A guide not so long in the making, here's a good explanation of how the phase system works and what each part does.
~Compressor
The compressor compresses. Seems pretty simple! The compressor has two sides though and acts as what I'll call one of the SPLIT POINTS of the phase loop. On one side of the compressor you have the High Side and one side the Low Side.
The compressor is fed my gas from the Low Side and sends it back out the high side of the compressor compressed as a hot compressed gas.
Comes After: Flex line/Copper U loop/Evaporator
Comes Before: Desuperheater/Codenser
~Desuperheater/Condenser
The Desuperheater/Condenser is on the High Side of the phase loop. Out of the compressor comes that hot compressed gas, the desuperheater coil (A simple coil of copper tube before the actual Condenser) is used for vibration dampening and removing some heat before the gas gets to the condenser. Inside the condenser the hot compressed gas because a NOT-so-hot compressed liquid. By removing the heat from a pressurized gas or refrigerant the refrigerant can then condense as the PT-Chart for that refrigerant allows.
The desuperheater is fed by the Compressor and sends out the refrigerant in a cooler condensed-liquid form.
Comes After: Compressor
Comes Before: Liquid Line Filter/Drier
***1*** SLHX Placement Point ****1****
~Liquid Line Filter/Drier
The Liquid Line Filter/Drier serves two purposes, Filtering and Drying, and is located on the High Side. At this point all of your refrigerant (if this is a basic single stage that has been properly vacuum'ed to remove moisture) should be a pressurized liquid. There are TWO TYPES OF FILTER/DRIERS. Those that operate on the LIQUID LINE and those that operate on the SUCTION LINE. For our basic single stages a LIQUID LINE IS PREFERRED. The filtering peice helps remove oxidation and crud from the circulating refrigerant, and the drier removes moisture.
The Liquid Line Filter/Drier is fed by the Condenser and sends cleaner less-moist refrigerant towards the Metering device.
Comes After: Desuperheater/Condenser,**SLHX**
Comes Before: Metering Device (CPEV, TXV, Capillary)
~The Metering Device
Their are many different forms of metering devices, but all serve the same purpose, to meter the amount of refrigerant flow into the suction side of the system. This is the other SPLIT POINT in the phase loop. In all essence this is still the HIGH SIDE.
Generally in standard single stage direct die systems Capillary Tubing is used. As the cheapest method, simply being a very small inner diameter copper tube cut to a certain length calculated by the heat load, it is quite effiecient and can be easily run to the evaporator.
The Capillary line meters the flow of liquid refrigerant to the evaporator, a longer capillary results in colder temperatures with less load capability and visa-versa.
Comes After: Liquid Line Filter/Drier
Comes Before: Evaporator
~The Evaporator/evap
The evaporator comes in many different shapes sizes and forms, but serves the same function in all. It is the first peice of the loop in the Low Side. When the compressed liquid refrigerant leaves its high pressure system and enters into the evaporator, it evaporates due to the loss of pressure. This is called a Phase Change
wavey: ). The refrigerant goes from liquid to vapor. During the process of changing from liquid to vapor heat is pulled into the refrigerant to allow it to reach the potential energy of the vapor, thus the evaporator gets COLD!
Comes After: Metering Device
Comes Before: Flex line/Copper U loop
~Flex line/Copper U loop
The Flex line/Copper U loop is located at the end of our loop right before the suction side of the compressor, and therefore is on the Low Side.
In our refrigeration systems, the evaporator is on the CPU or other heat source. To get it there we use a flexible hose, generally corrugated steel, to allow us a little flexibility in where we put the evap. Corrugated copper works as well, and "unbraided" (Not covered in a flexible steel braid) works well.
After the refrigerant has left the evaporator, it often is both liquid and gaseous. Since liquid cannot be compressed, and therefore would damage the compressor, we give it some space and room to evaporate. Since Liquid's are denser then gases, gravity helps us out by allowing us to use a simple U loop that requires the refrigerant to evaporate more before it enters the compressor.
A U loop is recommended in all systems since over time liquid returning to the compressor can kill or hinder performance.
Comes After: The Evaporator
Comes Before: The Compressor
***1*** SLHX Placement Point ****1****
The SLHX will remain seperate in this guide from the main parts as is somewhat of an unusual phase single stage part and brings a level of difficulty as well along with it.
A SLHX is a Suction Line Heat Exchanger. This peice of the puzzle falls inside both the High side AND the Low Side.
The SLHX sits before the filter/drier and also after the Flex Line. This item, which consists of two levels/paths of flow takes the cold gas coming from the evaporator and passes it along next to the hotter high side. The purpose is to improve capacity, but it also raises the Low side pressure. The difference with a SLHX may not be seen in temperature, but instead Load and overall heat load.
When using a SLHX you will also need to insulate all the new cold area's, generally from the condenser onwards, and double leak test because undoing insulation over a full unit can be quite a hardship.
Do not try a SLHX in your first unit as you may find yourself QUITE dissapointed.
