Every bathroom needs ventilation. Usually, the best answer is a bathroom exhaust fan. Opening a window for fresh air is fine, but it's really only useful in good weather. Many bathrooms are built without any venting, so they become a welcoming sauna for unhealthy molds, mildew and fungus.
Bathroom ventilation fan prices range from the simple and cheap (about $50) to the stylish and pricey (over $200). Size matters, too. Bathroom fans are rated by CFM (cubic feet / minute). Bigger rooms need bigger fans. The basic choice is a bathroom ceiling fan.
If you need more light, choose a bathroom fan light combination. These start at under $100. If possible, add a switch for the light. For about $50 more, consider a quiet bathroom fan. A rumbling fan that no one wants to use is money wasted. Other upgrades include fan / light / heat combinations and designer grill finishes. Let your budget make this decision.
Your fan will provide step-by-step instructions. Replacing an existing bath fan is easier, since the wiring is already in place. Venting in a new location requires some careful planning. Your fan should be installed in the ceiling, between rafters or floor joists. Two critical questions:
You might have to do some drywall cutting and patching. You may also need to climb onto your roof to add a vent cover.
Your best choice is to use a timer switch so the fan will run during and after every shower. Family members should be instructed on the need to run the fan in steamy conditions.
Keep an eye on your new fan. Fan grilles are removable, and easily washed or vacuumed. Clean the fan blades and housing with your vacuum's crevice tool and a damp cloth. Most fans require no lubrication, but a spray of WD-40 won't hurt. Never exceed the bulb wattage listed, and clean dusty light bulbs to avoid heat build-up.
When properly chosen and installed, a bathroom ventilation fan will run quietly and dependably for years, helping to prevent the unpleasant results of a bathroom that's too damp.