Superheat: HVAC Charge Calc

Superheat is a fast, accurate charging and diagnostic calculator for HVAC/R technicians.

Pick a refrigerant, enter the low-side and high-side gauge pressures and the line temperatures, and get:

- Saturation temperature (dew and bubble points)
- Superheat on the low side
- Subcooling on the high side
- Glide shown correctly for zeotropic blends

REFRIGERANTS
R-410A, R-454B, R-32, R-22, R-134a, R-404A, R-407C, R-407F, R-448A, R-449A, R-452B, R-513A, R-507A, R-290, R-600a, R-717 (ammonia), R-1234yf, R-1234ze(E), R-12.

BUILT FOR THE FIELD
- Pressure in psi, kPa, bar or MPa; gauge or absolute
- Temperature in Fahrenheit or Celsius
- Altitude compensation with adjustable atmospheric pressure
- PT chart browser with pressure to saturation-temperature lookup
- Target superheat estimate for fixed-orifice systems
- Save readings per unit and review them later
- Works fully offline. No account, no ads, no tracking

ACCURACY
Saturation pressure-temperature data is precomputed with CoolProp (Helmholtz equations of state). Zeotropic blends use separate bubble and dew curves derived from their component compositions, so glide is handled correctly.

For qualified HVAC/R technicians. Always follow the equipment and refrigerant manufacturer charging specifications.