***1*** SLHX Placement Point ****1****
I hope this helps you guys out, and I'll add the SLHX bit in an hour or so.
~Compressor
The compressor compresses. Seems pretty simple! The compressor has two sides though and acts as what I'll call one of the SPLIT POINTS of the phase loop. On one side of the compressor you have the High Side and one side the Low Side.
The compressor is fed my gas from the Low Side and sends it back out the high side of the compressor compressed as a hot compressed gas.
Comes After: Flex line/Copper U loop/Evaporator
Comes Before: Desuperheater/Codenser
~Desuperheater/Condenser
The Desuperheater/Condenser is on the High Side of the phase loop. Out of the compressor comes that hot compressed gas, the desuperheater coil (A simple coil of copper tube before the actual Condenser) is used for vibration dampening and removing some heat before the gas gets to the condenser. Inside the condenser the hot compressed gas because a NOT-so-hot compressed liquid. By removing the heat from a pressurized gas or refrigerant the refrigerant can then condense as the PT-Chart for that refrigerant allows.
The desuperheater is fed by the Compressor and sends out the refrigerant in a cooler condensed-liquid form.
Comes After: Compressor
Comes Before: Liquid Line Filter/Drier
***1*** SLHX Placement Point ****1****
~Liquid Line Filter/Drier
The Liquid Line Filter/Drier serves two purposes, Filtering and Drying, and is located on the High Side. At this point all of your refrigerant (if this is a basic single stage that has been properly vacuum'ed to remove moisture) should be a pressurized liquid. There are TWO TYPES OF FILTER/DRIERS. Those that operate on the LIQUID LINE and those that operate on the SUCTION LINE. For our basic single stages a LIQUID LINE IS PREFERRED. The filtering peice helps remove oxidation and crud from the circulating refrigerant, and the drier removes moisture.
The Liquid Line Filter/Drier is fed by the Condenser and sends cleaner less-moist refrigerant towards the Metering device.
Comes After: Desuperheater/Condenser,**SLHX**
Comes Before: Metering Device (CPEV, TXV, Capillary)
~The Metering Device
Their are many different forms of metering devices, but all serve the same purpose, to meter the amount of refrigerant flow into the suction side of the system. This is the other SPLIT POINT in the phase loop. In all essence this is still the HIGH SIDE.
Generally in standard single stage direct die systems Capillary Tubing is used. As the cheapest method, simply being a very small inner diameter copper tube cut to a certain length calculated by the heat load, it is quite effiecient and can be easily run to the evaporator.
The Capillary line meters the flow of liquid refrigerant to the evaporator, a longer capillary results in colder temperatures with less load capability and visa-versa.
Comes After: Liquid Line Filter/Drier
Comes Before: Evaporator
~The Evaporator/evap
The evaporator comes in many different shapes sizes and forms, but serves the same function in all. It is the first peice of the loop in the Low Side. When the compressed liquid refrigerant leaves its high pressure system and enters into the evaporator, it evaporates due to the loss of pressure. This is called a Phase Change

Comes After: Metering Device
Comes Before: Flex line/Copper U loop
~Flex line/Copper U loop
The Flex line/Copper U loop is located at the end of our loop right before the suction side of the compressor, and therefore is on the Low Side.
In our refrigeration systems, the evaporator is on the CPU or other heat source. To get it there we use a flexible hose, generally corrugated steel, to allow us a little flexibility in where we put the evap. Corrugated copper works as well, and "unbraided" (Not covered in a flexible steel braid) works well.
After the refrigerant has left the evaporator, it often is both liquid and gaseous. Since liquid cannot be compressed, and therefore would damage the compressor, we give it some space and room to evaporate. Since Liquid's are denser then gases, gravity helps us out by allowing us to use a simple U loop that requires the refrigerant to evaporate more before it enters the compressor.
A U loop is recommended in all systems since over time liquid returning to the compressor can kill or hinder performance.
Comes After: The Evaporator
Comes Before: The Compressor
***1*** SLHX Placement Point ****1****
The SLHX will remain seperate in this guide from the main parts as is somewhat of an unusual phase single stage part and brings a level of difficulty as well along with it.
A SLHX is a Suction Line Heat Exchanger. This peice of the puzzle falls inside both the High side AND the Low Side.
The SLHX sits before the filter/drier and also after the Flex Line. This item, which consists of two levels/paths of flow takes the cold gas coming from the evaporator and passes it along next to the hotter high side. The purpose is to improve capacity, but it also raises the Low side pressure. The difference with a SLHX may not be seen in temperature, but instead Load and overall heat load.
When using a SLHX you will also need to insulate all the new cold area's, generally from the condenser onwards, and double leak test because undoing insulation over a full unit can be quite a hardship.
Do not try a SLHX in your first unit as you may find yourself QUITE dissapointed.
***1*** SLHX Placement Point ****1****
I hope this helps you guys out, and I'll add the SLHX bit in an hour or so.