An extractor hood consists of three main components: a skirt or capture panel to contain the rising gases (also known as the "effluent plume"), one or more grease filters, and a fan or tangential blower for forced ventilation.
There are 2 major applications of extractor hoods: ducted (or vented) application, and ductless (or recirculating) application. In a ducted application, the output collar of the extractor hood's blower motor is attached to a duct system, which terminates outside of the residence. In a ductless application, a filter containing activated charcoal is used to remove odor and smoke particles from the air, before releasing the cleaned air back into the kitchen environment.
A ducted application is generally preferable, since it allows for removal of all forms of airborne contamination, while ductless application recirculates heat and moisture into the kitchen environment. In addition, a ducted application eliminates the need for replacing the activated charcoal filters on a regular basis, and avoids the airflow restriction (and resultant loss of power) caused by activated charcoal filter placement. However, some kitchen environments do not allow ducted application, due to lack of space or ability to install a duct system, make-up air requirements, or the additional cost of heating/cooling the make-up air.
Some range hood designs allow for both types of applications, and are typically noted as such in the manufacturer's product literature.
Exhaust hoods almost always include built-in lighting (incandescent, fluorescent, or halogen) to illuminate the cooking surface. In addition, some manufacturers offer matching accessories, such as: backsplash panels, shelf units, dish racks, and other attachments, allowing a greater flexibility of design.
The invention of various forms of extractor hood in mid 20th century allowed for the reintroduction of the Farmhouse kitchen into popular architecture.
Today's major manufacturers of extractor hoods include: Broan, Elica, Faber, Futuro Futuro, Gaggenau , Independent, and Vent-A-Hood. Each of those manufacturers offers a distinctive style, selection of materials, and price range. In addition, some of these manufacturers offer proprietary technological advances, such as:
Elica's "Elica Deep Space" noise reduction system
Futuro Futuro's "FaSteel" fingerprint-free stainless steel
Gaggenau's "Coanda Effect" airflow direction system
Vent-A-Hood's "Magic Lung" baffle filter/blower system
Extractor hoods may be made from a variety of materials, including: copper, steel, tempered glass, wood, aluminum, brass, heat-resistant plastics, and more.
Control systems for extractor hoods are typically electronic in nature. However, electromechanical controls (relatively rare on mid-market and high-end models) exist as well. Extractor hoods with electronic control systems may offer one or more of the following features: remote control, motorized height adjustment, thermal sensor, overheat protection, boost mode, delayed shut-off, filter cleaning reminder, active noise cancellation, temperature display, user presets (memory), or a combination of the above.
Prices for residential extractor hoods can range from US $100 to US $20,000 or more for custom-built models. The majority of products is located in the US $400 - US $2500 range (according to results from major online sources, including Google Base, Epinions.com, PriceGrabber.com, and other popular review sites.)