major differences. I'm familiar with 3 of those companies and we went with one. I'd be more than happy to go in to greater detail so feel free to pm. Personally I think the AluTimber was a much better product and we got a great price.

JuniorB

My understanding is Alu-clad windows have a thermal break, Alu-wood windows do not.

Here's an explanation from de web on the reason for the thermal break ...

Aluminum window frames are light, strong, durable, and easily extruded into the complex shapes required for window parts. Aluminum frames are available in anodized and factory-baked enamel finishes that are extremely durable and low-maintenance.

The biggest disadvantage of aluminum as a window frame material is its high thermal conductance. It readily conducts heat, greatly raising the overall U Value of a window unit. In cold climates, a simple aluminum frame can easily become cold enough to condense moisture or frost on the inside surfaces of window frames. Even more than the problem of heat loss, the condensation problem has spurred development of better insulating aluminum frames.

The most common solution to the heat conduction problem of aluminum frames is to provide a Thermal Break by splitting the frame components into interior and exterior pieces and use a less conductive material to join them. Current technology with standard thermal breaks has decreased aluminum frame U-factors (heat loss rate) from roughly 2.0 to about 1.0 Btu/hr-sq. ft-°F. In hot climates, where solar gain is often more important than conductive heat transfer, improving the insulating value of the frame can be much less important than using a higher-performance glazing system.

Phaictan

Phaictan wrote: »

The 3 front runners for us at the moment are <SNIP>. Also looked at <SNIP> but seem much more expensive.


Mod Edit: Please read the charter, in this forum keep company names to PM, or face a ban.

Sorry, thought that it was OK to mention when looking for recommendations. My Bad!

Cheers

PT

Mellor

JuniorB wrote: »

My understanding is Alu-clad windows have a thermal break, Alu-wood windows do not.

True, but that's because a termal break in a timber section would be pointless.

mad m

I got Alu-clad windows in over a yeah and a half now. Not any problems yet. But have noticed recently a build up of condensation on bottom of glass on inside of house. As far as I remember I never had this on the old pvc windows I had, but I could be wrong....

The windows are 110mm thick with alu on outside and wooden on inside.So basically two windows in one frame. I think these have a thermal break also,not sure. But with windows like these I thought I wouldn't expect to see any build up of condensation...

I had option of a trickle vent in these windows but think trickle vents are a waste of time....

Crab

I am in the process of a new build ( not started yet ) I have received prices from 3 companys for aluclad and am waiting for 2 more. how do i choose between suppliers there dosent seem to be to much of a difference on the spec has any one any experience or advice in this field would very much appriciate it

Poor Uncle Tom

Crab wrote: »

I am in the process of a new build ( not started yet ) I have received prices from 3 companys for aluclad and am waiting for 2 more. how do i choose between suppliers there dosent seem to be to much of a difference on the spec has any one any experience or advice in this field would very much appriciate it

You could ask for a reference of a local house/job they have carried out and go see the work, speak to the people and ask if they are happy. If the company have a showroom go and see their stock, etc., and most importantly agree terms and conditions when ordering and make sure you include your engineer's sign off before any payment is made.

RedLady

Hi,

I got alu-clad sash 2 years ago from a major american maker that is based here in Ireland and I have had nothing but trouble with them. They are no way airtight - they let in wind and rain which has led to them forming mould on them bottoms. All the cladding on the outside has come away from the wood. I have had 10 windows replaced already and before Xmas they came out to have a look and said that they all need to be replaced again. I am very sorry that I put them in and especially sorry that I spent so much money on them.

Wonky Knees

Got alu clad from a company in Ireland which is the agent for the Austrian manufacturer. Windows triple glaze and built like a tank. No sign of moisture buildup. On the outside between the alu clad and the internal wood frame is a layer of CO 2 Thermo Foam. 43 db soundproofing U of .68

The windows (5) cover an area 10 m wide and 2.8 high. The btu calculator states that the room size requires 26K. My rads cover 17K. The internal wall is 100mm kingspan, plaster board and plastered. External is cavity block rendered.

Bottom line, the room is warm and holds the heat and I believe that a lot of the credit goes to the triple glaze windows.

bealfeirste5

With al the confusion and debate, would it not just be simpler to stick with PVC? just a thought..

justflow1983

mad m wrote: »

I got Alu-clad windows in over a yeah and a half now. Not any problems yet. But have noticed recently a build up of condensation on bottom of glass on inside of house. As far as I remember I never had this on the old pvc windows I had, but I could be wrong....

The windows are 110mm thick with alu on outside and wooden on inside.So basically two windows in one frame. I think these have a thermal break also,not sure. But with windows like these I thought I wouldn't expect to see any build up of condensation...

I had option of a trickle vent in these windows but think trickle vents are a waste of time....

In our office we had issues with triple glazed units developing internal condensation on the glass. Apparently this seems to be an issue with extremely high performance windows, I can't remember the reason though.

mr_edge_to_you

bealfeirste5 wrote: »

With al the confusion and debate, would it not just be simpler to stick with PVC? just a thought..

I like the look and feel of timber on the inside!

justflow1983

What about just timber windows? If they're just normal windows set into a wall (as opposed to a screen of windows) they should be ok without the aluminium.

Timber or aluminium both are great window materials. In my experience, aluclad windows are preferable where there is a large exposed expanse such as a screen of windows (curtain wall sort of things). A normal window is protected enough from the walls around it that the timber should be okay, and you don't have to worry about moisture getting trapped between the two materials. A window supplier I work with often recommends unclad timber for regular windows and only alluclad for large expanses, which is based on his experience honoring warranties. I don't specify straight aluminium windows because of the bad thermal performance, thermal break or no. Still its a durable, recyclable, healthy (for occupants) material.

springpark10

Hey folks,
Would love to get all aluwood windows, But just can't afford it!
What do ye think of partial Aluwood (to my living area, Kitchen/Dining etc) & the remaining in PVC.....
We are going with a black possibly dark grey on the exterior so we can match the colours almost exactly & we have stone work which breaks up the two areas.

Any opinions or advice on this, thanks!!!!!