FAN, EMBEDDED. A fan that is part of a manufactured assembly where the assembly includes functions other than air movement.
FAN ARRAY. Multiple fans in parallel between two plenum sections in an air distribution system.
FAN BRAKE HORSEPOWER (BHP). The horsepower delivered to the fan's shaft. Brake horsepower does not include the mechanical drive losses (belts, gears, etc.).
FAN ELECTRICAL INPUT POWER (Fan kWdesign). The electrical input power in kilowatts required to operate an individual fan or fan array at design conditions. It includes the power consumption of motor controllers, if present.
FAN ENERGY INDEX (FEI). The ratio of the electric input power of a reference fan to the electric input power of the actual fan as calculated in accordance with AMCA 208.
FAN SYSTEM. Includes all the fans that contribute to the movement of air through a point of a common duct, plenum, or cabinet.
FAN SYSTEM, COMPLEX. A fan system that combines supply, exhaust and/or other fans, or is not captured by other fan system types.
FAN SYSTEM, EXHAUST/RELIEF. A fan system dedicated to the removal of air from interior spaces to the outdoors.
FAN SYSTEM, MULTI-ZONE VARIABLE AIR VOLUME (VAV). A fan system that serves three or more space-conditioning zones where airflow to each zone is individually controlled based on heating, cooling and/or ventilation requirements, indoor fan airflow varies as a function of load, and the sum of the minimum zone airflows is 40 percent or less of the fan system design conditions.
FAN SYSTEM, RETURN. A fan system dedicated to removing air from interior where some or all the air is to be recirculated except during economizer operation.
FAN SYSTEM, SINGLE-CABINET. A fan system where a single fan, single fan array, a single set of fans operating in parallel, or fans or fan arrays in series and embedded in the same cabinet, that both supplies air to a space and recirculates the air.
FAN SYSTEM, SUPPLY-ONLY. A fan system that provides supply air to interior spaces and does not recirculate the air.
FAN SYSTEM, TRANSFER. A fan system that exclusively moves air from one occupied space to another.
FAN SYSTEM AIRFLOW (cfm). The sum of the airflow of all fans with fan electrical input power greater than 1 kW at fan system design conditions, excluding the airflow that passes through downstream fans with fan input power less than 1 kW.
FAN SYSTEM BHP. The sum of the fan brake horsepower of all fans that are required to operate at fan system design conditions to supply air from the heating or cooling source to the conditioned space(s) and return it to the source or exhaust it to the outdoors.
FAN SYSTEM DESIGN CONDITIONS. Operating conditions that can be expected to occur during normal system operation that result in the highest supply fan airflow rate to conditioned spaces served by the system, other than during air economizer operation.
FAN SYSTEM ELECTRICAL INPUT POWER (Fan kWdesign, system). The sum of the fan electrical input power (Fan kWdesign) of all fans that are required to operate at fan system design conditions to supply air from the heating or cooling source to the conditioned spaces, return it to the source, exhaust it to the outdoors, or transfer it to another space.
FAN SYSTEM MOTOR NAMEPLATE HP. The sum of the motor nameplate horsepower of all fans that are required to operate at design conditions to supply air from the heating or cooling source to the conditioned space(s) and return it to the source or exhaust it to the outdoors.
FAULT DETECTION AND DIAGNOSTICS (FDD) SYSTEM. A software platform that utilizes building analytic algorithms to convert data provided by sensors and devices to automatically identify faults in building systems and provide a prioritized list of actionable resolutions to those faults based on cost or energy avoidance, comfort and maintenance impact.
FENESTRATION. Products classified as either skylights or vertical fenestration.
SKYLIGHTS. Glass or other transparent or translucent glazing material installed at a slope of less than 60 degrees (91.05 rad) from horizontal, including unit skylights, tubular daylighting devices and glazing materials in solariums, sunrooms, roofs, greenhouses, and sloped walls.
VERTICAL FENESTRATION. Windows that are fixed or operable, doors with more than 50 percent glazed area and glazed block composed of glass or other transparent or translucent glazing materials and installed at a slope not less than 60 degrees (91.05 rad) from horizontal. Opaque areas such as spandrel panels are not considered vertical fenestration.
CLERESTORY FENESTRATION. An upper region of vertical fenestration provided for the purpose of admitting daylight beyond the perimeter of a space. The entire clerestory fenestration assembly is installed at a height greater than 8 feet above the finished floor.
FENESTRATION AREA. Total area of the fenestration measured using the rough opening, and including the glazing, sash and frame.
FENESTRATION PRODUCT, FIELD-FABRICATED. A fenestration product whose frame is made at the construction site of standard dimensional lumber or other materials that were not previously cut, or otherwise formed with the specific intention of being used to fabricate a fenestration product or exterior door. Field fabricated does not include site-built fenestration.
FENESTRATION PRODUCT, SITE-BUILT. A fenestration designed to be made up of field-glazed or field-assembled units using specific factory cut or otherwise factory-formed framing and glazing units. Examples of site-built fenestration include storefront systems, curtain walls, and atrium roof systems.
F-FACTOR. The perimeter heat loss factor for slab-on-grade floors (Btu/h × ft × °F) [W/(m × K)].
FLOOR AREA, NET. The actual occupied area not including unoccupied accessory areas such as corridors, stairways, toilet rooms, mechanical rooms and closets.
FURNACE ELECTRICITY RATIO. The ratio of furnace electricity use to total furnace energy computed as ratio = (3.412 × EAE)/1000 × EF + 3.412 × EAE) where EAE (average annual auxiliary electrical consumption) and EF (average annual fuel energy consumption) are defined in Appendix N to Subpart B of Part 430 of Title 10 of the Code of Federal Regulations and EF is expressed in millions of Btus per year.
