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How to Clean Between Double Pane Windows

How to Clean Between Double Pane Windows

The double-pane windows use two pieces of glass that have an airtight seal between them. The purpose of this seal is to lock in the air so that it acts as an insulator.

You don’t have to clean the area between these panes every other time. However, there are instances when mold appears in between the window panes and you’ll be required to find a way to remove it.

Double pane windows get cloudy when dirty or mold starts building up between the double panes. You’ll not only find it difficult to see outside clearly, but the windows will not allow in much light either.

So, how can you clean double paned windows? Here are two ways to go about it:

Method #1: Drilling holes

This option involves the drilling of one or several holes into the glass in order to place small desiccate packets that absorb moisture that forms between the glasses. Desiccate packets will help clear the fog or condensation.

The holes can also be used to help rinse the dirt out hence clearing the fogging. Isopropyl alcohol is the best for rinsing dirt from the inside of a double pane window.

At times rinsing does not remove the dirt from between the window panes. In this case, you need to fashion a device that can thread through the dirt build up.

Check this too: How Do Self Cleaning Ovens Work?

You can use a pair of wool pantyhose on a drain snake or a sock duct tape on a piece of wire.

There is one more method you can try before you remove the glass from your double pane window. Point a fan towards the drilled holes.

Doing so will increase the air flow between the window panes thus causing the moisture to evaporate. This option only removes moisture.

Not knowing where the seal has broken will cause the problem to continue. Don’t cover the drilled holes as you will need them to clean the window again in the near future. Needless to say, sealing the drilled holes will seal moisture inside.

Method #2: Without drilling

If you are looking for an alternative way on how to clean fogged double pane windows without drilling, there are a couple of things you can try.

If dirt is not a problem, these three methods will be very effective when it comes to the cleaning of double hung windows from inside.

  • The first option is to place a dehumidifier close to the window that needs cleaning. It doesn’t need to be a huge dehumidifier. The dehumidifier will clear the fog in your double paned windows.
  • Laying moisture absorbent along the bottom edge of your window will also help. You can use desiccate packets or a water snake.
  • Place a heater near the affected window or point your hair dryer towards it. This will cause the moisture between the panes to evaporate.

How to Remove Haze From Double Pane Windows

Cleaning haze from double pane windows is not a simple task. However, you can start the process by placing a dehumidifier next to the foggy windows and see if the machine can remove the moisture trapped inside. 

If the above doesn’t work, you can also drill a tiny hole at the top of the window, if possible without cracking the frame, and then use a drain snake wrapped with pantyhose. You can also use this method to clean the inside of the window. 

Wrapping a hanger with a thin cloth or pantyhose is also effective in cleaning the window’s surface. Alternatively, you can also try using a turkey baster to drip in a few drops of rubbing alcohol. The alcohol will help clean the glass and help remove the moisture in between the glass panes. 

Why Is There Condensation Inside My Double Pane Windows? 

Condensation is most likely to form inside a single glazed window because there’s only one pane of glass separating the inside and outside temperatures. Therefore, double pane windows have become popular due to their superior insulating qualities. 

However, condensation might still occur on double pane windows, especially if they’re old or suffering from damaged window seals. If you don’t take prompt action, condensation might reduce your window’s lifespan, especially if the sealed unit sits in a substantial amount of water for a long time. Additionally, the moisture can also encourage mold growth, leading to frame damage. 

The main areas where you can get condensation in double pane windows are:

  • On the inside pane of your window.
  • Inside the ‘air gap’ between the two panes of glass.
  • On the outside window pane. 

Condensation on the Inside Pane of Your Window

Internal condensation often occurs when there’s little to no air circulation or too much humidity in the room. Low internal room temperatures often create cold surfaces on windows, allowing warm air to condense onto them easily. 

If your property has recently undergone major construction work, you should expect high moisture levels due to drying concrete, wet plaster, or paint. Sometimes these cases might take as long as six months or a year to dry out thoroughly.

If your home is suffering from condensation, it’s best to use a towel or cloth to wipe it off as soon as possible because allowing it to sit on the surfaces will eventually cause mold, damage, or rot. 

How to Deal With Condensation on the Inside Pane of Your Window

Improving air circulation is the best way of dealing with condensation on the inside pane of your window because doing so will reduce humidity and help clear moisture in the room. 

You can also keep your property at a constant and reasonably warm temperature to reduce the number of cold surfaces and make it harder for condensation to form. 

When cooking, cover pans or pots with a lid to reduce water vapor. Opening a window or using an extractor fan will also help remove moist air. 

