Single-pane windows are generally the least energy-efficient. These varieties do not create effective thermal barriers, so they allow conditioned air to escape while also allowing outside air in.
Single-pane windows have just a single sheet of glass. They are the least efficient but most affordable type of windows by far.
Of all of these, vinyl tends to be the most energy efficient material as it has better natural insulating properties than fiberglass and metal and won't warp or deteriorate as wood windows often do over time.
Low Emissivity Glass, also known as Low E glass, is glass that has a coating applied to it, making windows and doors substantially more energy efficient. Originally designed to keep in infrared light for colder climates, they're now a cost-efficient option that is effective in a variety of regions.
Look for the ENERGY STAR and NFRC labels . In colder climates, consider selecting gas-filled windows with low-e coatings to reduce heat loss. In warmer climates, select windows with coatings to reduce heat gain.
When it comes to saving energy, money, and keeping your home well insulated, double-pane windows are much more effective than single-pane windows. Double-pane windows provide much greater energy efficiency and insulating properties allowing for lower energy bills.
Energy Efficient Windows Only Perform as Well as Your Air Sealing. While new windows might offer energy savings, they can't really do much for your home if they aren't properly sealed. That ENERGY STAR certification only guarantees the windows' performance when they're installed and caulked correctly.
The best insulation comes from double pane windows that are soft coat Low-E glass with argon gas between the two panes. The argon gas actually serves double duty. It prevents the metals used in the soft coat from oxidizing, and it acts as a better insulator than just air.
Low-E is a window coating that is completely transparent. It's not the same as tinted glass, which blocks out light but doesn't reduce heat transfer. So, if you opt to add a low-E coating to your replacement windows, you won't sacrifice visibility for energy efficiency.
Your HVAC system will have to work much harder to heat and cool your home, which will be noticeable on your monthly bills. Air escaping through windows accounts for 25%-30% of the home's heating and cooling usage. Single pane windows do very little to prevent this loss.
Low-E Windows
Low-E glass helps block both ultraviolet and infrared light, but lets in the visible light. Infrared light is associated with heat energy. By blocking it out, Low-E windows help keep the heat from the sun from entering your home.
Vinyl windows are energy-efficient windows, according to the International Association of Certified Home Inspectors. Vinyl is a better thermal insulator than either wood or aluminum. It's also recyclable.
South-facing windows receive the most light and are the hottest. North-facing windows receive the least light and are the weakest and coolest. East-facing windows receive light in the morning and are weak and cool. West-facing windows receive light in the afternoon and are strong and hot.
Today's triple-pane or double-pane windows are the most highly recommended for maximum energy efficiency in virtually all climate zones. The insular space between the window panes saves energy and helps reduce electricity costs.
As mentioned, double glazed windows are the best option for reducing heat loss in the home, since their air gaps create an additional layer of insulation.
Double pane windows are the most common type of house window, and they typically have a hollow space between two panes of glass. The hollow space is filled with argon gas to improve insulation. Double pane windows can reduce heat transfer by up to 24%, making them one of the best materials for hot weather.
Some of the most common problems that people encounter with low e glass are: A gray-colored haze when viewed in direct sunlight or when up against a dark background. It's not as noticeable until it's in the right conditions. Then, it's hard to miss.
Low E glass makes your home more energy efficient, potentially saving you money on your heating bills, and performs better than standard double glazing.
Low-E windows still allow plenty of natural light to pass through because the coating is tintless and nearly colorless. Light is a little less visible than it would be through a completely clear pane, but natural light still flows through a home beautifully — without fading your upholstery in the process.
One of the primary benefits of low-E glass is to improve the insulating performance of your windows. Low-E Glass reduces the heat loss and solar gain. Better insulation makes it easier to keep temperatures constant, so your comfort level is increased and your carbon footprint reduced.
Energy-efficient windows that are multi-pane and come with a Low-E coating will lose their effectiveness after about 15 years. So, even if your windows are in great shape structurally, your windows will begin to let in heat in the summer and lose heat in the winter due to the Low-E coating wearing out.
Appearance. While Low-E glass doesn't block natural light, it does have a noticeable tint compared to clear glass. Some homeowners may opt for clear glass to avoid the blue-green hue.
Replace Windows When Not too Hot, but not too Cold
Your best bet is to plan your window replacement for a time of year when the weather will be warm, ideally in the spring or early summer.
Should I Replace 20-Year-Old Windows? Yes! Not only are 20-year-old windows at the end of their expected lifespan, but there are also more energy-efficient options now than when these windows were installed. And windows that are more energy efficient could start saving you money as soon as they replace the old windows!
Window replacement is a big job—one with a hefty price tag and major influence on the look and feel of your home. Whether it's because you're facing an issue with one particular window or because you hope to save money, it's often better to replace all your windows at once, rather than opting for just one or two fixes.