A
Accumulator: Storage tank that receives liquid refrigerant from the evaporator and prevents it from flowing into the suction line of the compressor before evaporating.
Air Handler: The indoor component of a split system, that houses the blower fan, evaporator coil and electric heat strips.
B
Boiler: Closed container in which a liquid may be heated and vaporized.
Brazing: Method of joining metals with a filler(solder) using heat between 800 degrees and the melting point of base metals.
British Thermal Unit (BTU): Quantity of heat required to raise the temperature of one pound of water one degree Fahrenheit.
C
Capacitor: Electrical storage device used to start and run circuits on many electrical motors.
Capillary Tube System: A refrigerant control system in which the pressure difference is maintained through the use of a thin capillary tube.
Carbon Monoxide: Colorless, odorless, and poisonous gas produced when carbon fuels are burned with an improper air mixture.
Check Valve: Device which permits fluid to flow in only one direction.
Chiller: Air Conditioning system that circulates chilled water to various cooling cools in an installation.
Compressor: The pump of a refrigerating mechanism that draws a low pressure gas on the cooling side of refrigerant cycle and compresses the gas into the high pressure or condensing side of the cycle.
Condensate Pump: Device used to remove water condensate that collects beneath an evaporator coil or from a condensing furnace.
Condenser: The part of the refrigeration mechanism which receives hot, high pressure refrigerant gas from the compressor and cools it until it returns to its liquid state.
Condensing Unit: The outdoor component of a split system, that houses the compressor, condenser coil, outdoor fan and other refrigerant components depending on the type of system.
Cubic Feet Per Minute(CFM): This measures how much air is flowing through a unit per minute.
D
Damper: Device for controlling airflow.
Diffuser: Attachment for duct openings that distribute the air in wide flow patterns.
Drier: Device used to remove moisture from a refrigeration system.
Duct: Tube or channel through which air is moved.
E
Evaporator: Part of a refrigerating mechanism in which the refrigerant vaporizes and absorbs heat.
Expansion Valve: Device in refrigerating system that reduces the pressure from the high side to the low side causing a temperature difference in the refrigerant.
F
Float Switch: Device that is attached to a drain pan that can shut the system down to prevent water from overflowing.
Furnace: Self-contained appliance designed to supply heated through ducts.
G
Gas Valve: Device in gas used for starting, stopping or regulating the flow of gas.
H
Head Pressure: Pressure that exists in condensing side of refrigerating system.
Heat Exchanger: Device used to transfer heat from a warm or hot surface to a cold or cooler surface.
Heat Pump: A refrigerating system used to supply heat to a temperature controlled space. The same system can also remove heat from the same space.
I
Indoor Air Quality (IAQ): The status of indoor air as measured by numerous factors: temperature, humidity, airflow, pollutants,etc.
L
Leak Detector: Device or instrument, electronic sniffer or soap solution, used to detect leaks.
Liquid Line: Tube that carries liquid refrigerant from the condenser to the evaporator.
M
Micron Gauge: Instrument for measuring vacuums very close to perfect vacuum.
N
Nitrogen: A gaseous element used for purging systems and pressure test.
O
Orifice: Accurate size opening for controlling fluid flow.
Overload Protector: Device that will stop operation of unit dangerous conditions arise.
P
Package Units: Complete refrigerating system in one cabinet.
R
R-Value: The thermal resistance of a given material.
Reclaiming: Taking the refrigerant that has been removed from a system and processing it in accordance with EPA rules.
Refrigerant: Substance used in refrigerating mechanism. It absorbs heat in evaporator by change of state from liquid to a gas, and releases its heat in a condenser as the substance returns from the gaseous state back to a liquid state.
Relay: An electromagnetic mechanism moved by a small electrical current in a control circuit. It operates a valve or switch in an operating circuit.
Reversing Valve: Device used to reverse direction of the refrigerant flow, depending on weather heating or cooling is desired.
S
Seasonal Energy Efficiency Ratio (SEER): A measure of cooling capacity and efficiency.
Sensor: Material or device that goes through physical or electronic change as surrounding conditions change.
Split System: Refrigerating system that places the condensing unit outside or away from the evaporator.
Sub cooling: Cooling of liquid refrigerant below its condensing temperature.
Suction Pressure: Pressure in the low side of the refrigerating system.
Superheat: 1- Temperature of vapor above its boiling temperature as a liquid at that pressure. 2- The difference between the temperature at the evaporator outlet and the lowering temperature of the refrigerant evaporating in the evaporator.
T
Ton Refrigerant Unit: Used for measuring the capacity of a system. Unit that removes same amount of heat in 24 hours as melting of one ton of ice.
Transformer: Electromagnetic device that transfer electricity energy from the primary circuit into variations of voltage in a secondary circuit.
V
Vacuum Pump: Device used for creating vacuums for testing or drying purposes.
Valve: Device used for controlling fluid flow.
Z
Zone Controls: Controls used to maintain each specific area or zone within a building at a desired condition.
