Fab:  Fabrication fabrication area (e.g., in electronics industry).

Fabric Filter: A cloth device that catches dust particles from industrial emissions.

Facade: The front of a building. Frequently, in architectural terms an artificial or decorative effort.

Face Brick: Brick made especially for exterior use with special consideration of color, texture and size, and used as a facing on a building.

Face Glazing: A system having a triangular bead of compound applied with a putty knife, after bedding, setting, and clipping the glazing infill in place on a rabetted sash.

Face Velocity: Air velocity at the cabinet work opening, velocity of the air entering the cabinet at the work opening.

Faced Concrete: To finish the front and all vertical sides of a concrete porch, step(s), or patio. Normally the “face” is broom finished.

Faceguard:  A screen affixed to the face of a filter unit to protect it against damage caused by mishandling.

Facepiece:  That portion of a respirator designed to make a seal with the face or to cover the head; they may be tight-fitting or loose-fitting; see also mouthpiece, quarter-mask, half-mask, full facepiece; hood, helmet.

Facing Brick: The brick used and exposed on the outside of a wall. Usually these have a finished texture.

Factory Mutual (FM): Insurance agency that has established stringent guidelines for maximum construction integrity as it relates to fire and environmental hazards. Their specifications have become industry standards.

Factory Serviced:  A product returned to the factory where it was repaired of any defects, thoroughly tested, and then repackaged in a factory carton.  The defects were spotted by a dealer who sent the product back to the manufacturer or the product was damaged in shipping.  Most of our factory serviced items come with an exclusive ABC warranty.

FAD:  Free air delivery. Air at the atmospheric conditions of the site and unaffected by the compressor. Flow is measured at the discharge valve of the compressor, after the aftercooler, the water separator and built in check valve. Capacity and power consumption are corrected to ISO 1217 standard reference conditions: Ambient temperature = °20C, Ambient pressure = 1 bar(a), Relative humidity = 0%, Cooling water/air = 20°C, Effective working pressure at discharge valve = 7 bar(a).

Fahrenheit: A temperature scale used in the United States and a few other countries. On the Fahrenheit scale, water boils at 212 degrees and freezes at 32 degrees.

Fahrenheit Scale:  The temperature scale that places the boiling point of water at 212’F and the freezing point at 32’F.

Fail Safe:  A design to give equipment the capability to fail without producing an unsafe condition.

Fail Safe Control:  A device that fails in the open or safe position if and when it ceases to operate.

Fall/Flow: The proper slope or pitch of a pipe for adequate drainage.

Family Unit: All persons living together in a dwelling unit.

Fan:  A device used for moving or producing artificial currents of air.

Fan or Propeller Fan:  An air moving device typically used to move high volumes of air against low static pressure systems. Fans occupy minimal cabinet space and will move a substantial volume of air where flow is virtually unimpeded. Packaged fans can be used for filtered panel or rack-mounted cooling in such applications.

Fan Capacity: Performance requirement for which a fan is selected to meet specific system calculations given in terms of ACFM at the fan inlet.

Fan, Centrifugal:  A fan rotor or wheel within a scroll type housing and including driving mechanism supports for either belt drive or direct connection.

Fan Class: Operating limits at which a fan must be physically capable of operating safely.

Fan Coil Unit (FCU):  A small packaged unit for both heating and cooling one zone.

Fan Control: A bimetal thermostat that turns the furnace blower on and off as it senses the presence of heat.

Fan Cycling:  The use of a pressure control to turn a condenser fan on and off to maintain a correct pressure within the system.

Fan Laws:  A family of mathematical relationships that allows the calculation of new operating characteristics from known system conditions.

Fan Performance Curve:  Fan performance curve refers to the constant speed performance curve. This is a graphical presentation of static or total pressure and power input over a range of air volume flow rate at a stated inlet density and fan speed. It may include static and mechanical efficiency curves. The range of air volume flow rate which is covered generally extends from shutoff (zero air volume flow rate) to free delivery (zero fan static pressure). The pressure curves are generally referred to as the pressure-volume curves.

Fan Relay Coil:  A magnetic coil that controls the starting and stopping of a fan.

Fan Static Pressure:  The pressure added to the system by the fan. It equals the sum of pressure losses in the system minus the velocity pressure in the air at the fan inlet.

Fan, Tubeaxial:  A propeller or disc type wheel within a cylinder and including driving mechanism supports for either belt drive or direct connection.

Fan, Vaneaxial:  A disc type wheel within a cylinder, a set of air guide vanes located either before or after the wheel and including driving mechanism supports for either belt drive or direct connection.

FAQ:  Stands for “frequently asked questions.”

Farad:  Unit of electrical capacity; used to value capacitors.

Faraday Cage:  A cage made of conductive material. Static fields and discharges do not pass through it. Electromagnetic energy passing through the skin or shield is attenuated to varying degrees.

Faraday Experiment:  Silver chloride absorbs ammonia when cool and releases it when heated.

Fascia: A flat, horizontal board enclosing the overhang under the eave.

FaST™:  Tennant’s proprietary, self-collapsing foam scrubbing technology leaves just-scrubbed floors immediately clean, dry and safe for traffic. The Safe Scrubbing Alternative® uses 70 percent less solution to attract and remove soil while also removing old, slippery detergent residue to increase floor traction by up to 21 percent (NFSI certified). As less water is used, less waste water is created. Only FaST creates cleaner, safer floors that help reduce the risk of slip-and-fall accidents.

Fast Food Freezing:  A freezing method that uses liquid nitrogen or carbon diox­ide to turn fresh food into long lasting frozen food.

Fasteners: A general term covering a wide variety of screws and nails, which may be used for mechanically securing various components of a building.

Fatigue:   Physical or mental exhaustion; weariness; tiredness.

Fatigued:  A structural failure of the filter medium due to flexing caused by cyclic differential pressure.

Faucet: A device for regulating the flow of a liquid from a reservoir such as a pipe or drum.

FC: Fan wheel design using forward-curved blades.

FDA:  Food and Drug Administration.

FDA cGMP:  Food and Drug Administration Current Good Manufacturing Practices.

Feathering Strips: Tapered wood filler strips placed along the butt edges of old wood shingles to create a level surface when re-roofing over existing wood shingle roofs. Also called “horsefeathers.”

