Can windows actually be smart? Well, when it comes to energy conservation and utility costs, the good news is YES, replacement windows are smart. To keep your house cool and the air conditioner bill under control, windows can be the leading variable in achieving a cool, comfortable home while saving energy doing it.
Buying the right replacement windows and sliding doors really can keep summer’s heat on the outside, where it belongs. That’s because windows and doors are more energy efficient than ever these days, thanks to both advanced window science and government energy efficiency regulations.
Easy Window Science for Homeowners
1. Dual Pane Glass Windows: Let’s start here because this is one of the most basic solutions. Dual pane glass windows have an extra sheet of glass that stalls heat from trying to penetrate your windows. It’s simple: heat has to struggle through that extra space between the panes to get into your home.
2. Argon Gas Fill: Energy-efficient dual panes these days will be filled with argon, an invisible, nontoxic, odorless gas that’s injected into the space between the two glass panes. While regular air is easily affected by heat, argon is considerably denser than air, so it dramatically reduces the amount of heat that can pass through the space between the glass.
3. Low-E (low-emissivity) Coating: One of the greatest advances in window science is this thin coating of transparent metallic material (silver oxide) that’s applied to the window glass for insulating purposes. The Low-E coating acts as a kind of reflective shield, pushing radiant heat back to its source. In other words, a Low-E coating reflects the summer heat away from your home, helping to maintain the cool temperature inside.
Look for Energy Star Ratings
Energy Star is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy. They set standards for acceptable energy efficiency.
The National Fenestration Rating Council, NFRC, is a non-profit organization that administers the only independent rating and labeling system for the energy performance of windows, doors, skylights, and attachment products.
Both of these organizations are your outside authority for making “smart” window purchases. Think of it this way: Energy Star is to the window industry what the Kelley Blue Book is to the automobile industry—an independent indicator of fair value and a source of reliable, unbiased information.
You learn about a car’s fuel efficiency by checking the sticker that indicates mileage per gallon. The government sets these measurement standards, not the car manufacturers.
Same for windows. The Department of Energy sets the standards, conducts the tests, and the NFRC label reports the results, so you know precisely how energy efficient those windows really are; for example, a window’s U-Factor indicates the rate at which a window conducts non-solar heat flow. The lower the U-Factor, the more energy-efficient the window. A typical U-Factor these days is .3, and the typical range is quite narrow, from .2 to .4.
So yes, there is a smart window that will keep you cool in the summer! Just do your research, read that NFRC label carefully, and rest assured that the information is accurate and unbiased.