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Why Your Windows Become Foggy


The cycle of “solar pumping” causes moisture to accumulate inside a window. When the inner airspace of a window gets heated by the sun or ambient air during the day, the glass flexes outward minutely, pushing some of the hot air through the window’s semi-permeable seal to the outdoors. In the evening, when the airspace cools, the glass returns to its normal position, drawing small amounts of air back into the cavity through the seal. The air drawn into the window naturally holds moisture which is absorbed by desiccant material in the window spacer. When the desiccant becomes saturated, fog will begin to show on the glass. As the moisture continues to accumulate, the fog turns into condensation and begins to leave mineral deposits on the glass. If left for too long, the minerals get baked onto the glass causing staining. Over time, these stains get thicker and eventually etch into the glass causing permanent damage. If you feel your windows have sustained permanent damage you may want to get into contact with a company like Window World Oahu.

Every window has a life expectancy determined partly by how much desiccant is built into the unit. They will all eventually show signs of fogging. A preventative defogging treatment is the only way to prevent it or to keep it from worsening through the five stages of deterioration so the best thing to do is contact a glass company nearby to come and start the defogging treatment. The sooner a customer calls to defog their windows, the faster the drying time and the better the result.



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