Fecal Coliform:  A sub-classification of the total coliform group.  Fecal coliforms are characterized by facultative anaerobic, gram negative, non-spore forming, rod shaped bacteria that ferment lactose with gas and acid formation within 48 hours at 44.5◦C.  Fecal coliform bacteria are primarily found in the intestinal track of humans and warm-blooded animals.

Fecal Coliform B:  Bacteria found in the intestinal tracts of animals. Their presence is an indicator of pollution and possible contamination by other pathogens.

Feces (Dust-Mite or Bedbug):  Excrement of these small parasite insects. Has been shown to be a powerful factor in allergies. 

Federal Clean Air Act (FCAA): A federal law passed in 1970 and amended in 1974, 1977 and 1990 which forms the basis for the national air pollution control effort. Basic elements of the act include national ambient air quality standards for major air pollutants, mobile and stationary control measures, air toxics standards, acid rain control measures, and enforcement provisions.

Federal Implementation Plan (FIP): In the absence of an approved State Implementation Plan (SIP), a plan prepared by the U.S. EPA which provides measures that nonattainment areas must take to meet the requirements of the Federal Clean Air Act.

Federal Facility:  Facility that is owned or operated by the federal government, subject to the same requirements as other responsible parties when placed on the Superfund National Priorities List.

Federal Facility Agreement (FFA):  Negotiated agreement that specifies required actions at a federal facility as agreed upon by various agencies (e.g., EPA, RWQCB, DOE).

Federal Register:  Document published daily by the federal government containing notification of government agency actions, including notification of EPA and DOE decisions concerning permit applications and rule-making.

Federal Standard 209E:  Standard 209E are the Federal Government’s basic design and performance requirements for cleanrooms. It describes methods for class verification, cleanliness monitoring and other maintenance issues.

Feed:  Materials to be filtered. Also referred to as concentrate, influent, intake, liquor, mud, prefilt, pulp, slime or sludge.

Feedback:  Information on current operation of a system or device used by the control system to modify future operation.

Feedback Control System:  A control system that is constantly cor­recting the condition.

Felt: A very general term used to describe composition of roofing ply sheets, consisting of a mat of organic or inorganic fibers either unsaturated, impregnated with asphalt or coal tar pitch, or impregnated and coated with asphalt.

Felted Fabric: Type bag used on most pulse jet dust collectors. Features a heavy, thick cloth of short fibers on a woven backing.

Female IPS: Pipe connection where the threads are on the inside of the fitting. See FIP.

Female Threads: See FIP.

FEMP - Federal Energy Management Program; A program of DOE that implements energy legislation and presidential directives. FEMP provides project financing, technical guidance and assistance, coordination and reporting, and new initiatives for the federal government. It also helps federal agencies identify the best technologies and technology demonstrations for their use.

Fenestration: Window and door openings in a building's wall.

Fermentation:  Enzymatically controlled breakdown of an energy rich compound as a sugar to produce ethyl alcohol, carbon dioxide, and energy, by the action of yeasts which carry the necessary enzymes. Bacterial fermentations also occur.

Ferrography:  An analytical method of assessing machine health by quantifying and examining ferrous wear particles suspended in the lubricant or hydraulic fluid.

Ferrous: Refers to objects made of or partially made of iron, such as ferrous pipe.

Ferrule: Metal tubes used to keep roof gutters “open.” Long nails (ferrule spikes) are driven through these tubes and hold the gutters in place along the fascia of the home.

Fertilizer:  A substance, often an artificial chemical mixture, which is spread on or through the soil to make it more fertile.

FEV:  Forced Expiratory Volume.

FEV-1 (Forced Expiratory Volume in One Second): The amount of air a person is able to blow out in one second of blowing as hard as they can. This measurement, obtained through spirometry, gives the doctor an idea of the level of blockage in the airways due to inflammation, mucus, or bronchoconstriction.

Fever:  An abnormal temperature of the body above 98.6oF (37oC). Exercise, anxiety, and dehydration may increase the temperature of healthy people. Infection, nerve disease, cancer, anemia, and many drugs may cause fever. No single theory explains why the temperature is increased. Fever increases metabolism 7% per oC, meaning more food needs to be eaten. Convulsions may occur in children whose fevers tend to rise quickly. Confusion is seen with high fevers in adults and in children. It may begin quickly or gradually. The period of highest fever is called the stadium or fastigium. It may last for a few days or up to 3 weeks.

FFU:  Fan Filter Unit. A product that contains both a fan and a filter, or set of filters.

FHA Strap: Metal straps that are used to repair a bearing wall “cut-out,” and to “tie together” wall corners, splices, and bearing headers. Also, they are used to hang stairs and landings to bearing headers.

FHP:  Force Health Protection.

Fiber: Any particle with length greater than or equal to 0.5 micron and at least five times greater than its diameter, leaving substantially parallel sides.

Fiber (Asbestos Fiber):  Generally, a slender or elongated structure, which results from the break up of ACM, PACM or asbestos material. However, the definition of an asbestos fiber is also dependent upon the approved accepted method of air sampling and analysis utilized for the specific phase of the asbestos project.

Fiber Metal Felt:  A nonwoven media consisting of extremely fine metal fibers (2-20 micron in diameter) which are compressed and sintered. Used to filter molten polymers in the manufacture of fibers and films and hydraulic fluids for use in aerospace filters.

Fiber Migration:  Downstream migration of fibers from a filter medium.

Fibered Aluminum Roof Coating: High-performance metallic reflective barrier for prepared roofing, metal surfaces and exterior masonry. Reflects sun’s harmful rays, reduces energy costs in summer and winter while prolonging surface life.

Fibered Roof and Foundation Coating: Combined application for this special medium-viscosity-grade fibered material. Use as a roof or foundation coating.

Fibered Roof Coating: Optimal protection for low-sloped roofs. This thick, high-quality coating seals fine cracks and openings. Renews and rejuvenates old composition roofing and prolongs roof life. Also performs well on metal or concrete surfaces.

Fiberglass: A fibrous material made by spinning molten glass used as an insulator and heat loss retardant.

Fiberglass Mat: An asphalt roofing base material manufactured from glass fibers.

Fick’s Law of Diffusion:  A law of chemistry and physics: the rate of diffusion of one substance in another is proportional to the negative gradient of the concentration of the first substance.

