VRV stand for variable refrigerant volume a patented trade name of for a system by Daikin of japan in 1982.

The system which use the principle of varying the amount of refrigeration flowing in the pipework are often known as VRV systems.

The principle of VRV/VRF system is similar to that of a multisplit system, The single condensing unit is connected to number of room evaporating units which may be installation as per Client Requirement that supposed to a Split Ac Unit, Cassette Type Unit, Cealing Concealed Unit, One Way Cassette Unit, Ductable Unit, Lastly A Chiller Type Unit.

The major difference is that these systems have only one set of pipe work common to all the indoor units as opposed to the multi-split Air conditioner system in which such indoor unit has its own pipe lines.

The nominal capacity of the outoor units range from 11.2 to 33.5kw and a combination of indoor units upto this capacity can be connected, The individual indoor units range from 2.2kw to 14,5kw cooling capacity.

The refrigerant volume flow rate varies to match the load of the evaporators by changing the speed of the compressor using a frequency inverter technology, This system is suitable for a wide range of applications, multi-storey projects or Apartments,Villas both new and old one

Advantages:

1. Less space. There is no requirement of plant room/Ahu Room, Plant room can be utilized for other purpose i.e.car parking and AHU room space be utilized for office area.
2. Easy design. In modern building cooling need may vary,When in some area Air-conditioning is required after working hour, with conventional system, the entire plant is to be run at part load with VRV/VRF system, the individual indoor unit is operated and the requirement is maintained efficiently.
3. Precise temperature control.  With this system, the room temperature can be maintained at constant level without variations with sophisticated control we can also fit a central remote system for controlling all the connected indoor units.
4. Capacity control of indoor unit. Because of electronic expansion valve provided in indoor unit, adjustment of the refrigerant volume flow rate in load response is possible.

Safety. 

1. Like split system, the refrigerant used in the system is R410a, The system is designed to be suitable for larger buildings as described erlier.
2. The refrigerant pipe work run throughout the building for the system passing through different areas.
3. The risk of a fire or physical damage may occur which be considered. In case of fracturing of copper pipes, all the refrigerant in that group could be released and the possible concentration of gas in the associated occupied space be assessed.
4.  Environmental considerations:  Placement of condensers outside the building should be considered from aesthetics point of view. The heat rejection by the condenser be alseo considered