Variable Refrigerant Flow

Variable refrigerant flow, or VRF, is an HVAC technology invented by Daikin Industries in 1982 that uses variable-speed compressors and direct refrigerant circulation to multiple indoor units rather than the ducted air handlers of conventional central systems. By 2007 VRF systems were installed in roughly half of mid-size Japanese office buildings, and the technology has been credited with energy savings of up to 55 percent compared with conventional chiller-based systems, along with finer zone-by-zone control and a smaller building footprint since it eliminates large duct runs. Modern installations increasingly integrate VRF systems with home automation and building management systems for centralized monitoring and control.