Electric Fan Glossary

Electric fans may seem like relatively simple appliances, but when it comes to choosing the right electric fan, you'll need to understand fan terminology such as RPMs (revolutions per minute) and CFMs (cubic feet per minute).  This glossary defines these terms, as well as some words commonly used in the heating and cooling industry. 

Air Change: Measures how quickly the air in an interior space is replaced by outside or conditioned air by ventilation and infiltration.  This is calculated by determining the number of times a home's air changes over with outside air. 

Air Conditioner: A device that decreases the temperature and humidity of air which moves through it via the refrigeration cycle. 

Air Cooler: Another term for an evaporative or swamp cooler.  This type of device uses simple evaporation of water to cool the air.

Air Delivery: Measures how much air is pumped out of a device in volume of air per time, either in cubic feet per minute or cubic feet per hour. 

Air Flow: Measures the flow of air, often in CFMs.  This should be carefully balanced to ensure maximum cooling efficiency and optimal operation. 

Air Mover: A type of fan often used in commercial and industrial settings for the purposes of air and gas movement; also useful for cooling or drying applications. 

Air Throw Rate: The average speed of air when it leaves the air cooler outlet or opening. 

Ambient Temperature: Also referred to as room temperature.  This is a common term used to describe a certain temperature within an enclosed space at which human beings are accustomed. 

Attic Fan: A type of ventilation fan that regulates the heat level of a building's attic by exhausting hot air. 

Axial Fan: Fans with blades that force air to move parallel to the shaft about which the blades rotate; used in a variety of applications such most household and industrial fans. 

Balancing Kit: A kit that includes a plastic clip and lead weights used to balance a ceiling fan.

Ball: Found in a ceiling fan; mounts to the mounting bracket and slides tightly into the slot located on the bracket. 

Bathroom Fan: A type of fan designed to be out of sight and anchored in a bathroom ceiling between joists; exhausted outside and used to provide ventilation, to control odors, and to remove moisture. 

Blade Arm: The metal bracket which attaches the blade to the motor. 

Blades: The flat panels in a fan that move through the air and create airflow; can be constructed out of wood, metal, or plastic. 

Blade Pitch: Measured in degrees and is the angle between the blade of a ceiling fan and the horizon; higher degree of blade pitch results in a higher amount of air movement. 

Blower: An air handling device that moves air in a distribution system. 

Blower Control: Used to describe the speed at which a blower fan rotates.  Sometimes used to describe swamp coolers, higher blower control ratings equal greater cooling effects. 

Box Fan: Device used to circulate air in order to keep it cool or to eliminate odors; consists of rotating blades encased in a square covering and remains low to the ground. 

BTU: An acronym for "British Thermal Units" and a unit of energy used in the power and heating and cooling industries.  In terms of air conditioners, this describes a unit's power and cooling capacity.  The higher the BTU rating, the stronger the air conditioner.

Canopy: The decorative cover which encloses a ceiling fan's mounting bracket. 

Capacity: The output or producing capability of a heating or cooling system; usually referred to in BTUs. 

Capacitor: A device that provides extra power to a fan's motor for needed power used to turn fan blades. 

Carbon Filter: A filter that uses a piece of activated carbon to remove odors, contaminants, and impurities; sometimes used in portable air conditioners and swamp coolers to help filter the air. 

Casters: A type of wheel; often found on the bottom of some appliances, including many types of fans, portable air conditioners, and swamp coolers for maneuverability. 

Ceiling Fan: A type of fan suspended from the ceiling of a room; employs hub-mounted paddles to circulate air in order to produce a cooling effect. 

Central Air Conditioner: A type of air conditioner that works from a central location to distribute air throughout a home or building. 

Central Diffusing Light: Provides diffused illumination; a larger diffuser creates a softer light. 

Centrifugal Fan: A type of fan that has a moving component that consists of a central shaft about which a set of blades are positioned; produces more pressure for a given volume and generally used in various industrial settings. 

CFM: An acronym for cubic feet per minute; can be used to measure the rate of air flow in a fan, air conditioner, or evaporative cooler. 

Collar Cover: In a ceiling fan, this refers to the decorative cover that hides the mounting hardware connecting the fan's downrod to the motor housing. 

Condensate: The result of condensation: the change of the physical state of aggregation of matter from the gaseous phase into the liquid phase; fans like bathroom or exhaust fans can help whisk condensate out of a room. 

Damp Location: Fans and light fixtures that are designed for areas that are susceptible to extreme weather conditions such as excessive dampness or humidity. 

