How To Reduce Condensation
The formation of condensation on interior surfaces of many new homes is dependent on a number of factors, including the outdoor temperature and the relative humidity inside the home. Improved building materials, insulation methods, and government requirements are designed for energy efficiency. While these methods save you money on heating and air conditioning, they also prevent excessive moisture from escaping. As the outside temperature falls, the indoor surface temperature of various products may fall below the interior dew point temperature causing condensation build-up on these interior surfaces, including windows, basement or crawl space walls, HVAC ducts, dryer vents, and bathroom mirrors. It is possible to experience ice or frost on these surfaces during extreme conditions, or when combined with other factors like closed window blinds or drapes. 

The major contributing factor to condensation problems is the humidity level in your home, sometimes aggravated by lifestyle and humidifiers. Temporary causes of condensation include excessive moisture during the first year due to the moisture content of concrete, drywall, paint and other building materials, changing seasons, and quick changes in temperature. Ask your builder to take extra precautions to reduce the risk of condensation in your new home. These methods include Low E* glass windows to maintain a higher glass surface temperature, and direct vent furnaces to bring fresh, dry outside air into your home.

It is your responsibility to wipe up any condensation or moisture that may settle on the surface in your home. Condensation is caused by excessive humidity in your home and is not a construction or material defect. Humidity levels can only be regulated by the individual occupants and their habits. Condensation collecting on the wood surfaces of your home can ruin the paint or stained finish and eventually cause rot, decay, mildew or mold. Condensation can also run down and damage drywall, drapes, etc.

*Low E glass may not be included in windows where building codes require tempered/safety glass. For example: Bathroom windows above tubs or glass in or beside doors. 

However, it is still your responsibility to control the humidity in your home. Your home’s warranty, the Building Industry Association of Ohio, individual product manufacturers and material suppliers, including the window manufacturer or supplier, do not warrant against condensation problems.

To control humidity levels, we suggest all of the following:

• If your home is equipped with a humidifier, maintain a low level. You must control the level in accordance with the outside temperature. We have included a chart to be used as a general guideline.

• Open drapes and blinds. When closed, they keep your window’s interior glass surfaces colder, while still allowing humid air to infiltrate around the drapes and blinds and condense on this colder surface.

• Do not use register deflectors. These prevent the warm air from circulating upward and warming window glass surfaces.

• Use bathroom exhaust fans during and up to 60 minutes after showers or baths.

• If available, run ceiling fans on low to circulate the air in your home.

• Periodically let additional outside air into your home.

• If necessary, run a dehumidifier. This is especially important in your basement during high humidity times.
  
  

Guidelines for Maximum Recommended Humidity Levels based on engineering studies conducted at the University of Minnesota Laboratories with a 70 degree Fahrenheit interior room temperature.

* Following the above guidelines does not guarantee that you will not have condensation, especially on windows and mirrors. Other factors, such as closed blinds; or temporary causes as mentioned above, may make it necessary to further lower humidity levels.