Specifications subject to change without notice. © 2013 Brivis Climate Systems Pty Ltd
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6.1 Piping Design
•
Pipe-work shall be installed in a manner which prevents drainage of liquid into the compressor and ensures
adequate oil return
•
Pipe insulation should be nitrile rubber, 13mm thick for pipes up to and including 20mm diameter and 19mm thick
for pipes above 20mm in diameter
•
It is generally necessary to insulate the suction pipe only. However, it is recommended the liquid line pipe also be
insulated where it is exposed to direct sunlight or if located in hot surroundings such as ceiling void, or buried
underground
•
Pipes should be run as directly as possible between indoor and outdoor units
•
If the indoor coil is located above the condensing unit the suction line shall have a loop at the evaporator
outlet to prevent refrigerant drainage into the compressor during off cycle
•
If the evaporator is located below the condensing unit, then the suction riser shall be U-Trapped at 3m above
ground level
•
Avoid burying pipes below ground. If necessary, they shall be insulated and encased in a PVC pipe, sealed at
both ends where the pipe exits above ground. The buried distance shall not exceed 5 metres and a liquid line
solenoid valve, interlocked with the compressor, shall be located adjacent to the indoor unit
•
Care should be taken if running pipe-work within wall cavities as this may lead to transmission of refrigerant noise
into the occupied space. The use of mufflers or oil separator can help reduce potential pulsation in the discharge
line
6.2 Recommended Interconnecting Pipe Sizing
RECOMMENDED PIPE SIZE (mm)
FOR EQUIVALENT LENGTH (m)
LIQUID
SUCTION
MODEL
1-10
10-30
1-10
10-30
MAXIMUM
EQUIVALENT
PIPE LENGTH
(m)
[Minimum Pipe
Length is 3m]
BASE
CHARGE
FOR 15m
PIPE
LENGTH
(kg)
ADDITIONAL
CHARGE FOR
>15m PIPE
LENGTH
(grams / m)
INDOOR COIL
PISTON
ORIFICE SIZE
DO-SC18Z9
9.52
12.7
22.2
28.6
30
5.1
90
0.084”
DO-SC22Z9
12.7
12.7
28.6
28.6
30
5.3
90
0.074”
Table 2 – Recommended Pipe Sizing
6.3 Max vertical pipe run
The height difference between indoor and outdoor units must not exceed 8 metres.
If the indoor unit is located more than 5 metres above the outdoor unit, then a solenoid valve should be installed in the liquid
line at the indoor unit, to prevent liquid refrigerant migrating back to the compressor in the off cycle. The solenoid shall be
interlocked with the compressor.
Note:
Both units’ liquid line connection sizes are 12.7mm. For pipe work less than 10m equivalent length, the DO-SC18Z9
system can be run with 9.52mm liquid line.
Therefore, two 12.7 to 9.52mm copper bushes are included (one with the indoor DI-XU18Z and one with the
DO-SC18Z9 outdoor unit). For pipe work more than 10m equivalent length, a 12.7mm liquid line is needed.
