Cooling air doesn't magically get rid of its moisture. When cooling, any water vapor above 100% RH will either condense onto the object cooling it or turn into fog / a cloud. The now-colder air has less water than before, so when it's warmed up by the windshield it can "absorb" more water.
Condensation forms when warm, humid air contacts a cold surface. Moisture is in the air all around us and warmer air can hold more moisture. As air cools, it contracts and its moisture condenses. When the temperature drops, the first place you will see any condensation is on the windows.
Warm air holds more moisture than cold air. The warmer it is, the more moisture it can hold. Heating one room, and leaving the others cold, will lead to more condensation forming in the cold rooms. If you have central heating with radiators in every room, it is best to have a medium level of heat throughout your home.
Condensation is caused by warm moist air coming into contact with cold surfaces such as windows and walls. It happens mainly during the colder months, regardless of whether the weather is wet or dry. Condensation is completely normal and is the most common cause of dampness in the home, especially in colder rooms.
Increasing the temperature in your room, particularly overnight and in the winter, will prevent the build-up of condensation on your windows and walls. This is because condensation occurs when water condenses on a cold surface.
Try to keep temperatures in all rooms above 15°C by keeping the heating on at low-to-medium levels all day in cold weather, but remember to keep a check on your meters to see how much it is costing you. Note that heating one room to a high level and leaving other rooms cold will make condensation worse.
Firstly, the colder temperatures lead to some walls in your house becoming cold themselves. These cold walls attract moisture which condenses into a liquid on their surface. At the same time, houses will typically be less ventilated because you want to keep your living space warm.
In most cases, internal condensation issues occur because of too much humidity in the room or little to no air circulation. Low internal room temperatures can also create cold surfaces (particularly on windows and exterior walls) which allows warm air to condense onto them easily.
Venting the humid air to the outside can prevent the condensation from coming back or even getting worse. The best way to remove the moist air is to use the car's air conditioning system. Part of the air conditioning is designed to cool the air, causing the moisture to condense.
It's also valuable to ventilate your property once the heating system gets turned off, whether it's opening a window before leaving the house or going to bed, it will alleviate condensation that will prevent a whole host of issues further down the line.
Probably the most effective way to tackle overnight condensation is with a Positive Input Ventilation system (PIV). A PIV draws outside air through a filtration system into a central unit installed in your house (typically in an attic). From there, the external air is evenly distributed to every room in your house.
Condensation occurs when humid, warm air becomes trapped in your home and then meets a cold surface, like a window. Opening a window allows humid air to escape from your home, thus reducing condensation.
Get a dehumidifier
In contrast to a humidifier, a dehumidifier will remove moisture in your home and absorb condensation.
The main cause of condensation is a lack of ventilation. The remedy is to improve ventilation to help equalise humidity inside and outside a property. Once upon a time, houses had badly-fitted windows, doors, chimneys and air vents that allowed for the circulation of air.
Removing condensation
Make a habit of removing window condensation first thing every morning — when it's at its worst. Use an absorbent paper towel or microfibre cloth to gently scoop and wipe the water off the surface of your windows. Use a fresh towel or a squeegee to dry the pane thoroughly afterwards.
In addition to opening windows and keeping rooms well-ventilated, investing in a dehumidifier is a good option. A dehumidifier will remove excess moisture from the air and work to prevent damp issues, but it's not a complete fix and needs to be used in conjunction with other techniques and solutions.
Mokler recommends even opening the windows for just 20 minutes a day as this can be enough to drastically reduce the effects of condensation and dampness in homes.
So how often should you open your windows? It's recommended that you do so once a day, for at least five minutes. Fifteen to 20 minutes is preferable. However, when you open them is also important.
The appearance of condensation between the panes of glass in your bedroom windows, or in any other windows in your home, indicates that the windows are not doing their job properly. The air-tight seal holding the insulating gas inside has failed, letting all the insulating gas out.
To permanently reduce and even eliminate condensation in your house, you must reduce the amount of water vapor in the air so that the relative humidity of the air in the rooms is within the normal range, between 30% and 50%. You can do this by using a high-performance indoor ventilation system.
'Salt has adsorption properties, which means that it can bind to moisture and prevent it from developing condensation. This is why salt is often used in the kitchen to stop water droplets from forming on dishes or silverware,' explains homecare expert and archeologist Barry Gray from The Tool Square.
“Cool air from an open window can help people breathe better, unless the air is very dry,” Dr. Benninger says. Fans also can dry the air, but the soothing white noise may lead to better sleep.