Saturation pressures for six common refrigerants, plus superheat, subcooling, and a quick system diagnose — computed from real refrigerant properties, right on your phone.
How it works: pick a refrigerant and enter a temperature to get bubble and dew pressures.
Use the dew point for superheat and the bubble point for subcooling —
for pure refrigerants they're identical; for blends like R-454B they differ by the temperature glide.
Reference tool, not a charging procedure. Always follow the equipment manufacturer's
charging procedure and verify with calibrated gauges. Pressures below 0 psig are vacuum — normal at low temperatures.
PT lookup
Saturation pressure at a temperature. Bubble = liquid starts boiling · Dew = vapor starts condensing.
Superheat
Suction-line temp minus the dew-point saturation temp at suction pressure. Typical TXV target: 8–12°F.
Subcooling
Bubble-point saturation temp at head pressure minus the liquid-line temp. Typical target: 8–12°F (follow the nameplate).
Quick diagnose
Enter your gauge and thermometer readings. The tool computes superheat, subcooling, and condenser approach, then tells you what to check first — in plain language.
Checking pressures all day? Keep the schedule full too.
Junior techs who live on their gauges become the techs customers ask for by name. CoolBooked fills your calendar with those customers automatically — no missed calls, no paperwork.
Free tools for HVAC pros