Refrigerant Piping; Refrigerant Piping Length; Refrigerant Piping Size - Hitachi RWM-(H)FSN3E Technical Catalogue

9 Piping work and
refrigerant charge

9.1 Refrigerant piping

9.1.1 Refrigerant piping length

The refrigerant piping between the indoor unit and the outdoor unit should be designed using the following chart.
Keep the design point within the area of the chart, which is showing the applicable height difference according to piping
length.
Height difference
Total length between outdoor unit
(m)
and each indoor unit.
When outdoor
unit is installed
higher than
indoor unit
When outdoor
unit is installed
lower than indo-
or unit
Maximum piping length (L)
Maximum height difference between indoor and
outdoor unit (H)

9.1.2 Refrigerant piping size

Piping connection size of outdoor unit & indoor unit
Outdoor unit
RAS-2HVRN2 Ø 12.7 (1/2")(1*)
RAS-3HVRNME-AF
RAS-4H(V)RNME-AF
RAS-5H(V)RNME-AF
RAS-6H(V)RNME-AF
RAS-8HRNME-AF
RAS-10HRNME-AF
N O T E
(1*): 2HP system only (RAS-2HVRN2 + RWM-2.0(H)FSN3E). If using different piping size for outdoor unit and in-
door unit, a pipe adapter will be required: (Ø12.7 → Ø15.88).
The pipe adapter is factory supplied with the outdoor unit.
112
TCGB0070 rev.3 - 04/2012
Item
Outdoor unit higher than indoor unit
Indoor unit higher than outdoor unit
Pipe size
Gas pipe Liquid pipe
Ø 6.35 (1/4")
Ø 15.88 (5/8") Ø 9.53 (3/8")
Ø 15.88 (5/8") Ø 9.53 (3/8")
Ø 15.88 (5/8") Ø 9.53 (3/8")
Ø 15.88 (5/8") Ø 9.53 (3/8")
Ø 25.4 (1") Ø 9.53 (3/8")
Ø 25.4 (1") Ø 12.7 (1/2")
Setting
before
shipment
Actual piping length
Equivalent piping length
Indoor Unit
RWM-2.0(H)FSN3E Ø 15.88 (5/8")(1*)
RWM-3.0(H)FSN3E Ø 15.88 (5/8")
RWM-4.0(H)FSN3E Ø 15.88 (5/8")
RWM-5.0(H)FSN3E Ø 15.88 (5/8")
RWM-6.0(H)FSN3E Ø 15.88 (5/8")
RWM-8.0(H)FSN3E Ø 25.4 (1")
RWM-10.0(H)FSN3E Ø 25.4 (1")
(2-10)HP
30
40
30
20
Pipe size
Gas pipe Liquid pipe
Ø 6.35 (1/4")
Ø 9.53 (3/8")
Ø 9.53 (3/8")
Ø 9.53 (3/8")
Ø 9.53 (3/8")
Ø 9.53 (3/8")
Ø 12.7 (1/2")