Each winter, after the first really cold period, I see a lot of comments on social media about moisture on windows. I am not a scientist but I understand the basic reason for this:
In simple terms, when air cannot hold anymore humidity (vapour) it begins to turn to liquid, or sometimes referred to as “sweating” Condensation on windows is an indicator of high humidity in a home. There are many sources of humidity that can cause your windows to sweat..
If your windows are sweating (have condensation forming) then likely you have too much humidity in your house. Many people find that when they buy a new home or upgrade their old windows to new ones they get more condensation – That is true. Why?
Why new homes can have more window condensation…
Most new homes are built very energy-efficient. That means they have a sealed combustion furnace and are built very air tight. That also means minimal fresh air from outside coming in to dilute the humidity in the house.
If the house is built energy-efficient and air tight you also won’t run the furnace as much which is how you get fresh air into the home. Unless you switch on the principal exhaust fan (located in the hallway near the thermostat) you won’t be able to reduce the humidity.