Due to the emergence of fourth-surface low-E coatings, the usage of Krypton gas in the door and window industries has been steadily declining over the last few years. While visiting various customers, many window fabricators tell me that they no longer use Krypton or use much less of it due to the high cost of this noble gas. By the way, it is called a noble gas because it is extremely unreactive due to its completely filled outer electron shell. The noble gas club also includes helium, neon, argon, xenon and radon, all found in Group 18 on the periodic table.
Years ago, Krypton was selling for as high as $1.50 per liter, and despite the high cost, many window companies were using it in triple-pane insulating glass (IG) configurations.
However, by using fourth-surface low-E coatings, window fabricators found that it is still possible to meet the new Energy Star 7 ratings, even in the Northern Zone, without having to resort to the use of a triple-pane configuration. So, outside of triple-pane fabrication, Krypton loses its advantage because it works its magic in the smaller air gaps, like those associated with three- and four-panel IG units (IGUs). It has much less of a thermal benefit in larger air gaps, such as ½- to 5/8-inch, which are typically found in double-pane units. So, in the absence of multi-pane IG fabrication, Krypton serves no cost-effective purpose.
However, there are several factors that will create a rally in the upcoming years for the re-emergence of Krypton gas as a filling.
1. Krypton is now much more affordable. Ten years ago, Krypton was selling for $1.50 per liter. That seems to be the price that is still stuck in everyone’s head, because when I bring up the subject while visiting accounts, I get the remark, “Well, isn’t Krypton something like ten or twenty thousand dollars a tank?” Yes, it once was in that range. However, today, depending upon volume, it can be sourced anywhere from $.22 to $.40 per liter. What other window components do you know that have decreased in cost by 85%?
2. The use of triple-pane glass is on the rise. Modern vinyl frame designs are now available which accommodate glazing units up to 1-1/8 inch thick, which means that triple-pane configurations will be right at home in these new windows. Given the fact that Krypton does its thing in triple-pane configurations, it is only natural that its usage will follow the increase in triple-pane IGUs.
3. Skinny triples are now a manufacturing reality. Skinny triples, which are capable of capitalizing upon the power of Krypton’s energy-enhancing effects in small spaces, are now capable of being made with highly efficient fabrication technology. At the GlassBuild America show, Forel North America launched its new automated skinny triples line, which was running units made with Quanex’s Super Spacer. This line was cranking out gas-filled skinny triples with a cycle time of approximately 45 seconds. This translates to 640 units in an 8-hour shift, assuming continuous production.
4. Condensation resistance has increased in importance. Condensation resistance has always been a concern over the years, with many window dealers having to respond to complaints in the winter months when moisture is trapped inside of homes as it condenses on cold window surfaces. The irony is that with the emergence of lower U-value requirements, the frequency of condensation complaints has increased over the years, due to the usage of fourth-surface low-E coatings. In case you missed it, check out a blog I wrote over a year ago entitled Condensation Conundrum. Now, triple-pane windows fabricated with non-metal spacer systems combined with Krypton gas can produce windows exhibiting both low U-values and exceptional CR ratings. This is what we will likely see with Energy Star’s Most Efficient category. Consumers will then have their cake and eat it, too. They will enjoy windows with the highest degree of energy efficiency but without the concern of having condensation appear on the inside pane during the cold winter months. And once again Krypton can be credited “with the assist!”
So, there you have it. While costs are increasing for many other window components, Krypton costs are trending downward, while its role in building high-performance window systems continues to gain momentum.