A dual pane window (aka, Insulated Glass Unit or IGU), is a window which is made up of 2 panes of glass that are separated by a gas or vacuum. Dual pane windows are twice as efficient as a single pane window as they are designed to reduce energy loss and outside noise (such as street traffic.) Dual pane windows keep warm air inside during winter and cool are inside during summer while also keeping your home quieter all year round.
While dual pane windows do cost more than single pane windows, when given the choice most homeowners will choose to install dual pane due to their efficiency in insulating your home. Single pane windows do not have air pockets so heat is able to pass though the glass than through the air pocket in a dual pane. Dual pane air pockets are conductive to creating a better insulated home. A moisture absorbing spacer called a desiccant holds the two panes of glass together and the entire unit is sealed to prevent the inner air from escaping.
Why dual pane windows?
Benefits below realized in varying degrees based on how many windows are replaced and other energy saving measures used.
Reduce your home energy bill
Reduce your carbon footprint
Reduce noise pollution
Prevent 25% of the suns heat from entering your home while also reducing glare and UV damage to your homes furnishings.
When good panes go bad
Dual panes have become the standard window option for new construction, however, many of our local homes were built between 1950 - 1980. Homes built before or during the 1980s are most likely to have single pane windows which have aged past their usefulness. If your windows are not energy efficient, your HVAC system makes up for it while your checking account suffers. If your home was built after the 1980s or you have already placed the original single pane windows, your dual pane windows may need replacement if:
They have a milky appearance
Condensation forms between the panes
Distorted or broken panes
The desiccant has expanded and is visible in the viewing area