United CoolAir Glossary
Temperature scale with, under standard atmospheric pressure, a water boiling point of 212° and water freezing point of 32°.
A device that opens a circuit when a sensing element loses its pressure.
Radial or axial flow device used for moving or producing flow of gases.
Unit of electrical capacity. Capacity of a condenser which, when charged with one coulomb of electricity, gives a difference of potential of one volt.
Fast food freezing
Method that uses liquid nitrogen or carbon dioxide to turn fresh food into long lasting frozen food. It is often referred to as Cryogenic Food Freezing.
A fuse that blows immediately when the rated load is reached.
Information on current operation of a system or device used by the control system to modify future operation.
Feedback control system
Control system that is constantly correcting the condition. Also called a "closed loop system."
The internal thread on fittings, valves, machine bodies, etc.
Part of the motor stator that concentrates the magnetic field of field winding.
Fill (cooling tower)
Material in a cooling tower over which water flows.
Device for removing small foreign particles from a fluid.
Refractory-lined combustion chamber.
Tendency to ignite.
Liquids having a flash point below 140°F (60°C) and a vapor pressure not exceeding 40 psia (276 kPa) at 100°F (38°C).
Thin metal valve used in refrigeration compressors that allows gaseous refrigerants to flow in only one direction.
An enlargement at the end of a piece of flexible tubing by which the tubing is connected to a fitting or another piece of tubing. This enlargement is made at about a 45° angle. Fittings grip it firmly to make the joint leak proof and strong.
Fitting used to clamp tubing flare against another fitting.
Instantaneous evaporation of some liquid refrigerant in evaporator, which cools the reÂ¬maining liquid refrigerant to the desired evaporation temperature.
Temperature at which flammable liquid will give off sufficient vapor to support a flash flame but will not support continuous combustion.
A duct that can be routed around obstacles by bending it gradually.
Lines that provide for easy bending.
Type of valve that is operated by a sphere or pan that floats on a liquid surface.
Type of refrigerant system where refrigerant is used to reduce the effective condenser surface, thus maintaining a head pressure for low ambient operation.
Type of refrigerating system in which the liquid refrigerant fills most of the evaporator at all times.
Flooded system, high-side float
Refrigeration system that has a float operated by the level of the high-side liquid refrigerant.
Flooded system, low-side float
Refrigerating system that has a low-side float refrigerant control.
Flow check piston
Piston assembly, with an orifice in the center that can operate as an expansion valve.
A device used to measure air flow through a register or grille.
Instrument used to measure velocity or volume of fluid movement.
Gas or air passage that usually depends on natural convection to cause the combustion gases to flow through it. Forced convection may sometimes be used.
Substance in either a liquid or gaseous state.
Capable of exhibiting fluorescence, the emission of electromagnetic radiation of visible light.
Operation to remove any material or fluids from refrigeration system parts by purging them to the atmosphere using refrigerant or other fluids.
Substance applied to surfaces to be joined by brazing or soldering to keep oxides from forming.
Foam leak detector
System of soap bubbles or special foaming liquids brushed over joints and connections to locate leaks.
Formation of a foam in an oil-refrigerant mixÂ¬ture due to the rapid evaporation of refrigerant dissolved in the oil. This is most likely to occur when the compressor starts and the pressure is suddenly reduced.
Unit of work. A foot-pound is the amount of work done in lifting one pound one foot.
Accumulated pressure multiplied by an area.
Lubrication system which uses a pump to force oil to surfaces of moving parts.
An air conditioning or heating system in which airflow is caused by a fan.
Movement of fluid by mechanical force such as fans or pumps.
A heating system that uses a fan to circulate the heated air.
An evaporator that uses a fan to circulate air.
Continued rotation of a magnetic clutch on an automotive compressor when the clutch is disengaged.
Process of food preservation wherein food is frozen and ice content changed rapidly into a vapor, which is then absorbed on an evaporator.
Formation of ice in the refrigerant control device, which may stop the flow of refrigerant into the evaporator. Frost formation on an evaporator, which may stop the airflow through the evaporator.
Change of state from liquid to solid.
Temperature at which a liquid will solidÂ¬ify upon removal of heat. The freezing temperature for water is 32°F (0°C) at atmospheric pressure.
Freezing point depression
Temperature at which ice will form in solution of water and salt.
Force of resistance produced when two surfaces rub together.
Condition in which liquid refrigerant flows from the evaporator into the suction line; usually indicated by sweating or frosting of the suction line.
Frost control, automatic
Control that automatically cycles refrigerating system to remove frost on evaporator.
Frost control, manual
Manual control used to change operation of refrigerating system to produce defrosting conditions.
Frost control, semiautomatic
Control that starts defrost part of a cycle manually and then returns system to normal operation automatically.
Refrigerating system that mainÂ¬tains the evaporator at frosting temperatures during all phases of cycle.
1-Water in its solid state. 2-Preserved by freezÂ¬ing. 3-Seized (as in machine parts) due to lack of lubrication.
Kerosene or any hydrocarbon oil as specified by U.S. Department of Commerce Commercial Standard CS12 or ASTM D296, or the Canadian Government Specification Board, 3-GP-28, and having a flash point not less than 100°F (38°C).
Fuel oil distillate
Fuel oil produced through distillation.
Self-contained appliance designed to supply heated air through ducts to spaces remote from the appliance location.
Electrical safety device consisting of strip of fusible metal in circuit, which melts when the circuit is overloaded.
Plug or fitting made with a metal of a known low-melting temperature. Used as safety device to release pressures in case of fire.