What Is A "Green" Window

As we've become more and more aware of "building green" I wondered what that really meant for the window and glass industries. I needed to know what is universally set as the criteria for "green". We're actually asking how different windows score on tough environmental measures through all life-cycle stages, including raw material acquisition, manufacture, transportation, installation, use, and waste management using those criteria.

To me, all wood windows are immediately disqualified from any conversation about "Green". They use up precious natural resources, create waste, don't last long enough, and aren't energy efficient enough.

Is a man made material like vinyl considered "green"? Surprisingly, the answer is yes. I'll use Preservation Windows as an example. They don't use up natural resources, create zero waste, last lifetimes, and are way more energy efficient than most windows.

Before I really looked into it I thought Renewal by Andersen was the greenest window because of their use of sawdust and recycled materials. They were the first to receive the "Green Seal" award. What is their lifecycle? Who knows, but they only warranty their frames for ten years where many other vinyl window manufacturer's provide lifetime warranties. I wonder if that is a reflection of their confidence in mixing sawdust, recycled pop bottles, and vinyl together as a frame material?

Then I looked at their NFRC ratings on their website. Preservation Windows standard units are significantly more energy efficient than Renewal and it isn't even close.

My new impression of what "green" means certainly changes everything.

Glass Designed For Zone 5

Energy Star's proposed standards for upcoming years have added two more zones to the United States. The northern most zone is zone 5 which includes Minneapolis, St. Paul, Fargo, Green Bay, and many others. It is also the zone where u-factor is the most important rating you will see on the NFRC label.

What is the NFRC label? It is the label on every manufacturer's window that reports the independent test rating of five major components. Heat loss is the term most often tied to u-factor and that is really a function of the glass used in manufacturing the replacement window. Now you see why I say that u-factor is most important in zone 5.

When Energy Star published their proposed standards for upcoming years they made it clear that they want the Energy Star logo to mean something on windows. They are setting much higher and harder to achieve energy efficiency standards.

EnergyMaxx10 glass is the heart of what makes the Preservation Window the most energy efficient window on the market. EnergyMaxx10 has a number of key components that make it so energy efficient. It has the SST spacer system, krypton gas, two gas-filled chambers, and one inch of total glass space.

The SST spacer system is the heart of 'warm edge technology'. The specifications for the SST system clearly show why but here is the short list.

• Exclusive, patented tru warm edge.
• Patented double seal system.
• 54% more thermally efficient than windows made with conventional spacers.
• 950 times less conductive than aluminum spacers.
• 85 times less conductive than stainless steel spacers.
• Krypton gas has more than two and half times as much insulating value as argon.
• The chambers are larger than other glass types.

There are a few of the reasons for those of you in Zone 5 to go with Preservation Windows with EnergyMaxx10 glass.

Using Krypton In Window Glass

The use of krypton in high performance glass is becoming more and more popular. The question in most people's mind is whether or not it's worth it. The answer is yes, definitely.

Krypton and argon are both used in between the lites of glass in Low E and High Performance glass products. Both are inert gases that are not harmful to humans. Both have higher density than air.

Krypton is a better insulator because it's more than twice as dense as argon. Here is an easy analogy for you:

If you were looking at a swimming pool and it was empty, you could hop in and walk the full length of it quite easily. That's what air between the panes of glass is like. If the pool had water in it you would take longer and spend quite a bit more energy walking from one end to the other. That would be like argon. Now let's fill that pool with Jello, Jello symbolizing krypton gas.

I'm sure you get the drift. Krypton is a far better insulator than argon simply because of its density. Here is some more from Efficient Windows.Org if you're more of a technical person.

Vinyl Clad Wood vs. Insulated Vinyl Windows

The Efficient Windows Collaborative recently had an article that compared the various types of replacement windows. Their rankings of window types was very interesting, especially when they compared energy efficiency.

The only glass pack that rated above average was the triple pane, low e, insulated vinyl replacement window. The reason I bring this to your attention is simple. That rules out any of the windows manufactured by the "Big Three" window makers. Yes that includes Renewal By Andersen.

If you've read my stuff before you probably see that I have about four favorite windows and they are all vinyl. Preservation Windows stand out from the crowd though. When you start looking at replacement window products start with Preservation Windows and compare the features. You'll see what I mean!