How To Keep Windows From Fogging Up on the Outside

There’s not much you can do to prevent windows from fogging up on the outside because it’s a process that occurs naturally. 

Whenever this happens, it means the outside air is warmer and more humid compared to the air indoors. Meanwhile, the window panes are chilly because of the cold air indoors.

So when the warm, outdoor air comes into contact with the window panes, condensation takes place, causing the windows to sweat from the outside. 

Although the situation is out of your hands when condensation occurs on the outside, you have control of condensation that occurs in between panes or the inside of your windows.

Here are some of the issues we’ll address in our article:

  • Why are house windows fogging up between panes?
  • How to fix condensation between panes
  • How to keep windows from fogging up when raining
  • How to keep car windows from fogging up in the morning

Why are house windows fogging up between panes?

This is an entirely different concept from what causes your windows to fog up on the exterior.

Usually, if your double pane windows are starting to appear misty, there’s just one thing that could be the culprit- a failed seal. 

Now, in between the two panes of glass is a layer of gas (typically argon) that’s trapped to serve as insulation. This is what prevents unnecessary heat loss or gains through the window. 

If the window panes start fogging up, it means the air-tight seal that holds the insulating gas has malfunctioned. As a result, the gas – that should otherwise remain trapped – is being let out, paving way for water vapor to build upon the panes. 

So just what causes the airtight seal to malfunction? Well, whenever the windows are exposed to heat, the panes expand and contract. This cycle of expansion and contraction can eventually cause the seal to weaken and start letting in moisture. 

How to fix condensation between double pane windows

Is there anything you can do to resolve the condensation issue if the damage is already done?

Yes, there is, but this only serves as a short-term solution. Ultimately, a replacement may be inevitable.

What’s good about this approach is that it also gives you an opportunity to clean in between the two panes. So here’s a step-by-step guide on cleaning and eliminating moisture from double-glazed windows. 

Step 1

Start by arming yourself with the right equipment, in this case, a glass-working drill bit. You should be able to get this from a hardware or home improvement store. 

While you’re at it, also look for safety gear, specifically, eye goggles, a dust mask and some ear plugs. The goggles will prevent flying pieces of glass from entering your eyes and nose whereas the plugs will protect your ears from the drill bit’s noise.

Step 2

Once you’re geared up, choose a spot close to one of the four corners of the window. This is where you’ll drill a hole.

When you’re drilling, be very gentle and precise. Don’t apply excess pressure as this could end up splintering your entire window. Stop drilling as soon as you’re able to breakthrough. 

Step 3

Gently remove the drill and place a hose to suction out the built-up moisture. Keep vacuuming until you’ve drawn all the moisture. 

If you’re drilling holes for the purpose of cleaning, then this would be the right time to rinse out your window with some rubbing alcohol. In the end, your window panes should be a lot clearer than they were before. 

Step 4

The last step involves inserting a defogging device into the holes you drilled. We recommend silica gel due to its high absorbency rate. Not only will it seal the holes but it will also absorb any moisture that finds its way into the gap between the panes. 

When to replace

The foolproof solution for your condensed double pane windows is a replacement. Although it will certainly be expensive, it will solve the issue permanently so you won’t have to keep looking for temporary fixes. 

Besides, you may not even have to replace the entire window; just the double pane glasses. The only time you may have to get a completely new window is if the frame is also damaged. For instance, if the frame holding the glass panes is rotten or broken, then replace the entire window unit. 

How to keep windows from fogging up when raining

If it’s chilly or raining outside, there’s a good chance that your windows will start fogging up. The easiest way to prevent this from happening is to control the moisture levels in your home. The best three things to do to simplify this is to:

  • Turn on the Ceiling Fans
  • Regulate Humidity settings on your thermostat
  • Invest in a dehumidifer

Here’s how to do it in-depth:

Turn on the ceiling fans

If you have a ceiling fan, ensure it’s switched on to keep air circulating efficiently inside your home.

Important to note though is that you’ll need to reverse the direction of the fan. Under normal conditions, your fan runs in a counterclockwise direction. This pushes cool air downwards, creating a wind-chill effect that keeps your home cool. 

But when it’s chilly, reverse this setting so the fan moves in a clockwise direction and at a lower speed. This will cause the fan’s blades to pull cool air from below while pushing warm air downwards. 

Regulate humidity settings on your thermostat

Another trick that works entails lowering the humidity control on your thermostat. Reducing the humidity levels helps to counteract the moisture buildup on your windows.

Invest in a dehumidifier

If your windows are constantly fogging up which can happen if you live in a very cold area- then the best thing you can do is to install a dehumidifier. 

These appliances aren’t as pricey as people assume them to be. In fact, you can get one for less than $50. 

How to keep car windows from fogging up in the morning

If you commute to your workplace, this scene is all too familiar. You jump into your car, eager to drive to your workplace. But after just a few minutes of driving, your windshield starts fogging up, impeding your visibility; hence, slowing you down. 

What causes this to happen? Well, the science behind this occurrence is pretty simple. It all boils down to the temperature and moisture differential between the air inside and that outside of your car. 

The air outside is very chilly and dry- even though it may not seem like it, cold air has very low humidity- while the air inside is much warmer and humid (moist). 

Now, when the warm, humid air comes into contact with a cold window, condensation occurs. Essentially, the air particles are converted into tiny droplets of water, and this is what causes the windows to become misty. 

How to defog car windows in rain without AC

When the car windows start fogging up, the first thing that most drivers think of doing is to turn on the ac. However, we recommend the best way to defog car windows without AC is to:

  1. Crank up the heat,
  2. Turn off the recirculation setting
  3. Activate the defrost/defogger setting

While effective, this tactic increases your car’s fuel consumption rate considerably. Just to put this into perspective, turning on your AC increases the fuel consumption rate by a staggering 20%. 

If you’d rather preserve that fuel, here are alternative ways to defog your car windows:

Crank up the heat

An easier and more cost-effective solution is to turn on the heat to its maximum setting. This will result in warm air being blown across your windshield, which will, in turn, cause the moisture to evaporate. 

Turn off the recirculation setting

As mentioned earlier, the air inside your car contains more moisture than the outside air. 

With the recirculation button turned on, this moist air is constantly circulated inside your vehicle, and this contributes to the condensation that causes your windshield to fog up. 

So to defog, turn off the recirculation feature, hence, allowing the dry air from the outside to be drawn in. This ensures that the air inside and outside of your vehicle have equal moisture levels; hence, preventing condensation. 

Activate the defogger/defrost feature

Modern cars come equipped with automatic defrost technology. So how does this work? First, fresh air is drawn in from the outside, then passed through your car’s heating core. The resulting warm air is directed to the windshield; hence, clearing up any fog. 

The takeaway

If your windows are fogging up on the outside, the best thing you can do is to wait until the weather warms up to clear the condensation. Sure, you can try and wipe your windows down from the outside to improve visibility.

But if the conditions are the same- meaning the outdoor air is warmer and more humid than the indoor air-  condensation will reoccur. 

However, if your windows are fogging up on the inside or in between the panes, you can solve these. For inside condensation, improve air circulation within your home. And, if moisture is trapped between the panes, drill holes to get rid of it, then seal using a desiccant like silica gel. 

NOTE FROM the author

It's a pleasure to have you here! We've written helpful information on all things that make your home so very special.

If you really enjoyed this article, please feel free to check out the entire website. I'm super excited to share more content to help you unleash your home!

- Tiffany B.