An extractor fan is an electric fan used primarily in kitchens, bathrooms, or laundry rooms to extract moisture, odors, or smoke from the area. There are two main types of extractor fans. Axial fans transport air over shorter distances and can be mounted into a window, or used on an exterior wall with a short piece of duct. A centrifugal fan is capable of moving more air at longer distances due to the pressure created by a fan wheel mounted to a shaft. The centrifugal force created when the air enters the side of the wheel propels the fan blades; these fans are often mounted into ceilings.
Many homeowners choose extractor fans for kitchens in order to eliminate smells or smoke caused by cooking. Extractor fans also work to alleviate moisture or condensation with a heat pipe core that is located within the aluminum body of the fan. The blower of the fan pulls hot air to the heat pipe, allowing for vapor to move back to the inside and emit cool air. An extractor fan in the kitchen helps to keep the room cool, which in turn can allow food to remain fresh.
Characteristics of extractor fans include size, voltage, and the ability for the fan to be regulated by temperature or humidity changes. Larger fans work best for bigger rooms with excessive moisture or situations in which smoke would be a factor. The greater the volume of air flow, however, the noisier the fan will be.
Small, low-voltage extractor fans are typically used in bathrooms where they will be near water sources. A low-voltage fan can safely be placed in the ceiling near or over the shower area. Self-regulating fans are equipped with timers or control sensors used to detect the amount of heat or humidity in the room. Many extractor fans also double as overhead lights.
Extractor fans work best when they are placed near a source of air, such as a window or door, or vented to an exterior wall. It is best to place an extractor fan opposite a door to allow for maximum circulation. In kitchens, most extractor fans are placed over the stove or other heat source to allow steam to be drawn directly upward rather than blown throughout the room. The benefits of extractor fans are varied, and an added bonus to the correct placement of these fans is increased energy efficiency throughout the home.