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).