Field Measure: To take measurements (cabinets, countertops, stairs, shower doors, etc.) in the home itself instead of using the blueprints.

Field Pole:  Part of the stator of a motor which concentrates magnetic field of field winding.

Filament-Mono: One continuous strand of fiber to indefinite length.

Filament-Multi: More than one mono-filament strand grouped together of definite length.

Fill:  Yarns that run in the filling or cross-machine direction of a woven fabric.

Fill Tube: A plastic or metal tube used for its stiffness to blow insulation inside a building cavity.

Fillet Bead: Caulking or sealant placed in such a manner that it forms an angle between the materials being caulked.

Filter: Filter is any porous device that allows the passage of air but traps air born particles, thus cleaning the air.

Filter or Air Purifying Element:  A component used in respirators to remove solid or liquid aerosols from the inspired air.

Filter, High Efficiency Particulate Air (HEPA):  A throwaway, extended-medium, dry-type filter in a rigid frame, having a minimum particle-collection efficiency of 99.97% (that is, a maximum particle penetration of 0.03%) for 0.3µm particles of thermally generated DOP or specified alternative aerosol.

Filter, Ultra Low Penetration Air (ULPA):  A throwaway, extended-medium, dry-type filter in a rigid frame, having a minimum particle-collection efficiency of 99.999% (that is, a maximum particle penetration of 0.001%) for particles in the size range of 0.01 to 0.02µm, when tested in accordance with the methods of IES-RP-CC007.

Filter (Air):  A device that removes contaminants, by mechanical filtration, from the fresh air stream before the air enters the living space. Filters can be installed as part of a heating/cooling system through which air flows for the purpose of removing particulates before or after the air enters the mechanical components.

Filter/Adsorber Bank:  A parallel arrangement of filters/adsorbers on a common mounting frame installed within a single housing.

Filter Breather:  A filtering unit for vented enclosures installed to prevent dirt and foreign matter from entering the enclosure. Also prevents oil loss by retaining oil droplets and draining the oil back to the sump.

Filter Coalescing:  A filter unit that combines three principles to filter out oil aerosols: (1.) Direct interception – A sieving action, (2.) Inertial impaction – Collision with filter media fibers, 3) Diffusion – Particles travel in a spiral motion, presenting an effective frontal area thus capturing particles within the filter medium.

Filter Efficiency:  The ability of a filter to remove specified test contaminants under specified test conditions from a specific test fluid, air, gas or liquid. Expressed as a percentage of the quantity of test contaminant introduced into the inlet of the filter test system.
 
Filter Element:  The porous device which perform the actual process of filtration.

Filter Head:  An end closure for the filter case or bowl that contains one or more ports.

Filter, HEPA:  High-efficiency particulate air filter that is at least 99.97 percent efficient in removing thermally generated monodisperse dioctylphthalate smoke particles with a diameter of 0.3u.
Filter Housing:  Something that covers or protects the filter assembly.

Filter Indicator Display:  This is an electric display found on certain vacuum cleaners measures the effectiveness of the exhaust filter. As the filter loads the display informs the user so that it can be changed at the appropriate time to maintain the highest levels of filtration.

Filter Inline:  Inlet and outlet connections are located at the same level on opposite sides of the filter or other device installed on the pipeline.

Filter Life:  Measure of the duration of a filter’s useful service. This is based on the amount of standard contaminant required to cause differential pressure to increase to an unacceptable level-typically 2-4 times the initial differential pressure, a 50-80% drop in initial flow, or an unacceptable downstream measure of particulate.

Filter Life Test:  A type of filter capacity test in which a clogging contaminant is added to the influent of a filter, under specified test conditions, to produce a given rise in pressure drop across the filter or until a specified reduction of flow is reached. Filter life may be expressed as test time required to reach terminal conditions at a specified contaminant addition rate.

Filter Media:  A porous material for separating suspended particulate matter from fluid.

Filter Media Migration:  Problem caused by a filter medium which is constructed of a non-continuous or fibrous polymeric matrix such that portions of the filter change structure causing undefined pore size/distribution, as a function of fluid flow.

Filter Medium:  The porous material contained inside the filter to (a) separate the contaminants from the incoming air, gas, or liquid. (b) separate the liquid from the gas. Filter medium is usually made of paper, wire mesh, special cellulose, or a combination.

Filter Oil Bath:  A labyrinth type filter having the active surfaces continuously splashed with oil. Most pollutants are absorbed by the oil which when circulated releases its pollutants, which sink by gravity to the bottom of the oil pan.

Filter Penetration: The passage of particles through a filter without removal from the air stream.

Filter Roll:  The 7 pleated filter sheets will last up to 7 years based on 7-8 hours running per day on auto. The sheet simply needs to be thrown out when the filter replacement indicator light comes on and a new one is sited in front of deodorizing catalyst.

Filter Separator:  Filtering unit that separates solids and liquid droplets from gas (air). Widely used in removing oil from a gas or air.

Filter Size:  The size of a filter is listed by its length, height and thickness.  For example, a common filter size would be listed as 20x20x1.  20 inches wide by 20 inches high and 1 inch thick.  We have manufactured filters in the following sizes since 1960:

Filter Sizes:   Nordic Pure manufactures MERV 12 pleated standard filters in the following sizes:  1 inch – 10x20x1, 12x12x1, 12x18x1, 12x24x1, 14x20x1, 14x24x1, 14x30x1, 15x20x1, 16x16x1, 16x20x1, 16x24x1,  16x25x1, 18x18x1, 18x20x1, 18x24x1, 18x25x1, 20x20x1, 20x24x1, 20x25x1, 20x30x1, 24x24x1,  24x30x1, 25x25x1;  2 inch – 10x20x2, 12x20x2, 12x24x2, 14x20x2, 14x24x2, 14x25x2, 15x20x2, 16x16x2, 16x20x2, 16x24x2, 16x25x2, 18x18x2, 18x20x2, 18x24x2, 18x25x2, 20x20x2, 20x24x2, 20x25x2, 20x30x2, 24x24x2, 24x30x2, 25x25x2; 4 inch – 16x20x4, 16x24x4, 16x25x4, 18x24x4, 20x20x4, 20x24x4, 20x25x4, 24x24x4.  Nordic also carries the following filter sizes by Honeywell:  16x25x5 (model #s – FC100A1029 & FC200E1029; 20x25x5 (model #s – FC100A1037 & FC200E1037).

