Quick Reference: R410A PT Chart
Every HVAC technician needs an accurate r410a pt chart in their pocket. This tool shows the relationship between pressure (PSIG) and saturation temperature (°F). We have highlighted the most common operating ranges for your convenience.
Common Check Points:
- Blue (40°F): Typical Evaporator Coil temperature.
- Orange (100°F - 110°F): Typical Condensing temperature on a mild day.
| Temp (°F) | R-22 (PSIG) | R-410A (PSIG) | R-404A (PSIG) |
|---|---|---|---|
| 30 | 54.9 | 97.5 | 72.5 |
| 32 | 57.7 | 101.6 | 76.0 |
| 34 | 60.6 | 105.7 | 79.6 |
| 36 | 63.5 | 110.0 | 83.3 |
| 38 | 66.5 | 114.4 | 87.0 |
| 40 (Evap) | 69.5 | 118.9 | 90.9 |
| 42 | 72.6 | 123.5 | 94.9 |
| 44 | 75.8 | 128.3 | 98.9 |
| 46 | 79.0 | 133.1 | 103.1 |
| 48 | 82.3 | 138.1 | 107.4 |
| 50 | 85.7 | 143.2 | 111.8 |
| ... | |||
| 95 | 185.1 | 295.3 | 222.0 |
| 100 | 198.4 | 317.3 | 239.6 |
| 105 | 212.4 | 340.5 | 258.1 |
| 110 | 227.0 | 365.0 | 277.6 |
| 115 | 242.3 | 390.8 | 298.1 |
| 120 | 258.3 | 418.0 | 319.7 |
*Pressures are in PSIG at sea level.
How to Read a PT Chart for R410A
Understanding the basics is crucial. A standard r410a pt chart tells you the "Saturation Temperature." This is the temperature where the refrigerant is changing state (boiling from liquid to vapor, or condensing from vapor to liquid).
When your gauge manifold reads a specific pressure (e.g., 118.9 PSIG), you look at the chart to find the corresponding saturation temperature (40°F). If the actual pipe temperature matches this, the system is saturated.
Calculating Superheat & Subcooling
You cannot charge a system correctly without calculating these values. You simply cross-reference the pressure on your r410a pt chart to find the saturation temp, then use these formulas:
Measure Superheat at the suction line (low side) and Subcooling at the liquid line (high side).
1. Superheat (Fixed Orifice)
Ensures only vapor enters the compressor.
- Formula: Actual Suction Line Temp - Saturation Temp (from chart) = Superheat.
- Target: Typically 10°F - 20°F (Check manufacturer specs).
2. Subcooling (TXV)
Ensures a full column of liquid reaches the metering device.
- Formula: Saturation Temp (from chart) - Actual Liquid Line Temp = Subcooling.
- Target: Typically 8°F - 12°F.
Ditch the Paper Chart
Stop squinting at tiny numbers on a laminated r410a pt chart. Our App has a built-in digital PT Chart/Calculator. Just slide to the pressure, and it tells you the temperature instantly.
Use Free Digital ToolBubble Point vs. Dew Point (The "Glide")
For single-component refrigerants like R-22 or azeotropes like R-410A, the boiling and condensing temperatures are the same at a given pressure. However, for Zeotropic blends (like R-407C), there is a "Temperature Glide."
- Bubble Point (Liquid): Use this when calculating Subcooling.
- Dew Point (Vapor): Use this when calculating Superheat.
Unlike older blends, reading a r410a pt chart is simple because R-410A has near-zero glide, behaving like a single component.
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