R-404A PT Chart | Refrigerant Pressure‑Temperature Calculator
R-404A Refrigerant PT Chart Tool – an interactive pressure‑temperature chart for commercial refrigeration. It allows users to look up saturation pressure from temperature (or temperature from pressure), displays a real‑time graph, and includes a rotating “refrigerant fact” tip
Incase you cannot see Temperature to Pressure, Click on Pressure to Temperature and then click again to show slider and values on the right.
❄️ R-404A Refrigerant PT Chart
Why Use This R‑404A PT Chart Tool?
R‑404A is a widely used HFC refrigerant in commercial refrigeration – supermarkets, walk‑in freezers, ice machines, and transport cooling. Understanding its pressure‑temperature relationship is essential for charging, troubleshooting, and system design. This interactive tool provides instant saturation pressures (psig) for any temperature, or vice versa, using accurate data from NIST REFPROP.
Key Features
- Two lookup modes – temperature → pressure, or pressure → temperature.
- Real‑time slider – adjust temperature or pressure and see immediate results.
- Interactive PT curve graph – visualise the relationship with a highlighted point.
- Pressure gauge – relative fill shows where you are on the scale (0‑650 psig).
- Rotating refrigerant facts – learn about GWP, glide, and applications.
- Dark/light mode toggle – comfortable for any work environment.
Frequently Asked Questions (FAQ)
What is the difference between psig and psia?
This chart uses psig (pounds per square inch gauge) – the most common reading on refrigeration gauges. Psia adds atmospheric pressure (14.7 psi). For most service work, psig is sufficient.
Is R‑404A being phased out?
Due to its high Global Warming Potential (GWP ~3922), R‑404A is being restricted in many regions. Lower‑GWP blends like R‑449A, R‑448A, or R‑452A are common retrofits, but millions of existing R‑404A systems still require service. This tool remains valuable for technicians.
How accurate is this PT data?
The data is generated from NIST REFPROP and matches major refrigerant manufacturer charts (e.g., Chemours, Honeywell). Small variations may occur due to blend composition – always verify with OEM specs.
Can I use this for low‑temperature applications?
Yes. The range extends down to -50°F (typical for freezers) and up to 150°F (high condensing temperatures). The saturation curve is accurate across the entire range.
What about superheat and subcooling?
This chart shows saturation conditions – the boiling point at a given pressure. Superheat is the temperature above saturation; subcooling is below saturation. Use a thermometer and gauge together to calculate both.
Disclaimer: This tool is for educational and diagnostic aid. Always follow manufacturer guidelines and local regulations when handling refrigerants.
