R-32 Charging Procedure — A2L Safety, Ventilation, Ignition Source

R-32 = A2L mildly flammable + procedure differs

Check: **R-32 safety data**: ① GWP 675 (vs R-410A 2088, 1/3). ② LFL 14% v/v. ③ Auto-ignition = 648°C. ④ MIE 30 mJ (lighter, electric spark). **Pre-charge safety**: ① Ventilation (natural or fan, CO₂ ≤1000 ppm). ② Eliminate ignition (saw/drill/lighter/phone vibration). ③ Gas leak conc. ≤0.5% (R-32 dedicated detector, MIE safety margin). ④ Korea High-Pressure Gas Act = ventilation + extinguisher mandatory in R-32 charging workspace. Counter-flow ventilation = 15 ACH.

What to do: **Procedure**: ① **Dedicated recovery+gauge**: R-32 only (not R-410A compat, copper cross-section differs). ② **2-stage vacuum ≤100 micron**: R-32 sensitive to O₂/moisture (more than R-410A). ③ **Start charging**: liquid proportional charge (full recovery first, then weight-based). ④ **No partial charge**: pressure-only adding 50g = liquid slug + flammable concentration risk. ⑤ **Post-charge**: leak test (electronic, ≤0.5%, 1.5 MPa hold 1 hr). Permanent card on outdoor: 'R-32 system = A2L mildly flammable, no nearby flame, call 119 if accident'.