Necessary knowledge of air conditioning and HVAC

Central air conditioning: central air conditioning is an air conditioning system in which a host controls different rooms through air passage or cold and hot water pipes connected to multiple ends to achieve the purpose of indoor air conditioning. That is to say, the heating and cooling of all rooms are supplied by it. There are only forced draft fans in each room, and all the external machines originally refrigerated are integrated into a box.

Central air conditioning system: there are main engine and terminal system. According to the medium used to bear the indoor heat and humidity load, it can be divided into all air system, all water system, air-water system and refrigerant system. According to the concentration degree of air treatment equipment, it can be divided into centralized and semi centralized. According to the source of treated air, it can be divided into closed type, direct flow type and mixed type (primary return air and secondary return air). The main equipment consists of air conditioning host (cold and heat source), air cabinet, fan coil, etc.