The snow is finally melting and your icy wet windows are returning to normal, so that you can see outside. If the inside of your windows were foggy, icy or wet during these past months of freezing temperatures it may be time to replace your windows. It may be time to get an assessment of the condition of your window’s.
Suffice it to say, it’s normal that as soon as Fall breaks toward Winter and outside temperatures drop, some windows in your home may appear a bit cloudy. It’s also common for windows to accumulate moisture droplets or worse yet ice up on the outside and the inside. It could be the Chicago Old Man Winter, or it could be time for new windows. Honestly, these conditions can have many causes, which with a little extra effort can be remediated. You can try turning up or down the humidity in your home, because the colder the glass, the less humidity it takes to cause moisture. To read up on causes and how to mitigate condensation in winter, read my previous blog “Window Condensation in Winter” or “Condensation and Ice Buildup on Windows in Extreme Weather”.
However, if this particular Winter your windows did little to keep out the cold weather, a more permanent solution may be needed.
A Seal Failure Produces Fog Between the Glass
Older windows can and eventually will experience seal failure causing fog between the panes of glass. The average lifespan of a double pane window is 15-30 years and in a challenging climate like Chicago it will be on the lower side of the range. These thermal windows, known as insulated glass units (IGUs) are factory-sealed together to form a single unit. The IGU is usually filled with an inert gas to act as a barrier to heat.
Foggy glass appears when the edges of the glass seals begin to fail, the inert gas escapes and outside air enters. When the outer glass gets cold, the warm air inside the two glass panes creates moisture and a hazy fog develops. It usually comes and goes depending on weather conditions, especially when weather cools in winter. When you see the fog come and go, you can bet it’s a seal failure.
Drafty Old Windows Contribute to Fog, Condensation or Ice
Seal failure is a common cause of fog between the glass, but older windows also tend to be drafty, allowing heat to escape from inside your home. When heat is escaping from your home, it’s much more difficult to control the temperature and humidity inside. Excess humidity in your home, when it’s extremely cold outside is the number one culprit contributing to fog, condensation or ice on the interior of your windows. To better understand and diagnose your window problems you might like to read “Foggy Windows? Condensation or A Broken Window Seal“.
Old drafty windows make it nearly impossible to maintain a comfortable interior temperature and healthy humidity. The long-term solution is to upgrade to today’s energy efficient windows. The new windows will be made of better insulated materials and the low-emissivity (Low-e) coatings on the glass control heat transfer through the windows.
When shopping for new windows, In addition to energy efficient low-e windows, ask about condensation resistance (CR). Condensation happens when the outside temperature is below the dew point of the indoor air and the warm moist air (your home’s humidity) comes in contact with colder dry air (outside). Many window manufacturers now list the CR rating on their Energy Star Label. Learn more from our previous blog, “Replacing Windows? Ask About Condensation Resistance“.
Winter is almost gone, but winter will come again, if the inside of your windows were foggy, icy or wet during these past months of freezing temperatures it may be time to replace your windows.