Decibel: Expressed as "dB," this is the unit used to measure the intensity of a sound, and is commonly used by many home appliances. 

Dehumidification: The process of reducing the level of humidity of the air. 

Downrod: The metal pipe that extends from the ceiling bracket to the top of a ceiling fan; most fans include a downrod that's approximately 3-5 inches long, but longer ones are available for high ceilings. 

Downrod Threading: When the installation of longer downrods is needed, the threaded end is installed in the ball, which then allows the smooth end to make contact with the fan yoke to prevent wobbling. 

Duct Connector: Connects an exhaust or bathroom fan to ductwork. 

Ductwork: Channels or pipes that carry air throughout a home or building.

EER: An acronym for "Energy Efficiency Ratio."  This measures how energy efficient an appliance is; the higher the EER, the more energy efficient the unit. 

Electric Fan: An electrically-powered device used to produce airflow for the purpose of creating a cooling effect or ventilation; comes in many different varieties. 

Energy Star: Energy Star qualified appliances must meet strict energy efficiency guidelines set by the EPA and the U.S. Department of Energy and use at least 10% less energy than conventional models. 

Evaporation: The process by which water is converted from its liquid form to its vapor form; the basic working principle behind evaporative coolers. 

Evaporative Cooler: Also known as a swamp or air cooler; uses the simple process of evaporating water into the air to provide a natural and energy-efficient means of cooling; best suited for hot, dry areas with low humidity. 

Exhaust Fan: A fan that extracts air or excess heat from the interior of a home and exhausts it outside; commonly used in bathrooms (see "Bathroom Fan") and can prevent excessive moisture. 

Extended Mount: A type of ceiling fan mounting system where the fan is hung at the desired 8-9 feet from the floor for tall ceiling heights. 

Fan Coil: The indoor section of a heat pump system which is made up of a blower and refrigerant coil. 

Filter: A device used to remove dust, dirt, and other particulates from the air; frequently employed by portable air conditioners and swamp coolers to improve air quality. 

Fitter: The metal part of a ceiling fan's light kit which attaches to the fan and contains the light socket. 

Floor Fan: A type of electric fan that is placed on the floor of a home or workplace. 

Flush Mount: A type of ceiling fan mounting system where the fan is anchored directly against the ceiling. 

Heat Loss: The amount of heat lost (measured in BTUs) from a space to be conditioned due to outside temperatures and design conditions.

Heat Pump: A type of air conditioner that contains a valve that lets it switch between cooling and heating. 

Hugger: A type of ceiling fan in which the motor mounts directly to the ceiling; usually used on lower ceilings. 

Humidistat: A controller that measures and controls relative humidity; may be used to control either humidifying or dehumidifying equipment; sometimes found on swamp coolers.

Humidity: The amount of moisture in the air. 

HVAC: An acronym for "Heating, Ventilation, and Air Conditioning."  An HVAC system can also include moisture control and air cleaning. 

HVI: Acronym for "Home Ventilating Institute."  HVI is an organization that certifies and tests the ventilation performance of ventilation products such as fans. 

Ice Tank: An ice receptacle often found in evaporative coolers; used to enhance cooling and to further reduce the ambient temperature. 

Indirect Evaporative Cooling: Refers to a type of evaporative cooling system in which a closed circuit makes use of a heat exchanger and does not add any moisture into the air. 

Ionizer: A device that purifies the air by creating negative ions which remove microscopic particles; can be found in some portable ACs and swamp coolers as a way to improve air quality. 

Light Kit: Contains a light fixture that can be affixed to the bottom of a fan. 

Louvers: Horizontal slats found on portable ACs or swamp coolers for admitting cool air; if adjustable, they can provide better control of air flow. 

Misting Fan: A type of fan that utilizes evaporative cooling but also adds a fine mist of water with the air movement of the fan; primarily used in outdoor settings. 

Motor Housing: The decorative body which houses a ceiling fan's motor; shields the internal motor parts and aligns the rotor and stator within the motor. 

Mounting Bracket: Device that attaches a fan to the electrical junction box on the ceiling. 

Night Light: A small light source that is placed for comfort or convenience in indoor dark areas or areas that become dark at certain times; found in many different types of fans such as bathroom fans. 

Operating Cost: The day-to-day cost of running your heating or cooling equipment based on energy usage. 

Oscillation: Refers to swinging fans or louvers that provide enhanced cooling and fanning performance, as well as improved air circulation. 