Filtering Facepiece:  An air-purifying respirator in which a particulate filter is the entire facepiece or is an integral part of the facepiece; also known as a dust mask in some cases: see Type N particulate filter, Type P particulate filter, Type R particulate filter.

Filtrate:  The end product of the filtration process. The liquid exiting the filtrate outlet.

Filtration:  The physical or mechanical process of separating insoluble particulate matter from a fluid, such as air or liquid, by passing the fluid through a filter medium that will not allow the particulate to pass through it.

Filtration Efficiency:  This term indicates the percentage of particles that a filter captures as air moves through it. Filtration efficiency is typically stated with regard to a specific particle size. For example, a HEPA filter retains 99.97% (filtration efficiency) of particles 0.3 microns (particle size) or larger. In order to make an informed decision about how well a vacuum cleaner or air purifier cleans the air, both specifications are necessary.

Filtration Rate:  The volume of liquid that passes through a given area of filter in a specific time.

Filtration System:  Vacuum cleaners and air purifiers use a variety of different designs and technologies to remove particles and sometimes odors from air flowing through them. These generally consist of a series of filters made from a wide variety of filter media including the dustbag (which may be made from paper as well as an ever increasing type of filter material), glass fibers, activated charcoal, cloth or foam filters, electrostatic filters, cyclonic chambers, water and so on.

Fin Comb: A comb-like tool used to straighten bent fins in air conditioning coils.

Final Filter:  The last filter unit in a set of filters arranged in series.

FindAnInspector.US: Foremost home inspector search engine.

Fine Particles: Minute particles dust with a diameter of less than 10µm (micrometers), namely ten times smaller than the diameter of a human hair.

Fines:  Portion of a powder like material composed of particles smaller then the size specified.

Finger Joint: A manufacturing process of interlocking two shorter pieces of wood end to end to create a longer piece of dimensional lumber or molding. Often used in jambs and casings and normally painted (instead of stained).

Finish: In hardware, metal fastenings on cabinets which are usually exposed such as hinges and locks.

Finish Carpentry: The hanging of all interior doors, installation of door molding, base molding, chair rail, built in shelves, etc.

Finish Coat: The last coat applied in plastering intended as a base for further decorating or as a final decorative surface. Finish coat usually consists of calcified gypsum, lime and sometimes an aggregate. Some may require the addition of lime or sand on the job. The three basic methods of applying it are trowel, flat and spray.

Finish Grade: Any surface which has been cut to or built to the elevation indicated for that point. Surface elevation of lawn, driveway or other improved surfaces after completion of grading operations.

FIP (Female Iron Pipe): Standard threads that are on the inside of a pipe fitting.

Fire Block: Short horizontal members sometimes nailed between studs, usually about halfway up a wall. See also ‘Fire Stop.’

Fire Brick: Brick made of refractory ceramic material which will resist high temperatures. Used in fireplaces and boilers.

Fire Damper:  A damper installed in a duct system that is normally open , upon the breakage of a heat sensitive link the damper will close.  
Fire Point:  The lowest temperature at which a material can evolve vapors fast enough to support continuous combustion.

Fire Rated: Descriptive of materials that have been tested for use in fire walls.

Fire Retardant Chemical: A chemical or preparation of chemicals used to reduce flammability or to retard spread of flame.

Fire Stop: A solid, tight closure of a concealed space, placed to prevent the spread of fire and smoke through such a space. In a frame wall, this will usually consist of 2x4s cross blocking between studs.

Fire Wall: Any wall built for the purpose of restricting or preventing the spread of fire in a building. Such walls of solid masonry or concrete generally sub-divide a building from the foundations to two or more feet above the plane of the roof.

Fire Resistance Rating:  A term associated with the qualification of fire barriers. Fire barriers are tested to a standard fire exposure detailed in ASTM E-119, Standard Method of Fire Tests of Building Construction and Materials.

Fire-Resistive: In the absence of a specific ruling by the authority having jurisdiction, applies to materials for construction not combustible in the temperatures of ordinary fires and that will withstand such fires without serious impairment of their usefulness for at least 1 hour.

Firebox: The compartment of a stove or fireplace where the wood is burned.

Fireplace Chase Flashing Pan: A large sheet of metal that is installed around and perpendicular to the fireplace flue pipe. Its purpose is to confine and limit the spread of fire and smoke to a small area.

Fireplace Insert:  A wood or gas burning heating appliance that fits into the opening or protrudes on to the hearth of a conventional fireplace.

First Aid:  Emergency measures to be taken when a person is suffering from overexposure to a hazardous material, before regular medical help can be obtained.

First Costs: The initial construction costs of products before performance savings are realized.

First Law of Thermodynamics:  The amount of work done on or by a system is equal to the amount of energy transferred to or from the system.

First Pass Metabolism:  First-pass metabolism refers to the phenomenon of a drug taken orally which is absorbed through the intestinal wall and goes directly to the liver through the portal vein system and gets metabolized there before reaching the target organ. This is avoided by giving the drugs by other routes (e.g., intramuscular, intravenous).

Fiscal Year:   LLNL’s fiscal year is from October 1 through September 30.

Fish Tape (Fish Wire): Material used to advance wire through a conduit.

Fishplate: A wood or plywood piece used to fasten the ends of two members together at a butt joint with nails or bolts. Sometimes used at the junction of opposite rafters near the ridge line.

Fission Track Analysis:  During neutron irradiation heavy nuclei such as uranium and plutonium undergo nuclear fission with release of large fission fragments. This property has led to the development of a number of measurement techniques such as delayed neutron activation analysis and fission track analysis. Fission track analysis is a measurement technique commonly employed in plutonium urinalysis (bioassay) monitoring programs. Urine samples are chemically treated to remove plutonium. The plutonium is then mounted in contact with a special plastic or quartz slide known as solid-state nuclear track detector (SSNTD).  The slide along with the sample is then irradiated in a reactor where neutron-induced fission of plutonium-239 (or uranium-235) causes emission of energetic fission fragments. Some of the fragments penetrate into the SSNTD damaging the integrity of the material before coming to rest. The SSNTD is separated from the sample and chemically etched to expose the damaged areas (known as fission tracks) on the detector surface.  The fission tracks are then counted under an optical microscope. The amount of plutonium (and/or uranium) present in the sample is a function of the total number of tracks and the neutron flux.

