What is the Variable Refrigerant Flow (VRF) or Variable Refrigerant Volume (VRV) Inverter air conditioning system?

In VRF/ VRV Inverter air conditioning systems, the refrigerant quantity to each indoor unit is absolutely controlled and proportional to the cooling loads of the space. It is consisted of the central outdoor unit (or modular units), with DC Inverter compressor and direct expansion indoor units of different models and capacities; which are supplied with electronic expansion valves for more precise flow control of the refrigerant. A VRF/VRV inverter air conditioning system provides comfort conditions of high standards in the air conditioned rooms and space saving (indoor and outdoor of the building), as the dimensions of the units and piping are significantly smaller. In addition the VRF /VRV Inverter air conditioning units operate at lower cost, in comparison to any other central air conditioning system.