The short answer
There's no technical difference in the idea. VRV (variable refrigerant volume) is Daikin's trademarked name for the technology, which Daikin introduced. VRF (variable refrigerant flow) is the general industry term that every other manufacturer uses. A Daikin system is called VRV; Mitsubishi Electric City Multi, Fujitsu / GENERAL Airstage and others are VRF.
How a VRV/VRF system works
One outdoor system is connected by refrigerant pipework to many indoor units, often a dozen or more. Each indoor unit has its own controller. Inverter compressors and electronic expansion valves vary the amount of refrigerant sent to each indoor unit, continuously, to match what that room needs.
- Every room is controlled separately. Each one is set to its own temperature, or switched off.
- Output follows the real load, rather than the system cycling on and off at full capacity.
- One outdoor system replaces a row of condensers.
Heat pump or heat recovery?
Most VRV/VRF systems come in two types:
- Heat pump: the whole system heats or cools at any one time, though each room still has its own set temperature. This suits most homes.
- Heat recovery: some areas can be heated while others are cooled at the same time, with heat moved from one to the other. This suits buildings with very different loads, such as a sunny office facade and an internal meeting room.
The main brands
- Daikin VRV, including the compact VRV-S units used in many homes.
- Mitsubishi Electric City Multi.
- Fujitsu / GENERAL Airstage VRF, including the compact J-IVS series.
All three make excellent equipment. How the brands compare.
What matters more than the name
The difference between a good and a poor VRV/VRF system is mostly in the design and installation: indoor units matched to each room, correctly sized pipework and branch joints, clean, nitrogen-brazed and pressure-tested pipework, sensible drainage, and careful commissioning. Those are the things to ask about when you compare quotes.
Planning a project? Read about VRV/VRF for homes, or, if you're a builder, how we work on VRV/VRF projects.