Manufacturers are offering more windows with clear gas as a thermal option. Here’s what you need to know to sell it to your customers.
As homeowners become more knowledgeable about products before they purchase them, many have detailed questions about product features and functionalities. This is especially true with windows, which can have a big impact on a homeowner’s gas and electricity costs. Here are frequently asked questions — and answers — to help educate yourself on energy-efficient and gas-filled windows.
Benefits of Argon Gas Windows
Argon is the gas most often used between panes in a double- or triple-glazed window. The gas is colorless and odorless, says Bill Lingnell, head of Lingnell Consulting Services in Rockwall, Texas, an independent consultant who works with the Insulating Glass Manufacturers Alliance (IGMA). Argon is denser than the atmosphere, providing more thermal efficiency than having air between the panes, he explains.
Other Types of Gases
Krypton gas is denser than argon, and xenon gas is denser than krypton, providing somewhat more thermal efficiency. Some manufacturers also may offer a mixture of two gases. But the incremental benefit of these higher densities doesn’t necessarily justify their prices, says Carroll Bogard, manager of Trade Segment Marketing for Pella Windows in Pella, Iowa. “Dollar for dollar, argon gas does the best job,” he says.
What Do Filled Windows Offer?
Added energy efficiency is the key benefit to having gas-filled windows, Bogard says. The gas acts as an insulator, working in both summer and winter to keep interiors protected from outside temperatures. Typically, gas infusion is provided in conjunction with applying a low-emissivity (low-E) coating film to the glass panes, he notes.
The other key advantage is making people’s homes more comfortable, Bogard says. The low-E coating and gas keep the interior pane of glass closer to the temperatures of the interior air, minimizing air currents that are created when different temperatures come into contact. This reduces drafts and cold spots. He stresses that proper installation is absolutely essential, and contractors should be trained in proper installation techniques and/or use experienced installers.
Is the Gas Harmful if It Leaks?
No. The gases are inert (nonreactive) and occur naturally in the Earth’s atmosphere. Argon, the most common, comprises about 2 percent of the air we breathe, Lingnell says. “It can’t hurt you or make you ill if it leaks,” he says.
How Do I Know the Gas Is There?
Scientific detectors can verify the presence of gas, Lingnell says. But homeowners usually rely on their contractor and the manufacturers’ reputation.
What if the Gas Leaks Out Over Time?
“Reputable companies have their windows certified against seal failures to ensure that won’t happen,” Lingnell says. Members of IGMA use standards created by ASTM International to certify against leakage. “The major window companies certify their windows, but many smaller ones do not,” he warns. “Contractors should look for certification to reassure their customers.”
Even if a small amount of gas does leak, it won’t hurt the window’s performance, says John Swanson, editor of Window & Door magazine, which is published by the National Glass Association (NGA). “Studies show that even if 80 percent of the gas remains, it will still maintain its effectiveness,” he says. “So, even if 1 percent was leaking out per year, the window would still be effective in 20 years.” Should the window lose all of its gas, Lingnell adds, it might be noticeable due to condensation on the windowpane or fog inside the pane.
How Much Do Gas-Filled Windows Cost?
Determining the incremental price of gas filling and its resulting payback or return on investment depends on many variables, including the size of the window, materials used, glazing options, location and climate conditions, Bogard says. Some companies provide an upgrade package that includes both low-E coating and argon gas, Swanson says. The value of the added comfort that can be gained by eliminated drafts can’t be summed up in a strict payback cost either, he adds.
Is Gas Filling a Popular Option Today?
“It’s a technology that has been around a long time, and it’s become popular because energy codes are more stringent,” Swanson says. Most codes are designed as performance standards, meaning they set a standard that must be met and allow the manufacturer to meet it however works best. Many find the best way to do that is with gas-filled windows. “Consumers are becoming more educated about this option and are asking about it,” he adds.