1) Central Air Conditioning Plant Room:
The plant room comprises of all the important components of the chilled water air conditioning plant. These include the compressor, condenser, thermostatic expansion valve and the evaporator or the chiller. The compressor is of open type and can be driven by the motor directly or by the belt via pulley arrangement connected to the motor. It is cooled by the water just like the automotive engine.
The condenser and the evaporator are of shell and tube type. The condenser is cooled by the water, with water flowing along the shell side and refrigerant along the tube side.The thermostatic expansion valve is operated automatically by the solenoid valve.
The evaporator is also called as the chiller, because it chills the water. If the water flows along the shell side and refrigerant on the tube side, it is called as the dry expansion type of chiller. If the water flows along tube side and the refrigerant along the shell side, it is called as the flooded chiller. The water chilled in the chiller is pumped to various parts of the building that are to be air conditioned. It enters the air handling unit, cools the air in cooling coil, absorbs the heat and returns back to the plant room to get chilled again. The amount of water passing into the chiller is controlled by the flow switch.
In the central air conditioning plant room all the components, the compressor, condenser, thermostatic expansion valve, and the chiller are assembled in the structural steel framework making a complete compact refrigeration plant, known as the chiller package. Piping required to connect these parts is also enclosed in this unit making a highly compact central air conditioning plant.