149
GMV5 HR HEAT RECOVERY
VRF Units Technical Sales Guide
13
CALCULATION METHOD OF REFRIGERANT ADDED FOR ENGINEERING PIPING
Added refrigerant quantity R = Added refrigerant quantity A for ∑Added refrigerant quantity B
for each module
(1) Pipeline charging amount
Added refrigerant quantity A for piping = ∑Liquid pipe length × Added refrigerant quantity for each
meter(inch) of liquid pipe
Diameter of liquid pipe mm(inch)
28.6(1-1/8)
25.4(1)
22.2(7/8)
19.05(3/4)
15.9(5/8)
12.7(1/2)
9.52(3/8)
6.35(1/4)
kg/m
0.680
0.520
0.350
0.250
0.170
0.110
0.054
0.022
OZ/inch
0.61
0.47
0.31
0.22
0.15
0.10
0.05
0.02
(2) ∑Refrigerant charging amount B of every module
Refrigerant charging amount B of every module
kg(Pounds)
Rated Capacity(1000Btu/h)
IDU/ODU rated
capacity collocation
ratio C
Quantity of included
IDUs(N)
72
96
120
144
168
50%
≤
C
≤
90%
N
＜
4
0
0
0
0
1.5(3.3)
N
≥
4
0.5(1.1)
0.5(1.1)
0.5(1.1)
1(2.2)
3.5(7.7)
90%
＜
C
≤
105%
N
＜
4
1(2.2)
1(2.2)
1.5(3.3)
2(4.4)
5.5(12.1)
8
＞
N
≥
4
2(4.4)
2(4.4)
3(6.6)
3.5(7.7)
6.5(14.3)
N
≥
8
4(8.8)
3.5(7.7)
4(8.8)
6.5(14.3)
8(17.6)
105%
＜
C
≤
135%
N
＜
4
2(4.4)
2(4.4)
2.5(5.5)
3(6.6)
6.5(14.3)
8
＞
N
≥
4
4(8.8)
3.5(7.7)
4(8.8)
4.5(9.9)
8(17.6)
N
≥
8
4.5(9.9)
4.5(9.9)
5(11.0)
7 (15.4)
9(19.8)
For example:
The OUD is composed of 3 modules: 72kBtu/h, 120 kBtu/h and 120 kBtu/h. The IDUs are made up of
7sets of 48 kBtu/h
IDU/ODU rated capacity collocation ratio C= 48×7/(72+120+120)=108%.The quantity of included
IDUs is more than 4 sets. Please refer to the above table.
Refrigerant charging amount B for 72 kBtu/h module is 4.0kg(8.8pounds).
Refrigerant charging amount B for 120 kBtu/h module is 4.0kg(8.8pounds).
Refrigerant charging amount B for 120 kBtu/h module is 4.0kg(8.8pounds).
So, ∑Refrigerant charging amount B of every module=4.0+4.0+4.0=12kg (8.8+8.8+8.8
=26.4pounds).
Suppose the Pipeline charging amount A=∑Liquid pipe length × refrigerant charging amount of every
1m (39.37inch) liquid pipe=25kg (55.1 pounds)
Total refrigerant charging amount R=25+12=37kg (55.1+26.4=81.5pounds).
After confirming that there is no leakage from the system, when the compressor is not in operation,
charge additional R410A with specified amount to the unit through the filling opening of the liquid
pipe valve of the outdoor unit. If required additional refrigerant cannot be quickly filled for increase of
pressure in the pipe, set the unit at cooling startup and then fill the refrigerant from gas valve of outdoor
unit. If ambient temperature is low, the unit can’t be set to cooling mode but heating mode.
