Understanding Window Ratings

Are you confused about all those energy ratings? It’s not just you. In fact, plenty of homeowners scratch their heads when it comes to figuring out how to ensure that their homes are as energy-efficient and cost-efficient as they can possibly be.

From a window standpoint, the type and style you choose can have a dramatic effect on how much you spend on monthly and yearly utility bills. In fact, replacing your windows can be one of the smartest moves when it comes to sealing your home from the outside heat and cold that’s draining your wallet.

How to Rate Your Windows

When it comes to rating windows, the terms “low-e” and “U-factor” often come into play. The first term covers the amount of heat your window lets come through the pane, and the second term has to do with the insulation of the pane. Think of it this way: As the sunlight is coming through your panes, heat is being transferred into your home.  Low-e and U-factor ratings determine the levels at which this is going to occur.

While you might naturally want the lowest low-e and U-factors, you’ll find that there are other elements to consider that may change the best ratings for you. This is where a window professional can help guide a homeowner to the right fit.

Another aspect to consider when rating windows is the SHGC or Solar Heat Gain Coefficient. As the wording indicates, it tells you how much solar heat your windows are allowing in the house. Again, you may want more or less depending upon certain factors.

There are many windows that also use VT or Visible Transmittance to numerically explain the percentage of sunlight that a window will allow into the house.

How to Choose the Right Window Rating

As you might have guessed, each window of your house will need to be evaluated to determine the ideal low-e, U-factor, SHGC and VT ratings. You’ll want to think about whether the window gets lots of sun or only a little, and you’ll also want to think about how you use the window. It’s important to know that ENERGY STAR® ratings as determined by the government require that all windows have a U-factor of between .30 and .60 depending upon the region a house is located in; similarly, SHGC must fall between .27 and .40.

The good news is that there is a window with the proper window rating for every household. It just takes a little upfront time and planning. You’ll see a difference every time you pay your utility bill, and your enjoyment of your home will increase as your bills decrease!