VRV issue

[Lc_shi]

Hi sirs
VRV can apply the situation of long distance between outside and inside units. I'm not sure how about the max pressure loss along the pipe. Who knows the practical data? thanks


regards
LC

[Brian_UK]

You would need to check with each manufacturer for those details.

Mitsubishi, Daikin, Sharp, Samsung etc, etc.

[DVaider]

Hi, Lc_chi!
I think you told about Daikin VRV. There are follow limits for this stuff: max. length between outdoor and indoor is 165 m (190 m equivalent length); max. difference between outdoor/indoor is 40 m (outdoor in bottom position) or 50 m (outdoor higher than indoor). You can rise the difference between outdoor and idoor units up to 90 m. In this case you should use reductor EKLD90P12 or EKLD90P18 (European kits) . This is official Daikin information for VRVIII. But Daikin didn't report anything about pressure loss along the pipe.

[leftjobrunning]

Lc_shi,

once you stick to the max piping lengths(which you will get from the supplier, I presume it's Daikin with the VRV), you install the pipework correctly and you charge the system correctly, you won't have any problems with pressure drops/ loss. You won't be able to make much sense from pressure readings around a running VRV anyway.

Good luck, Steve.

[mekaniko5]

VRF and VRV system manufacturers provide the restrictions on refrigeration pipe length and vertical elevation. Since pressure drops can’t be avoided, these restrictions will ensure that the pressure drop is within limit.

Correct refrigerant piping is important. Excess pressure drops resulting from incorrect pipe lengths will have an impact on your system capacity. System capacity will drop which leaves you buying bigger outdoor units, costing you more money.

You should also look out for oil return issues specially because you are dealing with a variable capacity system. If the VRV system is using an inverter compressor and is operating at low capacity, long pipe lengths will be an obstacle for low velocity refrigerant and oil to return to your compressor.