Defogging
Solar pumping naturally occurs during the change from day to night. Sunlight heats the inner airspace of the thermal window cavity during the day and causes the window to pressurize, which forces out small amounts of air within the window cavity through the semi-permeable seal. In the evening, as the temperature drops, the window cools and creates a low pressure area causing small amounts of air to be drawn back into the inner window cavity. The air being drawn back into the window naturally holds moisture and this moisture is absorbed by the windows desiccant material.Solar Pumping activity over a period of time saturates the Silica desiccant material in the thermal window cavity until eventually fog, condensation or moisture appear on the inside surface of the window. This moisture is trapped within the window and an endless cycle of heating, fogging, cooling, and condensing occurs.
- Eventually every thermal pane window will lose the ability to absorb condensation and fog up.
Foggy windows, or windows with condensation and moisture, are primarily due to the inability of the Silica desiccant materials in the thermal window cavity to absorb moisture that naturally builds over time from Solar Pumping. Windows are manufactured with a specific moisture absorption life span (i.e., 5 years, 20 years etc) that is based on solar pumping activity, which causes foggy windows.
- Thermal pane windows are made with eventual failure in mind.
Window manufacturers know and expect solar pumping to occur. Windows, by design, will without exception, fail. Window manufacturers design windows to have a certain life span based on the quality of the desiccant, or moisture absorbing materials placed inside the spacer bar of a thermal window. This is to prevent foggy window and window condensation problems.
Foggy windows indicate that the moisture absorbing desiccant materials are fully saturated. From this point on moisture accumulates and circulates between the glass window panes, which can cause permanent glass damage if not repaired quickly. Therefore, a foggy window indicates the end to a window’s life cycle.
- The average age of a window restored by our Specialists is 12 years.
As the saturation point of the moisture absorbing materials is further exceeded, the dangers begin. Moisture becomes permanent. This progressively leaves deposits, strips the insulating properties of the unit, and scars the window glass.
Once scarred, the window unit may not be salvageable.
Visible fog, condensation or moisture is a sign that the sealed window unit has simply reached Its threshold to absorb moisture, causing foggy window or condensation problems. This is a repairable and preventable condition.