
2. Every thermal double-paned window eventually fails; there is no such thing as a “lifetime” window despite the manufacturers claims. Wood framed windows tend to last about 20-24 years (if well maintained). Same with high-end wood and aluminum clad windows. Aluminum frames of the 70’s/80’s typically average 16-18 years. High quality vinyl framed windows should see at least 20 years if they have standard or Super spacers. Most of the vinyl windows installed in the subdivisions mass-built since 1998, however, have the low-quality Intercept Spacer and these windows begin failing in 5-8 years. See our Double Trouble article.
3. Choosing the best window is like buying anything else: you get what you pay for. For longevity and performance, the type of frame and IGU spacer are usually more important than who the manufacturer is. Best buy for longevity? Fiberglass or wood/aluminum clad frame with standard or Super spacers. Expect to pay for it, however. Add a high quality Low-E like the Cardinal 270 or the SolarBan 60 and you have a Cadillac window. For the best balance of value and performance, use a high performance Low-E in a quality vinyl frame.
4. Sunshine (solar expansion/contraction) is the biggest cause of window failure, which is why south and west facing windows fail first. Water exposure is the next biggest culprit. To increase the longevity of your windows, reduce the amount of sun and water exposure they receive. Consider sun screens, overhangs and planting trees.
6. Low-E (Low Emissivity) film is a coating applied to the inside surface of a double paned window IGU that is composed of microscopic particles of metal that selectively reflect long wave radiation (infrared heat) back to its source. A high performance low-e film blocks up to 90% of the sun’s heat coming in a window and reduces the heat escaping a window by at least 60% or more. That’s a difference you can feel! All without loss of clarity or obscuring your view.
7. The biggest cause of early failure in wood framed windows is lack of maintenance. Every two years the exterior seam where the glass meets the wood needs to be caulked and the frames painted. Otherwise, rain hits the glass and runs down between the wood-stop and glass where it pools at the bottom of the window IGU (Integrated Glass Unit), and rots both the seal on the IGU and the wood frame from the inside out. See picture at right. Read more about Wood Window repair here.
8. Sealed thermal or double-pane windows do not have a vacuum inside, just dry air that acts as an insulating layer. The Dirty Little Secret in the window industry is that windows are not 100% hermetically sealed. Windows breathe very slightly from heat expansion and contraction. That is partly why they build moisture absorbing desiccant into the spacers. Argon and Krypton gas help to slightly increase the insulation ability of your windows—but we have found that not only does it not make enough difference to warrant the extra cost, but after a few years of heat expansion cycles, it is soon gone.

10. Anything that makes a window hotter shortens its life. Use external sunshades rather than inside drapes. Be aware that aftermarket solar film—while useful in many places—significantly increases the heat inside a window IGU and always voids a manufacturer’s warranty. A high performance Low-E like Cardinal 366 can significantly reduce heat coming into your home and extend the life of the window as well.
For a free window consultation, call us today! 425-643-4444