Windows add light and charm to a home, allowing those inside to enjoy views of attractive outdoor features. Yet windows may also contribute to energy efficiency woes, particularly in hot and sunny regions. In fact, windows may account for as much as 87 percent of summer-time heat gain, drastically increasing your air conditioning costs.
For the most drastic efficiency improvement, homeowners should consider installing new windows. Yet not everybody can afford new windows. Fortunately, you can improve the performance of your existing windows by installing window film. This article takes a closer look at three key things to know about window films.
1. Window Films Come in Four Main Styles
Years ago, consumers only had one choice when it came to window film: dyed window tint film. Many homeowners still choose this option, which tends to cost less than other types of window film. The dark dyes in the film absorb solar rays, preventing them from passing into your house, while also boosting privacy.
Dyed films have certain limitations in terms of protecting against solar heat gain. Much of the heat absorbed by the film still manages to pass into your home. Metallized window films offer better results by reflecting sunlight away from your windows. Metallized films also boost the strength of a window, making it less prone to cracking or shattering.
Unfortunately, metallized films often block cell phone and radio signals. In addition, many homeowners dislike the mirror-like appearance metallized films give their windows. Carbon window films have neither of these drawbacks, while still providing highly effective protection against solar heat.
Homeowners who prize efficiency above all else should strongly consider investing in more expensive ceramic window film. Such film can stop up to half of the sun's heat from entering your home. Ceramic film also boasts a long life-span, excellent glare resistance, and unparalleled resistance to ultraviolet light.
2. Window Films Have a Confusing Array of Ratings
Manufacturers use a staggering array of ratings to define the performance of any given window film. These ratings include total solar reflectance, interior visible light reflectance, U-value, shading coefficient, and emissivity. If you’re not sure what all of these terms mean, focus on the most important of these.
Pay attention to two particular ratings: visible light transmittance and total solar energy rejected. Visible light transmittance, often shortened to VLT, expresses how much light the film allows through. A low VLT means that less light enters your home. Extremely dark films have a VLT in the range of 5-15 percent.
While VLT tells you a lot about how a film performs, VLT doesn't tell you everything. Not all of the sun's light rays fall on the visible spectrum. Human eyes cannot see infrared rays, which nonetheless contribute greatly to solar heat gain. The total solar energy rejected rating tells you how much heat a window film blocks.
The higher the total solar energy rejected rating, the better the film keeps heat out of your home. Those in warmer regions should look for window films with higher total solar energy rejected ratings. Such films will do a better job of managing the cooling load placed on your air conditioner.
3. Window Films May Cause Problems for Insulated Windows
If your home contains insulated windows — in other words, windows made up of two or more panes of glass — window film may cause unintentional problems. Specifically, the film causes inner pane to heat up at a greater rate than the outer pane. This difference in the rate of expansion may lead to stress that causes the window panes to crack.
For best results, always consult a professional before installing film on your windows. For more information about selecting the best product for your home's needs, please contact the window experts at Sunblockers Window Tinting.