HVAC Variable Refrigerant Flow

This online PDH or CE course reviews the attributes of an emerging space conditioning technology; variable refrigerant flow (VRF) systems. Material presented in this paper was synthesized from the open literature, private interviews with industry experts and data (sometimes proprietary data) obtained from manufacturers. VRF systems are enhanced versions of ductless multi-split systems, permitting more indoor units to be connected to each outdoor unit and providing additional features such as simultaneous heating and cooling and heat recovery. VRF technology uses smart integrated controls, variable speed drives, refrigerant piping, and heat recovery to provide products with attributes that include high energy efficiency, flexible operation, ease of installation, low noise, zone control, and comfort using all-electric technology. VRF systems are very popular in Asia and Europe and, with an increasing support available from major U.S. and Asian manufacturers are worth considering for multi-zone commercial building applications in the U.S.