Fit Check: Should be conducted each time a respirator is put on to determine if it is
properly sealed to the face.

Fit Factor:  A quantitative measure of the fit of a particular respirator to a particular individual; see fit test; refer to CSA Z94.4 for the definition.

Flammable Anesthetic Gas: A compressed gas which is flammable and administered as an anesthetic including cyclopropane, divinyl ether, ethyl chloride, ethyl ether and ethylene.

Flammable Liquid: Any liquid that has a closed-cup flash point below 100°F (37.8°C).
(a) Class I Liquid. Any liquid that has a closed-cup flash point below 100°F (37.8°C) and a Reid vapor pressure not exceeding 40 psia at 100°F (37.8°C).
1. Class IA liquids shall include those liquids that have flash points below 73°F
(22.8°C) and boiling points below 100°F (37.8°C).
2. Class IB liquids shall include those liquids that have flash points below 73°F
(22.8°C) and boiling points at or above 100°F (37.8°C).
3. Class IC liquids shall include those liquids that have flash points at or above
73°F (22.8°C), but below 100°F (37.8°C).

Flammability:  The ability for a material to burn.
Flammable Range:  The difference between the lower and upper flammable limits, expressed in terms of percentage of vapor or gas in air by volume, and is also often referred to as the “explosive range.”

Flapper Valve (Plumbing): A valve that replaces a tank stopper in a toilet. Creates a seal between the tank and the bowl.
Flash Pasteurization:  The process of briefly heating a beverage to destroy objectionable enzymes and microorganisms. See “Pasteurization.”

Flash Point: The minimum temperature of a liquid at which sufficient vapor is given off to form an ignitable mixture with air, near the surface of the liquid or within the vessel used.

Flash Streamer:  Produces high speed electrons which collide and unite with water, oxygen and nitrogen in the air turning into activated particles such as excited nitrogen molecules, oxygen radicals and hydrogen radicals. They breakdown odor molecules, (Ammonia etc.) into Nitrogen and water. Acetaldehyde is broken down into water and carbon dioxide.

Flash Weld:  A resistance type weld in which mating parts are brought together under considerable pressure while a heavy electrical current is passed through the joint to be welded.

Flashing: Waterproof material used to prevent leakage at intersections between the roof surface at walls or penetrations.

Flat Glass: A general term that describes float glass, sheet glass, plate glass, and rolled glass.

Flat Grain: Flat grain lumber has been sawed parallel to the pith of the log and approximately tangent to the growth rings, i.e., the rings form an angle of less than 45° with the surface of the piece.

Flat Mold: Thin wood strips installed over the butt seam of cabinet skins.

Flat Paint: An interior paint that contains a high proportion of pigment and dries to a flat or lusterless finish.

Flat Plate Collector: This is a solar collector, a flat assembly containing a panel of metal or other suitable material, usually a mat black color on its sunny side, that absorbs sunlight and converts it into heat. This panel is usually in an insulated box, covered with glass or plastic to take advantage of the greenhouse effect. In the collector, this heat transfers to a circulating fluid, such as air, water or oil.

Flat Seam: A seam at the junction of sheet metal roof components that has been bent at the plane of the roof.

Flatwork: Common word for concrete floors, driveways, basements, and sidewalks.

Fleet Averaging: By using a point system, builders can show compliance with energy building requirements by using average figures for all air conditioning units in the same sub division.

Flex-Duct:  Flexible ductwork made with an interior liner, a layer of insulation, and an outer covering of plastic.

Flex Hose: A flexible pipe or tube usually made of braided stainless steel. Commonly used with widespread or Roman tub faucets to provide variable centers.

Flexible Duct:  A duct that can be routed around obstacles by bending it gradually.

Flexible Film Isolators:  Isolators used for housing germ free (axenic) and gnotobiotic animals – a system with a complete barrier against contamination.

Flexible Fuel Vehicle (FFV): Vehicles that can use a combination of fuels such as alcohol fuel and unleaded gasoline.

Flexible Metal Conduit: Conduit similar to armored cable in appearance but does not have the pre-inserted conductors.

Flight Zone:  The flight zone is an animal’s “personal space.” The size of the flight zone varies with the tameness of the animal, and other animal-related factors. Wild animals have a much larger flight zone than most domestic animals that are used to humans.

Float:  The part of a switch that rises with the water level, and turns off the switch once the water has reached a certain level.

Float Glass: Glass formed on a bath of molten tin. The surface in contact with the tin is known as the tin surface or tin side. The top surface is known as the atmosphere surface or air side.

Floating: The next-to-last stage in concrete work, when it is smoothed and water is brought to the surface by using a hand float or bull float.

Floating Wall: A non-bearing wall built on a concrete floor. It is constructed so that the bottom two horizontal plates can compress or pull apart if the concrete floor moves up or down. Normally built on basements and garage slabs.

Flocculation:  Growing together of minute size particles to form larger ones, called floc’s.

Flood Plain:  The land area that  is subject to flooding in any year from any source.

Flooded System:  A refrigerating system in which liquid refrigerant fills most of the evaporator.

Flooded System, High-Side Float:  Refrigeration system which has a float operated by the rate of the high-side liquid refrigerant being condensed.

Flooded System, Low-Side Float:  Refrigeration system which has a float operated by the rate of evaporation of liquid refrigerant from the evaporator.

Flooding:  The allowing a liquid to flow into a part of a system.

Floor Heating: Heated floor, which gives off heat to the room.

Floor Joists: The framing members that support the floor area.

Floor Plan: The basic layout of building or addition, which includes placement of walls, windows and doors as well as dimensions.

Floor Plate: See Floor Plan.

Floor Puller:  A suction device used to remove smooth surface access flooring panels.

Floor Stand – Laminar Flow or Safety Cabinets:  Floor-standing support frames that are supplied with the option of castors (wheels) or leveling feet and may be fitted with an electric height-adjusting mechanism.

Flooring System:  Different types of flooring are used in cleanrooms, depending on the class and level of cleanliness needed. Flooring material can be made of material that controls static, it can be perforated for laminar flow, sticky for trapping dust or have sealed seams for contamination control. Many options are available and Angstrom offers them all.

