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2-20
Design of W-3WAY ECO-i SYSTEM Unit Specifi cations
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(3) Increasing the size of the refrigerant tubing
Increasing the tubing size of the gas tubes can reduce the loss of capacity caused by longer tubing lengths.
Refer to Table 2-13 to increase the tubing size. However, the maximum allowable tubing length must not be exceeded.
*
The amount of additional refrigerant charge is determined from the liquid tube size only.
Table 2-11 Correction coeffi cient for equivalent length when the size of the gas tube (LM) is increased
Standard tube diameter
(gas tube, in.(mm))
ø1/2"
(ø12.7)
ø5/8"
(ø15.88)
ø3/4"
(ø19.05)
ø7/8"
(ø22.22)
ø1-1/8"
(ø28.58)
Tube diameter after change
(gas tube, in.(mm))
ø5/8"
(ø15.88)
ø3/4"
(ø19.05)
ø7/8"
(ø22.22)
ø1-1/8"
(ø28.58)
ø1-3/8"
(ø34.93)
Equivalent length correction
coefficient
0.4
0.5
0.6
*
When increasing the size of the suction and discharge tubing (LM), multiply by the correction coeffi cient from Table 2-13 and
calculate the equivalent length for section LM.
Tubing equivalent length after size increase
= Standard tubing equivalent length × Equivalent length correction coeffi cient
2-2. Example of Tubing Size Selection for Extension and Additional Charge Amount
Sample calculation for the system below
Elevation difference
H=16.4 ft.
LM
LA
LB
LC
LG
LH
LD
LE1
LE2
Extension indoor units
LF
Lb
Type 09053
Type 14053
Type 3652
Type 4852 Type 1852 Type 1852
Type 1852 Type 0952
Type 3652 Type 3652 Type 1852
Solenoid Valve Kit
La
L2
L1
L7
L8
L9
L3
L4
L5
L6
Elevation difference
H=16.4 ft.
2. System Design
TD831139̲Sec2̲p18-23.indd 20
TD831139̲Sec2̲p18-23.indd 20
2008/04/17 15:32:15
2008/04/17 15:32:15