The Lifestyle of Green: The Three Numbers of Window Efficiency

If your aim is to go green you'll soon find that what really makes a long term positive effect on our environment is all the little, daily decisions you make. Going green is a lifestyle. Being able to make a difference that will last a long time to come is a result of living a life that will have beneficial results.

These sundry decisions we make add up. Taking a reusable grocery bag to the store. Maybe biking to the store rather than driving. Using energy efficient light bulbs. All these choices combine to make an important impact.

It's the same with your windows. Since you live with them everyday, making the choice to upgrade to well insulated energy efficient windows is a huge step you can take to keep heating and cooling costs way down and even reduce the amount of harmful C02 emissions that are released.

When you think about what kind of laundry detergent you purchase you usually look for the kind that's low in phosphorous. When you pick out a new window for your home why not select a replacement window that will reduce energy cost as well as give you a good conscience knowing you've cut down on emissions as well.

So here's a quick tip. When selecting an energy efficient window, pick the one that gives you the best numbers for your buck. There are three numbers to consider that will help you know the thermal value of each window you look at.

U-Value-This value measures the overall thermal value (glass, frames, and sashes) of a window by telling you how slowly heat is transferring through window. The lower the better. Most good windows will have a U-Value of around .28-.30. Anything higher than a .30 may not be worth a second look.

R-Value- It's the inverse of U-Value and uses a more is better scale. It usually measures the density of insulation and how well it blocks heat. Higher is better here. Most well insulated windows have an R-Value of 4 in the glass. The tricky thing about R-Values is that you can get different values from different components of the window. For example the glass may have a 4 while the sashes have an 11. That's why we mostly turn to U-values for an accurate assessment of a window's thermal value.

Solar Heat Gain Coefficient-(SHGC) measures how well a window blocks heat from sunlight. The SHGC is the fraction of the heat from the sun that enters through a window. SHGC is expressed as a number between 0 and 1. The lower a window's SHGC, the less solar heat it transmits. A good number to look for on a window is .23-.25.

So as you look into replacement windows, these numbers will give you a good idea of what you're comparing between products. The better the numbers the better the performance you'll get and your dollars can go a lot further. You'll be investing in a window that will not only last a long time but its insulation value will be one that you can feel good about.

For even better numbers in a vinyl replacement window, don't forget about the options of triple paned units, krypton (rather than argon) gas, and Super Spacer (one of the best spacers available).

What's the deal with gas?

You may have heard people talking about argon and krypton gas when discussing replacement windows lately. When these mentions of gas and windows come up do you scratch your head and reply "I didn't windows had gas!"?

It's a fairly new feature that replacement windows have nowadays to include some kind of slow moving gas in the space between the two panes in a modern replacement window. And though now it has become common to find on almost any vinyl window these days, questions still arise as to why people are even talking about gas when referring to their windows.

Let's start with argon gas. Almost any double paned replacement window on the market will have this gas as a standard feature. Along with low-e, argon gas is pretty much a non-issue when selecting a vinyl replacement double hung window because every insulated window has it. But what is argon gas, what does it do, and why should you make sure your window have it?

Argon is a very dense, slow moving, inert gas. The reason it is pumped in between the panes of replacement windows is because of its unique ability to slow down heat from entering into your home. It works along with the low-e coating replacement windows have to keep a high insulation value in your home (measured by U-values and R-values). Typically, a replacement window with argon gas and low-e will have a U-value somewhere around .25 to .30 (remember, the lower the better!). Again, argon gas is standard in most replacement windows and if it's not included as part of the insulation package it's not worth looking into.

Now there's also Krypton gas. No, Superman has nothing to do with this one. Much like its cousin argon, Krypton is an odorless, tasteless, invisible gas that is used for its inert, dense qualities. However, Krypton is much denser and has better insulation qualities than argon. Krypton is not typically offered as a standard item in insulated glass packages and with most windows is an upgraded or added option. Many vinyl window manufacturers offer Krypton gas as an option or even a krypton and argon blend for a better insulation value.

Typically, adding Krypton or a Krypton/Argon blend will provide your glass with a .16 to .10 U value (don't forget less is more).

There you have it. A little crash course in krypton and argon gas and why you should be sure it's a part of any replacement window you install in your home.

For more information visit us at Atlantawindows.com