What does VRF air conditioner mean?
VRF is Variable Refrigerant Flow abbreviated: "variable refrigerant flow." The name of the system describes its key feature. Thanks to the inverter compressor in the outdoor unit and the electronic expansion valves in the indoor units, each room receives exactly the amount of refrigerant it needs.
VRV (Variable Refrigerant Volume) is Daikin's registered name; technically it describes the same system family. Other manufacturers use their own product names, for example LG Multi V, Mitsubishi Electric City Multi, Samsung DVM, Toshiba SMMS and Hitachi Set Free. For general information about brands, see our air conditioner and VRF brands guide.
How does a VRF air conditioning system work?
- The outdoor unit (or modular outdoor unit group) runs on an inverter compressor and adjusts its capacity to the building's instantaneous load.
- The refrigerant is distributed to the indoor units through copper pipes and branching elements (refnets, branch units).
- The electronic expansion valve of each indoor unit adjusts the amount of refrigerant according to the room's needs.
- The indoor and outdoor units constantly communicate over a communication line; each indoor unit has its own address.
- The whole system can be monitored and managed from a single point through a central controller or building automation.
Difference between heat pump and heat recovery VRF
| Heat pump VRF (2-pipe) | Heat recovery VRF (3-pipe or with BS boxes) | |
|---|---|---|
| Operation | All indoor units either cool or heat at the same time | Some indoor units can cool while others heat |
| Suitable buildings | Buildings with rooms that are similar in orientation and use | Offices with different facades, hotels, mixed-use buildings |
| Energy | Standard | Savings are possible by transferring heat taken from one room to another |
We explain how much can be saved, with examples, in our article on heat recovery VRF.
Service or maintenance for your VRF system
Tell us the brand, outdoor unit model and number of indoor units, and we will get back to you about a maintenance plan or fault diagnosis.
VRF indoor unit types
- Wall-mounted type
- Cassette type (4-way or 1-way airflow)
- Concealed ceiling ducted type
- Ceiling and floor type
- Fresh air and heat recovery unit connections
In choosing an indoor unit, the ceiling structure of the space, noise expectations and air distribution are decisive. Details: cassette and ducted air conditioners.
Where are VRF air conditioning systems used?
VRF is common in mid-sized offices, hotels, schools, clinics and residences. Because it requires no water piping and can grow modularly, it can be installed faster than a chiller. In very large buildings or facilities with high fresh air demand, chiller and air handling unit solutions can come to the fore; for a comparison, see our article VRF or chiller.
VRF air conditioner maintenance and common faults
Maintenance on VRF systems covers outdoor unit coil cleaning, indoor unit filter and drain checks, pressure and temperature measurements, a refrigerant leak test and a check of the communication line. The most common problems are refrigerant leaks, addressing and communication errors, and sensor faults. Details: VRF air conditioner maintenance, VRF error codes, VRF refrigerant leaks. We are an authorized service for LG Multi V systems; on other brands we work as an independent technical service.
Frequently asked questions
Are VRF and VRV the same thing?
Technically they are the same system family. VRV is Daikin's registered name; other manufacturers use VRF or their own product names.
What is the difference between VRF and a multi-split air conditioner?
Both connect multiple indoor units to a single outdoor unit. VRF supports many more indoor units, longer piping distances, central control and heat recovery; it is designed for large buildings.
Does a VRF air conditioner heat?
Yes. VRF systems also heat, using the heat pump principle. With heat recovery types, some rooms can be cooled while others are heated at the same time.
How many indoor units can be connected to one VRF outdoor unit?
It depends on the outdoor unit capacity and the manufacturer's limits; large modular systems can connect dozens of indoor units. The exact number is determined by the project calculation.
How often should VRF air conditioner maintenance be done?
At least one comprehensive maintenance visit per year is generally recommended, along with intermediate filter checks depending on how heavily the system is used.