A kitchen hood, exhaust hood, extractor hood, or range hood is a device containing a mechanical fan that hangs above the stove or cooktop in the kitchen. It removes airborne grease, combustion products, fumes, smoke, heat, and steam from the air by evacuation of the air and filtration. In commercial kitchens exhaust hoods are often used in combination with fire suppression devices so that fumes from a grease fire are properly vented and the fire is put out quickly. Commercial vent hoods may also be combined with a fresh air fan that draws in exterior air, circulating it with the cooking fumes, which is then drawn out by the hood. In most exhaust hoods, a filtration system removes grease (the grease trap) and other particles. Although many vent hoods exhaust air to the outside, some recirculate the air to the kitchen. In a recirculating system, filters may be used to remove odors in addition to the grease. The device is known as an extractor hood in the United Kingdom, as a range hood in the United States, and as a rangehood in Australia. It is also called a stove hood, cooker hood, vent hood, or ventilation hood. Other names include cooking canopy, extractor fan, fume extractor, and electric chimney. Description An extractor hood consists of three main components: a skirt or capture panel to contain the rising gases (also known as the "effluent plume"), a grease filter, and a fan for ventilation. Extractor hoods may be ducted (or vented) or ductless (or recirculating). Ducted hoods blow the gases to the outdoors; ductless hoods filter the air, often using activated charcoal, to remove odor and smoke particles from the air and then release the cleaned air back into the kitchen. A ducted system removes of all forms of airborne contamination, while a ductless one recirculates heat and moisture. In addition, a ducted application eliminates the need for regular replacement of the filters and avoids the airflow restriction (and the resultant loss of power) caused by them. However, the ducted application can be impractical, due to lack of space or ability to install a duct system, make-up air requirements, or the additional cost of heating or cooling the make-up air. Exhaust hoods almost always include built-in lighting to illuminate the cooking surface. Extractor hood controls are typically electronic, though some low-end models use electromechanical controls. Extractor hoods with electronic controls can offer