Standard Vacuum Procedure — −100.7 kPa (5 torr), 2.5h Pump, 1h Hold

Korean standard procedure (KS / field standard)

Check: **Required**: vacuum pump (4 CFM residential / 6–8 CFM multi/VRF) + **digital vacuum gauge (microns or torr)** + manifold. Analog manifold alone CANNOT measure precision vacuum. **Connect**: manifold + pump to liquid line, gas line, and equalizing port (if any). **Target**: −100.7 kPa = 5 torr ≈ 5000 microns. New installs = recommend ≤500 microns (full moisture removal). **Run time**: basic lineset = 30–45 min, long/multi/VRF = 2.5+ hours.

What to do: **Full procedure**: 1) Run pump until 5 torr / 500 micron reached. 2) Close both manifold valves → stop pump. 3) **1-hour hold test** = maintain −100.7 kPa for 1 hour. Pressure rise = leak or residual moisture. 4) If pass → proceed to charging (liquid charge, by weight). 5) Per manual = below 5°C ambient with suspected moisture → triple evacuation (vacuum→nitrogen sweep→re-vacuum, 3 cycles). **New embedded piping** = 2.5+ hours vacuum required (Korean install standard).