Inside the ‘Air Gap’ Between the Two Panes of Glass

Double pane windows will deteriorate over time, depending on their build quality. When this happens, the seal around the two panes, which creates ‘the sealed unit,’ might start to degrade and crack. This cracking allows moist air (condensation) to get into the ‘air gap’ between the two panes of glass. 

On poorer quality or older windows, the sealant used to create the seal might be of a low grade or become loose over time. This deterioration can cause water to get into the frame. When large amounts of water settle in the frame for a long time, it will eventually affect the ‘air gap’ seal surrounding the two panes of glass. 

Condensation might also happen in double pane windows due to a fault with the ‘spacer’ bar. Most double pane windows have a ‘spacer’ in between the two panes of glass, and this is full of desiccant, a highly-absorptive material that sucks up any moisture in the ‘air gap’ void. 

If there is even the slightest imperfection in the seal, the desiccant can quickly become saturated by any moist air or water entering. When it can’t retain any more, the moisture appears like condensation. The issue might have been there for some time but only becomes apparent if the desiccant is no longer doing its job. 

How to Deal With Condensation Inside the ‘Air Gap’ Between the Two Panes of Glass

If you’re experiencing condensation between the two panes of glass, it’s most likely that the seal has completely failed. The likelihood is that the units have deteriorated until they aren’t doing their job correctly.

If you want to fix the issue, it’s best to understand that the cause will determine the solution and expense. However, you might consider these fixes:

  • Repairing 
  • Replacing

If the uPVC units are in good condition, you might replace the sealed units. In most cases, the process might involve drilling a hole into the ‘spacer’ bar or glass pane unit. A special drying agent or desiccant is then injected or pumped to dry out the air or expel the condensation within the unit. 

Sometimes you might use an anti-fogging agent to prevent the build-up of any further moisture before the unit is completely sealed again. 

If you’re thinking of a repair instead of a replacement, it’s best to remember that the seal’s failure is the most likely cause of the issue. Resealing might solve the problem but will not address the core issue. Also, before undertaking a repair, it’s best to consider whether the benefits and their expected life cycle will fully justify the expense involved.

Replacing is a more expensive solution; however, it might offer better value for money in the long term if you can afford it. 

If you’re experiencing condensation in your double pane windows and you’ve had them for less than ten years, you could check to see if your windows are under guarantee. If they are, get in touch with the company that installed them and report the problem. If the unit or seal is defective, they should replace for free. Don’t be tempted to tamper with the units or attempt to repair yourself because doing so will invalidate your guarantee. 

Condensation On the Outside Window Pane

Condensation on the outside windowpane isn’t an indication that there’s anything wrong. It often happens because the external air is warmer than the temperature of the glazed pane’s surface and the dew point of the air is higher. 

This type of condensation often occurs at night or early in the morning when temperatures are low, mainly if there’s a clear sky and almost no wind. 


If you want to deal with the issue, it’s best to allow more wind and air to flow past the windows to reduce the chances of condensation forming.

If you want to prevent the window’s surface area from cooling to the point where condensation forms, you could consider creating more shading areas, as doing so might help retain warmth. You can position tall trees, plants, shrubs, or some form of shelter to help you do this. 

Can Double Pane Windows Be Resealed?

While you can temporarily defog your double pane windows and attempt to block out any further moisture, it’s best to understand that resealing might not restore the window to its original energy efficiency. So you might have to replace the window instead.

Defogging a window can be tricky because there’s no easy way to wipe away the moisture or condensation as you would on the exterior sides of the glass. Adding more desiccant is a possible solution to the problem; however, it’s only a temporary fix because desiccant absorbs as much moisture as it can before more gets between the panes of glass. 

Check this too: How to Clean Dirty Blinds

How to Prevent Condensation from Forming Between My Double Pane Windows

You can prevent condensation in double pane windows by increasing indoor air circulation. For example, every time you cook or shower, you could turn on the kitchen or bathroom fan for at least fifteen to twenty minutes. 

It’s also advisable to use ceiling fans to reduce condensation in double pane windows, even during winter. For example, you could set them to rotate in a clockwise direction, which will push warm air downward.

It’s also best to manage humidity inside your home. Therefore, if you notice a humidity problem in your home, it’s best to try a dehumidifier, which takes in air, sucks out the moisture, and releases it back into your home.

You can also prevent condensation by simply keeping the windows open whenever the weather allows. Doing so will help release the warm, moist air trapped in the house. 

Learning how to clean between double pane windows will only give temporary results until you fix the broken seal or replace the window. Additionally, if the window is old or the seal is severely damaged, it is best to just replace it.