R-717 (Ammonia) Pressure at 120°F — Saturation P-T Data
How This Was Calculated
Saturation pressure interpolated from ASHRAE tabular data for R717. Very high pressure — elevated condensing conditions.
- P_sat
- Saturation pressure: 568 PSI
- T_input
- Input temperature: 120°F
- T_data
- ASHRAE tabular reference data: R717
Important Considerations
At 120°F, R717 reaches 568 PSI — well above the 450 PSI threshold. This is an extreme condensing condition. Verify system high-pressure cutout is properly set and functional. Check for blocked condenser airflow, dirty coil, or refrigerant overcharge. Operating at sustained high pressure significantly reduces compressor life and increases risk of safety relief valve opening.
The saturation pressure shown (for R717 at 120°F) is the baseline for measuring superheat and subcooling. Suction superheat = suction line temperature minus evaporator saturation temperature. Subcooling = condensing saturation temperature minus liquid line temperature. Typical targets: 8–12°F superheat at the evaporator (TXV systems), 10–20°F subcooling at the condenser. Deviations indicate improper charge, metering device issues, or non-condensables.
R-717 (ammonia) is classified B2L (toxic, mildly flammable). It has a strong, distinctive odor that provides a self-alarming warning at concentrations well below dangerous levels. Used only in industrial applications with dedicated machinery rooms, detection systems, and trained personnel.
R717 has no CO2 equivalent warming impact. This is a low-GWP refrigerant and is considered environmentally preferable under current and projected regulations. It aligns with AIM Act long-term goals and is unlikely to face near-term restrictions. Choosing low-GWP equipment protects against future regulatory compliance costs.
Saturation pressure-temperature data for R717 derived from ASHRAE Fundamentals Handbook, Chapter 30 (Thermophysical Properties of Refrigerants), and verified against manufacturer published data (Chemours Opteon, Honeywell Solstice). Values represent saturated conditions at sea level.