Hitachi RPI-6.0FSN4E - 9.3 ADDITIONAL REFRIGERANT CHARGE CALCULATION

Size of pipes (Ø mm)
For heat pump systems (2 pipes)
1 Pipe diameter for the outdoor unit.
2 Diameter of the main pipe (from the base unit or connection kit 1 to the rst branch)
(2)
.
Outdoor unit (HP)
Equivalent pipe length < 100 m
Outdoor unit (HP)
Equivalent pipe length < 100 m
Gas Liquid Gas Liquid
5 ø15.88 ø9.52 16 ø28.58 ø12.70
(6/8) ø19.05 ø9.52 (18-24) ø28.58 ø15.88
10 ø22.20 ø9.52 (26-34)(24-P) ø31.75 ø19.05
(12/14)(12-P) ø25.40 ø12.7 (36-54) ø38.1 ø19.05
3 Pipe diameter after rst branch
(3)
.
Total indoor unit capacity
after the rst branch (HP)
Gas Liquid
Total indoor unit capacity
after the rst branch (HP)
Gas Liquid
< 6 ø15.88 ø9.52 (16-17.99) ø28.58 ø12.7
(6-8.99) ø19.05 ø9.52 (18-25.99) ø28.58 ø15.88
(9-11.99) ø22.2 ø9.52 (26-35.99) ø31.75 ø19.05
(12-15.99) ø25.4 ø12.7 ≥ 36 ø38.1 ø19.05
4 Pipe diameter between multikit and indoor unit
(4)
.
Indoor unit (HP) Gas Liquid Indoor unit (HP) Gas Liquid
(0.8-1.5) ø12.7 ø6.35
(5)
10.0 ø22.2 ø9.52
2.0 ø15.88 ø6.35
(5)
16.0 ø28.58 ø12.7
(2.5-6.0) ø15.88 ø9.52 20.0 ø28.58 ø15.88
8.0 ø19.05 ø9.52
For heat recovery systems (3 pipes)
1 Pipe diameter for the outdoor unit.
2 Diameter of the main pipe (from the base unit or connection kit 1 to the rst branch) (3 pipes)
(2)
.
Outdoor unit
(HP)
Gas,
low pressure
Gas, high/low
pressure
Liquid
Outdoor unit
(HP)
Gas,
low pressure
Gas, high/low
pressure
Liquid
5 ø15.88 ø12.7 ø9.52 (22/24) ø28.58 ø25.4 ø15.88
(6/8) ø19.05 ø15.88 ø9.52 26 ø31.75 ø25.4 ø19.05
10 ø22.2 ø19.05 ø9.52 (28-34) ø31.75 ø28.58 ø19.05
(12/14) ø25.4 ø22.2 ø12.7 36 ø38.1 ø28.58 ø19.05
16 ø28.58 ø22.2 ø12.7 38-54 ø38.1 ø31.75 ø19.05
(18/20) ø28.58 ø22.2 ø15.88
3 Pipe diameter after rst branch (3 pipes)
(3)
.
Total HP
indoor unit
Gas, low
pressure
Gas, high/low
pressure
Liquid
Total HP
indoor unit
Gas,
low pressure
Gas, high/low
pressure
Liquid
< 6 ø15.88 ø12.7 ø9.52 (18-21.99) ø28.58 ø22.2 ø15.88
(6-8.99) ø19.05 ø15.88 ø9.52 (22-25.99) ø28.58 ø25.4 ø15.88
(9-11.99) ø22.2 ø19.05 ø9.52 (26-35.99) ø31.75 ø28.58 ø19.05
(12-15.99) ø25.4 ø22.2 ø12.7 ≥36 ø38.1 ø31.75 ø19.05
(16-17.99) ø28.58 ø22.2 ø12.7
45
PMML0294A rev.2 - 07/2014
Piping work and refrigerant charge
ENGLISH
PMML0294A_rev.2_02-2014.indb 45 14/07/2014 12:28:29