23.02.2021

Everything You Need to Know about a VRF-System

When selecting an AC, a person familiar with air conditioners and cooling systems, can often get confused when it comes to abbreviations such as VRF or VRV… So what do these designations mean and is there a difference? We will explain to you all the main points and nuances.

VRF-systems or systems with Variable Refrigerant Flow can be called a real Rolls-Royce in the air conditioning sector, both in their technology and functionality. Equipment of this type is purchased to ensure a comfortable climate in several spaces at the same time. That is why these aircon systems are sometimes called “multi-zone”.

Outdoor Unit

Indoor Units

IR Remote control

Wired control panel

Centralized controller

Communication wiring

Refrigerant piping

RC Line

Key Requirements of a VRF-System

A real VRF-system must comply with 4 key requirements:

This system only includes a single refrigerant medium. This is the main differentiating factor between a VRF-system and a chiller fan-coil system, which includes a hydraulic circuit in addition to a refrigerant circuit.

VRF-system includes inverter compressor. Remember that an inverter is a device, which allows for regulation of the compressor’s power. When turned on, an inverter AC unit immediately begins to work with increased power in order to achieve the set temperature as quickly as possible. Once this temperature is reached, the aircon does not turn off, like a regular one, but slowly reduces its power.

The number of internal units can be increased, depending on the customer’s requirements. In other words, a VRF-system possesses a scalability property.

Each external unit in a VRF-system is connected to several internal units (fancoils) installed in various locations (zones).

Typical Structure of a VRF-System

A standard “Variable Refrigerant Flow” system includes:

A single powerful external unit(which includes one or more compressors)
Several internal units (fancoils)
Pipelines for circulation of the refrigerant medium , which connect external block with internal ones
Electrical cables, which form a closed circuit, as well as connect all the internal units with external ones
A control system

A control system, in turn, has a complex structure and combines various control devices, connected either through electrical cables or wireless technology. As a rule, a VRF-system includes a central control and separate control devices for internal fancoils.

How Does a VRF-System Work?

Each producer of VRF-systems has their own unique control system for their products. So, you have a lot of choices, — you can find something that works best for you in terms of convenience and functionality.

The principle behind a control system for VRF-systems is rather simple, — the control system processes the signals, which are input by the user (for example, required temperature in the room), as well as external signals (for example, the temperature of the outside air). Next, the control system automatically chooses a working mode in accordance with selected parameters and optimal electrical energy consumption.

The user can select different climate modes for separate rooms, using control panels and remote controls for separate internal units. The power of the compressor(s) of the external unit is automatically regulated and would depend on how many internal devices are running in the system.

What are the Difference

Many mistakenly think that “Variable Refrigerant Volume” and “Variable Refrigerant Flow” are two distinct technologies, but it is not exactly the case. The truth is that the first VRF-systems were produced by the company named Daikin in 1982. Also, Daikin has registered the abbreviation VRV as their official trademark. All the other climate brands had no choice but to invent something of their own to label similar systems. This is how the VRF abbreviation came to be, which became commonly used among various brands. And VRV- systems are produced exclusively by Daikin.

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