Technical Data Manual

Design of 3WAY VRF SYSTEM
2 - 21
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2. System Design
Additional refrigerant charge before extension
Liquid tube
diameter
Tubing length (ft)
(A)
Additional refrigerant charge
per 1 ft (oz/ft) (B)
(A) × (B) oz
La
Lb
LA
LB
LC
LD
LE1
LG
LH
L1
L2
L3
L7
L8
L9
ø3/8
ø3/8
ø3/4
ø1/2
ø1/2
ø1/2
ø3/8
ø3/8
ø3/8
ø3/8
ø1/4
ø1/4
ø1/4
ø1/4
ø1/4
6.6
65.6
26.2
19.7
19.7
19.7
16.4
26.2
13.1
9.8
9.8
9.8
9.8
9.8
13.1
0.602
0.602
2.78
1.38
1.38
1.38
0.602
0.602
0.602
0.602
0.279
0.279
0.279
0.279
0.279
3.973
39.491
72.836
27.186
27.186
27.186
9.873
15.772
7.886
5.900
2.734
2.734
2.734
2.734
3.655
251.881Total (oz)
252 oz
Additional refrigerant charge after extension
Liquid tube
diameter
Tubing length (ft)
(A)
Additional refrigerant charge
per 1 ft (oz/ft) (B)
(A) × (B) oz
7.886
9.873
7.886
5.496
LE2
LF
L4
L5
L6
ø3/8
ø3/8
ø3/8
ø1/4
ø1/4
13.1
16.4
13.1
19.7
23.0
0.602
0.602
0.602
0.279
0.279 6.417
37.559Total (oz)
38 oz
Calculation of additional refrigerant charge for the entire 3WAY VRF system
(Additional refrigerant charge for entire 3WAY VRF system)
[Before extension]
= 416+252+42
=710
[After extension]
= (Refrigerant charge at outdoor unit) + (Additional refrigerant charge)
= (416+416=832) + (252+38=290) + (42+42=84)
= 1206
Remark:
When planning an extension model, be sure to include the values of the Table 2-1-1 (Page 2-5) Necessary Amount of
Refrigerant Charge per Outdoor Unit.
If the tubing length (LA) is less than 16.4 feet, it is necessary to add 71 oz/unit of refrigerant in addition to 42 oz.
TD831158-02_3WAY_VRF_SYS.indb 21TD831158-02_3WAY_VRF_SYS.indb 21 2013/06/18 11:46:362013/06/18 11:46:36