What is VRV/VRF ?/Advantage and disadvantage of VRV/VRF /Types of VRV/VRF /VRV/VRF part-1

VRV OR VRF:

• VRV stands for variable refrigerant volume.
• VRF stands for variable refrigerant flow.
• This technology is invented by Daikin in 1982.
• Daikin is called this technology by the name of VRV and this name is a trademark of Daikin so other companies are calling this technology as VRF. Both are the same but the names are different.
• In this system, we can use multiple indoors with single outdoor, hence it is also called a multi-split ac system.
• It consumes less energy.
• It controls the refrigerant flow to the evaporator unit as per load requirement.
• Indoor units can be in different modes in a single system.

Block diagram of VRV or VRF:

• In this system, you can use different indoors like cassette unit, floor mounted, ceiling-mounted, wall-mounted, etc with a single outdoor unit.
• In this system, you can use 60 or more indoors with a single outdoor.
• Different sizes indoors can use in a single system.
• R410a refrigerant is used in this system.
• The length of the pipe must not be more than 150 meters.
• Here inverter compressor is used hence it saves 30% electricity as compared to split ac.

Basic refrigeration cycle of VRV/VRF:

Its components are,

•         Compressor
•         Oil separator
•         Condensor
•         Expansion valve
•         Evaporator
•         Accumulator

Working:

Let's start with Accumulator, usually vapor refrigerant comes to the compressor from the evaporator but on less load, there are chances that liquid refrigerant can come out from the evaporator to compressor. If it happens then the compressor will damage. To avoid this, we use an accumulator. It helps to convert liquid refrigerant to vapor refrigerant.

Liquid refrigerant comes from an accumulator to the compressor, it compresses the refrigerant and converts into high-temperature vapor refrigerant and sent it to the condenser. At this time there are chances to pass lubricant oil with vapor refrigerant, hence oil separator is used to avoid this it helps to separate the oil from vapor refrigerant and sent it back to the compressor. With the help of oil separator only vapor refrigerant passes to the condenser, it rejects heat to the atmosphere and sent into an expansion device. It reduces the pressure and temperature of the hot liquid refrigerant and it is sent to the evaporator. It absorbs heat from the room, hence low-temperature liquid refrigerant converts it into vapor refrigerant.

If you want to know about the details of the refrigeration cycle then click here.

Advantage: 

• Multiple indoor with single Outdoor.
• Power consumption is 30 % less.
• It uses the inverter compressor which runs on various speeds as per load.
• The entire system can be operated from one location.
• It does not require a large space compared to others.
• At a time heating and cooling can provide.
• Noise is very less.
• High COP

Disadvantage:

• Piping limitation hence it cant be used in high rise buildings.
• The initial cost is higher.
• Higher skilled labor is required hence maintenance cost is high.
• Very difficult to make changes after commissioning.

Types of VRV/VRF:

• 1) Cooling type system
• 2) Heat pump system
• 3) Heat recover system