Bathroom condensation.

[mr.bungle]

My girlfriend always tells me to have the window open in the bathroom when having a shower to let the steam out. I say the cold air coming in Especially this time of year will cause more. Who is right please?

[sarnieken]

Condensation is caused when moist warm air comes into contact with a cold surface such as a window. Opening the window will allow the room to cool down faster so your condensation will be reduced.
You will, however, end up with a cold bathroom.
hope this helps,
ken

[mr.bungle]

Thanks Ken. That helps but also makes her right. Again.

[mibn2cweus]

Although it is true that a volume of cold air is more easily saturated with water vapor these molecules move very fast and there is a virtually limitless volume of air outside for the vapor to mix with.

more info

[mibn2cweus]

Of course if its raining/snowing outside the outside air may be saturated as well

[joko]

fit an extractor fan, or open the window when you have finished, or turn on a heater in the room to dry out the room,

[CT]

Open the window once you're finished.