HVAC Variable Refrigerant Flow Systems Course

 No: M03-014

CED Engineering


Variable Refrigerant Flow (VRF) Systems

Variable refrigerant flow (VRF) is an air-condition system configuration where there is
one outdoor condensing unit and multiple indoor units. The term variable refrigerant flow
refers to the ability of the system to control the amount of refrigerant flowing to the
multiple evaporators (indoor units), enabling the use of many evaporators of differing
capacities and configurations connected to a single condensing unit. The arrangement
provides an individualized comfort control, and simultaneous heating and cooling in
different zones.

Currently widely applied in large buildings especially in Japan and Europe, these
systems are just starting to be introduced in the U.S. The VRF technology/system was
developed and designed by Daikin Industries, Japan who named and protected the term
variable refrigerant volume (VRV) system so other manufacturers use the term VRF
"variable refrigerant flow". In essence both are same.

With a higher efficiency and increased controllability, the VRF system can help achieve a
sustainable design. Unfortunately, the design of VRF systems is more complicated and
requires additional work compared to designing a conventional direct expansion (DX)
system.

This course provides an overview of VRF system technology.

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