3-3.Refrigerant Charging Calculation - Mitsubishi Electric CITY MULTI PEFY-P22VMS-E-S Data Book

3. Piping Design
3-3. Refrigerant charging calculation
3-3-1. PUMY-P-YHMC-C/VHMC-S
Original refrigerant charge for PUMY-P-YHMC-C/VHMC-S is 8.5 kg, including 3 kg for 50 m 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 or less.
If the total extended piping length is over 50 m, calculate the additional refrigerant using following procedure. Yet, if the calculated
result is negative, no additional charge is needed.
Additional
refrigerant charge
(kg)
Example:
PUMY-P125YHMC-C
P63
Additional
refrigerant charge
(kg)
Total length of liquid Total length of liquid
pipe sized pipe sized
= +
ø ø
9.52 0.06 (kg/m) 6.35
x
(m) x 0.06 (kg/m)
A ( 30 m )
a ( 15 m)
b ( 10 m )
P40
Total length of liquid Total length of liquid
pipe sized pipe sized
= +
ø9.52 x 0.06 (kg/m) ø6.35 x 0.024 (kg/m)
45 (m) x 0.06 (kg/m) 40 (m) x 0.024 (kg/m)
= 2.70 +
= 0.66
0.7 kg (round-up)
SYSTEM DESIGN
Original charge
-
0.024 (kg/m)
x
(m) x 0.024 (kg/m)
Indoor 1: P63 A=ø9.52 30 m a=ø9.52
Indoor 2: P40
Indoor 3: P25
Indoor 4: P20
Total length of each liquid pipe is as follows
ø9.52 A + a = 30 + 15 = 45 m
ø6.35 b + c + d = 10 + 10 + 20 = 40 m
c ( 10 m)
P25
Original charge
-
0.96 -
3.0 (kg)
15 m
b=ø6.35 10 m
c=ø6.35 10 m
d=ø6.35 20 m
d ( 20 m )
P20
3.0(kg)
3.00
C7-R Rev.
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