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       #Post#: 4--------------------------------------------------
       Air Conditioning Systems
   DIR By: Master Tech
       Date: June 29, 2019, 10:08 pm
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       In order to be able to diagnose or repair any Air Conditioning
       system, first we must go over how it operates. Over the course
       of this topic we will elaborate on how the basic A/C system
       works, Components and operation, different variations of A/C
       systems (including Orifice Tube & TXV designs)
       The theory behind Refrigerant operation - how it changes state,
       vapor to liquid and back to vapor to create cooling.
       Air Conditioning systems operate on the principal of heat and
       cooling. Without dragging this topic on extensively, we'll keep
       it a bit more simple. The Compressor is used to create a high
       pressure side of the system, drawing in low pressure refrigerant
       vapor, compressing it to a working pressure of about 150-175psi,
       depending on conditions and other considerations, as the vapor
       passes through the compressor the molecules compress creating
       heat. Hot, high pressure refrigerant vapor then flows to the
       Condenser, which mounts in front of the Radiator. An electric
       fan is activated drawing cool air past the Condenser, which
       causes the Refrigerant to Condense, changing it's state from a
       high press vapor, to a high press liquid. Liquid exiting the
       condenser flows to the systems restriction which, is either a
       TXV or Orifice Tube design, causes a reaction when a high
       pressure is forced through an orifice. Passing through the
       orifice creates the low pressure, while the Refrigerant boils at
       this time. Low Pressure Liquid travels to the Evaporator within
       the vehicles HVAC plenum (Air box within the dash) As it passes
       through the Evaporator it changes state once again back to a
       vapor due to warm/hot air within the plenum and vehicle interior
       crossing the Evaporator fins.
       Since it is critical to not have any liquid refrigerant entering
       the compressor, due to the concept that liquid cannot be
       compressed, damage to the compressor will occur. In an Orifice
       tube system any remaining liquid is stored in the Accumulator
       and vaporized over time. The Accumulator also contains the
       system desiccant which is critical to keep moisture out of the
       system, moisture causes freezing within the cool temperatures of
       the Evaporator. TXV's will not be discussed in this topic as it
       adds much complexity to the most basic A/C system. If questions
       regarding a TXV system appear it will be discussed as needed.
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