Foggy Windows: Repair or Replace?

Windows are meant to be viewed through, not meant to be foggy or restrictive in viewing. So, why does my window fog up and what can be done about it?

Why do windows fog?foggy_window

The short answer is because they are doing their job. Condensation is actually a sign that the windows are working correctly. Drafty or leaky windows make little distinction between the interior and exterior climate factors related to a home. It’s when you are achieving a difference in temperature that windows will have condensation.

When windows do their job, they provide an interior climate that is slightly more humid than the exterior, making sure your home is better sealed from the external environment and more climate controlled to your liking.

Tighter homes retain humidity. Exterior air is drier, colder or warmer than your interior climate control. When this outside air draft leaks into your home it mixes with the interior more humid climate. The window now is trapping that difference between temperatures and condensation forms.

You can reduce this surface condensation by letting your home’s interior breathe more. A few steps to take would include: shutting off humidifiers, opening windows temporarily, opening fireplace grates, keeping heaters or other sources of heat to a minimum, etc.

What If Condensation Is Forming Inside The Glass Panes?

fix a fogged window condensationWhat you don’t want is for the condensation to form between the panes. These double or triple pane windows are designed to provide ever increasing seals between the interior and exterior temperatures of our homes. Most have a vacuumed seal of either argon or krypton gas that further strengthens the variance of temperature.

When the seal fails and the gas escapes, there is no advantage to the barrier any longer. Outside air finds its way between the glass pane, bringing with it dust, bugs, and moisture.

As the moisture and water vapor collects and then wicks away, it leaves behind mineral deposit that brings ugly streaking and a dull to dirty unsightly window.

What Can I Do To Get Clear Windows Again?

Fortunately we are talking about the window pane. That is, as long as adequate insulation was installed previously and there are proper window fins from the original construction to the house frame and a few other matters that can only be corrected by a complete replacement. (That’s why you need us to give you an estimate in all cases.)

If we are talking about just the pane, then there are at least three quick choices to consider.

Remove All But One Pane

Frankly, this would be an extreme temporary step and not one that we would recommend. However, it has been the practical solution to some of our customers so they have more time to consider their lasting solution. You must understand that in doing so, you forfeit any of the original benefit of saving utility costs.

The quick fix is a do-it-yourself project:

  1. Remove the exterior trim around the window frame. Be sure not to crack, break, or lose the trim.
  2. Remove the insulation ring carefully (this is usually a material foam ring that inserts between the window frame and the window pane.
  3. Remove the IGU (insulated glass unit) which is usually two or three panes mounted in a stand alone metal, aluminum or vinyl framework.
  4. Carefully separate the panes of glass by cutting down the rubber seal found at the perimeter edge of the entire window and remove the front facing window pane(s). The knife blade will slice between the front pane and frame. (It usually is a greasy texture of something like tar).
  5. Be sure to keep the second pane secured to the frame and do not attempt any displacement from the frame. This is the one pane that remains as you return the window unit to it’s original place
  6. Replace the window sash into the original opening with just one pane of glass.
  7. Clean both sides the window.
  8. Start saving up money because you can’t leave it like this.

Apply A New Barrier To Your Existing Insulated Window Unit

This is also a maybe-it-will-work type of project. An additional alternative to complete replacement is the application of a new barrier.

Kits are sold under generic names like: get out the mist, window defogger, and the like. Services can be purchased where a person will come out and essential use the same kit or process. Either way, it usually includes the following steps:

  1. Two 1/8 to 3/8 inch holes (as needed) are drilled in opposing corners of the affected exterior glass pane.
  2. Pressured nozzles are inserted into the holes and a variety of solutions are applied: washing, cleaning, demineralizing, rinsing, and finally a moisture evacuation agent. 
  3. Microvents are plugged into the 1/8 to 3/8 inch holes so that the window can breathe while also denying the entry of bugs, dirt, and moisture.
  4. It takes about 2 weeks for the entire process to wick and clear

It is commonly said that this choice has three distinct advantages at about half the cost of replacement:

  1. Restored view to the window
  2. Renewal of the insulation value of the window to retain original utility savings
  3. Saving the glass from loss and waste to a landfill.

Replace the IGU

When you choose to replace the insulated glass unit itself, the difference is cost between you doing it and having it done is minimal. But, if you’re set on a do-it-yourself project:

Step 1: If you have a wooden frame, you may want to use a screw driver rather than a drill to make sure the age of the install doesn’t result in stripped out screws (when the indention for screw driver bit is lost by a spinning screw bit rounding out the screw head…that’s a real pain).

Hint: When you remove the sash, be sure and make small mark that matches the sash to the frame so that when you replace it, it all lines up.

Hint 2: Take a quick pic of the sash before you begin dismantling it. It helps to know how it came apart. You may care to have a pic at each stage to walk you back through with confidence on the reassembly.

Step 2: Having separated the IGU window unit from the sash and jambs, you now take the measurements at three strategic points: the width, the height and the thickness. Thickness is crucial and usually measures 3/4, 7/8, or 5/8 in thickness.

Step 3: A glass shop can order the new IGU for you. It will take about a week for so for you to get the IGU back.

Step 4: If you are wise enough to order your new glass with a low-E coating, you will want to be sure to install the new glass low-E coating to the outside. Most will actually have a sticker identifying the low-E coating side.

Step 5: You should be able to use the insulating foam insert that originally came with the window you are replacing. If this foam is brittle or stiff to the touch, it is best to replace that as well.

Step 6: Take care to assure the foam insert lies flush around the perimeter of the new glass, between the glass and frame. This can be a challenge to avoid creases and thin spots as the foam insert shifts with each contact to the frame pieces. Don’t be impatient here and don’t leave wrinkles to work out on their own. If you get this wrong, the potential for future seal breaks are not reduced.

Step 7: Carefully keep equal pressure to each joint of the sash and frame as they come together.

Step 8: Clean the window both inside and outside facing. And, you’re done.

The real question: How Much Trouble Do I Want To Go To?

Give us a call and we’ll give you a cost for window replacement, provide an accurate work schedule and the problem is gone…you have wonderful windows again!

How You Can Be Sure In Your Own Home That Replacement Windows Pay For Themselves

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