Attic fan
Encyclopedia
An attic fan is a ventilation fan which regulates the heat level of a building's attic by exhausting hot air. A thermostat
is used to automatically turn the fan off and on, while sometimes a manual switch is used. An attic fan can be gable
mounted or roof
mounted. Additional vents are required to draw in fresh air as the hot air is exhausted. Attic fans are typically used in warmer months, when temperatures in a building's attic
may very well exceed 120 °F (48.9 °C).
. Another popular method is to have the fan plugged into an electric socket mounted nearby. An environmentally friendly method is to wire a specialized fan to a roof-mounted solar panel.
, and is also subject to lightning
strikes if mounted on a roof
, grounding
is extremely important. On some attic fans, grounding is achieved through a screw
mounted on the thermostat box of the attic fan. The grounding wire
is attached to the box via the screw and thereby grounds the external metal components. Most modern attic fans have this as well as a grounding wire connected directly to the motor
, thereby ensuring all parts are grounded.
Thermostat
A thermostat is the component of a control system which regulates the temperature of a system so that the system's temperature is maintained near a desired setpoint temperature. The thermostat does this by switching heating or cooling devices on or off, or regulating the flow of a heat transfer...
is used to automatically turn the fan off and on, while sometimes a manual switch is used. An attic fan can be gable
Gable
A gable is the generally triangular portion of a wall between the edges of a sloping roof. The shape of the gable and how it is detailed depends on the structural system being used and aesthetic concerns. Thus the type of roof enclosing the volume dictates the shape of the gable...
mounted or roof
Roof
A roof is the covering on the uppermost part of a building. A roof protects the building and its contents from the effects of weather. Structures that require roofs range from a letter box to a cathedral or stadium, dwellings being the most numerous....
mounted. Additional vents are required to draw in fresh air as the hot air is exhausted. Attic fans are typically used in warmer months, when temperatures in a building's attic
Attic
An attic is a space found directly below the pitched roof of a house or other building . Attic is generally the American/Canadian reference to it...
may very well exceed 120 °F (48.9 °C).
Wiring methods
Attic fans may be wired several different ways. Usually the fan is hardwired directly into an electric circuit, and is controlled by a thermostat most commonly ranging from 60 °F (15.6 °C) to 120 °F (48.9 °C). It may also be hardwired but controlled by a switchSwitch
In electronics, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another....
. Another popular method is to have the fan plugged into an electric socket mounted nearby. An environmentally friendly method is to wire a specialized fan to a roof-mounted solar panel.
Grounding/earthing
Because an attic fan is made of metalMetal
A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...
, and is also subject to lightning
Lightning
Lightning is an atmospheric electrostatic discharge accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms...
strikes if mounted on a roof
Roof
A roof is the covering on the uppermost part of a building. A roof protects the building and its contents from the effects of weather. Structures that require roofs range from a letter box to a cathedral or stadium, dwellings being the most numerous....
, grounding
Grounding
Grounding or grounded may refer to:* Ground * Grounding , about the collapse of the airline Swissair* Grounding , restrictions placed on movement or privileges...
is extremely important. On some attic fans, grounding is achieved through a screw
Screw
A screw, or bolt, is a type of fastener characterized by a helical ridge, known as an external thread or just thread, wrapped around a cylinder. Some screw threads are designed to mate with a complementary thread, known as an internal thread, often in the form of a nut or an object that has the...
mounted on the thermostat box of the attic fan. The grounding wire
Wire
A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various...
is attached to the box via the screw and thereby grounds the external metal components. Most modern attic fans have this as well as a grounding wire connected directly to the motor
Electric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
, thereby ensuring all parts are grounded.