There is no room in the house that needs ventilation more than a bathroom and the best solution are ceiling exhaust fans. When the bathroom is being used for a shower or bath there are high levels of humidity, it is this humidity that provides an ideal breeding ground for mold and mildew. It’s not just the mold and mildew that’s the problem, when the walls and ceiling of the room are exposed to high humidity over an extended period of time the walls can begin cracking, paint will peel, doors will warp and jamb and fixtures will begin to rust. Before you know it you will be facing a major renovation rather than a simple installation of a ceiling exhaust fan.
How does it work?
There are actually two types of fans that can be used in any room but in a bathroom the most common type of ceiling exhaust fans are axial fans. An axial fan is one which uses a propeller to move the air, similar in construction to a floor fan or desk fan that you may have in your home. These fans are designed to move lots of air but with little pressure. An axial fan is also cost effective when compared to a centrifugal fan which is designed for higher pressure which is rarely needed in a bathroom situation.
Although it may be called a ceiling exhaust fan it also can be installed as a through the wall fan. They are designed to extract the hot, muggy air from the bathroom and exhaust it outside allowing for a fresh air replacement. Ceiling exhaust fans are installed in conjunction with a section of duct that leads to the outside of the home. Because of the low pressure that is developed by an axial fan the duct must be as short and straight as possible. In days gone by the fan simply deposited the air in the attic or the space between the joists in the ceiling but all that did was to transfer the problem to a different part of the house, today this practice is prohibited by current building codes.
Using the fan:
When you are finished in the bathroom do not turn the fan off as you leave the room, let it run for another half hour or so as removing all the humidity takes a little time. When you purchase a high quality ceiling exhaust fan there will be very little noise so you don’t have to worry about that. In many cases people install a timer so that that the fan turns off in 30 minutes after they leave the room.