Know the VRF HVAC and VRV HVAC

Know the VRF HVAC and VRV HVAC

VRF stand for Variable refrigerant flow and VRV stand for Variable refrigerant volume. Both VRF and VRV are same . VRV name is used by Daikin, whereas other organisations are using term VRF.

This VRV or VRF HVAC system comprises of multiple indoor fan coil unit connected with a single outdoor unit. The outdoor unit is master unit and it control the flow of refrigerant to indoor fan coil unit as per demand. In another way , it is combination of various household Split AC with a single outdoor unit.

VRF and VRV HVAC
VRF / VRV HVAC

Outdoor Unit of a VRF or VRV have: –

Just like other Split AC , the outdoor unit contain Compressor. Along with it it has Oil separator.

All outdoor units may have any of the following compressor arrangement systems: –

  1. Single Variable frequency drive (VFD) compressor.
  2. Compressor with VFD and another compressor without VFD.
  3. Multiple compressors with VFD.

Traditional fixed speed compressor works on on-off mode,as It starts with load rise and get it off once the demand gets satisfied. However, the VFD compressor change their speed as per the load requirement and change the flow of refrigerant as per load demand. It does not work on on-off mode but it operates on continuous basis and boost life of compressor.

Type of compressor may be :-

  1. Twin rotary compressor.
  2. Scroll compressor.

Twin rotary compressor has excellent efficiency at all speeds.

The outdoor unit works on either of following principle.

  1. Single Phase Heat Pump (3 to 5 Tr).
  2. 3-Phase Heat Pump (6 to 36 Tr).
  3. 3-Phase Heat Recovery (6 to 28 Tr).

Each indoor unit of VRF or VRV has fan coil arrangement with its own metering device. Indoor units are available in : –

 

  1. 4-Way Cassette type (0.4 to 4 Tr).
  2. Hi-Wall mounted type (2 to 8 Tr).
  3. Split type (0.4 to 2.5 Tr).
  4. Floor Console (0.5 to 2 Tr).
  5. Ducting type ( 3 to 8 Tr).
  6. Vertical AHU type (1.5 to 4.5 Tr).
Metering system of VRF or VRV HVAC
Metering system of VRF or VRV HVAC

The indoor unit are available in different sizes and makes VRF flexible and compact.

The refrigerant used are 410 A or 407 C.

 

Advantages of VRF or VRV HVAC system: –

 

  1. One outdoor unit can serve to upto 64 Units.
  2. It has high flexibility and indoor units may be combination of any type.
  3. Indoor unit may have any capacity from 1 Tr to 16 Tr.
  4. High energy Saving.
  5. It works with zoning and send the refrigerant as per load demand.
  6. Duct free system.
  7. Very less foot print. Even it can be carried in lift.
  8. Very easy to install just like home AC.
  9. Suitable where zoning or part load is required.

See below for more clarification on VRF or VRV HVAC system.

The various supplier for VRF or VRV HVAC systems are:-

  1. Daikin
  2. Toshiba
  3. Hitachi
  4. Mitsubishi.

 

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