Condensation

What is condensation?

Condensation is the moisture that is evident on the glass of your windows. This is the same moisture that appears on the outside of a cold glass during the summer. Condensation is actually the result of high humidity levels in your home. It generally appears as moisture or ice on the interior panel of glass on your windows. The problem is more prevalent on the glass of your windows because the surface condenses more visibly. This means that the glass has the lowest temperature of any visible surface in your home. It needs to be noted that if moisture is visible here, it could be happening elsewhere as well. Problems such as peeling paint, rotting wood, mildew or moisture spots are typical symptoms of condensation.

We have compiled some possible solutions for your condensation problems. Please use your judgment as to which solutions may apply to your home. Remember, the windows are not the cause of condensation, they are simply an indicator of a larger problem.

Humidity

Humidity is the amount of moisture in the air. It may come from various sources. Your home needs a certain amount of moisture, but deciding how much you need is a critical decision.

The following chart will help you with the moisture level of your home; reducing humidity while maintaining comfort. The chart is based on the inside relative humidity for a 70° indoor temperature.

It's Cause

The cause of the condensation is extreme moisture in the air. When warm air meets a cooler surface, it condenses. This creates the visible moisture you see on the surface of your windows. Condensation also occurs when the flow of warm air is restricted from reaching window surfaces.

Too Much Humidity

If there is moisture on your windows, it is important to check your entire home. Problem areas could reveal themselves as damp spots on ceilings and walls. The end result could be the moisture passing through the walls, insulation, and to the exterior walls. This could eventually cause structural problems if left untreated.

Location & Time

Some regions are more prevalent to condensation than others. Generally areas that reach 35° Fahrenheit or below in the winter months are more susceptible to condensation.

Interior condensation is more likely in the winter months. This happens when moisture in the air contacts a surface whose temperature is lower than the dew point (the temperature in which air manufactures dew).

Exterior surface condensation usually occurs on warm, humid summer days. An example would be that moisture forms on the outside of a window in the summer when an air conditioner is being used in the home. This creates a surface temperature of the glass below the dew point.

New Home vs. Old Home

You tend to see less condensation in older homes. People were not so concerned about humidity levels or energy efficiency, of a home years ago.

Today new homes are manufactured more airtight. This leaves the moisture trapped or locked in the home. Condensation is common during the drying-out process, which commonly lasts between 6-18 months in new homes. The products that went into constructing your home contain moisture (water): i.e. wood products, concrete. etc. This moisture comes out of your walls by evaporation and stays trapped in your home especially during the winter months as the windows in your home are not regularly opened to enable fresh dry air to enter you home.

Measuring Humidity

An easier way for the average person to monitor humidity is to watch for the obvious signs in your residence. When you see the start of condensation on your windows, this is a sure sign that your humidity is reaching a level that could be too high. You may also wish to purchase a hygrometer, which will measure relative humidity.

Remember that watching the humidity level on the news has no bearing on the levels in your home. This is a humidity reading for the humidity in the air outside.

Reducing Humidity

You must get rid of this excessive moisture, as it will cause ‘excessive sweating’ or ‘ice build-up’ on your windows. ‘Excessive sweating’ and ‘ice build-up’ occurs when moist air is trapped on the inside of your windows and is not circulated and thus condensing or freezing due to the cold temperatures on the outside of your windows. Most of the problems associated with water or ice on your windows are due to excessive moisture in the home rather than from broken windows seals or broken glass.

Reducing the moisture in the home and replacing it with fresh drier air solves the problem. Please follow these steps if you are experiencing ‘excessive moisture’ or ‘ice build-up’ on your windows.

• If you have a humidifier, turn it OFF until you gain control of the moisture problem.
• Do not have drapes or blinds covering your windows entirely. They must be up a minimum of 6 inches from the bottom of the window and opened. This will enable warm air to circulate on the inside of the window. Remember that just as the windows are not the cause of condensation, neither are the curtains nor the blinds. They are merely another contributing factor to a condensation problem. The condensation is more likely to occur when window coverings are too tight to the windows- constricting the flow of warmer air.
• Your window coverings (drapes, blinds, etc.) must be up throughout the entire day, most importantly throughout the night.
• Use your principal exhaust fans (main bathroom, kitchen fans, etc.) with the doors to the bathrooms open, for continuous periods daily up to 4 hours. This will get rid of the moisture saturated air in your home.
• If moisture still persists around your windows after you have followed these steps, you will need to use a de-humidifier placed in your basement to remove the water in your air.

Temporary

Your condensation problem may be only a temporary situation. Below, we have outlined three examples of this.

The first is when a new home is built. A great deal of moisture is released from the building materials such as wood, concrete or plaster. During the winter months, the moisture will be discharged in to your home. This circumstance usually occurs only during the initial heating season.

The second is during the initial heating months of the winter. This is simply humidity stored in your home. This symptom should gradually dissipate during the season.

The third is a severe, rapid change in the temperature over a short period of time during the winter.

Summary

This is a general overview of the condensation problem and may not apply to every person or situation. The main thing to remember is that condensation is levels of high humidity in your home.

It is important that you, the homeowner, learn how to practice controlling and removing the moisture in your new home. It is not the builder’s responsibility.

Remember, run the ventilation fans in your home as much as possible and ensure your window coverings have access to heat and air flow. Open them up and raise them 6” from the windowsill and measure your humidity (if possible) on a regular basis.