Flow Check Piston:  A metering device that has a piston assembly, with an orifice in the center.

Flow Coefficient:  A dimensionless parameter relation air velocity to fan tip velocity. It’s used to determine approximate fan width for centrifugal impellers.

Flow Control Valve:  A valve that controls the flow of air that passes through the valve. Used often for retardation or timing circuits, but especially for regulating the piston speed in cylinders.

Flow Decay:  Decrease in flow rate caused by filter plugging or clogging.

Flow Diagram:  A schematic flow sheet showing all controls involved with the system.

Flow Hood: Device that easily measures airflow quantity, typically up to 2,500 cfm.

Flow Meter:  An instrument for measuring the amount of air flow of a compressor. Measured in CFM.

Flow Rate:  The rate (in liters or gallons per minute, cubic meters or cubic feet per second, or other quantity per time unit) Air related flows are usually expressed in CFM, SCFM, ACFM, ICFM.

Flow-Thru Cooled Motors:  A motor design that uses the primary airflow that carries the soil in a vacuum cleaner to also cool the motor. This system is very effective in vacuum cleaners that utilize a “Clean Air” system where this air is highly filtered before it reaches the motor. Air is typically filtered again after the motor to capture any residual dust or carbon soils produced by the motor brushes.

Flue: The channel of pipe used to control air flow of combustion gases.

Flue Collar: Round metal ring which fits around the heat flue pipe after the pipe passes out of the roof.

Flue Damper: An automatic door located in the flue that closes it off when the burner turns off; its purpose is to reduce heat loss up the flue from the still-warm furnace or boiler.

Flue Gas: The air coming out of a chimney after combustion in the burner it is venting. It can include nitrogen oxides, carbon oxides, water vapor, sulfur oxides, particles and many chemical pollutants.

Flue Gas Desulfurization (FGD): A technology that employs a sorbent, usually lime or limestone, to remove sulfur dioxide from the gases produced by burning fossil fuels. Flue gas desulfurization is current state-of-the art technology for major SO2 emitters, like power plants.

Flue Lining: Fire clay or terracotta pipe, round or square, usually made in all ordinary flue sizes and in 2-foot lengths, used for the inner lining of chimneys with the brick or masonry work around the outside. Flue lining in chimneys runs from about a foot below the flue connection to the top of the chimney.

Fluid:  Includes liquids, air or gas as a general term.

Fluorescent Lighting: A fluorescent lamp is a gas-filled glass tube with a phosphor coating on the inside, normally with two pins that extend from each end. Gas inside the tube is ionized by electricity which causes the phosphor coating to glow.

Fluorocarbon:  A non-flammable liquid or gas used as a propellant; often used in spray cans, they are classified as ozone-depleting substances.

Flush:  The process of using a fluid to push contaminants from a system.

Flush Glazing (Pocket Glazing): The setting of a light of glass or panel into a four-sided sash or frame opening containing a recessed “U” shaped channel without removable stops on three sides of the sash or frame and one channel with a removable stop along the fourth side.

Flush Out:  The operation of mechanical systems for a minimum of two weeks using 100 percent outside air at the end of construction and prior to building occupancy to ensure safe indoor air quality. See also “Bakeout.”

Flush Valve: The valve separating the water in the tank from the bowl.

Flushing:  A circulation process designed to remove contamination.

Flushometer:  Toilet valve that automatically shuts off after it meters a certain amount of water flow.

Flutter Valve: See mucus clearing device.

Flux: A material applied to the surface of copper pipes and fittings to assist in the cleaning and bonding process.

Flux lines:  Lines of force of a magnet.

Fly Ash: Particle matter from coal ash in which the particle diameter is less than 1 x 10-4 meter. This is removed from the flue gas using flue gas particulate collectors such as fabric filters and electrostatic precipitators.

Fly Rafters: End rafters of the gable overhang supported by roof sheathing and lookouts.

Flywheel Effect:  In HVAC systems, to even out temperature variations in a building due to the temperature storage capabilities of the building’s mass.

FM:  Factory Mutual.  A nationally recognized testing laboratory and approval service recognized by OSHA.

FM-200:  Chemically known as heptafluoropropane, FM-200 is an alternative fire suppression system agent manufactured in the United States by Great Lakes Chemical (FM-200) and DuPont Corporation (HFC-227). It is a replacement for the ozone depleting Halon1301 used extensively before 1994.

Foam Board: Plastic foam insulation manufactured most commonly in 4'x8' sheets in thickness of 1/4" to 3".

Foaming:  Formation of foam in an oil-refrigerant mixture due to rapid evaporation of liquid refrigerant dissolved in the oil.

Focusing Collector: A collector that has a reflector which focuses sunlight onto a smaller area for collection. A reflector of this type can obtain relatively high temperatures. The system is most effective for solar radiation not diffused by clouds.

Fog: The condensation of water vapor in air. Also see Smog.

Fogging:   Applying a liquid chemical by rapidly heating it to form fine droplets that resemble smoke or fog.

Folded Seam: In sheet metal work, a joint between sheets of metal wherein the edges of the sheets are crimped together and folded flat.

Follow Up Testing:  The testing designed to confirm the results of the initial testing using identical testing devices and similar test conditions.

Fomite:  Any object, that is not harmful itself, but may be capable of carrying an infectious microorganism on it and thus transmit disease.

Foot:  A device for mounting cylinders.

Foot Candle: A measure of light striking a surface.

Foot Pound:  Unit of work. A foot-pound is the amount of work done in lifting one pound one foot. 

Footing: The underground support for a foundation or support post.

Footings: Wide pours of cement reinforced with re-bar (reinforcing bar) that support foundation walls, pillars, or posts. Footings are part of the foundation and are often poured before the foundation walls.

Force:  Energy exerted.

Force-Feed Oiling:  Lubrication system that uses a pump to force oil to surfaces of moving parts.

Forced Air Heating: A common form of heating with natural gas, propane, oil or electricity as a fuel. Air is heated in the furnace and distributed through a set of metal plastic ducts to various areas of the house.

Forced Air System or Furnace:  HVAC term for a type of heating system in which heated air is blown by a fan through air channels or ducts to rooms.

Forced Convection: Convection heat transfer between a surface and an adjacent fluid (air in the present context) resulting from forced circulation of a liquid or a gas, as by a fan, jet or pump.

