Compressors can be classified into positive displacement compressors and dynamic compressors based on their operating principle. Positive displacement compressors are further divided into reciprocating compressors and rotary compressors; dynamic compressors are divided into axial flow compressors, centrifugal compressors, and mixed flow compressors.
Reciprocating compressors are generally classified according to their casing type: open, hermetic, and semi-hermetic compressors. Hermetic compressors are those where the entire compressor is housed within a single casing.
Based on application, compressors can be classified into low back pressure, medium back pressure, and high back pressure compressors. Low back pressure compressors (evaporation temperature -35 to -15°C) are generally used in household refrigerators and food freezers. Medium back pressure compressors (evaporation temperature -20 to 0°C) are generally used in beverage coolers and milk coolers. High back pressure compressors (evaporation temperature -5 to 15°C) are generally used in room air conditioners, dehumidifiers, and heat pumps.
There are five main types of compressors used in the refrigeration and air conditioning industry: reciprocating, screw, rotary, scroll, and centrifugal. Reciprocating compressors are the most widely used type in small and medium-sized commercial refrigeration systems. Screw compressors are mainly used in large commercial and industrial systems. Rotary and scroll compressors are mainly used in residential and small-capacity commercial air conditioning units, while centrifugal compressors are widely used in air conditioning systems in large buildings.
