Okna, Soft Lite are 2 off the top on my head.

Are they available impact yet?

Do you need Dade County/impact rated or just looking for laminated glass?

Where is the home?

Preferably the strongest, dade county impact rated, but below .20 u-factor is key and it being edge of glass as well. I really appreciate the assistance in trying to find the windows as I haven't had any luck

You are probably going to have a tough time based on those requirements.

The two driving factors of energy efficiency (U-Factor or 0.20 or below is certainly pushing the performance criteria beyond where many folks are today) impact resistance.

I don't know of any that will do that off the top of my head given the fact that all the ones I know of are double pane. There are some double pane numbers that are getting into the low 0.20's with interior Low-e coatings but none that I know of are sub-0.20

Best option you might have getting to that number is going to be a combination impact exterior window with interior storm.

Those units will be HEAVY with laminated glass and triple pane!

Someone has to be able to do this :( anyone else have an suggestions? It must exist? No?

Nick,

If you want to spend enough money, anything is doable.

I can think of a few companies off the top of my head who probably can do what you want, but there are the questions of "would they?" and "what's it going to cost?".

What are you looking at for the sash/frame? Are you looking for wood? Vinyl? Fiberglass? Aluminum? Other?

New construction? Replacement?

As a bit of window techno (meaning no disrespect, simply a bit of education since I get the impression that you have been doing a good bit of research), center-of-glass is the appropriate measure to use when comparing the energy performance between two IG units,.

When determining overall window energy performance you include all the various parts of the window unit including glass, sash, and frame.

Where you were using "edge-of-glass" for determining U-value, what you really want is the complete window energy performance. Edge-of-glass was pretty much a meaningless term when used in that context.

An impact resistant triple pane isn't a mutually exclusive concept but it is very (very!) unusual. Where do you live that you are looking for both impact and triple pane?

This post was edited by oberon on Tue, Sep 10, 13 at 10:23

Oberon,

Thanks for all of the very helpful information. What company do you know of that would do it since you mention you can think of a few? I live in Staten Island right on the water so it got hit terribly from Sandy.

Nick,

Oberon is hit or miss on the boards so I will send him a quick email to let him know.

Do you have an idea of what you want the window to look like (i.e. material choice)?

Starting there will narrow the scope a bit and move ball more forward.

I appreciate you reaching out to him. The material choice would either be fiberglass clad or aluminum on inside. Wood on the outside.

Are you sure you don't have that reversed?

i.e. wood in the inside and clad or fiberglass on the outside?

+1 WoW - I don't know of anyone who would make a window with wood outside and cladding inside...I admit I had to double take that one...

Nick,

I did a bit of research today on your questions and requirements.

I have never seen, nor have I heard of, anyone who had actually certified a triple pane impact window, so my first thought was to see if I could find out if anyone has already done the foot work.

Second, after thinking about it for awhile, I began to wonder if it was even allowed by either Miami-Dade or ASTM E1996 - the two standards that people who manufacture hurricane-impact resistant windows adhere to.

After researching, MDC doesn't address it at all; which I suspect may be because it never even occured to them.

ASTM E1996-09 on the other hand MAY address it, but the paragraph that I believe addresses it wasn't totally clear to me - however, my personal interpretation is that triple pane impact windows are allowed per ASTM.

The Miami-Dade County product control website has a listing of every product that has a current MDC NOA (Notice of Acceptance). I popped into the MDCA website and did a cursory look thru a couple of the companies that I thought MAY have tried triple glazing, but my results were ziltch, nada, nothing.

I say cursory because there are quite literally thousands of windows listed on the site and MDC doesn't offer a "triple-pane" search option. Of course they don't offer a dual pane or monolithic search option either.

Assuming (which I think is pretty much a given at this point) that no one has ever tested/certified a triple pane, you have a few options:

1) install the most energy efficient, impact resistant, dual pane widow that you can find,
2) talk a window company into fabricating a triple pane IGU using "impact-rated" laminated glass - but without testing and certificating (more on "impact-rated" laminated glass later),
3) install a triple pane for energy performance and not worry about impact resistance.

From the point of view of the window companies, triple pane impact windows are simply a no-win for them. They are going to be very expensive to develop, test, certify, and manufacture with a minimal ROI because there is, at best, a very limited market for that product.

