If you've got foggy or cloudy windows that no cleaning product in the world seems to be able to improve, you likely have a blown window. This occurs when condensation forms in the gaps between panes in a window with two or three panes. Since the fog is on the interior pane of the window, you'll never be able to remove it. A blown window also reduces your home's energy efficiency. Here's what causes blown windows and how to fix them.
What Is a Blown Window?
Modern energy-efficient windows are also called insulated glass units. These windows have two or three panes of glass separated slightly by a spacer, creating an air gap. This air gap is then filled with an inert gas such as krypton or argon. The net effect of having two or three panes of glass instead of a single pane is that it significantly reduces noise pollution and increases your home's energy efficiency. The inert gas and multiple panes better insulate your living space from fluctuations in the temperature outside.
The gap between the panes also has a seal that prevents outside air and moisture from intruding into the gap. Changes in the outside temperature will cause your window sash to expand and contract. Over time, this will shift the seal out of place so that the gap between the panes is no longer airtight. When this happens, moist outside air will intrude into the gap and cause condensation on the inside of the panes. This creates the window cloudiness that no amount of cleaning will remove.
Should I Repair or Replace My Blown Window?
Unfortunately, a blown window has to the replaced rather than repaired. You can replace the panes with new ones and reseal the air gap, but the seal will not be as tight as the one in a newly-manufactured insulated glass unit. The seal will quickly fail again after the sash begins to expand and contract. Also, all the inert gas used in the construction of the window leaked out once the seal initially failed, which lowers the window's energy efficiency.
If your window has a replaceable sash, you can simply replace the entire insulated glass unit with a new one. This is less expensive than replacing the entire window. If you do not know if your window has a replaceable sash, call a residential glass professional to examine your window and discuss replacement options.
Why Is It Important to Replace a Blown Window?
Once the seal in an insulated glass unit has blown, and the inert gas has leaked out, your window is no longer as energy efficient as it was. Replacing your insulated glass unit is the only way to restore its insulating capabilities.
In addition to that, you'll also have to deal with a foggy window that can never be cleaned. The condensation and oxidization of the low-emissivity coating becomes worse over time, so you may lose the ability to see out of the window at all.
To improve your house's energy efficiency and let you see out of your window again, call a residential glass expert. In many cases, a window installation professional can replace the insulated glass unit without replacing the entire window frame, saving you a significant amount of money.Share