Argon filled windows also reduce the tendency for condensation to form on the inside of windows reducing the likelihood of the window trim experiencing moisture related problems.
Argon filled windows condensation.
If an argon filled window has even the smallest gaps in it the argon gas that escapes can be replaced by moisture laden air.
In this case the insulation barrier reduces the heat transfer from the hot air outside so your home will stay cooler inside in the summer.
The short story is that the introduction of argon into the space between two panes of glass creates an insulation barrier.
By keeping the heat or cold air inside the house the windows provide a better insulator than windows with oxygen between the panes.
Argon gas windows are energy efficient due to the density of argon gas being heavier than oxygen.
Just like the insulation in the walls of your home argon gas filled windows keep the heat in and the cold out.
In this way the gas between the double paned windows are less effected by convection currents and drafts.
In general the lower the u factor the better job a material will do at insulating.
Of course the opposite is true when installing energy efficient insulated glass windows in warm climates.
Gases like argon are preferable to air because air contains moisture that can condense on the inside of the glass units making the window cloudy.
This saves you on maintenance and replacement costs.
Air also insulates less effectively than gas fills.
Another trademark problem of double pane windows that have become exposed to drafts and likely lost all the argon gas is when condensation builds up on the inner surface.
Double pane windows also called insulated or thermal windows are made with two panels of glass sandwiched over a spacer and sealant creating a space between the panes that is filled with air or with a gas usually argon or krypton.
It is this sealed space that gives the window most of its thermal performance.
When effective double pane windows should not produce much or any condensation.