Selecting and buying new windows for your home isn’t as easy as it may seem. There are hundreds of options to consider, from the glass to the frame to the style and finish. It’s important to choose windows that will not only be right for your home’s aesthetic, but also the climate where you live. Different types of windows are designed to perform based on whether you’re in a predominantly heating or cooling climate, as well as those areas in between. The type of glass, whether single, double or triple pane, is an important component. Which one is right for you? Here’s a closer look at these three options.
Single Pane Glass
This type of glass is exactly as the name implies: a singular panel of glass. They are available in different styles and window frames, and have a lower price point, compared to double or triple glazing.
However, since there is only one piece of glass, these windows do not offer as much insulating value as other options, and may not keep out as much noise. Single pane, clear glass has the highest rate of heat loss or heat gain (depending on the local climate), while permitting the highest daylight transmission. While the glass can be tinted bronze or gray to help reduce solar heat gain, this will also reduce visible light compared to clear glass or other tints such as green and blue that have higher visible light transmission.
However, for homes that are located in a quiet neighborhood and in a part of the country where seasonal temperatures are mild and consistent year-round, then single-pane windows may be an option for you.
Double Pane Glass
Double pane glass is the most common type of glass used in today’s residential windows. It is constructed with two pieces of glass spaced apart and sealed to be airtight, forming a single-glazed unit. Also known as an insulating glass unit, double pane glass is designed to increase a window’s thermal performance by reducing the heat gain or loss. According to the Efficient Windows Collaborative, compared to single glazing, double-pane glass cuts heat loss in half due to the insulating air space between the glass layers. In addition to reducing the heat flow, a double-glazed unit with clear glass will allow the transmission of high visible light and high solar heat gain.
The additional layers of glass helps create a more energy efficient window for your home, which will also be reflected in your monthly utility bills. In fact, according to the ENERGY STAR program, highly efficient windows can save $101 – $538 per year on average. Whether you’re located in a predominantly heating or predominantly cooling region of the country, the extra insulation from a dual pane window will help you control your home’s internal climate. You may find you need to use your air conditioner less in the summer and your heater less in the winter. While dual pane windows do cost more upfront compared to single pane, the savings you will see in energy costs makes them a solid investment.
Triple Pane Glass
This option is just like double pane, but with a third piece of glass. Triple pane glazing is the most expensive, but is also the most efficient when compared to single- and double-pane glass. This type of glass is more resistant to condensation than single or double glazing and in colder climates, will help your home be more energy efficient.
Keep in mind, though, that while triple glazing will help decrease a home’s energy bill, it could take 10-20 years for them to pay off.
Also, it’s important to remember that this type of glass option isn’t necessary for all different types of climate zones. Homes that see the greatest benefits are those located in the coldest climate zones.
As with single pane, tinted glass is also an option for double or triple pane glass. Remember, though, while bronze and gray tints reduce solar heat gain, they also reduce visible light transmission.
Other Details to Keep in Mind
In addition to single, double and triple glass options, there are a number of other details to consider when selecting new windows. Both triple and double pane glass can be improved even further with the addition of a low-E coating or inert gas fill between the panes.
Low-E coatings are common on today’s windows. This type of glass has a thin metallic coating that lowers the emissivity of the glass. This means it has a low rate of emitting absorbed radiant energy. These coatings are used to lower a window’s U-value (the rate of non-solar heat loss or gain through the window) and improve its thermal performance.
Insulating glass units can also be constructed to include an inert gas, such as Argon or Krypton, within the airspace. This is another way to improve the thermal performance of the window.
In addition, the type of material used between the two pieces of glass to create an insulating glass unit can also make a difference when it comes to the window’s level of energy performance. This material is known as a spacer and can be constructed of different types of material. These can include aluminum, stainless steel and silicone foam, among others.
Up to 80 percent of energy loss through a window can occur at its edge. Warm-edge spacer technology is another option that can help improve thermal properties, as well as reduce condensation and lower U-values. This technology refers to the edge construction of an insulating glass unit that conducts less heat or cold than traditional windows. These spacers thermally break the metal-to-glass contact point to some degree, so there is less heat flow through the glass.
Time to Start Shopping
Now that you know all about the differences in single, double and triple pane options, you can start your search for new windows, prepared to find the ones that are best for your home.