I worry about this with warm showers. My house plumbing is not made for me to be able to install a water filter. I'm surprised you did not notice this same effect with showers or baths. I suppose this is a good reason to open a window in the bathroom while showering. That would be no problem for me in the summer; but I don't like being cold in the winter. My current home does not have a vent in either of the 2 bathrooms.