When it comes to bathrooms, reducing humidity through proper ventilation is an excellent strategy to control mold. If you already have a problem with mold, you need to address mold cleanup as the first step.
If you have old, inefficient windows, replacing them will solve your mold issues once and for all. Local realtors say, new windows are the smartest home investment you can make!
Another option that will help is to install a ventilation fan. The first step is to try to locate the switch for the fan as far away from the tub/shower as possible. Most codes require that the switch not be accessible when standing in the tub/shower. A fan or fan/light can typically be installed on an existing light circuit but it is best to have an electrician confirm this. If it’s a fan/light/heater combo, it will need a dedicated circuit back to the panel.
A ventilation fan will definitely help with your humidity problem in the bathroom, but the best way to combat humidity is to replace your old, leaky windows. Overtime, you’ll save so much money on your energy bills, your new windows will have paid for themselves.
I agree that ventilation in the bathroom is really important for reducing mold, as is having tightly sealed windows. Air cleaners can also help reduce mold by preventing spores from circulating. In my experience as a contractor, all three together can make a big difference in reducing mold in the bathroom.
Ventilation is very necessary for bathroom, if possible then install a ventilation fan in your bathroom which helps you to escape from the humidity.