Firstly, we need to know what a VRV system or VRF system is.
A VRV or VRF system is an air conditioning system that consists of two types of units: the outdoor unit and the indoor unit.
Now, let us talk about the two types of units.
The outdoor unit includes a compressor that controls the refrigerant flow rate and volume.
This control depends on the number of indoor units, and the system is recommended for use in green buildings.
Also, in areas where it is difficult to provide a water source for the chilled water system, such as desert areas.
As its name suggests, this system is a variable system, meaning its load is variable, not fixed, unlike the direct expansion unit (as in a split AC unit & a Window AC unit).
This system allows the thermostat installed in each space to control the temperature in that space independently of the others.
This is because each space has its own internal unit.
Note: VRF was invented by a Japanese company called “Daikin”.
There are two types of VRF systems:
- Air-cooled VRF system.
- Water-cooled VRF system.
Pros or Benefits of VRF or VRV system:
- High efficiency.
- Lower power consumption because some internal units are switched off, so the load is part load, leading to a decrease in total power consumption.
Cons or disadvantages of the VRF system:
- It’s a more complicated system than the direct expansion system.
- It requires highly trained personnel to execute the work because the internal network relies on copper pipes that require welding during installation.
Important notes on these systems:
- The greater the distance between the internal & external units, the higher the cost of installing and operating the system.
- The outdoor unit of the same system can be connected to different indoor unit types, such as cassette, ceiling-mounted, wall-mounted, Split AC, and so on.
- VRF or VRV system can be a combined system to give cooling and heating at the same time.
- VRF is usually used with applications with a higher load capacity than 6tons. But in this case, the cost of the VRF heating/cooling system is higher than for VRF cooling or heating only.
Types of pipe routings:
Two-pipe system: this system is used when all indoor units operate cooling units only or heating units (not mixed).
Three-pipe system: This system is used when some indoor units operate for cooling while others operate for heating.
During the design of the VRF system, it shall be assumed that all internal units operate simultaneously (the worst case).
Here, some photos of the practical installations of the VRV system on site
In the above photo, you can see the supports of the copper pipes for the indoor units, which will be installed above the false ceiling level.
This photo is for the outdoor VRV unit on the roof.
I hope that you got a good brief about this system. So, if you like it, please share it with your friends.
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