Daikin H Series Technical Manual page 18

Application Information
REFRIGERANT PIPING
Maximum Piping Length and Maximum Number of Bends
When the pipe length becomes too long, both the capacity and reliability will drop and as the number of
bends increases, system piping resistance to the refrigerant flow increases, thus lowering the cooling
capacity. As a result the compressor may become defective. Always choose the shortest path and follow the
recommendation as tabulated below:
Cooling Only Model
Outdoor
Maximum Allowable Length, m
Maximum Allowable Elevation, m
Equivalent length for various fitting (meter)
Pipe Size
3/8" (OD 9.52mm)
1/2" (OD 12.70mm)
5/8" (OD 15.88mm)
3/4" (OD 19.05mm)
7/8" (OD 22.23mm)
1" (OD 25.40mm)
1 1/8" (OD 28.58mm)
1 3/8" (OD 34.92mm)
Notes:
1. Equivalent piping length is obtained with actual length of gas piping.
2. 90° bend of piping is equivalent to L joint.
Bending must be carefully made so as not to crush the pipe.
Use a pipe bender to bend a pipe where possible.
Our guarantee on the performance of our air-conditioners is strictly revoked if the height
and/or length of the refrigerant piping system installed is beyond the limit above.
Additional Charge
For Brazed type, if the piping is less than 7.5m, follow the charge level on serial number sticker. When the
piping is more than 7.5m, use the table below.
Liquid Pipe OD (in)
1/2''
5/8''
NOTE:
The additional refrigerant charge amount recommended is a guideline for long piping
application. The actual charge required may be different from the guideline due to different
application and variation in site condition.
14
RN80HY1/RCN100/125/150HY1
R410A
Additional Charge (kg/m)
0.08
0.14
75
30
L joint
0.18
0.20
0.25
0.35
0.40
0.45
0.50
0.60
CAUTION
Trap bend
1.30
1.50
2.00
2.40
3.00
3.40
3.70
4.40