Window Condensation | Heating and Air Conditioning

Window Condensation | Heating and Air Conditioning

WindowCondensation | Heating and Air Conditioning

Windowcondensation forms when warm, moist air meets the cooler surface of the window. Themoisture in the air causes condensation, and the draft free, energy-efficientwindows just installed may be the cause. As homes grow tighter and more energy-efficient,window condensation becomes a wider problem. The proper performance of a home’sheating and air conditioning system can assist in humidity control,while other actions may be required in high humidity conditions.

Modern construction methods, including new windows, are designed to keep outdoorair outside, and warm moist air inside. Older windows were less efficient,allowing air circulation, and moisture to escape. High quality windows andinsulation all create barriers to the circulation of air in an energy-efficienthome. When combined with the additional moisture from hot showers, cooking, orfrom clothes dryers not vented to the outside, excess moisture accumulates anda high relative indoor humidity level occurs – along with window condensation.

Treating Condensation

Treating condensation requires controlling the indoor humidity. Opening awindow briefly is a quick temporary solution in a moisture-filled room, such asa bathroom after a shower, or the kitchen while cooking. The open window willallow the moist air to escape. For moisture problems throughout the home,cracking a window may help, although that is not an attractive option duringextreme cold temperatures.

Use the exhaust fan when cooking or showering, and allow the bathroomexhaust fan to run for 20 minutes minimum after a steamy hot shower. However,this only works if the fan exhausts to the outside. A recirculating fan onlymoves air around and does not exhaust moisture.


Dry winter air can cause sore throats, bloody noses, dry, itchy skin anddry mucous membranes, increasing your vulnerability to illness, especially theflu. A humidifier can assist you with this, but may contribute to windowcondensation. Generally, when using a humidifier an ideal humidity is 30 to50%. If use of a humidifier is a necessity for family members with asthma, allergies,or other respiratory conditions, and your setting is currently set at 50%,reduce humidity to 40% and check the windows for condensation. However, do notgo below 30% to maintain the health benefits.

Furthermore, ensure your whole house humidifier has a humidistatto ensure accuracy. Our certified heating and air conditioning expertscan provide the solution you need.

If you are using a portable humidifier, and the windows with condensationare in the same room, the portable humidifier is likely the problem. Tryturning it off and watch the windows. A whole house humidifier is thebetter option for a consistent humidity throughout your home. In homes withconsistently high humidity, a dehumidifier may be your best option. Our heatingand air conditioning experts can determine the cause of excessive humidity,and provide a solution.

Plants BreathToo

Many plants in the home can increase humidity. Place them in a sunroom oran infrequently used room during extremely cold weather.

When your moisture problem is in a basement, consider adding waterproofingprotection to basement floors and walls.

Gas heat is moist heat; ensure your gas furnace is ventilated.Older styles of gas heaters may not be, consider replacing them for a modern,safer and ventilated source of heating and air conditioning.

Window condensation should only be occurring when there are extremedifferences in indoor and outdoor temperature. During the winter, condensationis on the inside of the glass, while during the summer it will be on theoutside of the glass. When condensation occurs between the two layers of glassin an insulated window, the airtight seal has probably failed, and repair willbe required.

Moisture on the ceiling or walls, peeling paint, rotting wood, andfungus, mold or mildew are signs of a serious moisture problem. If these signs occurin your home, contact a Cypress Heating and Air Conditioning expert for adiagnosis and solution.

·     Do not lower the thermostat below 68degrees. Heat all the rooms of your home evenly.

·     Cover pots when cooking to minimizefilling your kitchen with steam. An added benefit is you will be able to turnthe burner down, and save energy.

·     Take shorter showers, and gain the extraadvantage of saving water and energy.

·     In the laundry room, ensure that the dryervent is properly sealed and directed to the outdoors. Do not hang wet clothesup to dry.

·     Minimize the use of the fireplace, woodgives off moisture as it burns.

·     Ensure routine maintenance of the heating and air conditioning system forproper performance. In terms of humidity and safety, this is especiallyimportant when your home heating is fueled by humidity-producing natural gas.

·      Contact your heating and airconditioning technician for theinstallation of a dehumidifier when the problem is severe.

·      Ensure the moisture problem is not due to water accumulation in thebasement. If water accumulation or flooding has occurred, contact a plumber forsump pump installation to assist in keeping your home dry, and to prevent moldand mildew due to a wet basement.

If you are experiencing window condensation, or need heating and air conditioning repair,maintenance, or heating and airconditioning installation, contact a Cypress Heating and Air Conditioning professional. Our certified heating andair conditioning technicians serve Katy, Plano and the surrounding areas,and are a member of the BBB with a consistent A+ rating.