• Accumulator -
    A canister that contains filter screens and a desiccant to attract and hold moisture. Identical in function to a receiver drier, but the accumulator is located on the A/C system's low pressure side, between the evaporator and the compressor.
  • Air Conditioner -
    A mechanical device that will control the temperature, humidity and circulation of air.
  • Ambient Temperature -
    Abbreviated as ABM, it is the temperature of the air that surrounds an A/C system.
  • Blower -
    A mechanical device made of a fan and a motor mounted near an evaporator. It is used to create air current that can be used to heat or dry something.
  • Boiling Point -
    The temperature at which liquid substances change to vapor or gas.
  • Capillary Tube -
    A tube that is usually connected to a thermostatic switch or an expansion valve; a tube filled with a refrigerant to measure or gauge a remote temperature. Changes in temperature force the refrigerant to contract or expand. This helps operate or regulate the switch or the valve.
  • Carbon dioxide -
    An inert, odorless and colorless gas used to clean or purge air conditioning components.
  • Charge -
    (Noun) The exact amount of refrigerant in an A/C system. (Verb) The act of adding refrigerant into an AC system.
  • Cold -
    Low temperature.
  • Compressor -
    A pump used to suck low pressure refrigerant vapor from the evaporator. It compresses the low pressure or pumps it to a higher pressure gas or vapor and sends it to the condenser.
  • Condensing -
    The act of changing gas or vapor into a liquid state.
  • Contaminants -
    An impurity. Anything else apart from refrigerant oil or a refrigerant in an AC system. Occurs as a result of moisture or water. Causes corrosive acids to form when mixed with a refrigerant.
  • Cycling clutch system -
    An AC system that is controlled by engaging and disengaging the compressor clutch so as to control system pressure at the evaporator.
  • Dehumify -
    The act of removing moisture or water from the air.
  • Desiccant -
    A type of drying agent used in receiver dryers and accumulators to attract and remove moisture so as to ensure a dry system.
  • Dichlorodifluoromethane -
    Commonly referred to by its trademark name ‘freon’, Dichlorodifluoromethane is the chemical name of Refrigerant 12.
  • Discharge -
    To remove, get rid of or bleed the refrigerant from the AC system into a recovery system.
  • Discharge Line -
    Refers to the hose pipe or tube that connects the compressor outlet with the condenser.
  • Discharge pressure -
    Sometimes referred to as the high pressure. It is the refrigerant’s pressure at the discharge side of the compressor.
  • Evacuate -
    To remove moisture from an AC system by placing it under vacuum. The act has nothing to do with flushing or cleaning.
  • Evaporate -
    The process where a liquid substance changes into gas or vapor.
  • Evaporator coil -
    It is sometimes referred to as a coil expansion. It is the evaporator in an AC system.
  • Flooding -
    A condition that occurs when excess liquid refrigerant enters the evaporator. It usually occurs as a result of the expansion valve getting lodged.
  • Flushing -
    The process of cleaning all internal components of an AC system. The process requires the refrigerant to be first removed. It gets rid of corrosion and contamination. Driers, accumulators and compressors are never flushed.
  • Freeze up -
    A situation that occurs when an AC system gets contaminated with excess moisture. The moisture freezes and forms ice at the internal expansion valve, resulting in a no cooling condition.
  • Freon -
    Dupont’s registered trademark. An American conglomerate that manufactures refrigerants.
  • Head pressure -
    The level of refrigerant pressure on the discharge side of an AC system.
  • Heater core -
    A heater exchanger device that allows hot engine to flow as it cools before it heats the air that enters the vehicle passenger compartment.
  • Humidity -
    Water or moisture in the air.
  • Magnetic clutch -
    An electromagnetic gadget used to engage or disengage the compressor. It is made up of a clutch bub, a coil and a pulley.
  • Manifold gauges -
    A set of pressure gauges used to access an AC system so as to monitor pressures, recharge or perform a vacuum.
  • Nitrogen -
    An inert gas that is both colorless and odorless. It can be used to clean or purge contaminants from an air conditioning system. It can also be used as ‘final’ switch through an AC system so as to attract and get rid of moisture when an AC system has been opened for longer than necessary.
  • Orifice -
    A small passage or an opening.
  • Orifice tube -
    A small part that replaces the thermostatic expansion valve of an automotive AC system.
  • Overcharge -
    Having excess refrigerant in the AC.
  • Pressure switch -
    (Also known as the Pressure Cycling Switch) It is a switch activated by pressure that is used to engage or disengage the compressor clutch.
  • Receiver drier -
    A canister that contains screens, a desiccant and filter elements. It absorbs and holds moisture in an AC system.
  • Refrigerant -
    A cooling substance used for refrigeration.
  • Refrigerant oil -
    A special type of highly refined oil. It is free of contaminants and used in an AC system to lubricate the compressor.
  • Relative humidity -
    The amount of moisture or water vapor in the air.
  • Resistor -
    A gadget used to limit or drop voltage. It is made of wires that have different diameters wound into several coils. This provides an easy way or controlling and regulating voltage.
  • Schrader valve -
    A spring loaded valve located inside the service valve fitting that is similar to a tire valve. It holds the refrigerant charge in an AC system. It also provided special access to service adapters which depress the Schrader valve.
  • Sight glass -
    A window in an AC system. It is usually installed on the receiver drier or the liquid line. New AC systems that use R-134a may or may not have a sight glass.
  • Suction side -
    The low side of an AC system. The side includes the accumulator and the evaporator in an equipped AC system.
  • Tetrafluoroethane -
    Refrigerant R-134a. It is sometimes mistakenly referred to as ‘freon’.
  • Thermostatic switch -
    A temperature sensitive switch that is used to monitor, control and regulate the compressor clutch and the cycling process. It gets engaged and disengaged depending on the preset temperature levels of the switch.
  • Trinary pressure switch -
    A pressure activated switch that provides protection for the compressor against high side pressures that may be too high or too low.
  • Undercharge -
    The state of an AC system when it has insufficient refrigerant. It can result in lack of cooling and cause compressor damage or failure.
  • Vacuum -
    A state that is completely devoid of any matter. A level of pressure that is less than the atmospheric pressure.
  • Valve -
    A device in an AC system that regulates the flow of refrigerants into the evaporator.
  • Vapor -
    The gas that forms when a liquid substance exceeds its boiling point.