Forced Convection Cooling or Open Loop Ambient Air Cooling:  An industry term that describes an air system used to cool a chamber with just the available air surrounding the product. 

Forced Draft Fan:  A fan that generates (by pushing) a flow of ambient air over the exterior of the finned pipes to dissipate the sensible heat.

Forest Stewardship Council (FSC):  A non-profit organization, which administers a forestry certification program to assure that businesses supply trees and wood from a forest managed in an ecologically sustainable manner.
Forced Ventilation vs. Closed-Loop Cooling:  If ambient air is cool and clean enough, use it. If the ambient is too hot, dirty or corrosive, a closed-loop system is needed. A heat exchanger is usually a lower-cost choice than an air conditioner. See if it will do the job. Don’t over-cool. Don’t oversize the cooling equipment.

Form: Temporary structure erected to contain concrete during placing and initial hardening.

Formaldehyde:  A volatile organic compound (VOC); potential sources in the home include pressed wood products such as particleboard or fiberboard, smoking, as a component of glues and adhesives, etc.

Formalin:  Formalin, or formaldehyde, in solution is used as a tissue preservative and fixative for tissue specimens.

Forward Flow Test: An integrity test measuring air diffusion at a low pressure (approximately 5 psi). Similar to a pressure hold test.

Fossil Fuel: Any naturally occurring organic fuel, such as petroleum, coal, and natural gas.

Fossil-Fuel Plant: A plant using coal, petroleum, or gas as its source of energy.

Fouling:  Accumulation of foreign matter, such as mud or debris, in a cooler, pipe, or valve. In a cooler, H 2 O D P and D T will be seen to increase, as well as CTD.

Foundation: The supporting portion of a structure below the first floor construction, or below grade, including the footings.

Foundation Coating: High-quality below-grade moisture protection. Used for below-grade exterior concrete and masonry wall damp-proofing to seal out moisture and prevent corrosion.

FPM:  Feet per Minute.
Fractional Distillation: Input definition.

Fractionation:  In densitometry, the division of peaks into fractions in order to quantitate the electrophoretically separated bands. In chemistry, separation of a mixture of components into different portions (fractions).

Fragrances:  Fragrances are scents that are added to products. In many cases, fragrance is artificial. Artificial fragrances can often become allergens. If you have allergies, look for products that are fragrance free or which use hypoallergenic natural scents.

Frame:  Aluminum, wood, steel, or other material into which the filter pack is inserted.

Frame Inspection: An inspection of the home’s structural integrity and its compliance to local municipal codes.

Frame Size: A set of physical dimensions of motors established by National Electrical Manufacturers Association (NEMA) for interchangeability between manufacturers. Dimensions include: shaft diameter, shaft height and motor mounting footprint.

Framer: The carpenter contractor that installs the lumber and erects the frame, flooring system, interior walls, backing, trusses, rafters, decking, installs all beams, stairs, soffits and all work related to the wood structure of the home. The framer builds the home according to the blueprints and must comply with local building codes and regulations.

Framing: The structural wood and/or metal elements of most homes. The floor and ceiling framing is called the joist work. Wall framing is usually made out of 2x4 or 2x6 studs. See Rafters, Posts, and Beams.

Frazier Permeometer:  Porosity testing device. The normal measurement is air flow in CFM passed through one square foot of fabric at 0.5 inch differential water pressure.

Free Air (FAD):  Free air delivery. Air at the atmospheric conditions of the site and unaffected by the compressor. Flow is measured at the discharge valve of the compressor, after the aftercooler, the water separator and built in check valve. Capacity and power consumption are corrected to ISO 1217 standard reference conditions: Ambient temperature = °20C, Ambient pressure = 1 bar(a), Relative humidity = 0%, Cooling water/air = 20°C, Effective working pressure at discharge valve = 7 bar(a).

Free Area:  The actual measured perpendicular area between the fins of a grille or register.

Free Convection: See Convective heat transfer.

Free Cooling System:  Typically a water cooled or glycol cooled system with an additional coil that provides chilled water cooling when the outdoor ambient is cold thereby reducing or eliminating compressor operation. Provides efficient system operation in Nothern climates.

Free Delivery:  There are no ducts and the unit may be installed in the field without ducts if needed. Ground-Source –The ground or soil below the frost line is being used as the heat source or heat sink for a heat pump.

Free Radicals: A molecule or atom with an unpaired electron. This makes it highly reactive and able to destroy other molecules.

Free Wheeling:  Continued rotation of magnetic clutch on automotive compressor when clutch is disengaged.

Free-running Building: A building which is neither being mechanically heated nor cooled.

Free-Tab Shingles: Shingles that do not contain factory-applied strips or spots of self-sealing adhesive. See also self-sealing shingles.

Freeboard:  The vertical distance between the lowest point along the top of a surface impoundment dike, berm, levee, treatment works or other similar feature and the surface of the liquid contained therein.

Freeze Drying:  Uses liquid nitrogen or carbon dioxide to turn fresh food into long lasting, frozen food.

Freeze Up:  Excess ice or frost accumulation on an evaporator to the point that airflow may be affected.

Freezer Burn:  Condition applied to food which has not been properly wrapped and that has become hard, dry, and discolored.

Freezing Point:  The temperature at with if any more heat is removed it will solidify.

Freezing Point Depression:  The temperature at which ice will form in solution of water and salt. 

French Drain System:  A pit or trench filled with crushed rock and used to collect and divert ground water.

Freon:   A registered trademark for a cholorfluorocarbon (CFC) gas that is highly stable and that has been historically used as a refrigerant.

Freon-11:  Trichlorofluoromethane.

Freon-113:  1,1,2-trichloro-1,2,2-trifluoroethane; also known as CFC 113.

Frequency:  The number of vibrations, waves, or cycles of any periodic phenomenon per second. In architectural acoustics, the interest lies in the audible frequency range of 20 to 20,000 cps Hertz (cycles per second).

Frequency Spectrum:  Usually a visual representation of a complex sound or noise which has been resolved into frequency components. The detailed nature of a complex sound may be studied by obtaining its frequency spectrum. Frequency spectra are commonly obtained in octave bands, 1/3-octave bands, and various narrow bands.
FreshEffects™ (also Energy Recovery Ventilator or TRANE FreshEffects™): Energy efficient system to exchange stale indoor air for an equal amount of fresher outdoor air.

