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REFNET Branch Pipe Incorrect Direction Installation Causing Refrigerant Distribution Imbalance

Likely causes

REFNET joint installation angle exceeds ±15° — refrigerant/oil channeling occurs

Check: Measure REFNET joint installation angle → check if within ±15° → compare cooling capacity difference among each branch indoor unit

What to do: Rework REFNET joint → maintain installation angle within ±15° → re-verify capacity of each branch

REFNET joint liquid branch installed upward — oil retention

Check: Check REFNET joint liquid branch direction → verify downward or horizontal installation (upward installation prohibited) → check joint arrow direction (liquid line outlet direction)

What to do: Rework REFNET joint → install liquid branch in downward or horizontal direction → re-verify each indoor unit cooling capacity after rework

U-trap formed in piping route — oil/refrigerant pooling

Check: Visually inspect entire piping route for U-shaped sagging sections → check for signs of refrigerant pooling at sag points (condensation, frosting)

What to do: Rework U-trap sections → secure appropriate gradient → install oil trap at bottom of vertical riser pipes

Field tip

REFNET joint arrow indicates liquid line outlet direction — arrow should point branch downward for correct installation. Always check direction markings before installation.

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