A bathroom exhaust fan can work wonders. A bathroom exhaust fan, an integral part of any home’s ventilation system, is designed to remove moisture from the air caused by steam from hot water and also help keep the air in your bathroom smelling fresh. There are several different types of bathroom exhaust fans. Most are rectangular and white or off-white, but there are some decorative fans available. Other variations include the level of noise produced, or sone rating, amount of air flow, and aesthetic design. There are also several types of add-ons that are often available with bathroom exhaust fans. A quiet fan is generally the most desirable. Manufacturers rate the quietness of a fan with a unit of measurement called a sone. The higher the sone rating, the louder the fan. It is common for quieter fans to be more expensive than louder fans, though a fan with a rating between 0.5 to 1.2 sone will probably be fairly quiet without being too expensive. A fan which has a 2.0 to a 4.0 sone rating is usually too loud for home use.