Why is My Patio Door Foggy?

Last Updated on July 3, 2024


Patio doors are a great feature in a home because they connect your indoor and outdoor living spaces, providing a seamless transition to your patio.  They are also aesthetically pleasing and offer a view of your backyard while allowing in plenty of light and fresh air when open.  A good patio door can improve the energy efficiency of your home and even add to your property value.

A common problem that occurs with patio doors that can affect their aesthetic and the amount of natural light coming into your home is foggy windows.  Windows on patio doors become foggy due to condensation on the surface of the window glass and between the glass panes, as well as film forming on the glass.  There are several things that can cause the condensation to build up on the window glass and it must be removed to restore the clarity of your patio door windows.

In this guide, we explain how patio doors become foggy as well as what you can do to prevent and address foggy patio door windows.  If you cannot resolve your foggy patio door issue yourself, our professionals at Arax Windows Work can help with our window repair services.

How Condensation Causes Foggy Windows

Condensation is the formation of water droplets on a cool surface that comes into contact with warm, humid air.   When condensation forms on the outside surface of window glass, it can typically be wiped away or it will go away when the conditions become less humid.  However, the consistent formation of condensation on the surface of your windows inside your home could be an indication of a bigger problem.

Another way condensation can fog up your patio door windows is by forming in between the panes of glass.  This happens when moisture gets between the windowpanes, and it is very difficult to remove without the assistance of a professional.

The following are the main causes of foggy window glass:

  • Poor window seals: Double-pane windows consist of two glass panes with a sealed layer of insulating gas between them. As the seal deteriorates, moisture can get between the glass panes and cause condensation that fogs up the window.  This typically requires the help of a professional to clean the window and repair the seal.
  • High humidity: High humidity levels inside or outside a home or building can cause condensation which leads to window fogging. There are various things you can do to address condensation from humidity such as improving the ventilation.
  • Mineral deposits: Mineral deposits from hard water or cleaning solutions can create a cloudy film over your windows. You can prevent and remove the film with effective cleaning, but you may need the help of a professional if the film is difficult to remove.
  • Age and deterioration: Over time, windowsills, frames, and seals may wear out which leads to cracks and gaps that let air and water in the home and between the windowpanes. Damaged windows require professional repair or window replacement.
  • Poor ventilation: Poor ventilation can increase the humidity levels within the home which leads to condensation and fogging. Improving the ventilation and using dehumidifiers and exhaust fans can help resolve this issue.
Windows on patio doors become foggy due to condensation on the surface of the window glass

How to Prevent Condensation

Condensation is the main cause of foggy windows which means that you can prevent foggy patio door windows by stopping the condensation from forming.  You can take the following steps to prevent condensation from forming on your patio door windows both inside and outside your home.

Preventing Condensation Inside Your Home

The main causes of condensation on the inside surface of your windows are the humidity level inside the home and the temperature difference between the inside and outside air.  The following steps can help you reduce condensation inside your home.

  • Check your thermostat: The bigger the difference in temperature between the indoor and outdoor air, the more likely condensation is to form. No matter the season, try to keep the temperature in your home comfortable without being too much higher or lower than the outside air.  Adjust your thermostat if you see condensation starting to form on your windows.
  • Use a dehumidifier: If the area around your patio door tends to be more humid than the rest of your home, set up a dehumidifier. Dehumidifiers extract moisture from the air and even help remove musty odors.
  • Run exhaust fans in the kitchen and bathrooms: Moisture builds up quickly when cooking and washing dishes in the kitchen and when showering in the bathroom. When doing any of these activities in the kitchen or bathroom, run an exhaust fan to reduce the humidity.  This helps prevent the excess humidity from spreading throughout your home and affecting your patio door and other windows.
  • Let fresh air inside: Opening doors and windows throughout your home to let in fresh air improves air circulation and helps even out the temperature between the inside and outside air. You can also run ceiling fans to help improve air circulation.

If condensation inside your home occurs consistently, there may be an underlying problem with the ventilation or HVAC system that needs attention.  It is also important to clean up indoor condensation as ignoring it can result in mold growth and water damage.

Preventing Condensation on the Outside of Your Windows

When condensation forms on the outside of your windows, this is typically due to contact with warm, humid outside air.  Condensation on the outside of your windows is nothing to worry about, but you can still take these steps to prevent condensation and keep your patio door and other windows clear and dry.

  • Trim bushes and shrubs: Keep any bushes or shrubs near your patio door and other windows trimmed. This allows more sunlight to hit the windows which will cause any condensation to quickly evaporate.
  • Raise air conditioner temperature: Condensation forms on surfaces that are colder than the surrounding air. During the summer, you can reduce condensation on the outside of your windows by raising the temperature of your air conditioner.  This will make the surface of the windows warmer.

How to Clean Window Film

As mentioned above, mineral deposits from hard water, rain, and cleaning products can create a film on the patio door window over time.  This film is unsightly, and it can obscure the view out your window as well as the natural light coming inside.  If the film is not too severe, you can likely remove it yourself using the following steps.  For window film that is too difficult to remove with these steps, you may need to consult a professional for cleaning or window glass replacement.

  • Create a solution that is equal parts white vinegar and water and put it in a spray bottle. You can also use rubbing alcohol instead of white vinegar to create an equal parts solution.
  • Spray the film on the window.
  • Gently scrub the glass using a sponge or microfiber cloth.
  • For stubborn mineral deposits, you can create a paste with baking soda and water and use it to scrub the area.
  • Rinse the window thoroughly with clean water and use a lint-free cloth or paper towels to wipe the glass dry.

Repeating this process on a regular basis can help prevent window film from forming again.

What to Do for Condensation Between the Windowpanes

Double pane windows are the standard for patio doors as they help improve insulation and energy efficiency.  If condensation has formed between the windowpanes of a double pane patio door window, this is likely because the seal around the insulation layer between the glass panes is broken.  Condensation buildup between windowpanes due to a poor seal requires the intervention of a professional.

Professionals such as those at Arax Windows Work can remove the foggy glass and clean the condensation before reinstalling and sealing the window.  In severe cases, it may be necessary to replace the patio door window glass with a new, clear double pane window.

Call Arax Windows Work for Patio Door and Foggy Glass Repair

Foggy patio door windows can affect the aesthetic of your patio door and prevent natural light from coming into your home.  In many cases, foggy windows can be resolved by preventing condensation and cleaning window film.  However, condensation between the windowpanes requires you to call our professionals at Arax Windows Work.

Arax provides foggy window repair to clear up foggy glass, including window glass for patio doors.  You can expect our professionals to not only clear up your window glass, but also make any repairs necessary to your patio door, such as repairs to the frame or seal, to prevent your patio door from fogging up again.

You can call Arax Windows Work at (815) 230-1890 for window repair and glass replacement services throughout the Chicago area.