What You Need to Know about IGUs on Replacement Windows

Windows are one of the weakest links in the exterior envelope of your home and the common culprit for air leaks and energy losses. So if you want to start saving energy, windows are a good place to start. These devices of glass, framing material, and moving parts are exposed to some brutal elements. Insulating glass units (IGUs) on replacement windows in El Cajon, CA go a long way towards increasing the efficiency of these products. Here is what you need to know about this standard window technology:  

What are Insulating Glass Units?  

The reason it is called a unit is because all the parts depend on the others for the highest level of insulation. The five primary components of IGUs include multiple panes of glass (typically two or three), spacers, inert gas fills, sealant, and the window frame. Here is a quick breakdown of each feature:  

• Glass: The standard for modern windows is two panes of glass, but some windows feature three or even four. Thickness ranges from 1/8” to 3/8” in various applications. Clear glass is most common, but homeowners can also choose tinted, laminated, low-E, reflective, and decorative coatings on the glass.  

• Spacers: The spacer separates the panes of glass where they meet the frame so they remain held apart at an appropriate distance. Aside from that, the spacer also accommodates stress from pressure differences in thermal expansion and contraction. Spacers are usually aluminum with a desiccant coating to help absorb residual moisture. Spacers vary in width depending on the type of gas between the panes.   

• Gas Fills: Each manufacturer uses a unique formula for the gas between the glass. Argon, krypton, and xenon are the most common. These noble gasses are chemically non-reactive. They have more density than normal air and improve the efficiency of the IGU.  

• Sealant: To hold the unit together manufactures use two sealing systems. A single-seal system uses organic sealant, typically butyl material to seal the spacer to the glass. A double-seal system also has a butyl material behind the spacer but also has a secondary sealant, usually silicone, for extra strength.  

• Window Frame: There are many variables to choose from, but perhaps the most important when making energy efficiency a priority is the frame material. Aluminum is strong and light, but more readily conducts heat. Wood windows are excellent insulators, but the maintenance on all wood window frames is expensive and time consuming. Vinyl window frames are some of the most affordable and are great insulators, but they don’t have the strength and durability of other materials. Fiberglass frames offer high thermal performance and strength and durability.  

Over Time IGUs Fail 

Eventually, the seals on IGUs will fail. This is due to a partial pressure differential between the noble class and outside air along with the thermal expansion of various materials. And if the seal fails it diminishes the efficiency of the window. Typically the noble gas leaks at a rate of about 1% per year. You might not notice right away, but over time moisture and particles will leech between the panes making the window appear hazy or foggy. And once that happens you need window replacement.   

Looking for the best replacement windows in El Cajon, CA? Call Pelican Replacement Windows at (760) 598-6422. Our experts can help you navigate all the variables and find the best solutions for your home. Stop by 2210 La Mirada Dr., Vista, CA 92081 today.