Kathleen Ng/ January 18, 2018/ Automotive Cars


The compressor pumps the refrigerant throughout the system. The benefit is to suck the low pressure gas and the lowest temperature of the evaporator and then press / compress the gas, so that it becomes gas with high pressure and temperature, then flowed to the condenser. So the compressor work is to:

  1. Lower the pressure in the evaporator, so that the liquid coolant in the evaporator can evaporate at a lower temperature and absorb more heat from the surrounding.
  2. Vacuuming the refrigerant gas from the evaporator, then raising the pressure and temperature of the refrigerant gas, and draining it into the condenser so that the gas can condense and provide heat to the cooling medium of the condenser.

There are three kinds of compressors that are widely used in carrier refrigeration service are:

  1. Compressor Toorak, compression is done by piston.
  2. Rotation compressor, the compression is done by blade or vane and roller
  3. Centrifugal compressors, centrifugal compressors do not have these tools compression arising due to centrifugal force that occurs because the gas is rotated by high speed rotation and impeller. The three kinds of compressors have their respective advantages. Its use is determined by its capacity, its usage, its installation and the type of refrigerant used.


A condenser is a means for converting a refrigerant from a gas to a liquid. Cooling material from a compressor with high temperature and pressure, the heat exits through the surface of the condenser ribs into the air. As a result of heat loss, the gas coolant is initially cooled to saturated gas, then condensed into liquid.


An evaporator is a device in which the coolant evaporates from liquid to gas. Through the heat transfer from the wall, taking heat from the surrounding room into the system, the heat is then brought to the compressor and discharged by the condenser.


The filter for air conditioners made from copper pipe is useful for filtering impurities in the system, such as lead, mud, rust and other dirt not to enter the capillary pipe or the expansion faucet. The filter should filter out all the dirt inside the system, but should not cause pressure drops or make the system clogged.

Capillary Pipe

  1. Lowering the pressure of the liquid cooling material flowing inside the pipe.
  2. Controlling or adjusting the amount of liquid refrigerant that flows from the high pressure side to the low pressure side.

Expanse Taps

  1. Automatic Expansion Valve
  2. Thermostatic Expansion Valve Thermostatic Expansion Valve is better and more widely used, but in AC only use automatic expansion valve, so here we will only talk about automatic expansion valve only. Its purpose is to lower the fluid and pressure of the evaporator pressure within the specified limits by flowing a certain amount of liquid coolant into the evaporator.

Cooling Materials

The refrigerant is a substance which is readily converted from gas to liquid or vice versa, used to remove heat from the evaporator and dispose of it in the condenser. Refrigerant-11 (R-11), R-12, R-13, R-22.

Compressor Oil

The compressor oil for refrigerating machines shall have special properties for this purpose. The compressor oil is used to protect and lubricate the moving parts of the compressor. Because in fact the compressor oil is always connected, even mixed with the refrigerant inside the compressor and flows together to all parts of the system. The oil must withstand the high temperature and pressure of the compressor and still can provide lubrication and protect the compressor parts move to avoid wear and break.