If you are considering replacing your home’s windows and have been shopping around for the right product and contractor, you have no doubt run across the term “energy efficient window.” But not all window companies do a good job of explaining what it means for a window to be energy efficient.
At Rescom Exteriors, we believe the more you know about your windows, the better able you will be to make the best choice for your home. So here is our definitive definition of what makes a window “energy efficient” and effective in reducing home heating and cooling costs – with the added benefit of keeping you more comfortable!
All replacement windows are made up of various component parts, primarily: frame, sash, glass, and spacers. It is the combination of these parts, the materials of which they are made, and the way they are assembled and installed, that make a window truly energy efficient.
Frame and Sash Materials
For hundreds of years, windows frames and sashes (which hold the glass) were made of wood. Unfortunately, wood is not a good insulator, allowing cold and heat to pass through pretty easily. Later, window manufacturers tried aluminum as a frame material. It was easier to maintain than wood, but was even worse when it came to insulating properties.
Advances in materials technology over the past twenty-five years have given us many more options for windows. By far the most popular – and for good reason – has been rigid vinyl frames and sashes. Vinyl is strong and durable, and requires virtually no maintenance. It won’t crack or rot like wood, or expand and warp like aluminum (which can allow air infiltration). Best of all, as a low-conductivity material, vinyl offers superior insulating properties.
A pane of glass is not a good insulator. Just look at how quickly condensation forms on the outside of a cold drink poured into a glass. The same transfer of heat and cold – known as “emissivity” – occurs through your old windows with plain glass.
New treatments for glass have created a class called “low-emissivity,” or Low-E glass. Through a combination of virtually invisible tinting or microscopic reflective coatings applied to the surface, Low-E glass panes can block up to 99.9 percent of the sun’s UV rays, as well as sharply reducing the transfer of energy between your home and the outside.
Double and Triple Pane Glass
Quick: how many panes of glass are in your current windows? Most homes have windows with just a single pane of glass, especially if they were built more than 20 years ago. One pane of plain glass offers virtually no barrier to energy loss. Which is why your windows ice up in chilly weather, or form condensation when humidity is high, or you feel a breeze even when the window is closed!
The windows we install at Rescom feature double or triple pane glass packages, each with Low-E glass panels to reduce energy loss. We go further by filling the space between the panes of glass with inert gas that, with proper sealing, creates a virtually impenetrable barrier to further lessen energy transfer.
Energy-Efficient Window Spacers
This is an often overlooked part of the window. The spacers are the small brackets that hold the glass panels tight against the window sash and frame. No big deal, right? Except many window manufacturers use inexpensive aluminum spacers, which act as energy conductors and sharply reduce the overall thermal efficiency of the window.
Rescom’s Bristol® Windows use advanced “warm spacers” that actually contribute to the thermal performance of the window, completing the package that makes the window “energy efficient.”
Now that you know what goes into making a window energy efficient, it is time to give serious consideration to upgrading your home with replacement windows from Rescom Exteriors. Give us a call at (866) 410-5884 and we’ll schedule a time to give you a full demonstration of what goes into making our windows the best choice for your home.