Take a look at the three options I have listed and if you have thoughts about one, two, or all three, please feel free to ask and we will explore further.

There are possibilites with each one of them....

This post was edited by oberon on Wed, Sep 11, 13 at 18:29

Oberon,

Is there a dual pane impact resistant window that is below a .2 u-factor? Option 2 also sounds good but which companies could be a possibility?

Thanks so much,

Nick

Nick,

You won't find a dual pane window with a sub 0.20 U-Factor regardless. Some are close but they just aren't quite there.

On the 2nd item, I am not sure you will find anyone that has the spacer systems to accommodate a triple pane IGU with a laminated panel.

Most triple IGUs are designed to run with a single strength glass to offset some of the weight and the spacers are designed to work within the assembled glazing depth with those thicknesses.

Good morning Nick,

Exactly as WoW stated above, you can get in the low .20's with a dual pane but you aren't going to reach .2.

Per triple pane, in addition to what was brought up in earlier posts, for a triple pane with a laminated impact lite included you would need to find a window company that had a glazing reglet, or glazing channel, that was at least 1-1/4" wide (and possibly wider yet - 1-1/4" is really pushing the lower limit) in order to accommodate the width of the finished IG unit.

As you stated earlier, you are looking for clad wood windows - and as follow up to that, did you really mean the cladding to the interior and wood to the exterior, or was that a misstatement? If you really meant that you wanted the cladding internal and wood external, I strongly suggest that you reconsider for two reasons:

first, I don't know of any window company that can or would make a window in that configuration simply because it would be a very bad idea.

second, refer to the first reason.

There are companies that manufacture windows with really wide glazing channels to accommodate wide triples. If they are vinyl companies, then they are likely to be using European extrusions for their windows since European triples tend to use wider IGU's than their North American counterparts.

Over near Vancouver BC there is a company called Innotech that offers both wide triples with U values as low as .17 or so, and Miami Dade tested impact units. I suspect that they may be seriously willing to talk about the idea of a triple pane impact window, but the cost (especially when you throw in shipping) could be scary. Innotech windows use European vinyl extrusions.

Per wood manufacturer's, Loewen, Marvin, Kolbe, Weathershield, Jeld-Wen, and others, all make triples and all make impact. I don't know if any of them have ever combined the two.

Per dual pane impact windows, there are literally hundred's of companies in that pool. Wood, fiberglass, vinyl, aluminum are all available.

Energy performance is going to vary by both material and manufacturer.

For the very best U value performance you are going to want a triple-silver LowE coating on IG surface 2 combined with a surface 4 coating and a 90% argon fill. That will get you numbers in the low .20's.

Some companies will offer windows with the laminated impact lite to the exterior and some companies will have the laminated lite to the interior. Some even offer it both ways depending on product line.

There is no difference in energy or impact performance either way - assuming that you are making an apples to apples comparison.

And as a final follow up (for this post at least), as I mentioned earlier, based on my review of the requirements, I do believe that companies who are ASTM E1996 impact certified can manufacture a triple pane impact window that is within their certification, even though they certified a dual pane, without having to retest.

(anyone know a grammarian who might grade that last sentence/paragraph?)

However, every company that I mentioned earlier is Miami-Dade certified and MDC doesn't even recognize the existence of triple pane.

In the past five years or so (probably longer), I think yours might be only the second or maybe third truly original question that I have seen online...all else aside, you brought up one heck of an interesting idea.

This post was edited by oberon on Sat, Sep 14, 13 at 9:01

I am not certain what window manufacturer has this glass available but you may be able to get a manufacturer use this glass as an option but you very well may get close to your numbers. I know in some commercial applications I was able to get quite impressive "U" values (.22 in an ultra thermal aluminum curtain-wall application) using this glass.

Here is a link that might be useful: Heat Mirror Glass

This post was edited by millworkman on Sat, Sep 14, 13 at 15:41

Good suggestion Millworkman. Forgot about heat mirror.

That would get him very close to the end game number he is looking for.

Still no luck. I really appreciate everyone's help. Heat film isn't something I'm looking to do. If anyone can find a triple pane hurricane wondow with a u-factor .2 or below I would absolutely love you :)