Ammonia refrigeration calculators
Free engineering tools built for ammonia refrigeration professionals. Reference data, unit conversions, and thermodynamic calculations — all in one place.
NH3 Pressure-Temperature Chart
Interactive saturation curve for anhydrous ammonia (R-717). Hover tooltips, unit toggling between °F/psig and °C/kPa, searchable data table, superheat/subcooling calculator, and key reference points.
- Interactive saturation curve with hover data
- Toggle °F/psig ↔ °C/kPa
- Superheat & subcooling calculator
- Searchable saturation data table
- Critical & boiling point markers
BTU to Ton of Refrigeration
Full unit conversion between BTU/hr, MBH, MMBTU/hr, tons of refrigeration, kW, and kcal/hr. Auto-calculates as you type. Includes common refrigeration load reference tables and cold storage sizing helpers.
- 6-way simultaneous unit conversion
- Auto-calculates as you type
- Common refrigeration load reference table
- Cold storage quick-sizing helpers
- Educational explanation of a ton of refrigeration
Ammonia Vessel Charge Calculator
Pounds of ammonia in a single receiver, accumulator, intercooler, or condenser from its inside diameter, shell length, liquid level, and operating pressure. Liquid and vapor mass split, saturation conditions, and comparison to the 10,000 lb PSM/RMP threshold.
- Horizontal cylinder liquid volume from level
- ASHRAE/NIST liquid and vapor densities
- Liquid vs. vapor mass breakdown
- Percent of the 10,000 lb threshold
- Typical operating pressures by vessel type
PSM Applicability Checker
Five questions that sort a facility into clearly covered, clearly not covered, or uncertain under OSHA PSM and EPA RMP, based on ammonia quantity, how the inventory was determined, whether piping was included, and recent system changes.
- 10,000 lb threshold logic for PSM and RMP
- Flags estimates and nameplate-only inventories
- Accounts for omitted piping charge
- Recommended next actions for each outcome
- Preliminary screen, not a formal determination
Compliance Deadline Calculator
Enter the dates of your last PHA, PSM compliance audit, RMP submission, and operator refresher training to get the next required date for each, with overdue and due-soon flags.
- PHA revalidation: 5 years, 1910.119(e)(6)
- Compliance audit: 3 years, 1910.119(o)
- RMP resubmission: 5 years, 40 CFR 68.190
- Refresher training: 3 years, 1910.119(g)(2)
- Reference table of required intervals
All thermodynamic data sourced from ASHRAE Fundamentals (2017) and NIST Webbook. Calculators are provided for reference purposes — verify critical calculations with a qualified professional engineer.