How do I check the refrigerant charge with superheat or subcooling?
On a fixed-orifice system, measure suction pressure and suction-line temperature: superheat equals the suction-line temp minus the saturated-vapor (dew) temperature at that pressure, and the tool compares it against a target derived from indoor wet-bulb and outdoor dry-bulb. On a TXV system, measure liquid-line pressure and temperature: subcooling equals the saturated-liquid (bubble) temperature minus the liquid-line temp, compared against the manufacturer target. The unit charging chart is always authoritative; this is a field cross-check.
Answers
- What target superheat should a fixed-orifice system have?
- Do I need a license to charge a refrigerant system?
- Should I charge by superheat or subcooling?
- What does high superheat and low subcooling mean together?
- Why does my target subcool come from the nameplate?
- What if outdoor temperature is very low during charging?
- Does refrigerant blend glide affect this calculation?