Refrigerant Pressure-Temperature Chart
Reference and compare pressure-temperature relationships for common HVAC refrigerants. All values shown in Fahrenheit and PsiG.
Created by Sam Ruf
Interactive PT Chart
Select the refrigerants you want to compare on the pressure-temperature graph. Adjust the temperature range as needed.
Understanding PT Charts
PT charts show the relationship between pressure and temperature at saturation (where liquid and vapor states exist together). At any given point on these curves, the refrigerant is at its boiling/condensing point. These relationships are critical for HVAC technicians to diagnose system issues and ensure proper operation.
PT Tables
Select a refrigerant to view its detailed pressure-temperature values. Click on any cell to highlight that specific pressure-temperature point.
| Temperature (°F) | Pressure (PsiG) | Liquid Density (lb/ft³) | Vapor Density (lb/ft³) | Latent Heat (BTU/lb) |
|---|
Using PT Data in HVAC
- System Diagnosis: Compare actual system pressures with the PT chart to determine if refrigerant charge is correct.
- Superheat/Subcooling: Calculate system superheat and subcooling by measuring pressure, then finding the corresponding saturation temperature.
- Leak Detection: Use pressure readings to detect potential refrigerant leaks by comparing to expected values.
- System Design: Properly size components based on expected operating conditions and pressure drops.