Pipe Length Extra Charge — g/m Calc Beyond 7m

Pre-charge = 7m. Add g/m beyond

Check: **R-410A standard add** (residential 7-13py): ① 1/4″ liquid line (6.35mm) ~20 g/m. ② 1/2″ (12.7mm) ~50 g/m. ③ 5/8″ (15.88mm) ~60 g/m. **R-32**: ~0.7x same pipe (less dense). **R-22**: ~60-80 g/m. **Height correction**: indoor-outdoor diff ≥5m → check OEM table (LG/Samsung apply -5% to -10%). 25% of 1-yr 'weak cooling' = missed extra charge.

What to do: **Procedure**: ① Weigh with recovery scale → exact g. ② Stable operation (35°C ambient, 27°C indoor, 10 min stabilize) → first charge. ③ Verify with pressure gauge → add 50g increments. ④ No overcharge (>300g = liquid slug risk). Document on commissioning sheet 'pipe length / height / extra g'. Photo of OEM table → prevent dispute. R-32: never partial-charge (recover all → proportional refill).