Depending on the size of the premises and the capacity of the air conditioner, it is customary to distinguish three main segments:    household air conditioners;    semi-industrial or commercial air conditioners;    industrial air conditioners.Household air conditioners include split systems of wall and floor-ceiling, channel type with an indoor unit capacity of up to 5 kW. Such equipment is intended for air conditioning of apartments.Semi-industrial air conditioners include all split systems of channel, cassette, columnar, floor-ceiling and wall-mounted type with a capacity of over 5 kW.Industrial air conditioners are formed by parallel connection of cassette, duct, floor-ceiling or columnar indoor units to one or more outdoor units with a capacity of over 10 kW (they are also called VRV (VRF) systems).Separate categories are highlighted:duct air conditioners, rooftops and cabinet monoblocks for indoor installation (category "Duct Unitary");central air conditioners, air handling units and air-cooling machines (category of central air conditioning systems).