Specifications

3. Piping Design
DATA U10
SYSTEM DESIGN 4 - 26
S.D. S
3-3. Refrigerant charging calculation
Example:
PUMY-P48NHMU
Original refrigerant charge for PUMY-P-NHMU is 8.5 kg [18.75 lbs], including 3 kg [106 oz] for 50 m [164 ft.] total extended piping length use.
Thus, there is no need to charge additional refrigerant to the system if the total extended piping length is 50 m [164 ft.] or less.
If the total extended piping length is over 50 m [164 ft.], calculate the additional refrigerant using following procedure. Yet, if the calculated
result is negative, no additional charge is needed.
3-3-1. PUMY-P-NHMU
P24 P15 P08 P06
A ( 30 m [98 ft.] )
b ( 10 m [32 ft.] )
b ( 20 m [65 ft.] )
c ( 10 m [32 ft.] )
a ( 15 m [49 ft.] )
=+-
[oz] (ft.) x 0.65 [oz/ft.]
Additional
refrigerant charge
Total length of liquid
pipe sized
ø3/8" x 0.65 [oz/ft.]
(ft.) x 0.26 [oz/ft.]
Total length of liquid
pipe sized
ø1/4" x 0.26 [oz/ft.]
ø9.52 x 0.06 (kg/m) ø6.35 x 0.024 (kg/m)
106 [oz]
(kg) (m) x 0.06 (kg/m) (m) x 0.024 (kg/m) 3.0 (kg)
Original charge
Indoor 1: P24 A=ø9.52 [3/8"] 30 m [98 ft.] a=ø9.52 [3/8"] 15 m [49 ft.]
Indoor 2: P15
b=ø6.35 [1/4"] 10 m [32 ft.]
Indoor 3: P08 c=ø6.35 [1/4"] 10 m [32 ft.]
Indoor 4: P06 d=ø6.35 [1/4"] 20 m [65 ft.]
Total length of each liquid pipe is as follows
ø9.52 [3/8"] A + a = 30 [98] + 15 [49] = 45 m [147 ft.]
ø6.35 [1/4"] b + c + d = 10 [32] + 10 [32] + 20 [65] = 40 m [129 ft.]
=+-
+-
(kg) 45 (m) x 0.06 (kg/m)
Additional
refrigerant charge
= 2.70
= 0.66
0.7
kg (round-up)
0.96 3.00
Total length of liquid
pipe sized
ø9.52 x 0.06 (kg/m)
40 (m) x 0.024 (kg/m)
Total length of liquid
pipe sized
ø6.35 x 0.024 (kg/m)
3.0(kg)
Original charge
=+-
+-
(oz) 147 (ft.) x 0.65 [oz/ft.]
Additional
refrigerant charge
= 95.55
= 23.09 [oz]
1.5 [lbs] (round-up)
33.54 106
Total length of liquid
pipe sized
ø3/8" x 0.65 [oz/ft.]
129 (ft.) x 0.26 [oz/ft.]
Total length of liquid
pipe sized
ø1/4" x 0.26 [oz/ft.]
106 [oz]
Original charge