GlossaryA list of industry terms and definitions to help you brush up on your HVAC lingo!
Air Velocity (FPM) At 20 ft
Speed of the air being moved by the air circulator at a distance of 2 feet from the fan.
Air Velocity (FPM) At 40 ft
Speed of the air being moved by the air circulator at a distance of 4 feet from the fan.
Air Velocity (FPM) At 60 ft
Speed of the air being moved by the air circulator at a distance of 6 feet from the fan.
Applications/uses for a particular fan or ventilator.
Height of the curb cap on power roof ventilators.
Base Top To Shroud
Distance between the top of the curb cap to where the shroud begins on downblast power roof ventilators.
Base Top to Shroud Top
Dimension from the top of the base to the top of the shroud on a downblast exhaust ventilator.
Base/Panel Length X Width
Square base dimension on power roof ventilators. Square fan panel dimension on sidewall propeller fans.
Bore size on the bearings utilized on a ventilator.
Style of bearings that are utilized on a ventilator or a motor.
Material thickness of the blades on a particular damper.
Construction material of the blades on a product.
Curb Cap Size
Square base dimension on power roof ventilators.Tells you what size roof curb is needed.
The "ACTUAL" damper diameter. Dampers are undersized to allow them to be mounted into the duct work/wall opening.
Damper Width x Damper Height
The "ACTUAL" damper width and height. Dampers are undersized to allow them to be mounted into the duct work/wall opening.
Maximum depth of a product.
Drive Package Description
Describes whether the drive package on a particular ventilator is assembled, shipped loose, or must be provided by the customer.
Transmission type of the ventilator (belt drive or direct drive).
Portion of the curb that mounts to the roof deck.
For Use With
Describes the fans or ventilators a particular accessory can be used with.
Material thickness of the frame on a particular damper.
Construction material of the frame of a given product.
The entire area of the opening that is used for air passage. Measured in square feet.
The height of a given product.
Measure of the frequency or cycles per second.
Type of material the housing of a ventilator is constructed of.
The power required to drive an air moving device. Horsepower required varies with system conditions.
Dimension of the impeller (propeller or wheel) in inches.
Type of material the impeller of a fan or ventilator is constructed of.
Style of impeller that is utilized on a product (i.e. Centrifugal or Axial).
Describes items that a particular product includes such as mounting hardware, etc.
The diameter of the opening of a fan where air is drawn in.
Inlet Width x Height
Describes the size (width x height) of the opening where air is drawn into a ventilator.
Thickness of the insulation utilized on access doors.
Describes the length of a given product.
Max Inlet Temp
The maximum entering air temperature that a fan or ventilator can withstand while in operation, without compromising the life of the unit.
The recommended maximum speed at which air should pass through an HVAC opening.
Max. Operating Amps
The maximum amperage that a given fan or ventilator will draw while in operation.
The housing or frame of the motor.
The class of motor insulation for a given motor. The temperature capabilities of each insulation class is defined as being the maximum temperature at which the insulation can be operated to yield an average life of 2, hours (A = 15?C, B = 135?C, F =
This describes the way a motor can be mounted.
Refers to the location where a fan or ventilator can be mounted.
Refers to the orientation in which a product can be mounted.
NEMA Frame Size
Refers to a set of physical dimensions of motors as established by NEMA (National Electrical Manufacturers Association). These dimensions include critical mounting dimensions.
This dimension describes the discharge diameter of a given product.
Outlet Width x Height
This dimension refers to the size of the discharge (where air leaves the ventilator) on a particular unit.
Describes the diameter at the widest point for a given product.
Indicates the space relationships of windings and changing values of the recurring cycles of AC voltages and currents. The most common power supplies are either single- or three-phase.
Pressure Differential Max
Describes the maximum static pressure that a given damper can withstand and still be fully operational in an HVAC system.
Describes what accessory(s) must be purchased in addition to make the product fully functional.
Roof Opening Width x Roof Opening Length
Describes the size (width x lenght) of the roof opening that is required in order to properly install a given fan or ventilator.
The number of times per minute the shaft of the motor (machine) rotates. This is a function of design and the power supply.
A safety factor to be used when the load temporarily exceeds the nominal horse power rating of a given motor. When used on a motor nameplate, a number which indicates how much above the nameplate rating a motor can be loaded without causing serious degrad
Describes whether a fan or ventilator can be used with a solid state speed control. (NOTE: A speed control cannot be used with any belt-drive fan or ventilator.)
This is a feature which protects the motor from overheating and thus prolongs service life of the machine. In the event that the motor approaches overheating the thermal protection cuts power and only returns it after a cooling period.
The force that causes a current to flow in an electrical circuit. The voltage of a motor is usually determined by the supply to which it is attached. NEMA requires that motor be able to carry its rated horsepower at nameplate voltage plus or minus 1% al
Describes the width of a given product.