Variable refrigerant flow (VRF) is an HVAC technology invented in Japan by Daikin company in 1982. Like ductless mini-split air-conditioners.
 
VRF systems use refrigerant as the cooling and heating medium for the whole system. It supports variable motor speed and thus acts with variable refrigerant flow rather than simply perform on/off operation.
 
By operating at varying speeds, the VRF units work only at the needed rate, allowing for substantial energy savings at partial-load conditions.
Heat recovery VRF technology allows individual indoor units to heat or cool as required, while the compressor load benefits from the internal heat recovery.
 
This system is mostly deployed in businesses, offices and commercial locations. The size and needed capacity may be varying depending on space, site conditions and lay-out of the target installation area.