DC Inverter Multi VRF System User Manual
16
Notes:
①
The refrigerant amount charged before delivery doesn’t include the amount that needs to be
added to indoor units and the connection pipeline.
②
Length of connection pipe is decided on site. Therefore the amount of additional refrigerant
shall be decided on site according to the dimension and length of field-installed liquid pipe.
③
Record the amount of additional refrigerant for convenience of after-sales service.
2) Calculation of the amount of additional refrigerant
Calculation method of the quantity of additional refrigerant (based on liquid pipe)
Quantity of additional refrigerant = ∑length of liquid pipe X quantity of additional refrigerant per meter
Quantity of additional refrigerant per meter for liquid pipe(kg/m)
Φ22.2
Φ19.05
Φ15.9
Φ12.7
Φ9.52
Φ6.35
0.35
0.25
0.17
0.11
0.054
0.022
Note:
Liquid pipe that is within 20m doesn’t need to be added with refrigerant.
First confirm that there is no leakage from the system. When compressor is not working, charge
additional R410a with specific amount to the unit through the filling opening of the liquid pipe valve of
the outdoor unit. If required amount cannot be quickly filled due to pressure increase of the pipe, then
set the unit in cooling startup and fill refrigerant from the low pressure check valve of the outdoor unit.
3) Calculation example
Outdoor
Indoor
Fig.22
Indoor
No.
Indoor
①
Indoor
②
Indoor
③
Indoor
④
Model
Duct type
CHV-5SDS72NK
Duct type
CHV-5SDS5
0
NK
Duct type
CHV-5SDS3
6
NK
Duct type
CHV-5SDS2
5
NK
Liquid pipe:
No.
A
B
C
D
Pipe size
Φ
9.52
Φ
9.52
Φ
9.52
Φ
6.35
Length
10m
5m
5m
5m
No.
a
b
c
d
Pipe size
Φ
9.52
Φ
6.35
Φ
6.35
Φ
6.35
Length
3m
3m
2m
1m
Total length of each liquid pipe
φ9.52: A+B+C+a=10+5+5+3=23m
φ6.35: D+b+c+d=5+3+2+1=11m
Note: Liquid pipe that is within 20m doesn’t need to be added with refrigerant.
Therefore, the minimum quantity of additional refrigerant = (23-20)×0.054+11×0.022 = 0.404kg