Fresh Waters:  All freshwater lakes and streams downstream to the limit of tidal action.

Friable:  Any material that when dry, can be crumbled, pulverized, or reduced to powder by hand pressure, or is capable of being released into the air by hand pressure.  

Friction:  Surface resistance to relative motion, which slows down movement and causes heat.

Friction Loss: Resistance to air flow through any duct or fitting, given in terms of static pressure.

Frieze: In house construction, a horizontal member connecting the top of the siding with the soffit of the cornice.

FRL:  Filter, Regulator and lubricator sometimes combined in one unit.

Frost Back:  This is caused my the flooding of refrigerant liquid in the suction line.

Frost Control, Automatic:  Control that automatically cycles refrigerating system to remove frost formation on evaporator.

Frost Control, Manual:  Manual control used to change operation of refrigerating system to produce defrosting conditions.

Frost Control, Semiautomatic:  Control which starts defrost part of a cycle manually and then returns system to normal operation automatically.

Frost Free Refrigerator:  A refrigerator that incorporates automatic defrost.

Frost Line: The maximum depth of the soil where water will freeze during the coldest weather.

Frost Point:  Is the unique temperature to which the air (or any gas) must be cooled in order that it shall be saturated with respect to ice.

Frost-Protected Shallow Foundation (FPSF):  Foundation system in which foam insulation is placed around the perimeter of a foundation to reduce heat loss through the slab and/ or below-grade walls, subsequently raising the frost depth of a building and allowing foundations to be as shallow as 16inches below grade.
Frosting Type Evaporator:  Refrigerating system which maintains the evaporator at frosting temperatures during all phases of cycle.

Frostline: The depth of frost penetration in soil. This depth varies in different parts of the country. Footings should be placed below this depth to prevent movement.

Frozen:  (1). Water in its solid state. (2). Seized (as in machine parts) due to lack of lubrication. The term “freeze-up” is often applied to this situation.

FRP: Abbreviation for fiberglass-reinforced-plastic.

FSC (Forest Stewardship Council): A not-for-profit, non-governmental organization based in Bonn, Germany that provides standard setting, trademark assurance and accredi-
tation services for companies and organizations interested in environmentally responsible, sustainable forestry management.

Ft2: Square feet.

Ft3/min:  See cubic feet per minute.

Fuel: Any substance that can be burned to produce heat; also, materials that can be fissioned in a chain reaction to produce heat.

Fuel Cell: An electrochemical engine (no moving parts) that converts the chemical energy of a fuel, such as hydrogen, and an oxidant, such as oxygen, directly to electricity. The principal components of a fuel cell are catalytically activated electrodes for the fuel (anode) and the oxidant (cathode) and an electrolyte to conduct ions between the two electrodes.

Fuel Cell Technology: A technology that uses an electromagnetic process to convert energy into electrical power. Often powered by natural gas, fuel cell power is cleaner than grid connected power sources. In addition, hot water is produced as a by-product that can be utilized as a thermal resource for the building.

Fuel Efficiency:  The ratio of heat produced by a fuel for doing work to the available heat in the fuel.

Fuel Oil:  Any liquid petroleum product burned for the generation of heat in a furnace or firebox, or for the generation of power in an engine. Domestic (residential) heating fuels are classed as Nos. 1, 2, 3; Industrial fuels as Nos. 4, 5, and 6.

Fugitive Dust: Dust particles that are introduced into the air through certain activities such as soil cultivation, or vehicles operating on open fields or dirt roadways. A subset of fugitive emissions.

Fugitive Emissions: Emissions not caught by a capture system which are often due to equipment leaks, evaporative processes and windblown disturbances.

Full Floating:  Mechanism construction in which a shaft is free to turn in all parts in which it is inserted.

Full Package:  Self contained heat pump which has blower and compressor section integrated into one unit.

Full-Cost Accounting:  An accounting system in which environmental costs are built directly into the prices of products and services.

Full-Load Speed: The speed at which the rated horsepower is developed. This speed is less than synchronous speed and varies with the motor type and manufacturer.

Full-Load Torque: The torque required to produce the rated horsepower at fullload speed.

Fully Tempered Glass: Flat or bent glass that has been heat-treated to a high surface and/or edge compression to meet the requirements of ASTM C
1048 kind FT. Fully tempered glass, if broken, will fracture into many small pieces (dice) which are more or less cubical. Fully tempered glass is approximately four times stronger than annealed glass of the same thickness when exposed to uniform static pressure loads.

Fully-Adhered: A completely attached (adhered) roof membrane.

Fume: Solid particles under 1 micron in diameter formed as vapors condense, or as chemical reactions take place.

Functional Design:  The establishment of airflow rates, airflow capacities, types of components to be employed, general system layout, operational objectives and criteria, decontamination factors and rates, space allocations, and other overall features of a system.

Fundamental Building Systems Commissioning:  Verification by an outside source that the fundamental building elements and systems are designed, installed and calibrated to operate as intended.

Fungistat:  Chemical agent that inhibits the growth and reproduction of fungi.

Furans: One of a group of colorless, volatile, toxic chlorinated chemicals.

Furnace:  That part of the heating system in which the combustion of fossil fuel and transfer of heat occurs.

Furnace, Central:  A self-contained appliance designed to supply heated air through ducts to spaces remote from or adjacent to the appliance location.

Furnace (Residential):  In HVAC a combustion heating appliance in which heat is captured from the burning of a fuel for distribution, comprised mainly of a combustion chamber and heat exchanger.

Furring: Strips of wood or metal applied to a wall or other surface to even it and normally to serve as a fastening base for finish material.

Fuse: This is a small piece of metal found in all electrical circuits that is designed to melt when a surplus amount of electrical current passes through it. This is preventative measure taken to avoid damage to the other components of the system. They are commonly found in electrical plugs.

Fusible Link:  A heat sensitive link designed to break in a fire.

Future Costs:  Environmental costs of a product which are not paid now, but rather are passed on to future generations.

FVC:  Forced Vital Capacity.

FVC (Forced vital capacity): Total amount of air a person can blow out after taking a deep breath. It is one of the measurements doctors obtain through pulmonary function tests.