Outdoor Air: Air that is taken from the external atmosphere and not previously circulated through the system. 

Pedestal Fan: A type of electric fan that offers the versatility of moving air at shoulder height. 

Portable Air Conditioner: Compact air conditioners that do not require permanent installation and can be moved from room to room to provide spot or supplemental cooling. 

Refrigerant: A substance that produces a refrigerating effect while expanding or vaporizing, and is used by portable air conditioners during the refrigeration cycle. 

Relative Humidity: The ratio of the amount of water vapor in the air at a specific temperature to the maximum amount that the air could hold at that temperature; normally expressed as a percentage. 

Reverse Switch: Controls a fan's motor rotation by changing the electrical current flow. 

Rotor: The moving part of a fan's motor. 

RPM: Acronym for "Revolutions per Minute."  Measures the number of full rotations completed in one minute around a fixed axis and most commonly used as measure of rotational speed of some sort of mechanical component such as a fan.  In an electric fan, this measures the speed at which a fan rotates; faster rotation equals greater airflow. 

SEER: An acronym for "Seasonal Energy Efficiency Ratio."  Rating that describes the efficiency of an air conditioner, and is the amount of cooling the equipment delivers for every dollar spent on electricity.  The higher the SEER, the more efficient the unit. 

Self-Contained System: Refers to a unit where all the components are contained within one cabinet, such as portable air conditioners and window ACs. 

Sloped Mount: A type of ceiling fan mount used for angled or vaulted ceilings. 

Sone: A subjective unit of loudness for an average listener equal to the loudness of a 1000-hertz sound that has an intensity 40 decibels above the listener's own threshold of hearing; often used to describe the sound level of many fans. 

Split Air Conditioner: A type of air conditioner that is similar to a central air conditioning unit but more affordable.  They work by splitting the hot side from the cold side of the air conditioner, and are flexible for zoning, heating, or cooling individual rooms. 

Split Capacitor: A type of fan motor that has an auxiliary winding with a capacitor, but also runs continuously; well-suited to variable speed applications. 

Standard Mount: A type of ceiling fan mounting system that usually comes with a 3-5 inch downrod (the metal pipe that extends from the ceiling bracket to the top of the fan). 

Stator: The part of a fan's motor that does not move and creates magnetic force used to drive the motor. 

Swamp Cooler: Also known as an evaporative or air cooler; uses the simple process of evaporating water into the air to provide a natural and energy-efficient means of cooling; best suited for hot, dry areas with low humidity. 

Switch Housing: The part of a fan's motor where the switches are located to change a fan's rotational direction, speed, and sometimes light. 

Thermostat: A device used for regulating the temperature of a system so that the system's temperature is maintained near a desired set point temperature; commonly found in air conditioners.

Through-the-Wall Air Conditioner: A type of air conditioner that is mounted into a wall and provides a cooling effect by exchanging inside air with outside air.

Timer: On a portable cooler, this describes a device located on the unit that is used to control the sequence of the cooling process. 

Tower Fan: A type of electric fan that is elongated in shape and fits discreetly in small spaces. 

UL Listed: A product that has been evaluated to be compliant with the standards set in place by Underwriters Laboratories, a privately owned testing and certification organization that develops standards and test procedures for products, chiefly dealing with product safety. 

Uplight: A light fixture that concentrates light in an upward position and used to create soft illumination. 

Variable Speed Motor: A type of fan motor used in some cooling systems that is designed to change its speed based on your cooling requirements.  When used in conjunction with a thermostat, this helps keep the appropriate temperature air circulating throughout your home. 

Venting: In portable air conditioners, this describes the process in which warm, humid air from the indoors is transferred outdoors via a hose and window kit; this is necessary for a portable air conditioner to cool. 

Wet/Damp Rating: Fans that are UL listed with a "damp" rating can be used in areas where the fan may come in direct contact with water; usually include features such as moisture-resistant motors and stainless steel hardware. 

Whole House Fan: A type of fan that is installed in a building's ceiling and designed to suck hot air out of the building. 

Wind Chill: The apparent temperature felt on exposed skin; electric fans create a wind chill effect as opposed to lowering temperatures directly.

Window Air Conditioner: A type of air conditioner that is installed into a window of a room and designed to cool that room. 

Window Fan: A type of fan designed to be placed inside the frame of a window; used to maintain comfortable temperatures and ventilation. 

Yoke: Connects the downrod to a ceiling fan. 

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