What are the main disadvantages of the VRF system?

Cost is mainly the diasadvantage.  Particularly, the need for a back-up unit because when the condenser unit bogs down the whole system would not be operational.  Therefore, should that happen multiple offices or departments can be disrupted of business operation.  As opposed to conventional units which are "1 is to1" and individualized in respective offices the problem is contained only in one specific location.  To have a back-up unit, however, would mean double the installation cost and since VRF units are already expensive so it all boils down to costing.  Otherwise, in terms of electricity consumption, installation space, etc... the VRF system is ideal.

Dear

In m opinion the system is good overall and very rapidly increasing in the market but it has the following disadvantages or you can say limitations

1. Price per ton is too high.

2. cooling heating simultaneously is limited. (2 or3 pipe system also very expensive)

3. for high rise building the system cannot be used.

4. for not so high rise building the compressor will be very big to over come additional piping and pressure loss.

5. All manufacturers are not providing this.

6. Limited BMS System and integration with IBMS System is not possible.

7. Standby system is also limited for critical areas.

8. need to increase tonnage for longer piping.

Hope this will work

very expensive

not suitable for High rise building

limited standby sysytem

potential for Refrigernat leaks

Less economizer cycle benefit may occur with the smaller ventilation system since the 

ducting is sized just for ventilation. 

• Use of supplementary heat may be required for quick recovery from night setback. This 

can be avoided to a great extent by providing sufficient time to allow the heat pump cycle 

to be used with the compressors running at maximum capacity to provide morning warm 

up. 

• Use of backup strip heat for space heating in cold weather would be a detriment to the 

efficiency of the system. However, as indicated above in the list of advantages, speed 

variation and other features help increase the heat pump capacity to offset some of the 

vapor compression cycle degradation with lower temperatures. This can avoid or 

minimize the need for backup heat. Integrated gas heating systems are not available as 

yet as a dual fuel option. 

• It may be less economical to provide high efficiency components (such as fans, or filter 

systems) for many decentralized indoor units compared to the efficiency of these systems 

when installed in a single larger centralized system. 

Control system between outdoor and indoorunits is proprietary; this means no independentcontrols contractor can service, or repair, orupgrade the control system-you “are married” tothe manufacturer for the life of the system and Complex oil management/recovery system;approximately every 6-9 hours an “oil recovery”cycle occurs in which all compressors are forcedto full load and all electronic valves open fullyfans are reduced to minimum cfm. Cycle lasts6-8 minutes

1. Per TR Cost is High.  Particularly, the need for a back-up unit because when the condenser unit bogs down the whole system would not be operational.  Therefore, should that happen multiple offices or departments can be disrupted of business operation.  As opposed to conventional units which are "1 is to1" and individualized in respective offices the problem is contained only in one specific location.  To have a back-up unit, however, would mean double the installation cost and since VRF units are already expensive so it all boils down to costing.  Otherwise, in terms of electricity consumption, installation space, etc... the VRF system is ideal.

In m opinion the system is good overall and very rapidly increasing in the market but it has the following disadvantages or you can say limitations

1. Price per ton is too high.

2. cooling heating simultaneously is limited. (2 or3 pipe system also very expensive)

3. for high rise building the system cannot be used.

4. for not so high rise building the compressor will be very big to over come additional piping and pressure loss.

5. All manufacturers are not providing this.

6. Limited BMS System and integration with IBMS System is not possible.

7. Standby system is also limited for critical areas.

8. need to increase tonnage for longer piping.

Potential for refrigerant leaks