Condensation in Double Glazed Windows: Causes and How To Prevent It

When assembling a double glazed unit, careful steps are taken.

Two glass panes are affixed to a hollow spacer bar, often appearing as a silver or occasionally black strip within your windows. This spacer bar is partially filled with a silica desiccant, akin to those small packets of silica beads found in shoeboxes.

The purpose of this desiccant is to extract moisture from the air that becomes trapped between the two glass panes. Without this desiccant, the moisture within this confined space would condense, leading to fogging on the interior of the glass.

Over time, the poly sulfide adhesive bonding the glass panes to the spacer bar may deteriorate, allowing external air to infiltrate. In instances such as this double-glazed unit, you may notice a small gap where the glass separates from the spacer bar.

When this occurs, both air and moisture infiltrate the gap, entering the space between the two panes.

The desiccant has a finite capacity to absorb moisture, and when it reaches its saturation point, moisture begins to accumulate between the glass panes.

The extent of this depends on external temperatures. Generally, during warm weather, the moisture between the panes evaporates, seemingly eliminating condensation.

However, as temperatures drop, it re-condenses. This cycle of evaporation and condensation results in the unsightly staining between the panes.

The severity of staining typically corresponds to the amount of moisture infiltrating between the panes, as seen in this example of a double-glazed unit.

Regrettably, once the seal has deteriorated, the only practical solution is to replace the entire double-glazed unit.

How To Fix Window Condensation in Double Glazed Windows

Now that we know the cause, let's discuss some practical solutions to fix window condensation in double glazed windows.

Install an Exhaust Fan

Installing an exhaust fan in high-moisture areas of your home can significantly help reduce condensation. These fans work by expelling excess moisture, ensuring that the air inside your home remains at an optimal humidity level.

Adjust Humidifier Settings

If you're using a humidifier in your home, consider turning it down to decrease indoor humidity levels. While humidifiers are essential for maintaining indoor comfort during dry winter months, excessive humidity can contribute to condensation issues.

Choose the Right Double Glazed Windows

Replacing your windows may seem like a solution, but it's crucial to choose the right ones. Surprisingly, if you replace your windows with ones that have better sealing but the same insulation value as the original ones, you might actually increase window condensation.

This is because new windows tend to reduce air leakage and natural ventilation, creating an environment where condensation is more likely to occur.

To make an informed decision, opt for windows with a higher R-value.

These windows are more effective at handling humidity and preventing condensation from forming. While they may be an investment, they will ultimately provide better long-term results.

While there are videos on YouTube demonstrating individuals drilling holes in one of the glass panes to wash out stains or disassembling the unit for glass cleaning, desiccant replacement, and re-gluing, these methods are unlikely to be more cost-effective or efficient than having a new double-glazed unit manufactured and installed.

By taking proactive measures like installing exhaust fans, adjusting humidifier settings, and selecting the right windows, you can effectively address and minimize condensation buildup in your home.

Remember that maintaining the ideal indoor humidity level is key to ensuring your home remains comfortable and condensation-free.

Invest in the best windows you can afford to enjoy a warm, dry, and condensation-free winter season.

JRC Glass Solutions offers the best double glazed windows in Brisbane. We use the highest quality glass materials sourced from industry-leading glass manufacturers to ensure the quality of our glass is at the highest level.

If you are looking for double glazing in Brisbane, contact our glaziers today. We offer free quotes and consultations and are always happy to help. Call us today!

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