How Moisture Develops
Thermal windows, which consist of two or three glass panels separated by spacer bars, are expected to eventually fail. It's simply the nature of the product. They may be designed to last five years, or as many as 20 years, but they are expected to fail.
During a process known as "solar pumping," the air trapped between the window's glass panels heats and cools along with temperature variances throughout the day. As the air is heated, pressure inside the window rises and small amounts of air escape through the window's seals. When the air cools, pressure drops and moist air is drawn inside. All windows will allow a certain amount of air to be exchanged, and is to be expected.
Knowing that some moisture will enter the air chambers, spacer bars are designed to contain silica desiccant material, specifically to absorb dampness. It's the absorption capacity of this material that determines the life of the window, and generally it functions well for many years.
80 percent of the time, thermal windows fail because the desiccant has reached its saturation threshold, due to many years of solar pumping. Damaged seals around windows and between the glass and spacer bars can also contribute to full saturation by letting in more moisture.
When a window's desiccant has become fully saturated, fog or condensation will appear inside the window. This signals the need for action: If condensation is allowed to remain it will begin to damage the glass surface. Fortunately, costly replacements are not always needed.
Caught in time, condensation can be removed and certain effects can be repaired. Left untreated, etching and a white haze will develop, which will lead to permanent window damage.
At the first sign of condensation, call Window Medics at 519-455-0070 or use our contact form - we service Southwestern Ontario from Windsor to Hamilton. Our unique one-way valve technology reads the pressure level inside the window and opens and closes accordingly; moisture is let out, but not let in. Foggy windows can become a thing of the past, significantly extending the life of your thermal windows.