There is several bath exhaust fans available, most are simple white in color and square in shape, although there are fans which are more decorative. Other variables are the design aesthetics, the air flow and the noise generated while in operation.
There is little doubt that the more desirable bath exhaust fans are those which run quietly. The manufacturers of these types of fans rate the quietness of their products; the unit of measurement that is used is a “sone”. A sone does not refer directly to the volume of noise; it is a value of how sound is sensed. To put this into perspective, a quiet refrigerator will be measured at one sone and a high quality fan can be as low as .5 sone. It is common that the quieter fans will cost more than fans which are louder although a fan rated up to 1.2 sone or so will be reasonably quiet and not overly expensive, anything above that is considered too high for use in the home.
A bath exhaust fan that is functioning well with produces about 1 CFM (cubic feet per minute) of airflow for every square foot of bathroom floor space. If the bathroom was five feet x eight feet which is 40 square feet the fan should be rated at least 40 CFM. Larger baths, especially if they contain a whirlpool as well as a shower many require two fans, one at each end of the room otherwise the moisture in the bath may not be removed efficiently.
Although the objective of bath exhaust fans is to pull air out of the room they can also be fitted with other accessories. It is not unusual to see bathroom fans that have lights, heat lamps or night lights as part of the assembly. If the exhaust fan is the only light in the room then not only must the fan be chosen with volume and noise in mind, it is also important to consider the amount of light. Generally speaking a 40 watt bulb will not provide enough light. For those fans which have integral heater you can expect up to 1500 watts, if the fan is fitted with a heat lamp expect wattages from 100 to 250 as a standard.
The standard fan is square with a central light integrated into the grill. The casing color is usually white as this will blend with most ceiling colors. Decorative fans are available where the grill is made to look like a flush mounted ceiling fixture; the grills are available in a host of colors and different finishes.
