R-Pro › Field cases › Air conditioning
Setpoint ≠ Actual Temp — Control Algorithm Explained
Likely causes
Sensor position / hysteresis / compressor protection time
Check: **Why setpoint 24°C but actual 26°C?** ① **Sensor location** = return air grille (top of indoor unit, 1-2°C higher than living zone). ② **Hysteresis** = compressor protection ±1°C or ±2°C (limits ON-OFF freq). ③ **Compressor protection time** = OFF→3-5 min before restart (during which temp rises +1-2°C). ④ **Outdoor effect** = ambient >35°C → capacity 70%, can't reach 24°C even normal op. ⑤ **Where user sits** = below ceiling (different feel).
What to do: **Fix direction**: ① **User education first** = 'unit is OK, this is standard behavior, set 2°C lower'. ② **Mode 'auto'** = self-adjusts. ③ **Fan combo** = 1°C cooler feel (5% more power). ④ **Wireless remote with proximity sensor** = LG/Samsung new models (external sensor at user position). ⑤ **Portable sensor mat** = AS techs can measure accurately. **Wrong DIY**: 'palm on remote' (no signal block), 'set 16°C for faster cool' = compressor full + 1.5x power + condensation risk.
40% of Korean 'not cool' = perception gap (unit actually OK). On visit, IR-measure living zone + return grille, show user (clears confusion). Charge ₩30k trip fee for normal-op call (no dispute, standard). New apartments with embedded ceiling = sensor near ceiling = frequent 'not cool' (advise during install).
All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.
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