What is Solar Pumping?

Solar Pumping heats the inner airspace of the window and causes the window to pressurize. Small amounts of air within the window are pushed 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 descant material.

Day after day, year after year, this endless cycle of expansion and contraction occurs. The window literally acts like a pump, stressing the integrity of the seals and drawing air through the side. With that inflow of air comes moisture. Temperature inside can easily reach 170° during the Solar Pumping process and at that temperature failure is eight times more likely to occur.

No window is ever hermetically sealed. In fact if it was... it would explode!

Depending on the type of window, 0845 Glassman+ has found, on average, 75% of failed windows do not have a seal failure but are simply fully saturated from years of Solar Pumping. (See Left Sidebar "What is Solar Pumping?")

Eventually every double glazed window will lose the ability to absorb condensation and fog up.

Foggy windows or windows with condensation and moisture is primarily due to the inability of the window to absorb moisture that naturally builds. Windows are manufactured with a specific moisture absorption life span (i.e., 5 years, 10 years etc) that is based on solar pumping activity, which causes foggy windows.

The Solar Pumping activity from the sun slowly over a period of time saturates the Silica desiccant material until eventually fog, condensation or moisture appear on the inside surface of the window. Once this occurs the moisture is trapped within the window and the endless cycle of heating, fogging, cooling, condensing begins until eventually the window is fully saturated. This cycle usually starts as foggy windows..

double glazed 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 manufactures design windows to have a certain life span based on the quality of the desiccant, or moisture absorbing material placed inside the spacer bar of double glazed. This is to prevent foggy window and window condensation problems.

Foggy windows indicate that the desiccant moisture absorbing materials are fully saturated. From this point on moisture accumulates and circulates between the glass panes, which can cause permanent glass damage if not repaired quickly. Therefore, foggy windows indicates the end of your window 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 glass.
Once scarred, the unit may not be salvageable