VRF

Variable Refrigerant Flow

Note:- Information sourced from Ashrae.

VRF systems are larger capacity, more complex versions of the ductless multisplit systems, with the additional capability of connecting ducted style fan coil units. They are inherently more sophisticated than multisplits, with multiple compressors, many evaporators, and complex oil and refrigerant management and control systems. They do not provide ventilation, so a separate ventilation system is necessary.

The term variable refrigerant flow refers to the ability of the system to control the amount of refrigerant flowing to each of the evaporators, enabling the use of many evaporators of differing capacities and configurations, individualized comfort control, simultaneous heating and cooling in different zones, and heat recovery from one zone to another. This refrigerant flow control lies at the heart of VRF systems and is the major technical challenge as well as the source of many of the system’s advantages.

For further information refer to http://www.ashrae.org/doclib/20070327_goetzler.pdf