DESIGN & EXECUTION (Refrigerant tubing)
In regard to the refrigerant tubing length
System Example
Outdoor unit
H3 
LA
1
H1
LA
1
: Header tube (purchased separately)
: Branch tube (purchased separately)
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: Closed (pinch) weld
Distance (cm) from flammable materials
L1
L2
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| LG |
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| 8 |
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L4
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| L2 |
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L4 | |
2 | branch tube |
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| 7 | 8 |
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Unit main tube |
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| Indoor unit |
(between unit branch tubes) |
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Unit main tube |
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No. 1 branch |
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1 | 6 | 7 | 8 |
Unit branch tube |
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4 m or less
Over 2X
*Limit of elevation difference between indoor units after the final branch
Over 4 m
X
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| L1 | Maximum allowable tubing length |
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| 170 (200)*1 |
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| 120 (145)*1 | |||||||||
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| LA | Maximum main tubing length |
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| 120 |
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Allowable tubing length | L(L2 L4) | Difference between longest and |
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shortest tubing lengths after the |
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| 40 |
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| 30 | |||
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| No. 1 branch (first branching point) |
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| 1, 2, 8 | Maximum length of each branch tube |
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| 30 |
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| L5 | Maximum length between outdoor units |
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| 10 |
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| H1 | If outdoor unit is above |
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| 50 |
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Allowable elevation | If outdoor unit is below |
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| 35*2 |
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difference |
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H2 | Maximum difference between indoor units |
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| 15*3 |
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| H3 | Maximum difference between outdoor units |
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| 4 |
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Allowable header | L3 | Maximum length from the first |
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tubing length | tees to the front seal |
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(*1) Equivalent length
(*2) If cooling mode is expected to be used when the external temperature is 10˚C or below, install so the maximum length is 30 m.
(*3) Install so that the height difference between indoor units after the final branch is within the limits shown in the figure.
S T A I M S DESIGN & EXECUTION
66
