Condensing unit (also called compressor unit) is the most important part of whole cold room system. A condensing unit typically is a high side assembly of a refrigeration system. It is an assembly of compressor, condenser, fan motor, controls and a mounting plate. It has the function of a heat exchanger to cool down and condense the incoming refrigerant vapor into liquid and a fan for blowing outside air through the heat exchanger section to cool the refrigerant inside. Condensing units have various designs and come in many sizes ranging from small household appliance units to very large industrial units used in food and manufacturing processes.